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light/Dependencies/stb_image/stb_image.c
Light c252c80093 Added back stb_image
2021-09-09 19:59:53 +04:30

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#include "stb_image.h"
#if defined(STBI_ONLY_JPEG) || defined(STBI_ONLY_PNG) || defined(STBI_ONLY_BMP) \
|| defined(STBI_ONLY_TGA) || defined(STBI_ONLY_GIF) || defined(STBI_ONLY_PSD) \
|| defined(STBI_ONLY_HDR) || defined(STBI_ONLY_PIC) || defined(STBI_ONLY_PNM) \
|| defined(STBI_ONLY_ZLIB)
#ifndef STBI_ONLY_JPEG
#define STBI_NO_JPEG
#endif
#ifndef STBI_ONLY_PNG
#define STBI_NO_PNG
#endif
#ifndef STBI_ONLY_BMP
#define STBI_NO_BMP
#endif
#ifndef STBI_ONLY_PSD
#define STBI_NO_PSD
#endif
#ifndef STBI_ONLY_TGA
#define STBI_NO_TGA
#endif
#ifndef STBI_ONLY_GIF
#define STBI_NO_GIF
#endif
#ifndef STBI_ONLY_HDR
#define STBI_NO_HDR
#endif
#ifndef STBI_ONLY_PIC
#define STBI_NO_PIC
#endif
#ifndef STBI_ONLY_PNM
#define STBI_NO_PNM
#endif
#endif
#if defined(STBI_NO_PNG) && !defined(STBI_SUPPORT_ZLIB) && !defined(STBI_NO_ZLIB)
#define STBI_NO_ZLIB
#endif
#include <stdarg.h>
#include <stddef.h> // ptrdiff_t on osx
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR)
#include <math.h> // ldexp, pow
#endif
#ifndef STBI_NO_STDIO
#include <stdio.h>
#endif
#ifndef STBI_ASSERT
#include <assert.h>
#define STBI_ASSERT(x) assert(x)
#endif
#ifdef __cplusplus
#define STBI_EXTERN extern "C"
#else
#define STBI_EXTERN extern
#endif
#ifndef _MSC_VER
#ifdef __cplusplus
#define stbi_inline inline
#else
#define stbi_inline
#endif
#else
#define stbi_inline __forceinline
#endif
#ifndef STBI_NO_THREAD_LOCALS
#if defined(__cplusplus) && __cplusplus >= 201103L
#define STBI_THREAD_LOCAL thread_local
#elif defined(__GNUC__) && __GNUC__ < 5
#define STBI_THREAD_LOCAL __thread
#elif defined(_MSC_VER)
#define STBI_THREAD_LOCAL __declspec(thread)
#elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)
#define STBI_THREAD_LOCAL _Thread_local
#endif
#ifndef STBI_THREAD_LOCAL
#if defined(__GNUC__)
#define STBI_THREAD_LOCAL __thread
#endif
#endif
#endif
#ifdef _MSC_VER
typedef unsigned short stbi__uint16;
typedef signed short stbi__int16;
typedef unsigned int stbi__uint32;
typedef signed int stbi__int32;
#else
#include <stdint.h>
typedef uint16_t stbi__uint16;
typedef int16_t stbi__int16;
typedef uint32_t stbi__uint32;
typedef int32_t stbi__int32;
#endif
// should produce compiler error if size is wrong
typedef unsigned char validate_uint32[sizeof(stbi__uint32) == 4 ? 1 : -1];
#ifdef _MSC_VER
#define STBI_NOTUSED(v) (void)(v)
#else
#define STBI_NOTUSED(v) (void)sizeof(v)
#endif
#ifdef _MSC_VER
#define STBI_HAS_LROTL
#endif
#ifdef STBI_HAS_LROTL
#define stbi_lrot(x,y) _lrotl(x,y)
#else
#define stbi_lrot(x,y) (((x) << (y)) | ((x) >> (32 - (y))))
#endif
#if defined(STBI_MALLOC) && defined(STBI_FREE) && (defined(STBI_REALLOC) || defined(STBI_REALLOC_SIZED))
// ok
#elif !defined(STBI_MALLOC) && !defined(STBI_FREE) && !defined(STBI_REALLOC) && !defined(STBI_REALLOC_SIZED)
// ok
#else
#error "Must define all or none of STBI_MALLOC, STBI_FREE, and STBI_REALLOC (or STBI_REALLOC_SIZED)."
#endif
#ifndef STBI_MALLOC
#define STBI_MALLOC(sz) malloc(sz)
#define STBI_REALLOC(p,newsz) realloc(p,newsz)
#define STBI_FREE(p) free(p)
#endif
#ifndef STBI_REALLOC_SIZED
#define STBI_REALLOC_SIZED(p,oldsz,newsz) STBI_REALLOC(p,newsz)
#endif
// x86/x64 detection
#if defined(__x86_64__) || defined(_M_X64)
#define STBI__X64_TARGET
#elif defined(__i386) || defined(_M_IX86)
#define STBI__X86_TARGET
#endif
#if defined(__GNUC__) && defined(STBI__X86_TARGET) && !defined(__SSE2__) && !defined(STBI_NO_SIMD)
// gcc doesn't support sse2 intrinsics unless you compile with -msse2,
// which in turn means it gets to use SSE2 everywhere. This is unfortunate,
// but previous attempts to provide the SSE2 functions with runtime
// detection caused numerous issues. The way architecture extensions are
// exposed in GCC/Clang is, sadly, not really suited for one-file libs.
// New behavior: if compiled with -msse2, we use SSE2 without any
// detection; if not, we don't use it at all.
#define STBI_NO_SIMD
#endif
#if defined(__MINGW32__) && defined(STBI__X86_TARGET) && !defined(STBI_MINGW_ENABLE_SSE2) && !defined(STBI_NO_SIMD)
// Note that __MINGW32__ doesn't actually mean 32-bit, so we have to avoid STBI__X64_TARGET
//
// 32-bit MinGW wants ESP to be 16-byte aligned, but this is not in the
// Windows ABI and VC++ as well as Windows DLLs don't maintain that invariant.
// As a result, enabling SSE2 on 32-bit MinGW is dangerous when not
// simultaneously enabling "-mstackrealign".
//
// See https://github.com/nothings/stb/issues/81 for more information.
//
// So default to no SSE2 on 32-bit MinGW. If you've read this far and added
// -mstackrealign to your build settings, feel free to #define STBI_MINGW_ENABLE_SSE2.
#define STBI_NO_SIMD
#endif
#if !defined(STBI_NO_SIMD) && (defined(STBI__X86_TARGET) || defined(STBI__X64_TARGET))
#define STBI_SSE2
#include <emmintrin.h>
#ifdef _MSC_VER
#if _MSC_VER >= 1400 // not VC6
#include <intrin.h> // __cpuid
static int stbi__cpuid3(void)
{
int info[4];
__cpuid(info, 1);
return info[3];
}
#else
static int stbi__cpuid3(void)
{
int res;
__asm {
mov eax, 1
cpuid
mov res, edx
}
return res;
}
#endif
#define STBI_SIMD_ALIGN(type, name) __declspec(align(16)) type name
#if !defined(STBI_NO_JPEG) && defined(STBI_SSE2)
static int stbi__sse2_available(void)
{
int info3 = stbi__cpuid3();
return ((info3 >> 26) & 1) != 0;
}
#endif
#else // assume GCC-style if not VC++
#define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16)))
#if !defined(STBI_NO_JPEG) && defined(STBI_SSE2)
static int stbi__sse2_available(void)
{
// If we're even attempting to compile this on GCC/Clang, that means
// -msse2 is on, which means the compiler is allowed to use SSE2
// instructions at will, and so are we.
return 1;
}
#endif
#endif
#endif
// ARM NEON
#if defined(STBI_NO_SIMD) && defined(STBI_NEON)
#undef STBI_NEON
#endif
#ifdef STBI_NEON
#include <arm_neon.h>
// assume GCC or Clang on ARM targets
#define STBI_SIMD_ALIGN(type, name) type name __attribute__((aligned(16)))
#endif
#ifndef STBI_SIMD_ALIGN
#define STBI_SIMD_ALIGN(type, name) type name
#endif
#ifndef STBI_MAX_DIMENSIONS
#define STBI_MAX_DIMENSIONS (1 << 24)
#endif
///////////////////////////////////////////////
//
// stbi__context struct and start_xxx functions
// stbi__context structure is our basic context used by all images, so it
// contains all the IO context, plus some basic image information
typedef struct
{
stbi__uint32 img_x, img_y;
int img_n, img_out_n;
stbi_io_callbacks io;
void* io_user_data;
int read_from_callbacks;
int buflen;
stbi_uc buffer_start[128];
int callback_already_read;
stbi_uc* img_buffer, * img_buffer_end;
stbi_uc* img_buffer_original, * img_buffer_original_end;
} stbi__context;
static void stbi__refill_buffer(stbi__context* s);
// initialize a memory-decode context
static void stbi__start_mem(stbi__context* s, stbi_uc const* buffer, int len)
{
s->io.read = NULL;
s->read_from_callbacks = 0;
s->callback_already_read = 0;
s->img_buffer = s->img_buffer_original = (stbi_uc*)buffer;
s->img_buffer_end = s->img_buffer_original_end = (stbi_uc*)buffer + len;
}
// initialize a callback-based context
static void stbi__start_callbacks(stbi__context* s, stbi_io_callbacks* c, void* user)
{
s->io = *c;
s->io_user_data = user;
s->buflen = sizeof(s->buffer_start);
s->read_from_callbacks = 1;
s->callback_already_read = 0;
s->img_buffer = s->img_buffer_original = s->buffer_start;
stbi__refill_buffer(s);
s->img_buffer_original_end = s->img_buffer_end;
}
#ifndef STBI_NO_STDIO
static int stbi__stdio_read(void* user, char* data, int size)
{
return (int)fread(data, 1, size, (FILE*)user);
}
static void stbi__stdio_skip(void* user, int n)
{
int ch;
fseek((FILE*)user, n, SEEK_CUR);
ch = fgetc((FILE*)user); /* have to read a byte to reset feof()'s flag */
if (ch != EOF) {
ungetc(ch, (FILE*)user); /* push byte back onto stream if valid. */
}
}
static int stbi__stdio_eof(void* user)
{
return feof((FILE*)user) || ferror((FILE*)user);
}
static stbi_io_callbacks stbi__stdio_callbacks =
{
stbi__stdio_read,
stbi__stdio_skip,
stbi__stdio_eof,
};
static void stbi__start_file(stbi__context* s, FILE* f)
{
stbi__start_callbacks(s, &stbi__stdio_callbacks, (void*)f);
}
//static void stop_file(stbi__context *s) { }
#endif // !STBI_NO_STDIO
static void stbi__rewind(stbi__context* s)
{
// conceptually rewind SHOULD rewind to the beginning of the stream,
// but we just rewind to the beginning of the initial buffer, because
// we only use it after doing 'test', which only ever looks at at most 92 bytes
s->img_buffer = s->img_buffer_original;
s->img_buffer_end = s->img_buffer_original_end;
}
enum
{
STBI_ORDER_RGB,
STBI_ORDER_BGR
};
typedef struct
{
int bits_per_channel;
int num_channels;
int channel_order;
} stbi__result_info;
#ifndef STBI_NO_JPEG
static int stbi__jpeg_test(stbi__context* s);
static void* stbi__jpeg_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__jpeg_info(stbi__context* s, int* x, int* y, int* comp);
#endif
#ifndef STBI_NO_PNG
static int stbi__png_test(stbi__context* s);
static void* stbi__png_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__png_info(stbi__context* s, int* x, int* y, int* comp);
static int stbi__png_is16(stbi__context* s);
#endif
#ifndef STBI_NO_BMP
static int stbi__bmp_test(stbi__context* s);
static void* stbi__bmp_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__bmp_info(stbi__context* s, int* x, int* y, int* comp);
#endif
#ifndef STBI_NO_TGA
static int stbi__tga_test(stbi__context* s);
static void* stbi__tga_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__tga_info(stbi__context* s, int* x, int* y, int* comp);
#endif
#ifndef STBI_NO_PSD
static int stbi__psd_test(stbi__context* s);
static void* stbi__psd_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri, int bpc);
static int stbi__psd_info(stbi__context* s, int* x, int* y, int* comp);
static int stbi__psd_is16(stbi__context* s);
#endif
#ifndef STBI_NO_HDR
static int stbi__hdr_test(stbi__context* s);
static float* stbi__hdr_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__hdr_info(stbi__context* s, int* x, int* y, int* comp);
#endif
#ifndef STBI_NO_PIC
static int stbi__pic_test(stbi__context* s);
static void* stbi__pic_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__pic_info(stbi__context* s, int* x, int* y, int* comp);
#endif
#ifndef STBI_NO_GIF
static int stbi__gif_test(stbi__context* s);
static void* stbi__gif_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static void* stbi__load_gif_main(stbi__context* s, int** delays, int* x, int* y, int* z, int* comp, int req_comp);
static int stbi__gif_info(stbi__context* s, int* x, int* y, int* comp);
#endif
#ifndef STBI_NO_PNM
static int stbi__pnm_test(stbi__context* s);
static void* stbi__pnm_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri);
static int stbi__pnm_info(stbi__context* s, int* x, int* y, int* comp);
#endif
static
#ifdef STBI_THREAD_LOCAL
STBI_THREAD_LOCAL
#endif
const char* stbi__g_failure_reason;
STBIDEF const char* stbi_failure_reason(void)
{
return stbi__g_failure_reason;
}
#ifndef STBI_NO_FAILURE_STRINGS
static int stbi__err(const char* str)
{
stbi__g_failure_reason = str;
return 0;
}
#endif
static void* stbi__malloc(size_t size)
{
return STBI_MALLOC(size);
}
// stb_image uses ints pervasively, including for offset calculations.
// therefore the largest decoded image size we can support with the
// current code, even on 64-bit targets, is INT_MAX. this is not a
// significant limitation for the intended use case.
//
// we do, however, need to make sure our size calculations don't
// overflow. hence a few helper functions for size calculations that
// multiply integers together, making sure that they're non-negative
// and no overflow occurs.
// return 1 if the sum is valid, 0 on overflow.
// negative terms are considered invalid.
static int stbi__addsizes_valid(int a, int b)
{
if (b < 0) return 0;
// now 0 <= b <= INT_MAX, hence also
// 0 <= INT_MAX - b <= INTMAX.
// And "a + b <= INT_MAX" (which might overflow) is the
// same as a <= INT_MAX - b (no overflow)
return a <= INT_MAX - b;
}
// returns 1 if the product is valid, 0 on overflow.
// negative factors are considered invalid.
static int stbi__mul2sizes_valid(int a, int b)
{
if (a < 0 || b < 0) return 0;
if (b == 0) return 1; // mul-by-0 is always safe
// portable way to check for no overflows in a*b
return a <= INT_MAX / b;
}
#if !defined(STBI_NO_JPEG) || !defined(STBI_NO_PNG) || !defined(STBI_NO_TGA) || !defined(STBI_NO_HDR)
// returns 1 if "a*b + add" has no negative terms/factors and doesn't overflow
static int stbi__mad2sizes_valid(int a, int b, int add)
{
return stbi__mul2sizes_valid(a, b) && stbi__addsizes_valid(a * b, add);
}
#endif
// returns 1 if "a*b*c + add" has no negative terms/factors and doesn't overflow
static int stbi__mad3sizes_valid(int a, int b, int c, int add)
{
return stbi__mul2sizes_valid(a, b) && stbi__mul2sizes_valid(a * b, c) &&
stbi__addsizes_valid(a * b * c, add);
}
// returns 1 if "a*b*c*d + add" has no negative terms/factors and doesn't overflow
#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR)
static int stbi__mad4sizes_valid(int a, int b, int c, int d, int add)
{
return stbi__mul2sizes_valid(a, b) && stbi__mul2sizes_valid(a * b, c) &&
stbi__mul2sizes_valid(a * b * c, d) && stbi__addsizes_valid(a * b * c * d, add);
}
#endif
#if !defined(STBI_NO_JPEG) || !defined(STBI_NO_PNG) || !defined(STBI_NO_TGA) || !defined(STBI_NO_HDR)
// mallocs with size overflow checking
static void* stbi__malloc_mad2(int a, int b, int add)
{
if (!stbi__mad2sizes_valid(a, b, add)) return NULL;
return stbi__malloc(a * b + add);
}
#endif
static void* stbi__malloc_mad3(int a, int b, int c, int add)
{
if (!stbi__mad3sizes_valid(a, b, c, add)) return NULL;
return stbi__malloc(a * b * c + add);
}
#if !defined(STBI_NO_LINEAR) || !defined(STBI_NO_HDR)
static void* stbi__malloc_mad4(int a, int b, int c, int d, int add)
{
if (!stbi__mad4sizes_valid(a, b, c, d, add)) return NULL;
return stbi__malloc(a * b * c * d + add);
}
#endif
// stbi__err - error
// stbi__errpf - error returning pointer to float
// stbi__errpuc - error returning pointer to unsigned char
#ifdef STBI_NO_FAILURE_STRINGS
#define stbi__err(x,y) 0
#elif defined(STBI_FAILURE_USERMSG)
#define stbi__err(x,y) stbi__err(y)
#else
#define stbi__err(x,y) stbi__err(x)
#endif
#define stbi__errpf(x,y) ((float *)(size_t) (stbi__err(x,y)?NULL:NULL))
#define stbi__errpuc(x,y) ((unsigned char *)(size_t) (stbi__err(x,y)?NULL:NULL))
STBIDEF void stbi_image_free(void* retval_from_stbi_load)
{
STBI_FREE(retval_from_stbi_load);
}
#ifndef STBI_NO_LINEAR
static float* stbi__ldr_to_hdr(stbi_uc* data, int x, int y, int comp);
#endif
#ifndef STBI_NO_HDR
static stbi_uc* stbi__hdr_to_ldr(float* data, int x, int y, int comp);
#endif
static int stbi__vertically_flip_on_load_global = 0;
STBIDEF void stbi_set_flip_vertically_on_load(int flag_true_if_should_flip)
{
stbi__vertically_flip_on_load_global = flag_true_if_should_flip;
}
#ifndef STBI_THREAD_LOCAL
#define stbi__vertically_flip_on_load stbi__vertically_flip_on_load_global
#else
static STBI_THREAD_LOCAL int stbi__vertically_flip_on_load_local, stbi__vertically_flip_on_load_set;
STBIDEF void stbi_set_flip_vertically_on_load_thread(int flag_true_if_should_flip)
{
stbi__vertically_flip_on_load_local = flag_true_if_should_flip;
stbi__vertically_flip_on_load_set = 1;
}
#define stbi__vertically_flip_on_load (stbi__vertically_flip_on_load_set \
? stbi__vertically_flip_on_load_local \
: stbi__vertically_flip_on_load_global)
#endif // STBI_THREAD_LOCAL
static void* stbi__load_main(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri, int bpc)
{
memset(ri, 0, sizeof(*ri)); // make sure it's initialized if we add new fields
ri->bits_per_channel = 8; // default is 8 so most paths don't have to be changed
ri->channel_order = STBI_ORDER_RGB; // all current input & output are this, but this is here so we can add BGR order
ri->num_channels = 0;
#ifndef STBI_NO_JPEG
if (stbi__jpeg_test(s)) return stbi__jpeg_load(s, x, y, comp, req_comp, ri);
#endif
#ifndef STBI_NO_PNG
if (stbi__png_test(s)) return stbi__png_load(s, x, y, comp, req_comp, ri);
#endif
#ifndef STBI_NO_BMP
if (stbi__bmp_test(s)) return stbi__bmp_load(s, x, y, comp, req_comp, ri);
#endif
#ifndef STBI_NO_GIF
if (stbi__gif_test(s)) return stbi__gif_load(s, x, y, comp, req_comp, ri);
#endif
#ifndef STBI_NO_PSD
if (stbi__psd_test(s)) return stbi__psd_load(s, x, y, comp, req_comp, ri, bpc);
#else
STBI_NOTUSED(bpc);
#endif
#ifndef STBI_NO_PIC
if (stbi__pic_test(s)) return stbi__pic_load(s, x, y, comp, req_comp, ri);
#endif
#ifndef STBI_NO_PNM
if (stbi__pnm_test(s)) return stbi__pnm_load(s, x, y, comp, req_comp, ri);
#endif
#ifndef STBI_NO_HDR
if (stbi__hdr_test(s)) {
float* hdr = stbi__hdr_load(s, x, y, comp, req_comp, ri);
return stbi__hdr_to_ldr(hdr, *x, *y, req_comp ? req_comp : *comp);
}
#endif
#ifndef STBI_NO_TGA
// test tga last because it's a crappy test!
if (stbi__tga_test(s))
return stbi__tga_load(s, x, y, comp, req_comp, ri);
#endif
return stbi__errpuc("unknown image type", "Image not of any known type, or corrupt");
}
static stbi_uc* stbi__convert_16_to_8(stbi__uint16* orig, int w, int h, int channels)
{
int i;
int img_len = w * h * channels;
stbi_uc* reduced;
reduced = (stbi_uc*)stbi__malloc(img_len);
if (reduced == NULL) return stbi__errpuc("outofmem", "Out of memory");
for (i = 0; i < img_len; ++i)
reduced[i] = (stbi_uc)((orig[i] >> 8) & 0xFF); // top half of each byte is sufficient approx of 16->8 bit scaling
STBI_FREE(orig);
return reduced;
}
static stbi__uint16* stbi__convert_8_to_16(stbi_uc* orig, int w, int h, int channels)
{
int i;
int img_len = w * h * channels;
stbi__uint16* enlarged;
enlarged = (stbi__uint16*)stbi__malloc(img_len * 2);
if (enlarged == NULL) return (stbi__uint16*)stbi__errpuc("outofmem", "Out of memory");
for (i = 0; i < img_len; ++i)
enlarged[i] = (stbi__uint16)((orig[i] << 8) + orig[i]); // replicate to high and low byte, maps 0->0, 255->0xffff
STBI_FREE(orig);
return enlarged;
}
static void stbi__vertical_flip(void* image, int w, int h, int bytes_per_pixel)
{
int row;
size_t bytes_per_row = (size_t)w * bytes_per_pixel;
stbi_uc temp[2048];
stbi_uc* bytes = (stbi_uc*)image;
for (row = 0; row < (h >> 1); row++) {
stbi_uc* row0 = bytes + row * bytes_per_row;
stbi_uc* row1 = bytes + (h - row - 1) * bytes_per_row;
// swap row0 with row1
size_t bytes_left = bytes_per_row;
while (bytes_left) {
size_t bytes_copy = (bytes_left < sizeof(temp)) ? bytes_left : sizeof(temp);
memcpy(temp, row0, bytes_copy);
memcpy(row0, row1, bytes_copy);
memcpy(row1, temp, bytes_copy);
row0 += bytes_copy;
row1 += bytes_copy;
bytes_left -= bytes_copy;
}
}
}
#ifndef STBI_NO_GIF
static void stbi__vertical_flip_slices(void* image, int w, int h, int z, int bytes_per_pixel)
{
int slice;
int slice_size = w * h * bytes_per_pixel;
stbi_uc* bytes = (stbi_uc*)image;
for (slice = 0; slice < z; ++slice) {
stbi__vertical_flip(bytes, w, h, bytes_per_pixel);
bytes += slice_size;
}
}
#endif
static unsigned char* stbi__load_and_postprocess_8bit(stbi__context* s, int* x, int* y, int* comp, int req_comp)
{
stbi__result_info ri;
void* result = stbi__load_main(s, x, y, comp, req_comp, &ri, 8);
if (result == NULL)
return NULL;
// it is the responsibility of the loaders to make sure we get either 8 or 16 bit.
STBI_ASSERT(ri.bits_per_channel == 8 || ri.bits_per_channel == 16);
if (ri.bits_per_channel != 8) {
result = stbi__convert_16_to_8((stbi__uint16*)result, *x, *y, req_comp == 0 ? *comp : req_comp);
ri.bits_per_channel = 8;
}
// @TODO: move stbi__convert_format to here
if (stbi__vertically_flip_on_load) {
int channels = req_comp ? req_comp : *comp;
stbi__vertical_flip(result, *x, *y, channels * sizeof(stbi_uc));
}
return (unsigned char*)result;
}
static stbi__uint16* stbi__load_and_postprocess_16bit(stbi__context* s, int* x, int* y, int* comp, int req_comp)
{
stbi__result_info ri;
void* result = stbi__load_main(s, x, y, comp, req_comp, &ri, 16);
if (result == NULL)
return NULL;
// it is the responsibility of the loaders to make sure we get either 8 or 16 bit.
STBI_ASSERT(ri.bits_per_channel == 8 || ri.bits_per_channel == 16);
if (ri.bits_per_channel != 16) {
result = stbi__convert_8_to_16((stbi_uc*)result, *x, *y, req_comp == 0 ? *comp : req_comp);
ri.bits_per_channel = 16;
}
// @TODO: move stbi__convert_format16 to here
// @TODO: special case RGB-to-Y (and RGBA-to-YA) for 8-bit-to-16-bit case to keep more precision
if (stbi__vertically_flip_on_load) {
int channels = req_comp ? req_comp : *comp;
stbi__vertical_flip(result, *x, *y, channels * sizeof(stbi__uint16));
}
return (stbi__uint16*)result;
}
#if !defined(STBI_NO_HDR) && !defined(STBI_NO_LINEAR)
static void stbi__float_postprocess(float* result, int* x, int* y, int* comp, int req_comp)
{
if (stbi__vertically_flip_on_load && result != NULL) {
int channels = req_comp ? req_comp : *comp;
stbi__vertical_flip(result, *x, *y, channels * sizeof(float));
}
}
#endif
#ifndef STBI_NO_STDIO
#if defined(_MSC_VER) && defined(STBI_WINDOWS_UTF8)
STBI_EXTERN __declspec(dllimport) int __stdcall MultiByteToWideChar(unsigned int cp, unsigned long flags, const char* str, int cbmb, wchar_t* widestr, int cchwide);
STBI_EXTERN __declspec(dllimport) int __stdcall WideCharToMultiByte(unsigned int cp, unsigned long flags, const wchar_t* widestr, int cchwide, char* str, int cbmb, const char* defchar, int* used_default);
#endif
#if defined(_MSC_VER) && defined(STBI_WINDOWS_UTF8)
STBIDEF int stbi_convert_wchar_to_utf8(char* buffer, size_t bufferlen, const wchar_t* input)
{
return WideCharToMultiByte(65001 /* UTF8 */, 0, input, -1, buffer, (int)bufferlen, NULL, NULL);
}
#endif
static FILE* stbi__fopen(char const* filename, char const* mode)
{
FILE* f;
#if defined(_MSC_VER) && defined(STBI_WINDOWS_UTF8)
wchar_t wMode[64];
wchar_t wFilename[1024];
if (0 == MultiByteToWideChar(65001 /* UTF8 */, 0, filename, -1, wFilename, sizeof(wFilename)))
return 0;
if (0 == MultiByteToWideChar(65001 /* UTF8 */, 0, mode, -1, wMode, sizeof(wMode)))
return 0;
#if _MSC_VER >= 1400
if (0 != _wfopen_s(&f, wFilename, wMode))
f = 0;
#else
f = _wfopen(wFilename, wMode);
#endif
#elif defined(_MSC_VER) && _MSC_VER >= 1400
if (0 != fopen_s(&f, filename, mode))
f = 0;
#else
f = fopen(filename, mode);
#endif
return f;
}
STBIDEF stbi_uc* stbi_load(char const* filename, int* x, int* y, int* comp, int req_comp)
{
FILE* f = stbi__fopen(filename, "rb");
unsigned char* result;
if (!f) return stbi__errpuc("can't fopen", "Unable to open file");
result = stbi_load_from_file(f, x, y, comp, req_comp);
fclose(f);
return result;
}
STBIDEF stbi_uc* stbi_load_from_file(FILE* f, int* x, int* y, int* comp, int req_comp)
{
unsigned char* result;
stbi__context s;
stbi__start_file(&s, f);
result = stbi__load_and_postprocess_8bit(&s, x, y, comp, req_comp);
if (result) {
// need to 'unget' all the characters in the IO buffer
fseek(f, -(int)(s.img_buffer_end - s.img_buffer), SEEK_CUR);
}
return result;
}
STBIDEF stbi__uint16* stbi_load_from_file_16(FILE* f, int* x, int* y, int* comp, int req_comp)
{
stbi__uint16* result;
stbi__context s;
stbi__start_file(&s, f);
result = stbi__load_and_postprocess_16bit(&s, x, y, comp, req_comp);
if (result) {
// need to 'unget' all the characters in the IO buffer
fseek(f, -(int)(s.img_buffer_end - s.img_buffer), SEEK_CUR);
}
return result;
}
STBIDEF stbi_us* stbi_load_16(char const* filename, int* x, int* y, int* comp, int req_comp)
{
FILE* f = stbi__fopen(filename, "rb");
stbi__uint16* result;
if (!f) return (stbi_us*)stbi__errpuc("can't fopen", "Unable to open file");
result = stbi_load_from_file_16(f, x, y, comp, req_comp);
fclose(f);
return result;
}
#endif //!STBI_NO_STDIO
STBIDEF stbi_us* stbi_load_16_from_memory(stbi_uc const* buffer, int len, int* x, int* y, int* channels_in_file, int desired_channels)
{
stbi__context s;
stbi__start_mem(&s, buffer, len);
return stbi__load_and_postprocess_16bit(&s, x, y, channels_in_file, desired_channels);
}
STBIDEF stbi_us* stbi_load_16_from_callbacks(stbi_io_callbacks const* clbk, void* user, int* x, int* y, int* channels_in_file, int desired_channels)
{
stbi__context s;
stbi__start_callbacks(&s, (stbi_io_callbacks*)clbk, user);
return stbi__load_and_postprocess_16bit(&s, x, y, channels_in_file, desired_channels);
}
STBIDEF stbi_uc* stbi_load_from_memory(stbi_uc const* buffer, int len, int* x, int* y, int* comp, int req_comp)
{
stbi__context s;
stbi__start_mem(&s, buffer, len);
return stbi__load_and_postprocess_8bit(&s, x, y, comp, req_comp);
}
STBIDEF stbi_uc* stbi_load_from_callbacks(stbi_io_callbacks const* clbk, void* user, int* x, int* y, int* comp, int req_comp)
{
stbi__context s;
stbi__start_callbacks(&s, (stbi_io_callbacks*)clbk, user);
return stbi__load_and_postprocess_8bit(&s, x, y, comp, req_comp);
}
#ifndef STBI_NO_GIF
STBIDEF stbi_uc* stbi_load_gif_from_memory(stbi_uc const* buffer, int len, int** delays, int* x, int* y, int* z, int* comp, int req_comp)
{
unsigned char* result;
stbi__context s;
stbi__start_mem(&s, buffer, len);
result = (unsigned char*)stbi__load_gif_main(&s, delays, x, y, z, comp, req_comp);
if (stbi__vertically_flip_on_load) {
stbi__vertical_flip_slices(result, *x, *y, *z, *comp);
}
return result;
}
#endif
#ifndef STBI_NO_LINEAR
static float* stbi__loadf_main(stbi__context* s, int* x, int* y, int* comp, int req_comp)
{
unsigned char* data;
#ifndef STBI_NO_HDR
if (stbi__hdr_test(s)) {
stbi__result_info ri;
float* hdr_data = stbi__hdr_load(s, x, y, comp, req_comp, &ri);
if (hdr_data)
stbi__float_postprocess(hdr_data, x, y, comp, req_comp);
return hdr_data;
}
#endif
data = stbi__load_and_postprocess_8bit(s, x, y, comp, req_comp);
if (data)
return stbi__ldr_to_hdr(data, *x, *y, req_comp ? req_comp : *comp);
return stbi__errpf("unknown image type", "Image not of any known type, or corrupt");
}
STBIDEF float* stbi_loadf_from_memory(stbi_uc const* buffer, int len, int* x, int* y, int* comp, int req_comp)
{
stbi__context s;
stbi__start_mem(&s, buffer, len);
return stbi__loadf_main(&s, x, y, comp, req_comp);
}
STBIDEF float* stbi_loadf_from_callbacks(stbi_io_callbacks const* clbk, void* user, int* x, int* y, int* comp, int req_comp)
{
stbi__context s;
stbi__start_callbacks(&s, (stbi_io_callbacks*)clbk, user);
return stbi__loadf_main(&s, x, y, comp, req_comp);
}
#ifndef STBI_NO_STDIO
STBIDEF float* stbi_loadf(char const* filename, int* x, int* y, int* comp, int req_comp)
{
float* result;
FILE* f = stbi__fopen(filename, "rb");
if (!f) return stbi__errpf("can't fopen", "Unable to open file");
result = stbi_loadf_from_file(f, x, y, comp, req_comp);
fclose(f);
return result;
}
STBIDEF float* stbi_loadf_from_file(FILE* f, int* x, int* y, int* comp, int req_comp)
{
stbi__context s;
stbi__start_file(&s, f);
return stbi__loadf_main(&s, x, y, comp, req_comp);
}
#endif // !STBI_NO_STDIO
#endif // !STBI_NO_LINEAR
// these is-hdr-or-not is defined independent of whether STBI_NO_LINEAR is
// defined, for API simplicity; if STBI_NO_LINEAR is defined, it always
// reports false!
STBIDEF int stbi_is_hdr_from_memory(stbi_uc const* buffer, int len)
{
#ifndef STBI_NO_HDR
stbi__context s;
stbi__start_mem(&s, buffer, len);
return stbi__hdr_test(&s);
#else
STBI_NOTUSED(buffer);
STBI_NOTUSED(len);
return 0;
#endif
}
#ifndef STBI_NO_STDIO
STBIDEF int stbi_is_hdr(char const* filename)
{
FILE* f = stbi__fopen(filename, "rb");
int result = 0;
if (f) {
result = stbi_is_hdr_from_file(f);
fclose(f);
}
return result;
}
STBIDEF int stbi_is_hdr_from_file(FILE* f)
{
#ifndef STBI_NO_HDR
long pos = ftell(f);
int res;
stbi__context s;
stbi__start_file(&s, f);
res = stbi__hdr_test(&s);
fseek(f, pos, SEEK_SET);
return res;
#else
STBI_NOTUSED(f);
return 0;
#endif
}
#endif // !STBI_NO_STDIO
STBIDEF int stbi_is_hdr_from_callbacks(stbi_io_callbacks const* clbk, void* user)
{
#ifndef STBI_NO_HDR
stbi__context s;
stbi__start_callbacks(&s, (stbi_io_callbacks*)clbk, user);
return stbi__hdr_test(&s);
#else
STBI_NOTUSED(clbk);
STBI_NOTUSED(user);
return 0;
#endif
}
#ifndef STBI_NO_LINEAR
static float stbi__l2h_gamma = 2.2f, stbi__l2h_scale = 1.0f;
STBIDEF void stbi_ldr_to_hdr_gamma(float gamma) { stbi__l2h_gamma = gamma; }
STBIDEF void stbi_ldr_to_hdr_scale(float scale) { stbi__l2h_scale = scale; }
#endif
static float stbi__h2l_gamma_i = 1.0f / 2.2f, stbi__h2l_scale_i = 1.0f;
STBIDEF void stbi_hdr_to_ldr_gamma(float gamma) { stbi__h2l_gamma_i = 1 / gamma; }
STBIDEF void stbi_hdr_to_ldr_scale(float scale) { stbi__h2l_scale_i = 1 / scale; }
//////////////////////////////////////////////////////////////////////////////
//
// Common code used by all image loaders
//
enum
{
STBI__SCAN_load = 0,
STBI__SCAN_type,
STBI__SCAN_header
};
static void stbi__refill_buffer(stbi__context* s)
{
int n = (s->io.read)(s->io_user_data, (char*)s->buffer_start, s->buflen);
s->callback_already_read += (int)(s->img_buffer - s->img_buffer_original);
if (n == 0) {
// at end of file, treat same as if from memory, but need to handle case
// where s->img_buffer isn't pointing to safe memory, e.g. 0-byte file
s->read_from_callbacks = 0;
s->img_buffer = s->buffer_start;
s->img_buffer_end = s->buffer_start + 1;
*s->img_buffer = 0;
}
else {
s->img_buffer = s->buffer_start;
s->img_buffer_end = s->buffer_start + n;
}
}
stbi_inline static stbi_uc stbi__get8(stbi__context* s)
{
if (s->img_buffer < s->img_buffer_end)
return *s->img_buffer++;
if (s->read_from_callbacks) {
stbi__refill_buffer(s);
return *s->img_buffer++;
}
return 0;
}
#if defined(STBI_NO_JPEG) && defined(STBI_NO_HDR) && defined(STBI_NO_PIC) && defined(STBI_NO_PNM)
// nothing
#else
stbi_inline static int stbi__at_eof(stbi__context* s)
{
if (s->io.read) {
if (!(s->io.eof)(s->io_user_data)) return 0;
// if feof() is true, check if buffer = end
// special case: we've only got the special 0 character at the end
if (s->read_from_callbacks == 0) return 1;
}
return s->img_buffer >= s->img_buffer_end;
}
#endif
#if defined(STBI_NO_JPEG) && defined(STBI_NO_PNG) && defined(STBI_NO_BMP) && defined(STBI_NO_PSD) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) && defined(STBI_NO_PIC)
// nothing
#else
static void stbi__skip(stbi__context* s, int n)
{
if (n == 0) return; // already there!
if (n < 0) {
s->img_buffer = s->img_buffer_end;
return;
}
if (s->io.read) {
int blen = (int)(s->img_buffer_end - s->img_buffer);
if (blen < n) {
s->img_buffer = s->img_buffer_end;
(s->io.skip)(s->io_user_data, n - blen);
return;
}
}
s->img_buffer += n;
}
#endif
#if defined(STBI_NO_PNG) && defined(STBI_NO_TGA) && defined(STBI_NO_HDR) && defined(STBI_NO_PNM)
// nothing
#else
static int stbi__getn(stbi__context* s, stbi_uc* buffer, int n)
{
if (s->io.read) {
int blen = (int)(s->img_buffer_end - s->img_buffer);
if (blen < n) {
int res, count;
memcpy(buffer, s->img_buffer, blen);
count = (s->io.read)(s->io_user_data, (char*)buffer + blen, n - blen);
res = (count == (n - blen));
s->img_buffer = s->img_buffer_end;
return res;
}
}
if (s->img_buffer + n <= s->img_buffer_end) {
memcpy(buffer, s->img_buffer, n);
s->img_buffer += n;
return 1;
}
else
return 0;
}
#endif
#if defined(STBI_NO_JPEG) && defined(STBI_NO_PNG) && defined(STBI_NO_PSD) && defined(STBI_NO_PIC)
// nothing
#else
static int stbi__get16be(stbi__context* s)
{
int z = stbi__get8(s);
return (z << 8) + stbi__get8(s);
}
#endif
#if defined(STBI_NO_PNG) && defined(STBI_NO_PSD) && defined(STBI_NO_PIC)
// nothing
#else
static stbi__uint32 stbi__get32be(stbi__context* s)
{
stbi__uint32 z = stbi__get16be(s);
return (z << 16) + stbi__get16be(s);
}
#endif
#if defined(STBI_NO_BMP) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF)
// nothing
#else
static int stbi__get16le(stbi__context* s)
{
int z = stbi__get8(s);
return z + (stbi__get8(s) << 8);
}
#endif
#ifndef STBI_NO_BMP
static stbi__uint32 stbi__get32le(stbi__context* s)
{
stbi__uint32 z = stbi__get16le(s);
return z + (stbi__get16le(s) << 16);
}
#endif
#define STBI__BYTECAST(x) ((stbi_uc) ((x) & 255)) // truncate int to byte without warnings
#if defined(STBI_NO_JPEG) && defined(STBI_NO_PNG) && defined(STBI_NO_BMP) && defined(STBI_NO_PSD) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) && defined(STBI_NO_PIC) && defined(STBI_NO_PNM)
// nothing
#else
//////////////////////////////////////////////////////////////////////////////
//
// generic converter from built-in img_n to req_comp
// individual types do this automatically as much as possible (e.g. jpeg
// does all cases internally since it needs to colorspace convert anyway,
// and it never has alpha, so very few cases ). png can automatically
// interleave an alpha=255 channel, but falls back to this for other cases
//
// assume data buffer is malloced, so malloc a new one and free that one
// only failure mode is malloc failing
static stbi_uc stbi__compute_y(int r, int g, int b)
{
return (stbi_uc)(((r * 77) + (g * 150) + (29 * b)) >> 8);
}
#endif
#if defined(STBI_NO_PNG) && defined(STBI_NO_BMP) && defined(STBI_NO_PSD) && defined(STBI_NO_TGA) && defined(STBI_NO_GIF) && defined(STBI_NO_PIC) && defined(STBI_NO_PNM)
// nothing
#else
static unsigned char* stbi__convert_format(unsigned char* data, int img_n, int req_comp, unsigned int x, unsigned int y)
{
int i, j;
unsigned char* good;
if (req_comp == img_n) return data;
STBI_ASSERT(req_comp >= 1 && req_comp <= 4);
good = (unsigned char*)stbi__malloc_mad3(req_comp, x, y, 0);
if (good == NULL) {
STBI_FREE(data);
return stbi__errpuc("outofmem", "Out of memory");
}
for (j = 0; j < (int)y; ++j) {
unsigned char* src = data + j * x * img_n;
unsigned char* dest = good + j * x * req_comp;
#define STBI__COMBO(a,b) ((a)*8+(b))
#define STBI__CASE(a,b) case STBI__COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b)
// convert source image with img_n components to one with req_comp components;
// avoid switch per pixel, so use switch per scanline and massive macros
switch (STBI__COMBO(img_n, req_comp)) {
STBI__CASE(1, 2) { dest[0] = src[0]; dest[1] = 255; } break;
STBI__CASE(1, 3) { dest[0] = dest[1] = dest[2] = src[0]; } break;
STBI__CASE(1, 4) { dest[0] = dest[1] = dest[2] = src[0]; dest[3] = 255; } break;
STBI__CASE(2, 1) { dest[0] = src[0]; } break;
STBI__CASE(2, 3) { dest[0] = dest[1] = dest[2] = src[0]; } break;
STBI__CASE(2, 4) { dest[0] = dest[1] = dest[2] = src[0]; dest[3] = src[1]; } break;
STBI__CASE(3, 4) { dest[0] = src[0]; dest[1] = src[1]; dest[2] = src[2]; dest[3] = 255; } break;
STBI__CASE(3, 1) { dest[0] = stbi__compute_y(src[0], src[1], src[2]); } break;
STBI__CASE(3, 2) { dest[0] = stbi__compute_y(src[0], src[1], src[2]); dest[1] = 255; } break;
STBI__CASE(4, 1) { dest[0] = stbi__compute_y(src[0], src[1], src[2]); } break;
STBI__CASE(4, 2) { dest[0] = stbi__compute_y(src[0], src[1], src[2]); dest[1] = src[3]; } break;
STBI__CASE(4, 3) { dest[0] = src[0]; dest[1] = src[1]; dest[2] = src[2]; } break;
default: STBI_ASSERT(0); STBI_FREE(data); STBI_FREE(good); return stbi__errpuc("unsupported", "Unsupported format conversion");
}
#undef STBI__CASE
}
STBI_FREE(data);
return good;
}
#endif
#if defined(STBI_NO_PNG) && defined(STBI_NO_PSD)
// nothing
#else
static stbi__uint16 stbi__compute_y_16(int r, int g, int b)
{
return (stbi__uint16)(((r * 77) + (g * 150) + (29 * b)) >> 8);
}
#endif
#if defined(STBI_NO_PNG) && defined(STBI_NO_PSD)
// nothing
#else
static stbi__uint16* stbi__convert_format16(stbi__uint16* data, int img_n, int req_comp, unsigned int x, unsigned int y)
{
int i, j;
stbi__uint16* good;
if (req_comp == img_n) return data;
STBI_ASSERT(req_comp >= 1 && req_comp <= 4);
good = (stbi__uint16*)stbi__malloc(req_comp * x * y * 2);
if (good == NULL) {
STBI_FREE(data);
return (stbi__uint16*)stbi__errpuc("outofmem", "Out of memory");
}
for (j = 0; j < (int)y; ++j) {
stbi__uint16* src = data + j * x * img_n;
stbi__uint16* dest = good + j * x * req_comp;
#define STBI__COMBO(a,b) ((a)*8+(b))
#define STBI__CASE(a,b) case STBI__COMBO(a,b): for(i=x-1; i >= 0; --i, src += a, dest += b)
// convert source image with img_n components to one with req_comp components;
// avoid switch per pixel, so use switch per scanline and massive macros
switch (STBI__COMBO(img_n, req_comp)) {
STBI__CASE(1, 2) { dest[0] = src[0]; dest[1] = 0xffff; } break;
STBI__CASE(1, 3) { dest[0] = dest[1] = dest[2] = src[0]; } break;
STBI__CASE(1, 4) { dest[0] = dest[1] = dest[2] = src[0]; dest[3] = 0xffff; } break;
STBI__CASE(2, 1) { dest[0] = src[0]; } break;
STBI__CASE(2, 3) { dest[0] = dest[1] = dest[2] = src[0]; } break;
STBI__CASE(2, 4) { dest[0] = dest[1] = dest[2] = src[0]; dest[3] = src[1]; } break;
STBI__CASE(3, 4) { dest[0] = src[0]; dest[1] = src[1]; dest[2] = src[2]; dest[3] = 0xffff; } break;
STBI__CASE(3, 1) { dest[0] = stbi__compute_y_16(src[0], src[1], src[2]); } break;
STBI__CASE(3, 2) { dest[0] = stbi__compute_y_16(src[0], src[1], src[2]); dest[1] = 0xffff; } break;
STBI__CASE(4, 1) { dest[0] = stbi__compute_y_16(src[0], src[1], src[2]); } break;
STBI__CASE(4, 2) { dest[0] = stbi__compute_y_16(src[0], src[1], src[2]); dest[1] = src[3]; } break;
STBI__CASE(4, 3) { dest[0] = src[0]; dest[1] = src[1]; dest[2] = src[2]; } break;
default: STBI_ASSERT(0); STBI_FREE(data); STBI_FREE(good); return (stbi__uint16*)stbi__errpuc("unsupported", "Unsupported format conversion");
}
#undef STBI__CASE
}
STBI_FREE(data);
return good;
}
#endif
#ifndef STBI_NO_LINEAR
static float* stbi__ldr_to_hdr(stbi_uc* data, int x, int y, int comp)
{
int i, k, n;
float* output;
if (!data) return NULL;
output = (float*)stbi__malloc_mad4(x, y, comp, sizeof(float), 0);
if (output == NULL) { STBI_FREE(data); return stbi__errpf("outofmem", "Out of memory"); }
// compute number of non-alpha components
if (comp & 1) n = comp; else n = comp - 1;
for (i = 0; i < x * y; ++i) {
for (k = 0; k < n; ++k) {
output[i * comp + k] = (float)(pow(data[i * comp + k] / 255.0f, stbi__l2h_gamma) * stbi__l2h_scale);
}
}
if (n < comp) {
for (i = 0; i < x * y; ++i) {
output[i * comp + n] = data[i * comp + n] / 255.0f;
}
}
STBI_FREE(data);
return output;
}
#endif
#ifndef STBI_NO_HDR
#define stbi__float2int(x) ((int) (x))
static stbi_uc* stbi__hdr_to_ldr(float* data, int x, int y, int comp)
{
int i, k, n;
stbi_uc* output;
if (!data) return NULL;
output = (stbi_uc*)stbi__malloc_mad3(x, y, comp, 0);
if (output == NULL) { STBI_FREE(data); return stbi__errpuc("outofmem", "Out of memory"); }
// compute number of non-alpha components
if (comp & 1) n = comp; else n = comp - 1;
for (i = 0; i < x * y; ++i) {
for (k = 0; k < n; ++k) {
float z = (float)pow(data[i * comp + k] * stbi__h2l_scale_i, stbi__h2l_gamma_i) * 255 + 0.5f;
if (z < 0) z = 0;
if (z > 255) z = 255;
output[i * comp + k] = (stbi_uc)stbi__float2int(z);
}
if (k < comp) {
float z = data[i * comp + k] * 255 + 0.5f;
if (z < 0) z = 0;
if (z > 255) z = 255;
output[i * comp + k] = (stbi_uc)stbi__float2int(z);
}
}
STBI_FREE(data);
return output;
}
#endif
//////////////////////////////////////////////////////////////////////////////
//
// "baseline" JPEG/JFIF decoder
//
// simple implementation
// - doesn't support delayed output of y-dimension
// - simple interface (only one output format: 8-bit interleaved RGB)
// - doesn't try to recover corrupt jpegs
// - doesn't allow partial loading, loading multiple at once
// - still fast on x86 (copying globals into locals doesn't help x86)
// - allocates lots of intermediate memory (full size of all components)
// - non-interleaved case requires this anyway
// - allows good upsampling (see next)
// high-quality
// - upsampled channels are bilinearly interpolated, even across blocks
// - quality integer IDCT derived from IJG's 'slow'
// performance
// - fast huffman; reasonable integer IDCT
// - some SIMD kernels for common paths on targets with SSE2/NEON
// - uses a lot of intermediate memory, could cache poorly
#ifndef STBI_NO_JPEG
// huffman decoding acceleration
#define FAST_BITS 9 // larger handles more cases; smaller stomps less cache
typedef struct
{
stbi_uc fast[1 << FAST_BITS];
// weirdly, repacking this into AoS is a 10% speed loss, instead of a win
stbi__uint16 code[256];
stbi_uc values[256];
stbi_uc size[257];
unsigned int maxcode[18];
int delta[17]; // old 'firstsymbol' - old 'firstcode'
} stbi__huffman;
typedef struct
{
stbi__context* s;
stbi__huffman huff_dc[4];
stbi__huffman huff_ac[4];
stbi__uint16 dequant[4][64];
stbi__int16 fast_ac[4][1 << FAST_BITS];
// sizes for components, interleaved MCUs
int img_h_max, img_v_max;
int img_mcu_x, img_mcu_y;
int img_mcu_w, img_mcu_h;
// definition of jpeg image component
struct
{
int id;
int h, v;
int tq;
int hd, ha;
int dc_pred;
int x, y, w2, h2;
stbi_uc* data;
void* raw_data, * raw_coeff;
stbi_uc* linebuf;
short* coeff; // progressive only
int coeff_w, coeff_h; // number of 8x8 coefficient blocks
} img_comp[4];
stbi__uint32 code_buffer; // jpeg entropy-coded buffer
int code_bits; // number of valid bits
unsigned char marker; // marker seen while filling entropy buffer
int nomore; // flag if we saw a marker so must stop
int progressive;
int spec_start;
int spec_end;
int succ_high;
int succ_low;
int eob_run;
int jfif;
int app14_color_transform; // Adobe APP14 tag
int rgb;
int scan_n, order[4];
int restart_interval, todo;
// kernels
void (*idct_block_kernel)(stbi_uc* out, int out_stride, short data[64]);
void (*YCbCr_to_RGB_kernel)(stbi_uc* out, const stbi_uc* y, const stbi_uc* pcb, const stbi_uc* pcr, int count, int step);
stbi_uc* (*resample_row_hv_2_kernel)(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs);
} stbi__jpeg;
static int stbi__build_huffman(stbi__huffman* h, int* count)
{
int i, j, k = 0;
unsigned int code;
// build size list for each symbol (from JPEG spec)
for (i = 0; i < 16; ++i)
for (j = 0; j < count[i]; ++j)
h->size[k++] = (stbi_uc)(i + 1);
h->size[k] = 0;
// compute actual symbols (from jpeg spec)
code = 0;
k = 0;
for (j = 1; j <= 16; ++j) {
// compute delta to add to code to compute symbol id
h->delta[j] = k - code;
if (h->size[k] == j) {
while (h->size[k] == j)
h->code[k++] = (stbi__uint16)(code++);
if (code - 1 >= (1u << j)) return stbi__err("bad code lengths", "Corrupt JPEG");
}
// compute largest code + 1 for this size, preshifted as needed later
h->maxcode[j] = code << (16 - j);
code <<= 1;
}
h->maxcode[j] = 0xffffffff;
// build non-spec acceleration table; 255 is flag for not-accelerated
memset(h->fast, 255, 1 << FAST_BITS);
for (i = 0; i < k; ++i) {
int s = h->size[i];
if (s <= FAST_BITS) {
int c = h->code[i] << (FAST_BITS - s);
int m = 1 << (FAST_BITS - s);
for (j = 0; j < m; ++j) {
h->fast[c + j] = (stbi_uc)i;
}
}
}
return 1;
}
// build a table that decodes both magnitude and value of small ACs in
// one go.
static void stbi__build_fast_ac(stbi__int16* fast_ac, stbi__huffman* h)
{
int i;
for (i = 0; i < (1 << FAST_BITS); ++i) {
stbi_uc fast = h->fast[i];
fast_ac[i] = 0;
if (fast < 255) {
int rs = h->values[fast];
int run = (rs >> 4) & 15;
int magbits = rs & 15;
int len = h->size[fast];
if (magbits && len + magbits <= FAST_BITS) {
// magnitude code followed by receive_extend code
int k = ((i << len) & ((1 << FAST_BITS) - 1)) >> (FAST_BITS - magbits);
int m = 1 << (magbits - 1);
if (k < m) k += (~0U << magbits) + 1;
// if the result is small enough, we can fit it in fast_ac table
if (k >= -128 && k <= 127)
fast_ac[i] = (stbi__int16)((k * 256) + (run * 16) + (len + magbits));
}
}
}
}
static void stbi__grow_buffer_unsafe(stbi__jpeg* j)
{
do {
unsigned int b = j->nomore ? 0 : stbi__get8(j->s);
if (b == 0xff) {
int c = stbi__get8(j->s);
while (c == 0xff) c = stbi__get8(j->s); // consume fill bytes
if (c != 0) {
j->marker = (unsigned char)c;
j->nomore = 1;
return;
}
}
j->code_buffer |= b << (24 - j->code_bits);
j->code_bits += 8;
} while (j->code_bits <= 24);
}
// (1 << n) - 1
static const stbi__uint32 stbi__bmask[17] = { 0,1,3,7,15,31,63,127,255,511,1023,2047,4095,8191,16383,32767,65535 };
// decode a jpeg huffman value from the bitstream
stbi_inline static int stbi__jpeg_huff_decode(stbi__jpeg* j, stbi__huffman* h)
{
unsigned int temp;
int c, k;
if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
// look at the top FAST_BITS and determine what symbol ID it is,
// if the code is <= FAST_BITS
c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS) - 1);
k = h->fast[c];
if (k < 255) {
int s = h->size[k];
if (s > j->code_bits)
return -1;
j->code_buffer <<= s;
j->code_bits -= s;
return h->values[k];
}
// naive test is to shift the code_buffer down so k bits are
// valid, then test against maxcode. To speed this up, we've
// preshifted maxcode left so that it has (16-k) 0s at the
// end; in other words, regardless of the number of bits, it
// wants to be compared against something shifted to have 16;
// that way we don't need to shift inside the loop.
temp = j->code_buffer >> 16;
for (k = FAST_BITS + 1; ; ++k)
if (temp < h->maxcode[k])
break;
if (k == 17) {
// error! code not found
j->code_bits -= 16;
return -1;
}
if (k > j->code_bits)
return -1;
// convert the huffman code to the symbol id
c = ((j->code_buffer >> (32 - k)) & stbi__bmask[k]) + h->delta[k];
STBI_ASSERT((((j->code_buffer) >> (32 - h->size[c])) & stbi__bmask[h->size[c]]) == h->code[c]);
// convert the id to a symbol
j->code_bits -= k;
j->code_buffer <<= k;
return h->values[c];
}
// bias[n] = (-1<<n) + 1
static const int stbi__jbias[16] = { 0,-1,-3,-7,-15,-31,-63,-127,-255,-511,-1023,-2047,-4095,-8191,-16383,-32767 };
// combined JPEG 'receive' and JPEG 'extend', since baseline
// always extends everything it receives.
stbi_inline static int stbi__extend_receive(stbi__jpeg* j, int n)
{
unsigned int k;
int sgn;
if (j->code_bits < n) stbi__grow_buffer_unsafe(j);
sgn = (stbi__int32)j->code_buffer >> 31; // sign bit is always in MSB
k = stbi_lrot(j->code_buffer, n);
if (n < 0 || n >= (int)(sizeof(stbi__bmask) / sizeof(*stbi__bmask))) return 0;
j->code_buffer = k & ~stbi__bmask[n];
k &= stbi__bmask[n];
j->code_bits -= n;
return k + (stbi__jbias[n] & ~sgn);
}
// get some unsigned bits
stbi_inline static int stbi__jpeg_get_bits(stbi__jpeg* j, int n)
{
unsigned int k;
if (j->code_bits < n) stbi__grow_buffer_unsafe(j);
k = stbi_lrot(j->code_buffer, n);
j->code_buffer = k & ~stbi__bmask[n];
k &= stbi__bmask[n];
j->code_bits -= n;
return k;
}
stbi_inline static int stbi__jpeg_get_bit(stbi__jpeg* j)
{
unsigned int k;
if (j->code_bits < 1) stbi__grow_buffer_unsafe(j);
k = j->code_buffer;
j->code_buffer <<= 1;
--j->code_bits;
return k & 0x80000000;
}
// given a value that's at position X in the zigzag stream,
// where does it appear in the 8x8 matrix coded as row-major?
static const stbi_uc stbi__jpeg_dezigzag[64 + 15] =
{
0, 1, 8, 16, 9, 2, 3, 10,
17, 24, 32, 25, 18, 11, 4, 5,
12, 19, 26, 33, 40, 48, 41, 34,
27, 20, 13, 6, 7, 14, 21, 28,
35, 42, 49, 56, 57, 50, 43, 36,
29, 22, 15, 23, 30, 37, 44, 51,
58, 59, 52, 45, 38, 31, 39, 46,
53, 60, 61, 54, 47, 55, 62, 63,
// let corrupt input sample past end
63, 63, 63, 63, 63, 63, 63, 63,
63, 63, 63, 63, 63, 63, 63
};
// decode one 64-entry block--
static int stbi__jpeg_decode_block(stbi__jpeg* j, short data[64], stbi__huffman* hdc, stbi__huffman* hac, stbi__int16* fac, int b, stbi__uint16* dequant)
{
int diff, dc, k;
int t;
if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
t = stbi__jpeg_huff_decode(j, hdc);
if (t < 0) return stbi__err("bad huffman code", "Corrupt JPEG");
// 0 all the ac values now so we can do it 32-bits at a time
memset(data, 0, 64 * sizeof(data[0]));
diff = t ? stbi__extend_receive(j, t) : 0;
dc = j->img_comp[b].dc_pred + diff;
j->img_comp[b].dc_pred = dc;
data[0] = (short)(dc * dequant[0]);
// decode AC components, see JPEG spec
k = 1;
do {
unsigned int zig;
int c, r, s;
if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS) - 1);
r = fac[c];
if (r) { // fast-AC path
k += (r >> 4) & 15; // run
s = r & 15; // combined length
j->code_buffer <<= s;
j->code_bits -= s;
// decode into unzigzag'd location
zig = stbi__jpeg_dezigzag[k++];
data[zig] = (short)((r >> 8) * dequant[zig]);
}
else {
int rs = stbi__jpeg_huff_decode(j, hac);
if (rs < 0) return stbi__err("bad huffman code", "Corrupt JPEG");
s = rs & 15;
r = rs >> 4;
if (s == 0) {
if (rs != 0xf0) break; // end block
k += 16;
}
else {
k += r;
// decode into unzigzag'd location
zig = stbi__jpeg_dezigzag[k++];
data[zig] = (short)(stbi__extend_receive(j, s) * dequant[zig]);
}
}
} while (k < 64);
return 1;
}
static int stbi__jpeg_decode_block_prog_dc(stbi__jpeg* j, short data[64], stbi__huffman* hdc, int b)
{
int diff, dc;
int t;
if (j->spec_end != 0) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
if (j->succ_high == 0) {
// first scan for DC coefficient, must be first
memset(data, 0, 64 * sizeof(data[0])); // 0 all the ac values now
t = stbi__jpeg_huff_decode(j, hdc);
if (t == -1) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
diff = t ? stbi__extend_receive(j, t) : 0;
dc = j->img_comp[b].dc_pred + diff;
j->img_comp[b].dc_pred = dc;
data[0] = (short)(dc << j->succ_low);
}
else {
// refinement scan for DC coefficient
if (stbi__jpeg_get_bit(j))
data[0] += (short)(1 << j->succ_low);
}
return 1;
}
// @OPTIMIZE: store non-zigzagged during the decode passes,
// and only de-zigzag when dequantizing
static int stbi__jpeg_decode_block_prog_ac(stbi__jpeg* j, short data[64], stbi__huffman* hac, stbi__int16* fac)
{
int k;
if (j->spec_start == 0) return stbi__err("can't merge dc and ac", "Corrupt JPEG");
if (j->succ_high == 0) {
int shift = j->succ_low;
if (j->eob_run) {
--j->eob_run;
return 1;
}
k = j->spec_start;
do {
unsigned int zig;
int c, r, s;
if (j->code_bits < 16) stbi__grow_buffer_unsafe(j);
c = (j->code_buffer >> (32 - FAST_BITS)) & ((1 << FAST_BITS) - 1);
r = fac[c];
if (r) { // fast-AC path
k += (r >> 4) & 15; // run
s = r & 15; // combined length
j->code_buffer <<= s;
j->code_bits -= s;
zig = stbi__jpeg_dezigzag[k++];
data[zig] = (short)((r >> 8) << shift);
}
else {
int rs = stbi__jpeg_huff_decode(j, hac);
if (rs < 0) return stbi__err("bad huffman code", "Corrupt JPEG");
s = rs & 15;
r = rs >> 4;
if (s == 0) {
if (r < 15) {
j->eob_run = (1 << r);
if (r)
j->eob_run += stbi__jpeg_get_bits(j, r);
--j->eob_run;
break;
}
k += 16;
}
else {
k += r;
zig = stbi__jpeg_dezigzag[k++];
data[zig] = (short)(stbi__extend_receive(j, s) << shift);
}
}
} while (k <= j->spec_end);
}
else {
// refinement scan for these AC coefficients
short bit = (short)(1 << j->succ_low);
if (j->eob_run) {
--j->eob_run;
for (k = j->spec_start; k <= j->spec_end; ++k) {
short* p = &data[stbi__jpeg_dezigzag[k]];
if (*p != 0)
if (stbi__jpeg_get_bit(j))
if ((*p & bit) == 0) {
if (*p > 0)
*p += bit;
else
*p -= bit;
}
}
}
else {
k = j->spec_start;
do {
int r, s;
int rs = stbi__jpeg_huff_decode(j, hac); // @OPTIMIZE see if we can use the fast path here, advance-by-r is so slow, eh
if (rs < 0) return stbi__err("bad huffman code", "Corrupt JPEG");
s = rs & 15;
r = rs >> 4;
if (s == 0) {
if (r < 15) {
j->eob_run = (1 << r) - 1;
if (r)
j->eob_run += stbi__jpeg_get_bits(j, r);
r = 64; // force end of block
}
else {
// r=15 s=0 should write 16 0s, so we just do
// a run of 15 0s and then write s (which is 0),
// so we don't have to do anything special here
}
}
else {
if (s != 1) return stbi__err("bad huffman code", "Corrupt JPEG");
// sign bit
if (stbi__jpeg_get_bit(j))
s = bit;
else
s = -bit;
}
// advance by r
while (k <= j->spec_end) {
short* p = &data[stbi__jpeg_dezigzag[k++]];
if (*p != 0) {
if (stbi__jpeg_get_bit(j))
if ((*p & bit) == 0) {
if (*p > 0)
*p += bit;
else
*p -= bit;
}
}
else {
if (r == 0) {
*p = (short)s;
break;
}
--r;
}
}
} while (k <= j->spec_end);
}
}
return 1;
}
// take a -128..127 value and stbi__clamp it and convert to 0..255
stbi_inline static stbi_uc stbi__clamp(int x)
{
// trick to use a single test to catch both cases
if ((unsigned int)x > 255) {
if (x < 0) return 0;
if (x > 255) return 255;
}
return (stbi_uc)x;
}
#define stbi__f2f(x) ((int) (((x) * 4096 + 0.5)))
#define stbi__fsh(x) ((x) * 4096)
// derived from jidctint -- DCT_ISLOW
#define STBI__IDCT_1D(s0,s1,s2,s3,s4,s5,s6,s7) \
int t0,t1,t2,t3,p1,p2,p3,p4,p5,x0,x1,x2,x3; \
p2 = s2; \
p3 = s6; \
p1 = (p2+p3) * stbi__f2f(0.5411961f); \
t2 = p1 + p3*stbi__f2f(-1.847759065f); \
t3 = p1 + p2*stbi__f2f( 0.765366865f); \
p2 = s0; \
p3 = s4; \
t0 = stbi__fsh(p2+p3); \
t1 = stbi__fsh(p2-p3); \
x0 = t0+t3; \
x3 = t0-t3; \
x1 = t1+t2; \
x2 = t1-t2; \
t0 = s7; \
t1 = s5; \
t2 = s3; \
t3 = s1; \
p3 = t0+t2; \
p4 = t1+t3; \
p1 = t0+t3; \
p2 = t1+t2; \
p5 = (p3+p4)*stbi__f2f( 1.175875602f); \
t0 = t0*stbi__f2f( 0.298631336f); \
t1 = t1*stbi__f2f( 2.053119869f); \
t2 = t2*stbi__f2f( 3.072711026f); \
t3 = t3*stbi__f2f( 1.501321110f); \
p1 = p5 + p1*stbi__f2f(-0.899976223f); \
p2 = p5 + p2*stbi__f2f(-2.562915447f); \
p3 = p3*stbi__f2f(-1.961570560f); \
p4 = p4*stbi__f2f(-0.390180644f); \
t3 += p1+p4; \
t2 += p2+p3; \
t1 += p2+p4; \
t0 += p1+p3;
static void stbi__idct_block(stbi_uc* out, int out_stride, short data[64])
{
int i, val[64], * v = val;
stbi_uc* o;
short* d = data;
// columns
for (i = 0; i < 8; ++i, ++d, ++v) {
// if all zeroes, shortcut -- this avoids dequantizing 0s and IDCTing
if (d[8] == 0 && d[16] == 0 && d[24] == 0 && d[32] == 0
&& d[40] == 0 && d[48] == 0 && d[56] == 0) {
// no shortcut 0 seconds
// (1|2|3|4|5|6|7)==0 0 seconds
// all separate -0.047 seconds
// 1 && 2|3 && 4|5 && 6|7: -0.047 seconds
int dcterm = d[0] * 4;
v[0] = v[8] = v[16] = v[24] = v[32] = v[40] = v[48] = v[56] = dcterm;
}
else {
STBI__IDCT_1D(d[0], d[8], d[16], d[24], d[32], d[40], d[48], d[56])
// constants scaled things up by 1<<12; let's bring them back
// down, but keep 2 extra bits of precision
x0 += 512; x1 += 512; x2 += 512; x3 += 512;
v[0] = (x0 + t3) >> 10;
v[56] = (x0 - t3) >> 10;
v[8] = (x1 + t2) >> 10;
v[48] = (x1 - t2) >> 10;
v[16] = (x2 + t1) >> 10;
v[40] = (x2 - t1) >> 10;
v[24] = (x3 + t0) >> 10;
v[32] = (x3 - t0) >> 10;
}
}
for (i = 0, v = val, o = out; i < 8; ++i, v += 8, o += out_stride) {
// no fast case since the first 1D IDCT spread components out
STBI__IDCT_1D(v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7])
// constants scaled things up by 1<<12, plus we had 1<<2 from first
// loop, plus horizontal and vertical each scale by sqrt(8) so together
// we've got an extra 1<<3, so 1<<17 total we need to remove.
// so we want to round that, which means adding 0.5 * 1<<17,
// aka 65536. Also, we'll end up with -128 to 127 that we want
// to encode as 0..255 by adding 128, so we'll add that before the shift
x0 += 65536 + (128 << 17);
x1 += 65536 + (128 << 17);
x2 += 65536 + (128 << 17);
x3 += 65536 + (128 << 17);
// tried computing the shifts into temps, or'ing the temps to see
// if any were out of range, but that was slower
o[0] = stbi__clamp((x0 + t3) >> 17);
o[7] = stbi__clamp((x0 - t3) >> 17);
o[1] = stbi__clamp((x1 + t2) >> 17);
o[6] = stbi__clamp((x1 - t2) >> 17);
o[2] = stbi__clamp((x2 + t1) >> 17);
o[5] = stbi__clamp((x2 - t1) >> 17);
o[3] = stbi__clamp((x3 + t0) >> 17);
o[4] = stbi__clamp((x3 - t0) >> 17);
}
}
#ifdef STBI_SSE2
// sse2 integer IDCT. not the fastest possible implementation but it
// produces bit-identical results to the generic C version so it's
// fully "transparent".
static void stbi__idct_simd(stbi_uc* out, int out_stride, short data[64])
{
// This is constructed to match our regular (generic) integer IDCT exactly.
__m128i row0, row1, row2, row3, row4, row5, row6, row7;
__m128i tmp;
// dot product constant: even elems=x, odd elems=y
#define dct_const(x,y) _mm_setr_epi16((x),(y),(x),(y),(x),(y),(x),(y))
// out(0) = c0[even]*x + c0[odd]*y (c0, x, y 16-bit, out 32-bit)
// out(1) = c1[even]*x + c1[odd]*y
#define dct_rot(out0,out1, x,y,c0,c1) \
__m128i c0##lo = _mm_unpacklo_epi16((x),(y)); \
__m128i c0##hi = _mm_unpackhi_epi16((x),(y)); \
__m128i out0##_l = _mm_madd_epi16(c0##lo, c0); \
__m128i out0##_h = _mm_madd_epi16(c0##hi, c0); \
__m128i out1##_l = _mm_madd_epi16(c0##lo, c1); \
__m128i out1##_h = _mm_madd_epi16(c0##hi, c1)
// out = in << 12 (in 16-bit, out 32-bit)
#define dct_widen(out, in) \
__m128i out##_l = _mm_srai_epi32(_mm_unpacklo_epi16(_mm_setzero_si128(), (in)), 4); \
__m128i out##_h = _mm_srai_epi32(_mm_unpackhi_epi16(_mm_setzero_si128(), (in)), 4)
// wide add
#define dct_wadd(out, a, b) \
__m128i out##_l = _mm_add_epi32(a##_l, b##_l); \
__m128i out##_h = _mm_add_epi32(a##_h, b##_h)
// wide sub
#define dct_wsub(out, a, b) \
__m128i out##_l = _mm_sub_epi32(a##_l, b##_l); \
__m128i out##_h = _mm_sub_epi32(a##_h, b##_h)
// butterfly a/b, add bias, then shift by "s" and pack
#define dct_bfly32o(out0, out1, a,b,bias,s) \
{ \
__m128i abiased_l = _mm_add_epi32(a##_l, bias); \
__m128i abiased_h = _mm_add_epi32(a##_h, bias); \
dct_wadd(sum, abiased, b); \
dct_wsub(dif, abiased, b); \
out0 = _mm_packs_epi32(_mm_srai_epi32(sum_l, s), _mm_srai_epi32(sum_h, s)); \
out1 = _mm_packs_epi32(_mm_srai_epi32(dif_l, s), _mm_srai_epi32(dif_h, s)); \
}
// 8-bit interleave step (for transposes)
#define dct_interleave8(a, b) \
tmp = a; \
a = _mm_unpacklo_epi8(a, b); \
b = _mm_unpackhi_epi8(tmp, b)
// 16-bit interleave step (for transposes)
#define dct_interleave16(a, b) \
tmp = a; \
a = _mm_unpacklo_epi16(a, b); \
b = _mm_unpackhi_epi16(tmp, b)
#define dct_pass(bias,shift) \
{ \
/* even part */ \
dct_rot(t2e,t3e, row2,row6, rot0_0,rot0_1); \
__m128i sum04 = _mm_add_epi16(row0, row4); \
__m128i dif04 = _mm_sub_epi16(row0, row4); \
dct_widen(t0e, sum04); \
dct_widen(t1e, dif04); \
dct_wadd(x0, t0e, t3e); \
dct_wsub(x3, t0e, t3e); \
dct_wadd(x1, t1e, t2e); \
dct_wsub(x2, t1e, t2e); \
/* odd part */ \
dct_rot(y0o,y2o, row7,row3, rot2_0,rot2_1); \
dct_rot(y1o,y3o, row5,row1, rot3_0,rot3_1); \
__m128i sum17 = _mm_add_epi16(row1, row7); \
__m128i sum35 = _mm_add_epi16(row3, row5); \
dct_rot(y4o,y5o, sum17,sum35, rot1_0,rot1_1); \
dct_wadd(x4, y0o, y4o); \
dct_wadd(x5, y1o, y5o); \
dct_wadd(x6, y2o, y5o); \
dct_wadd(x7, y3o, y4o); \
dct_bfly32o(row0,row7, x0,x7,bias,shift); \
dct_bfly32o(row1,row6, x1,x6,bias,shift); \
dct_bfly32o(row2,row5, x2,x5,bias,shift); \
dct_bfly32o(row3,row4, x3,x4,bias,shift); \
}
__m128i rot0_0 = dct_const(stbi__f2f(0.5411961f), stbi__f2f(0.5411961f) + stbi__f2f(-1.847759065f));
__m128i rot0_1 = dct_const(stbi__f2f(0.5411961f) + stbi__f2f(0.765366865f), stbi__f2f(0.5411961f));
__m128i rot1_0 = dct_const(stbi__f2f(1.175875602f) + stbi__f2f(-0.899976223f), stbi__f2f(1.175875602f));
__m128i rot1_1 = dct_const(stbi__f2f(1.175875602f), stbi__f2f(1.175875602f) + stbi__f2f(-2.562915447f));
__m128i rot2_0 = dct_const(stbi__f2f(-1.961570560f) + stbi__f2f(0.298631336f), stbi__f2f(-1.961570560f));
__m128i rot2_1 = dct_const(stbi__f2f(-1.961570560f), stbi__f2f(-1.961570560f) + stbi__f2f(3.072711026f));
__m128i rot3_0 = dct_const(stbi__f2f(-0.390180644f) + stbi__f2f(2.053119869f), stbi__f2f(-0.390180644f));
__m128i rot3_1 = dct_const(stbi__f2f(-0.390180644f), stbi__f2f(-0.390180644f) + stbi__f2f(1.501321110f));
// rounding biases in column/row passes, see stbi__idct_block for explanation.
__m128i bias_0 = _mm_set1_epi32(512);
__m128i bias_1 = _mm_set1_epi32(65536 + (128 << 17));
// load
row0 = _mm_load_si128((const __m128i*) (data + 0 * 8));
row1 = _mm_load_si128((const __m128i*) (data + 1 * 8));
row2 = _mm_load_si128((const __m128i*) (data + 2 * 8));
row3 = _mm_load_si128((const __m128i*) (data + 3 * 8));
row4 = _mm_load_si128((const __m128i*) (data + 4 * 8));
row5 = _mm_load_si128((const __m128i*) (data + 5 * 8));
row6 = _mm_load_si128((const __m128i*) (data + 6 * 8));
row7 = _mm_load_si128((const __m128i*) (data + 7 * 8));
// column pass
dct_pass(bias_0, 10);
{
// 16bit 8x8 transpose pass 1
dct_interleave16(row0, row4);
dct_interleave16(row1, row5);
dct_interleave16(row2, row6);
dct_interleave16(row3, row7);
// transpose pass 2
dct_interleave16(row0, row2);
dct_interleave16(row1, row3);
dct_interleave16(row4, row6);
dct_interleave16(row5, row7);
// transpose pass 3
dct_interleave16(row0, row1);
dct_interleave16(row2, row3);
dct_interleave16(row4, row5);
dct_interleave16(row6, row7);
}
// row pass
dct_pass(bias_1, 17);
{
// pack
__m128i p0 = _mm_packus_epi16(row0, row1); // a0a1a2a3...a7b0b1b2b3...b7
__m128i p1 = _mm_packus_epi16(row2, row3);
__m128i p2 = _mm_packus_epi16(row4, row5);
__m128i p3 = _mm_packus_epi16(row6, row7);
// 8bit 8x8 transpose pass 1
dct_interleave8(p0, p2); // a0e0a1e1...
dct_interleave8(p1, p3); // c0g0c1g1...
// transpose pass 2
dct_interleave8(p0, p1); // a0c0e0g0...
dct_interleave8(p2, p3); // b0d0f0h0...
// transpose pass 3
dct_interleave8(p0, p2); // a0b0c0d0...
dct_interleave8(p1, p3); // a4b4c4d4...
// store
_mm_storel_epi64((__m128i*) out, p0); out += out_stride;
_mm_storel_epi64((__m128i*) out, _mm_shuffle_epi32(p0, 0x4e)); out += out_stride;
_mm_storel_epi64((__m128i*) out, p2); out += out_stride;
_mm_storel_epi64((__m128i*) out, _mm_shuffle_epi32(p2, 0x4e)); out += out_stride;
_mm_storel_epi64((__m128i*) out, p1); out += out_stride;
_mm_storel_epi64((__m128i*) out, _mm_shuffle_epi32(p1, 0x4e)); out += out_stride;
_mm_storel_epi64((__m128i*) out, p3); out += out_stride;
_mm_storel_epi64((__m128i*) out, _mm_shuffle_epi32(p3, 0x4e));
}
#undef dct_const
#undef dct_rot
#undef dct_widen
#undef dct_wadd
#undef dct_wsub
#undef dct_bfly32o
#undef dct_interleave8
#undef dct_interleave16
#undef dct_pass
}
#endif // STBI_SSE2
#ifdef STBI_NEON
// NEON integer IDCT. should produce bit-identical
// results to the generic C version.
static void stbi__idct_simd(stbi_uc* out, int out_stride, short data[64])
{
int16x8_t row0, row1, row2, row3, row4, row5, row6, row7;
int16x4_t rot0_0 = vdup_n_s16(stbi__f2f(0.5411961f));
int16x4_t rot0_1 = vdup_n_s16(stbi__f2f(-1.847759065f));
int16x4_t rot0_2 = vdup_n_s16(stbi__f2f(0.765366865f));
int16x4_t rot1_0 = vdup_n_s16(stbi__f2f(1.175875602f));
int16x4_t rot1_1 = vdup_n_s16(stbi__f2f(-0.899976223f));
int16x4_t rot1_2 = vdup_n_s16(stbi__f2f(-2.562915447f));
int16x4_t rot2_0 = vdup_n_s16(stbi__f2f(-1.961570560f));
int16x4_t rot2_1 = vdup_n_s16(stbi__f2f(-0.390180644f));
int16x4_t rot3_0 = vdup_n_s16(stbi__f2f(0.298631336f));
int16x4_t rot3_1 = vdup_n_s16(stbi__f2f(2.053119869f));
int16x4_t rot3_2 = vdup_n_s16(stbi__f2f(3.072711026f));
int16x4_t rot3_3 = vdup_n_s16(stbi__f2f(1.501321110f));
#define dct_long_mul(out, inq, coeff) \
int32x4_t out##_l = vmull_s16(vget_low_s16(inq), coeff); \
int32x4_t out##_h = vmull_s16(vget_high_s16(inq), coeff)
#define dct_long_mac(out, acc, inq, coeff) \
int32x4_t out##_l = vmlal_s16(acc##_l, vget_low_s16(inq), coeff); \
int32x4_t out##_h = vmlal_s16(acc##_h, vget_high_s16(inq), coeff)
#define dct_widen(out, inq) \
int32x4_t out##_l = vshll_n_s16(vget_low_s16(inq), 12); \
int32x4_t out##_h = vshll_n_s16(vget_high_s16(inq), 12)
// wide add
#define dct_wadd(out, a, b) \
int32x4_t out##_l = vaddq_s32(a##_l, b##_l); \
int32x4_t out##_h = vaddq_s32(a##_h, b##_h)
// wide sub
#define dct_wsub(out, a, b) \
int32x4_t out##_l = vsubq_s32(a##_l, b##_l); \
int32x4_t out##_h = vsubq_s32(a##_h, b##_h)
// butterfly a/b, then shift using "shiftop" by "s" and pack
#define dct_bfly32o(out0,out1, a,b,shiftop,s) \
{ \
dct_wadd(sum, a, b); \
dct_wsub(dif, a, b); \
out0 = vcombine_s16(shiftop(sum_l, s), shiftop(sum_h, s)); \
out1 = vcombine_s16(shiftop(dif_l, s), shiftop(dif_h, s)); \
}
#define dct_pass(shiftop, shift) \
{ \
/* even part */ \
int16x8_t sum26 = vaddq_s16(row2, row6); \
dct_long_mul(p1e, sum26, rot0_0); \
dct_long_mac(t2e, p1e, row6, rot0_1); \
dct_long_mac(t3e, p1e, row2, rot0_2); \
int16x8_t sum04 = vaddq_s16(row0, row4); \
int16x8_t dif04 = vsubq_s16(row0, row4); \
dct_widen(t0e, sum04); \
dct_widen(t1e, dif04); \
dct_wadd(x0, t0e, t3e); \
dct_wsub(x3, t0e, t3e); \
dct_wadd(x1, t1e, t2e); \
dct_wsub(x2, t1e, t2e); \
/* odd part */ \
int16x8_t sum15 = vaddq_s16(row1, row5); \
int16x8_t sum17 = vaddq_s16(row1, row7); \
int16x8_t sum35 = vaddq_s16(row3, row5); \
int16x8_t sum37 = vaddq_s16(row3, row7); \
int16x8_t sumodd = vaddq_s16(sum17, sum35); \
dct_long_mul(p5o, sumodd, rot1_0); \
dct_long_mac(p1o, p5o, sum17, rot1_1); \
dct_long_mac(p2o, p5o, sum35, rot1_2); \
dct_long_mul(p3o, sum37, rot2_0); \
dct_long_mul(p4o, sum15, rot2_1); \
dct_wadd(sump13o, p1o, p3o); \
dct_wadd(sump24o, p2o, p4o); \
dct_wadd(sump23o, p2o, p3o); \
dct_wadd(sump14o, p1o, p4o); \
dct_long_mac(x4, sump13o, row7, rot3_0); \
dct_long_mac(x5, sump24o, row5, rot3_1); \
dct_long_mac(x6, sump23o, row3, rot3_2); \
dct_long_mac(x7, sump14o, row1, rot3_3); \
dct_bfly32o(row0,row7, x0,x7,shiftop,shift); \
dct_bfly32o(row1,row6, x1,x6,shiftop,shift); \
dct_bfly32o(row2,row5, x2,x5,shiftop,shift); \
dct_bfly32o(row3,row4, x3,x4,shiftop,shift); \
}
// load
row0 = vld1q_s16(data + 0 * 8);
row1 = vld1q_s16(data + 1 * 8);
row2 = vld1q_s16(data + 2 * 8);
row3 = vld1q_s16(data + 3 * 8);
row4 = vld1q_s16(data + 4 * 8);
row5 = vld1q_s16(data + 5 * 8);
row6 = vld1q_s16(data + 6 * 8);
row7 = vld1q_s16(data + 7 * 8);
// add DC bias
row0 = vaddq_s16(row0, vsetq_lane_s16(1024, vdupq_n_s16(0), 0));
// column pass
dct_pass(vrshrn_n_s32, 10);
// 16bit 8x8 transpose
{
// these three map to a single VTRN.16, VTRN.32, and VSWP, respectively.
// whether compilers actually get this is another story, sadly.
#define dct_trn16(x, y) { int16x8x2_t t = vtrnq_s16(x, y); x = t.val[0]; y = t.val[1]; }
#define dct_trn32(x, y) { int32x4x2_t t = vtrnq_s32(vreinterpretq_s32_s16(x), vreinterpretq_s32_s16(y)); x = vreinterpretq_s16_s32(t.val[0]); y = vreinterpretq_s16_s32(t.val[1]); }
#define dct_trn64(x, y) { int16x8_t x0 = x; int16x8_t y0 = y; x = vcombine_s16(vget_low_s16(x0), vget_low_s16(y0)); y = vcombine_s16(vget_high_s16(x0), vget_high_s16(y0)); }
// pass 1
dct_trn16(row0, row1); // a0b0a2b2a4b4a6b6
dct_trn16(row2, row3);
dct_trn16(row4, row5);
dct_trn16(row6, row7);
// pass 2
dct_trn32(row0, row2); // a0b0c0d0a4b4c4d4
dct_trn32(row1, row3);
dct_trn32(row4, row6);
dct_trn32(row5, row7);
// pass 3
dct_trn64(row0, row4); // a0b0c0d0e0f0g0h0
dct_trn64(row1, row5);
dct_trn64(row2, row6);
dct_trn64(row3, row7);
#undef dct_trn16
#undef dct_trn32
#undef dct_trn64
}
// row pass
// vrshrn_n_s32 only supports shifts up to 16, we need
// 17. so do a non-rounding shift of 16 first then follow
// up with a rounding shift by 1.
dct_pass(vshrn_n_s32, 16);
{
// pack and round
uint8x8_t p0 = vqrshrun_n_s16(row0, 1);
uint8x8_t p1 = vqrshrun_n_s16(row1, 1);
uint8x8_t p2 = vqrshrun_n_s16(row2, 1);
uint8x8_t p3 = vqrshrun_n_s16(row3, 1);
uint8x8_t p4 = vqrshrun_n_s16(row4, 1);
uint8x8_t p5 = vqrshrun_n_s16(row5, 1);
uint8x8_t p6 = vqrshrun_n_s16(row6, 1);
uint8x8_t p7 = vqrshrun_n_s16(row7, 1);
// again, these can translate into one instruction, but often don't.
#define dct_trn8_8(x, y) { uint8x8x2_t t = vtrn_u8(x, y); x = t.val[0]; y = t.val[1]; }
#define dct_trn8_16(x, y) { uint16x4x2_t t = vtrn_u16(vreinterpret_u16_u8(x), vreinterpret_u16_u8(y)); x = vreinterpret_u8_u16(t.val[0]); y = vreinterpret_u8_u16(t.val[1]); }
#define dct_trn8_32(x, y) { uint32x2x2_t t = vtrn_u32(vreinterpret_u32_u8(x), vreinterpret_u32_u8(y)); x = vreinterpret_u8_u32(t.val[0]); y = vreinterpret_u8_u32(t.val[1]); }
// sadly can't use interleaved stores here since we only write
// 8 bytes to each scan line!
// 8x8 8-bit transpose pass 1
dct_trn8_8(p0, p1);
dct_trn8_8(p2, p3);
dct_trn8_8(p4, p5);
dct_trn8_8(p6, p7);
// pass 2
dct_trn8_16(p0, p2);
dct_trn8_16(p1, p3);
dct_trn8_16(p4, p6);
dct_trn8_16(p5, p7);
// pass 3
dct_trn8_32(p0, p4);
dct_trn8_32(p1, p5);
dct_trn8_32(p2, p6);
dct_trn8_32(p3, p7);
// store
vst1_u8(out, p0); out += out_stride;
vst1_u8(out, p1); out += out_stride;
vst1_u8(out, p2); out += out_stride;
vst1_u8(out, p3); out += out_stride;
vst1_u8(out, p4); out += out_stride;
vst1_u8(out, p5); out += out_stride;
vst1_u8(out, p6); out += out_stride;
vst1_u8(out, p7);
#undef dct_trn8_8
#undef dct_trn8_16
#undef dct_trn8_32
}
#undef dct_long_mul
#undef dct_long_mac
#undef dct_widen
#undef dct_wadd
#undef dct_wsub
#undef dct_bfly32o
#undef dct_pass
}
#endif // STBI_NEON
#define STBI__MARKER_none 0xff
// if there's a pending marker from the entropy stream, return that
// otherwise, fetch from the stream and get a marker. if there's no
// marker, return 0xff, which is never a valid marker value
static stbi_uc stbi__get_marker(stbi__jpeg* j)
{
stbi_uc x;
if (j->marker != STBI__MARKER_none) { x = j->marker; j->marker = STBI__MARKER_none; return x; }
x = stbi__get8(j->s);
if (x != 0xff) return STBI__MARKER_none;
while (x == 0xff)
x = stbi__get8(j->s); // consume repeated 0xff fill bytes
return x;
}
// in each scan, we'll have scan_n components, and the order
// of the components is specified by order[]
#define STBI__RESTART(x) ((x) >= 0xd0 && (x) <= 0xd7)
// after a restart interval, stbi__jpeg_reset the entropy decoder and
// the dc prediction
static void stbi__jpeg_reset(stbi__jpeg* j)
{
j->code_bits = 0;
j->code_buffer = 0;
j->nomore = 0;
j->img_comp[0].dc_pred = j->img_comp[1].dc_pred = j->img_comp[2].dc_pred = j->img_comp[3].dc_pred = 0;
j->marker = STBI__MARKER_none;
j->todo = j->restart_interval ? j->restart_interval : 0x7fffffff;
j->eob_run = 0;
// no more than 1<<31 MCUs if no restart_interal? that's plenty safe,
// since we don't even allow 1<<30 pixels
}
static int stbi__parse_entropy_coded_data(stbi__jpeg* z)
{
stbi__jpeg_reset(z);
if (!z->progressive) {
if (z->scan_n == 1) {
int i, j;
STBI_SIMD_ALIGN(short, data[64]);
int n = z->order[0];
// non-interleaved data, we just need to process one block at a time,
// in trivial scanline order
// number of blocks to do just depends on how many actual "pixels" this
// component has, independent of interleaved MCU blocking and such
int w = (z->img_comp[n].x + 7) >> 3;
int h = (z->img_comp[n].y + 7) >> 3;
for (j = 0; j < h; ++j) {
for (i = 0; i < w; ++i) {
int ha = z->img_comp[n].ha;
if (!stbi__jpeg_decode_block(z, data, z->huff_dc + z->img_comp[n].hd, z->huff_ac + ha, z->fast_ac[ha], n, z->dequant[z->img_comp[n].tq])) return 0;
z->idct_block_kernel(z->img_comp[n].data + z->img_comp[n].w2 * j * 8 + i * 8, z->img_comp[n].w2, data);
// every data block is an MCU, so countdown the restart interval
if (--z->todo <= 0) {
if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
// if it's NOT a restart, then just bail, so we get corrupt data
// rather than no data
if (!STBI__RESTART(z->marker)) return 1;
stbi__jpeg_reset(z);
}
}
}
return 1;
}
else { // interleaved
int i, j, k, x, y;
STBI_SIMD_ALIGN(short, data[64]);
for (j = 0; j < z->img_mcu_y; ++j) {
for (i = 0; i < z->img_mcu_x; ++i) {
// scan an interleaved mcu... process scan_n components in order
for (k = 0; k < z->scan_n; ++k) {
int n = z->order[k];
// scan out an mcu's worth of this component; that's just determined
// by the basic H and V specified for the component
for (y = 0; y < z->img_comp[n].v; ++y) {
for (x = 0; x < z->img_comp[n].h; ++x) {
int x2 = (i * z->img_comp[n].h + x) * 8;
int y2 = (j * z->img_comp[n].v + y) * 8;
int ha = z->img_comp[n].ha;
if (!stbi__jpeg_decode_block(z, data, z->huff_dc + z->img_comp[n].hd, z->huff_ac + ha, z->fast_ac[ha], n, z->dequant[z->img_comp[n].tq])) return 0;
z->idct_block_kernel(z->img_comp[n].data + z->img_comp[n].w2 * y2 + x2, z->img_comp[n].w2, data);
}
}
}
// after all interleaved components, that's an interleaved MCU,
// so now count down the restart interval
if (--z->todo <= 0) {
if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
if (!STBI__RESTART(z->marker)) return 1;
stbi__jpeg_reset(z);
}
}
}
return 1;
}
}
else {
if (z->scan_n == 1) {
int i, j;
int n = z->order[0];
// non-interleaved data, we just need to process one block at a time,
// in trivial scanline order
// number of blocks to do just depends on how many actual "pixels" this
// component has, independent of interleaved MCU blocking and such
int w = (z->img_comp[n].x + 7) >> 3;
int h = (z->img_comp[n].y + 7) >> 3;
for (j = 0; j < h; ++j) {
for (i = 0; i < w; ++i) {
short* data = z->img_comp[n].coeff + 64 * (i + j * z->img_comp[n].coeff_w);
if (z->spec_start == 0) {
if (!stbi__jpeg_decode_block_prog_dc(z, data, &z->huff_dc[z->img_comp[n].hd], n))
return 0;
}
else {
int ha = z->img_comp[n].ha;
if (!stbi__jpeg_decode_block_prog_ac(z, data, &z->huff_ac[ha], z->fast_ac[ha]))
return 0;
}
// every data block is an MCU, so countdown the restart interval
if (--z->todo <= 0) {
if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
if (!STBI__RESTART(z->marker)) return 1;
stbi__jpeg_reset(z);
}
}
}
return 1;
}
else { // interleaved
int i, j, k, x, y;
for (j = 0; j < z->img_mcu_y; ++j) {
for (i = 0; i < z->img_mcu_x; ++i) {
// scan an interleaved mcu... process scan_n components in order
for (k = 0; k < z->scan_n; ++k) {
int n = z->order[k];
// scan out an mcu's worth of this component; that's just determined
// by the basic H and V specified for the component
for (y = 0; y < z->img_comp[n].v; ++y) {
for (x = 0; x < z->img_comp[n].h; ++x) {
int x2 = (i * z->img_comp[n].h + x);
int y2 = (j * z->img_comp[n].v + y);
short* data = z->img_comp[n].coeff + 64 * (x2 + y2 * z->img_comp[n].coeff_w);
if (!stbi__jpeg_decode_block_prog_dc(z, data, &z->huff_dc[z->img_comp[n].hd], n))
return 0;
}
}
}
// after all interleaved components, that's an interleaved MCU,
// so now count down the restart interval
if (--z->todo <= 0) {
if (z->code_bits < 24) stbi__grow_buffer_unsafe(z);
if (!STBI__RESTART(z->marker)) return 1;
stbi__jpeg_reset(z);
}
}
}
return 1;
}
}
}
static void stbi__jpeg_dequantize(short* data, stbi__uint16* dequant)
{
int i;
for (i = 0; i < 64; ++i)
data[i] *= dequant[i];
}
static void stbi__jpeg_finish(stbi__jpeg* z)
{
if (z->progressive) {
// dequantize and idct the data
int i, j, n;
for (n = 0; n < z->s->img_n; ++n) {
int w = (z->img_comp[n].x + 7) >> 3;
int h = (z->img_comp[n].y + 7) >> 3;
for (j = 0; j < h; ++j) {
for (i = 0; i < w; ++i) {
short* data = z->img_comp[n].coeff + 64 * (i + j * z->img_comp[n].coeff_w);
stbi__jpeg_dequantize(data, z->dequant[z->img_comp[n].tq]);
z->idct_block_kernel(z->img_comp[n].data + z->img_comp[n].w2 * j * 8 + i * 8, z->img_comp[n].w2, data);
}
}
}
}
}
static int stbi__process_marker(stbi__jpeg* z, int m)
{
int L;
switch (m) {
case STBI__MARKER_none: // no marker found
return stbi__err("expected marker", "Corrupt JPEG");
case 0xDD: // DRI - specify restart interval
if (stbi__get16be(z->s) != 4) return stbi__err("bad DRI len", "Corrupt JPEG");
z->restart_interval = stbi__get16be(z->s);
return 1;
case 0xDB: // DQT - define quantization table
L = stbi__get16be(z->s) - 2;
while (L > 0) {
int q = stbi__get8(z->s);
int p = q >> 4, sixteen = (p != 0);
int t = q & 15, i;
if (p != 0 && p != 1) return stbi__err("bad DQT type", "Corrupt JPEG");
if (t > 3) return stbi__err("bad DQT table", "Corrupt JPEG");
for (i = 0; i < 64; ++i)
z->dequant[t][stbi__jpeg_dezigzag[i]] = (stbi__uint16)(sixteen ? stbi__get16be(z->s) : stbi__get8(z->s));
L -= (sixteen ? 129 : 65);
}
return L == 0;
case 0xC4: // DHT - define huffman table
L = stbi__get16be(z->s) - 2;
while (L > 0) {
stbi_uc* v;
int sizes[16], i, n = 0;
int q = stbi__get8(z->s);
int tc = q >> 4;
int th = q & 15;
if (tc > 1 || th > 3) return stbi__err("bad DHT header", "Corrupt JPEG");
for (i = 0; i < 16; ++i) {
sizes[i] = stbi__get8(z->s);
n += sizes[i];
}
L -= 17;
if (tc == 0) {
if (!stbi__build_huffman(z->huff_dc + th, sizes)) return 0;
v = z->huff_dc[th].values;
}
else {
if (!stbi__build_huffman(z->huff_ac + th, sizes)) return 0;
v = z->huff_ac[th].values;
}
for (i = 0; i < n; ++i)
v[i] = stbi__get8(z->s);
if (tc != 0)
stbi__build_fast_ac(z->fast_ac[th], z->huff_ac + th);
L -= n;
}
return L == 0;
}
// check for comment block or APP blocks
if ((m >= 0xE0 && m <= 0xEF) || m == 0xFE) {
L = stbi__get16be(z->s);
if (L < 2) {
if (m == 0xFE)
return stbi__err("bad COM len", "Corrupt JPEG");
else
return stbi__err("bad APP len", "Corrupt JPEG");
}
L -= 2;
if (m == 0xE0 && L >= 5) { // JFIF APP0 segment
static const unsigned char tag[5] = { 'J','F','I','F','\0' };
int ok = 1;
int i;
for (i = 0; i < 5; ++i)
if (stbi__get8(z->s) != tag[i])
ok = 0;
L -= 5;
if (ok)
z->jfif = 1;
}
else if (m == 0xEE && L >= 12) { // Adobe APP14 segment
static const unsigned char tag[6] = { 'A','d','o','b','e','\0' };
int ok = 1;
int i;
for (i = 0; i < 6; ++i)
if (stbi__get8(z->s) != tag[i])
ok = 0;
L -= 6;
if (ok) {
stbi__get8(z->s); // version
stbi__get16be(z->s); // flags0
stbi__get16be(z->s); // flags1
z->app14_color_transform = stbi__get8(z->s); // color transform
L -= 6;
}
}
stbi__skip(z->s, L);
return 1;
}
return stbi__err("unknown marker", "Corrupt JPEG");
}
// after we see SOS
static int stbi__process_scan_header(stbi__jpeg* z)
{
int i;
int Ls = stbi__get16be(z->s);
z->scan_n = stbi__get8(z->s);
if (z->scan_n < 1 || z->scan_n > 4 || z->scan_n > (int)z->s->img_n) return stbi__err("bad SOS component count", "Corrupt JPEG");
if (Ls != 6 + 2 * z->scan_n) return stbi__err("bad SOS len", "Corrupt JPEG");
for (i = 0; i < z->scan_n; ++i) {
int id = stbi__get8(z->s), which;
int q = stbi__get8(z->s);
for (which = 0; which < z->s->img_n; ++which)
if (z->img_comp[which].id == id)
break;
if (which == z->s->img_n) return 0; // no match
z->img_comp[which].hd = q >> 4; if (z->img_comp[which].hd > 3) return stbi__err("bad DC huff", "Corrupt JPEG");
z->img_comp[which].ha = q & 15; if (z->img_comp[which].ha > 3) return stbi__err("bad AC huff", "Corrupt JPEG");
z->order[i] = which;
}
{
int aa;
z->spec_start = stbi__get8(z->s);
z->spec_end = stbi__get8(z->s); // should be 63, but might be 0
aa = stbi__get8(z->s);
z->succ_high = (aa >> 4);
z->succ_low = (aa & 15);
if (z->progressive) {
if (z->spec_start > 63 || z->spec_end > 63 || z->spec_start > z->spec_end || z->succ_high > 13 || z->succ_low > 13)
return stbi__err("bad SOS", "Corrupt JPEG");
}
else {
if (z->spec_start != 0) return stbi__err("bad SOS", "Corrupt JPEG");
if (z->succ_high != 0 || z->succ_low != 0) return stbi__err("bad SOS", "Corrupt JPEG");
z->spec_end = 63;
}
}
return 1;
}
static int stbi__free_jpeg_components(stbi__jpeg* z, int ncomp, int why)
{
int i;
for (i = 0; i < ncomp; ++i) {
if (z->img_comp[i].raw_data) {
STBI_FREE(z->img_comp[i].raw_data);
z->img_comp[i].raw_data = NULL;
z->img_comp[i].data = NULL;
}
if (z->img_comp[i].raw_coeff) {
STBI_FREE(z->img_comp[i].raw_coeff);
z->img_comp[i].raw_coeff = 0;
z->img_comp[i].coeff = 0;
}
if (z->img_comp[i].linebuf) {
STBI_FREE(z->img_comp[i].linebuf);
z->img_comp[i].linebuf = NULL;
}
}
return why;
}
static int stbi__process_frame_header(stbi__jpeg* z, int scan)
{
stbi__context* s = z->s;
int Lf, p, i, q, h_max = 1, v_max = 1, c;
Lf = stbi__get16be(s); if (Lf < 11) return stbi__err("bad SOF len", "Corrupt JPEG"); // JPEG
p = stbi__get8(s); if (p != 8) return stbi__err("only 8-bit", "JPEG format not supported: 8-bit only"); // JPEG baseline
s->img_y = stbi__get16be(s); if (s->img_y == 0) return stbi__err("no header height", "JPEG format not supported: delayed height"); // Legal, but we don't handle it--but neither does IJG
s->img_x = stbi__get16be(s); if (s->img_x == 0) return stbi__err("0 width", "Corrupt JPEG"); // JPEG requires
if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__err("too large", "Very large image (corrupt?)");
if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__err("too large", "Very large image (corrupt?)");
c = stbi__get8(s);
if (c != 3 && c != 1 && c != 4) return stbi__err("bad component count", "Corrupt JPEG");
s->img_n = c;
for (i = 0; i < c; ++i) {
z->img_comp[i].data = NULL;
z->img_comp[i].linebuf = NULL;
}
if (Lf != 8 + 3 * s->img_n) return stbi__err("bad SOF len", "Corrupt JPEG");
z->rgb = 0;
for (i = 0; i < s->img_n; ++i) {
static const unsigned char rgb[3] = { 'R', 'G', 'B' };
z->img_comp[i].id = stbi__get8(s);
if (s->img_n == 3 && z->img_comp[i].id == rgb[i])
++z->rgb;
q = stbi__get8(s);
z->img_comp[i].h = (q >> 4); if (!z->img_comp[i].h || z->img_comp[i].h > 4) return stbi__err("bad H", "Corrupt JPEG");
z->img_comp[i].v = q & 15; if (!z->img_comp[i].v || z->img_comp[i].v > 4) return stbi__err("bad V", "Corrupt JPEG");
z->img_comp[i].tq = stbi__get8(s); if (z->img_comp[i].tq > 3) return stbi__err("bad TQ", "Corrupt JPEG");
}
if (scan != STBI__SCAN_load) return 1;
if (!stbi__mad3sizes_valid(s->img_x, s->img_y, s->img_n, 0)) return stbi__err("too large", "Image too large to decode");
for (i = 0; i < s->img_n; ++i) {
if (z->img_comp[i].h > h_max) h_max = z->img_comp[i].h;
if (z->img_comp[i].v > v_max) v_max = z->img_comp[i].v;
}
// compute interleaved mcu info
z->img_h_max = h_max;
z->img_v_max = v_max;
z->img_mcu_w = h_max * 8;
z->img_mcu_h = v_max * 8;
// these sizes can't be more than 17 bits
z->img_mcu_x = (s->img_x + z->img_mcu_w - 1) / z->img_mcu_w;
z->img_mcu_y = (s->img_y + z->img_mcu_h - 1) / z->img_mcu_h;
for (i = 0; i < s->img_n; ++i) {
// number of effective pixels (e.g. for non-interleaved MCU)
z->img_comp[i].x = (s->img_x * z->img_comp[i].h + h_max - 1) / h_max;
z->img_comp[i].y = (s->img_y * z->img_comp[i].v + v_max - 1) / v_max;
// to simplify generation, we'll allocate enough memory to decode
// the bogus oversized data from using interleaved MCUs and their
// big blocks (e.g. a 16x16 iMCU on an image of width 33); we won't
// discard the extra data until colorspace conversion
//
// img_mcu_x, img_mcu_y: <=17 bits; comp[i].h and .v are <=4 (checked earlier)
// so these muls can't overflow with 32-bit ints (which we require)
z->img_comp[i].w2 = z->img_mcu_x * z->img_comp[i].h * 8;
z->img_comp[i].h2 = z->img_mcu_y * z->img_comp[i].v * 8;
z->img_comp[i].coeff = 0;
z->img_comp[i].raw_coeff = 0;
z->img_comp[i].linebuf = NULL;
z->img_comp[i].raw_data = stbi__malloc_mad2(z->img_comp[i].w2, z->img_comp[i].h2, 15);
if (z->img_comp[i].raw_data == NULL)
return stbi__free_jpeg_components(z, i + 1, stbi__err("outofmem", "Out of memory"));
// align blocks for idct using mmx/sse
z->img_comp[i].data = (stbi_uc*)(((size_t)z->img_comp[i].raw_data + 15) & ~15);
if (z->progressive) {
// w2, h2 are multiples of 8 (see above)
z->img_comp[i].coeff_w = z->img_comp[i].w2 / 8;
z->img_comp[i].coeff_h = z->img_comp[i].h2 / 8;
z->img_comp[i].raw_coeff = stbi__malloc_mad3(z->img_comp[i].w2, z->img_comp[i].h2, sizeof(short), 15);
if (z->img_comp[i].raw_coeff == NULL)
return stbi__free_jpeg_components(z, i + 1, stbi__err("outofmem", "Out of memory"));
z->img_comp[i].coeff = (short*)(((size_t)z->img_comp[i].raw_coeff + 15) & ~15);
}
}
return 1;
}
// use comparisons since in some cases we handle more than one case (e.g. SOF)
#define stbi__DNL(x) ((x) == 0xdc)
#define stbi__SOI(x) ((x) == 0xd8)
#define stbi__EOI(x) ((x) == 0xd9)
#define stbi__SOF(x) ((x) == 0xc0 || (x) == 0xc1 || (x) == 0xc2)
#define stbi__SOS(x) ((x) == 0xda)
#define stbi__SOF_progressive(x) ((x) == 0xc2)
static int stbi__decode_jpeg_header(stbi__jpeg* z, int scan)
{
int m;
z->jfif = 0;
z->app14_color_transform = -1; // valid values are 0,1,2
z->marker = STBI__MARKER_none; // initialize cached marker to empty
m = stbi__get_marker(z);
if (!stbi__SOI(m)) return stbi__err("no SOI", "Corrupt JPEG");
if (scan == STBI__SCAN_type) return 1;
m = stbi__get_marker(z);
while (!stbi__SOF(m)) {
if (!stbi__process_marker(z, m)) return 0;
m = stbi__get_marker(z);
while (m == STBI__MARKER_none) {
// some files have extra padding after their blocks, so ok, we'll scan
if (stbi__at_eof(z->s)) return stbi__err("no SOF", "Corrupt JPEG");
m = stbi__get_marker(z);
}
}
z->progressive = stbi__SOF_progressive(m);
if (!stbi__process_frame_header(z, scan)) return 0;
return 1;
}
// decode image to YCbCr format
static int stbi__decode_jpeg_image(stbi__jpeg* j)
{
int m;
for (m = 0; m < 4; m++) {
j->img_comp[m].raw_data = NULL;
j->img_comp[m].raw_coeff = NULL;
}
j->restart_interval = 0;
if (!stbi__decode_jpeg_header(j, STBI__SCAN_load)) return 0;
m = stbi__get_marker(j);
while (!stbi__EOI(m)) {
if (stbi__SOS(m)) {
if (!stbi__process_scan_header(j)) return 0;
if (!stbi__parse_entropy_coded_data(j)) return 0;
if (j->marker == STBI__MARKER_none) {
// handle 0s at the end of image data from IP Kamera 9060
while (!stbi__at_eof(j->s)) {
int x = stbi__get8(j->s);
if (x == 255) {
j->marker = stbi__get8(j->s);
break;
}
}
// if we reach eof without hitting a marker, stbi__get_marker() below will fail and we'll eventually return 0
}
}
else if (stbi__DNL(m)) {
int Ld = stbi__get16be(j->s);
stbi__uint32 NL = stbi__get16be(j->s);
if (Ld != 4) return stbi__err("bad DNL len", "Corrupt JPEG");
if (NL != j->s->img_y) return stbi__err("bad DNL height", "Corrupt JPEG");
}
else {
if (!stbi__process_marker(j, m)) return 0;
}
m = stbi__get_marker(j);
}
if (j->progressive)
stbi__jpeg_finish(j);
return 1;
}
// static jfif-centered resampling (across block boundaries)
typedef stbi_uc* (*resample_row_func)(stbi_uc* out, stbi_uc* in0, stbi_uc* in1,
int w, int hs);
#define stbi__div4(x) ((stbi_uc) ((x) >> 2))
static stbi_uc* resample_row_1(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs)
{
STBI_NOTUSED(out);
STBI_NOTUSED(in_far);
STBI_NOTUSED(w);
STBI_NOTUSED(hs);
return in_near;
}
static stbi_uc* stbi__resample_row_v_2(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs)
{
// need to generate two samples vertically for every one in input
int i;
STBI_NOTUSED(hs);
for (i = 0; i < w; ++i)
out[i] = stbi__div4(3 * in_near[i] + in_far[i] + 2);
return out;
}
static stbi_uc* stbi__resample_row_h_2(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs)
{
// need to generate two samples horizontally for every one in input
int i;
stbi_uc* input = in_near;
if (w == 1) {
// if only one sample, can't do any interpolation
out[0] = out[1] = input[0];
return out;
}
out[0] = input[0];
out[1] = stbi__div4(input[0] * 3 + input[1] + 2);
for (i = 1; i < w - 1; ++i) {
int n = 3 * input[i] + 2;
out[i * 2 + 0] = stbi__div4(n + input[i - 1]);
out[i * 2 + 1] = stbi__div4(n + input[i + 1]);
}
out[i * 2 + 0] = stbi__div4(input[w - 2] * 3 + input[w - 1] + 2);
out[i * 2 + 1] = input[w - 1];
STBI_NOTUSED(in_far);
STBI_NOTUSED(hs);
return out;
}
#define stbi__div16(x) ((stbi_uc) ((x) >> 4))
static stbi_uc* stbi__resample_row_hv_2(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs)
{
// need to generate 2x2 samples for every one in input
int i, t0, t1;
if (w == 1) {
out[0] = out[1] = stbi__div4(3 * in_near[0] + in_far[0] + 2);
return out;
}
t1 = 3 * in_near[0] + in_far[0];
out[0] = stbi__div4(t1 + 2);
for (i = 1; i < w; ++i) {
t0 = t1;
t1 = 3 * in_near[i] + in_far[i];
out[i * 2 - 1] = stbi__div16(3 * t0 + t1 + 8);
out[i * 2] = stbi__div16(3 * t1 + t0 + 8);
}
out[w * 2 - 1] = stbi__div4(t1 + 2);
STBI_NOTUSED(hs);
return out;
}
#if defined(STBI_SSE2) || defined(STBI_NEON)
static stbi_uc* stbi__resample_row_hv_2_simd(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs)
{
// need to generate 2x2 samples for every one in input
int i = 0, t0, t1;
if (w == 1) {
out[0] = out[1] = stbi__div4(3 * in_near[0] + in_far[0] + 2);
return out;
}
t1 = 3 * in_near[0] + in_far[0];
// process groups of 8 pixels for as long as we can.
// note we can't handle the last pixel in a row in this loop
// because we need to handle the filter boundary conditions.
for (; i < ((w - 1) & ~7); i += 8) {
#if defined(STBI_SSE2)
// load and perform the vertical filtering pass
// this uses 3*x + y = 4*x + (y - x)
__m128i zero = _mm_setzero_si128();
__m128i farb = _mm_loadl_epi64((__m128i*) (in_far + i));
__m128i nearb = _mm_loadl_epi64((__m128i*) (in_near + i));
__m128i farw = _mm_unpacklo_epi8(farb, zero);
__m128i nearw = _mm_unpacklo_epi8(nearb, zero);
__m128i diff = _mm_sub_epi16(farw, nearw);
__m128i nears = _mm_slli_epi16(nearw, 2);
__m128i curr = _mm_add_epi16(nears, diff); // current row
// horizontal filter works the same based on shifted vers of current
// row. "prev" is current row shifted right by 1 pixel; we need to
// insert the previous pixel value (from t1).
// "next" is current row shifted left by 1 pixel, with first pixel
// of next block of 8 pixels added in.
__m128i prv0 = _mm_slli_si128(curr, 2);
__m128i nxt0 = _mm_srli_si128(curr, 2);
__m128i prev = _mm_insert_epi16(prv0, t1, 0);
__m128i next = _mm_insert_epi16(nxt0, 3 * in_near[i + 8] + in_far[i + 8], 7);
// horizontal filter, polyphase implementation since it's convenient:
// even pixels = 3*cur + prev = cur*4 + (prev - cur)
// odd pixels = 3*cur + next = cur*4 + (next - cur)
// note the shared term.
__m128i bias = _mm_set1_epi16(8);
__m128i curs = _mm_slli_epi16(curr, 2);
__m128i prvd = _mm_sub_epi16(prev, curr);
__m128i nxtd = _mm_sub_epi16(next, curr);
__m128i curb = _mm_add_epi16(curs, bias);
__m128i even = _mm_add_epi16(prvd, curb);
__m128i odd = _mm_add_epi16(nxtd, curb);
// interleave even and odd pixels, then undo scaling.
__m128i int0 = _mm_unpacklo_epi16(even, odd);
__m128i int1 = _mm_unpackhi_epi16(even, odd);
__m128i de0 = _mm_srli_epi16(int0, 4);
__m128i de1 = _mm_srli_epi16(int1, 4);
// pack and write output
__m128i outv = _mm_packus_epi16(de0, de1);
_mm_storeu_si128((__m128i*) (out + i * 2), outv);
#elif defined(STBI_NEON)
// load and perform the vertical filtering pass
// this uses 3*x + y = 4*x + (y - x)
uint8x8_t farb = vld1_u8(in_far + i);
uint8x8_t nearb = vld1_u8(in_near + i);
int16x8_t diff = vreinterpretq_s16_u16(vsubl_u8(farb, nearb));
int16x8_t nears = vreinterpretq_s16_u16(vshll_n_u8(nearb, 2));
int16x8_t curr = vaddq_s16(nears, diff); // current row
// horizontal filter works the same based on shifted vers of current
// row. "prev" is current row shifted right by 1 pixel; we need to
// insert the previous pixel value (from t1).
// "next" is current row shifted left by 1 pixel, with first pixel
// of next block of 8 pixels added in.
int16x8_t prv0 = vextq_s16(curr, curr, 7);
int16x8_t nxt0 = vextq_s16(curr, curr, 1);
int16x8_t prev = vsetq_lane_s16(t1, prv0, 0);
int16x8_t next = vsetq_lane_s16(3 * in_near[i + 8] + in_far[i + 8], nxt0, 7);
// horizontal filter, polyphase implementation since it's convenient:
// even pixels = 3*cur + prev = cur*4 + (prev - cur)
// odd pixels = 3*cur + next = cur*4 + (next - cur)
// note the shared term.
int16x8_t curs = vshlq_n_s16(curr, 2);
int16x8_t prvd = vsubq_s16(prev, curr);
int16x8_t nxtd = vsubq_s16(next, curr);
int16x8_t even = vaddq_s16(curs, prvd);
int16x8_t odd = vaddq_s16(curs, nxtd);
// undo scaling and round, then store with even/odd phases interleaved
uint8x8x2_t o;
o.val[0] = vqrshrun_n_s16(even, 4);
o.val[1] = vqrshrun_n_s16(odd, 4);
vst2_u8(out + i * 2, o);
#endif
// "previous" value for next iter
t1 = 3 * in_near[i + 7] + in_far[i + 7];
}
t0 = t1;
t1 = 3 * in_near[i] + in_far[i];
out[i * 2] = stbi__div16(3 * t1 + t0 + 8);
for (++i; i < w; ++i) {
t0 = t1;
t1 = 3 * in_near[i] + in_far[i];
out[i * 2 - 1] = stbi__div16(3 * t0 + t1 + 8);
out[i * 2] = stbi__div16(3 * t1 + t0 + 8);
}
out[w * 2 - 1] = stbi__div4(t1 + 2);
STBI_NOTUSED(hs);
return out;
}
#endif
static stbi_uc* stbi__resample_row_generic(stbi_uc* out, stbi_uc* in_near, stbi_uc* in_far, int w, int hs)
{
// resample with nearest-neighbor
int i, j;
STBI_NOTUSED(in_far);
for (i = 0; i < w; ++i)
for (j = 0; j < hs; ++j)
out[i * hs + j] = in_near[i];
return out;
}
// this is a reduced-precision calculation of YCbCr-to-RGB introduced
// to make sure the code produces the same results in both SIMD and scalar
#define stbi__float2fixed(x) (((int) ((x) * 4096.0f + 0.5f)) << 8)
static void stbi__YCbCr_to_RGB_row(stbi_uc* out, const stbi_uc* y, const stbi_uc* pcb, const stbi_uc* pcr, int count, int step)
{
int i;
for (i = 0; i < count; ++i) {
int y_fixed = (y[i] << 20) + (1 << 19); // rounding
int r, g, b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
r = y_fixed + cr * stbi__float2fixed(1.40200f);
g = y_fixed + (cr * -stbi__float2fixed(0.71414f)) + ((cb * -stbi__float2fixed(0.34414f)) & 0xffff0000);
b = y_fixed + cb * stbi__float2fixed(1.77200f);
r >>= 20;
g >>= 20;
b >>= 20;
if ((unsigned)r > 255) { if (r < 0) r = 0; else r = 255; }
if ((unsigned)g > 255) { if (g < 0) g = 0; else g = 255; }
if ((unsigned)b > 255) { if (b < 0) b = 0; else b = 255; }
out[0] = (stbi_uc)r;
out[1] = (stbi_uc)g;
out[2] = (stbi_uc)b;
out[3] = 255;
out += step;
}
}
#if defined(STBI_SSE2) || defined(STBI_NEON)
static void stbi__YCbCr_to_RGB_simd(stbi_uc* out, stbi_uc const* y, stbi_uc const* pcb, stbi_uc const* pcr, int count, int step)
{
int i = 0;
#ifdef STBI_SSE2
// step == 3 is pretty ugly on the final interleave, and i'm not convinced
// it's useful in practice (you wouldn't use it for textures, for example).
// so just accelerate step == 4 case.
if (step == 4) {
// this is a fairly straightforward implementation and not super-optimized.
__m128i signflip = _mm_set1_epi8(-0x80);
__m128i cr_const0 = _mm_set1_epi16((short)(1.40200f * 4096.0f + 0.5f));
__m128i cr_const1 = _mm_set1_epi16(-(short)(0.71414f * 4096.0f + 0.5f));
__m128i cb_const0 = _mm_set1_epi16(-(short)(0.34414f * 4096.0f + 0.5f));
__m128i cb_const1 = _mm_set1_epi16((short)(1.77200f * 4096.0f + 0.5f));
__m128i y_bias = _mm_set1_epi8((char)(unsigned char)128);
__m128i xw = _mm_set1_epi16(255); // alpha channel
for (; i + 7 < count; i += 8) {
// load
__m128i y_bytes = _mm_loadl_epi64((__m128i*) (y + i));
__m128i cr_bytes = _mm_loadl_epi64((__m128i*) (pcr + i));
__m128i cb_bytes = _mm_loadl_epi64((__m128i*) (pcb + i));
__m128i cr_biased = _mm_xor_si128(cr_bytes, signflip); // -128
__m128i cb_biased = _mm_xor_si128(cb_bytes, signflip); // -128
// unpack to short (and left-shift cr, cb by 8)
__m128i yw = _mm_unpacklo_epi8(y_bias, y_bytes);
__m128i crw = _mm_unpacklo_epi8(_mm_setzero_si128(), cr_biased);
__m128i cbw = _mm_unpacklo_epi8(_mm_setzero_si128(), cb_biased);
// color transform
__m128i yws = _mm_srli_epi16(yw, 4);
__m128i cr0 = _mm_mulhi_epi16(cr_const0, crw);
__m128i cb0 = _mm_mulhi_epi16(cb_const0, cbw);
__m128i cb1 = _mm_mulhi_epi16(cbw, cb_const1);
__m128i cr1 = _mm_mulhi_epi16(crw, cr_const1);
__m128i rws = _mm_add_epi16(cr0, yws);
__m128i gwt = _mm_add_epi16(cb0, yws);
__m128i bws = _mm_add_epi16(yws, cb1);
__m128i gws = _mm_add_epi16(gwt, cr1);
// descale
__m128i rw = _mm_srai_epi16(rws, 4);
__m128i bw = _mm_srai_epi16(bws, 4);
__m128i gw = _mm_srai_epi16(gws, 4);
// back to byte, set up for transpose
__m128i brb = _mm_packus_epi16(rw, bw);
__m128i gxb = _mm_packus_epi16(gw, xw);
// transpose to interleave channels
__m128i t0 = _mm_unpacklo_epi8(brb, gxb);
__m128i t1 = _mm_unpackhi_epi8(brb, gxb);
__m128i o0 = _mm_unpacklo_epi16(t0, t1);
__m128i o1 = _mm_unpackhi_epi16(t0, t1);
// store
_mm_storeu_si128((__m128i*) (out + 0), o0);
_mm_storeu_si128((__m128i*) (out + 16), o1);
out += 32;
}
}
#endif
#ifdef STBI_NEON
// in this version, step=3 support would be easy to add. but is there demand?
if (step == 4) {
// this is a fairly straightforward implementation and not super-optimized.
uint8x8_t signflip = vdup_n_u8(0x80);
int16x8_t cr_const0 = vdupq_n_s16((short)(1.40200f * 4096.0f + 0.5f));
int16x8_t cr_const1 = vdupq_n_s16(-(short)(0.71414f * 4096.0f + 0.5f));
int16x8_t cb_const0 = vdupq_n_s16(-(short)(0.34414f * 4096.0f + 0.5f));
int16x8_t cb_const1 = vdupq_n_s16((short)(1.77200f * 4096.0f + 0.5f));
for (; i + 7 < count; i += 8) {
// load
uint8x8_t y_bytes = vld1_u8(y + i);
uint8x8_t cr_bytes = vld1_u8(pcr + i);
uint8x8_t cb_bytes = vld1_u8(pcb + i);
int8x8_t cr_biased = vreinterpret_s8_u8(vsub_u8(cr_bytes, signflip));
int8x8_t cb_biased = vreinterpret_s8_u8(vsub_u8(cb_bytes, signflip));
// expand to s16
int16x8_t yws = vreinterpretq_s16_u16(vshll_n_u8(y_bytes, 4));
int16x8_t crw = vshll_n_s8(cr_biased, 7);
int16x8_t cbw = vshll_n_s8(cb_biased, 7);
// color transform
int16x8_t cr0 = vqdmulhq_s16(crw, cr_const0);
int16x8_t cb0 = vqdmulhq_s16(cbw, cb_const0);
int16x8_t cr1 = vqdmulhq_s16(crw, cr_const1);
int16x8_t cb1 = vqdmulhq_s16(cbw, cb_const1);
int16x8_t rws = vaddq_s16(yws, cr0);
int16x8_t gws = vaddq_s16(vaddq_s16(yws, cb0), cr1);
int16x8_t bws = vaddq_s16(yws, cb1);
// undo scaling, round, convert to byte
uint8x8x4_t o;
o.val[0] = vqrshrun_n_s16(rws, 4);
o.val[1] = vqrshrun_n_s16(gws, 4);
o.val[2] = vqrshrun_n_s16(bws, 4);
o.val[3] = vdup_n_u8(255);
// store, interleaving r/g/b/a
vst4_u8(out, o);
out += 8 * 4;
}
}
#endif
for (; i < count; ++i) {
int y_fixed = (y[i] << 20) + (1 << 19); // rounding
int r, g, b;
int cr = pcr[i] - 128;
int cb = pcb[i] - 128;
r = y_fixed + cr * stbi__float2fixed(1.40200f);
g = y_fixed + cr * -stbi__float2fixed(0.71414f) + ((cb * -stbi__float2fixed(0.34414f)) & 0xffff0000);
b = y_fixed + cb * stbi__float2fixed(1.77200f);
r >>= 20;
g >>= 20;
b >>= 20;
if ((unsigned)r > 255) { if (r < 0) r = 0; else r = 255; }
if ((unsigned)g > 255) { if (g < 0) g = 0; else g = 255; }
if ((unsigned)b > 255) { if (b < 0) b = 0; else b = 255; }
out[0] = (stbi_uc)r;
out[1] = (stbi_uc)g;
out[2] = (stbi_uc)b;
out[3] = 255;
out += step;
}
}
#endif
// set up the kernels
static void stbi__setup_jpeg(stbi__jpeg* j)
{
j->idct_block_kernel = stbi__idct_block;
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_row;
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2;
#ifdef STBI_SSE2
if (stbi__sse2_available()) {
j->idct_block_kernel = stbi__idct_simd;
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
}
#endif
#ifdef STBI_NEON
j->idct_block_kernel = stbi__idct_simd;
j->YCbCr_to_RGB_kernel = stbi__YCbCr_to_RGB_simd;
j->resample_row_hv_2_kernel = stbi__resample_row_hv_2_simd;
#endif
}
// clean up the temporary component buffers
static void stbi__cleanup_jpeg(stbi__jpeg* j)
{
stbi__free_jpeg_components(j, j->s->img_n, 0);
}
typedef struct
{
resample_row_func resample;
stbi_uc* line0, * line1;
int hs, vs; // expansion factor in each axis
int w_lores; // horizontal pixels pre-expansion
int ystep; // how far through vertical expansion we are
int ypos; // which pre-expansion row we're on
} stbi__resample;
// fast 0..255 * 0..255 => 0..255 rounded multiplication
static stbi_uc stbi__blinn_8x8(stbi_uc x, stbi_uc y)
{
unsigned int t = x * y + 128;
return (stbi_uc)((t + (t >> 8)) >> 8);
}
static stbi_uc* load_jpeg_image(stbi__jpeg* z, int* out_x, int* out_y, int* comp, int req_comp)
{
int n, decode_n, is_rgb;
z->s->img_n = 0; // make stbi__cleanup_jpeg safe
// validate req_comp
if (req_comp < 0 || req_comp > 4) return stbi__errpuc("bad req_comp", "Internal error");
// load a jpeg image from whichever source, but leave in YCbCr format
if (!stbi__decode_jpeg_image(z)) { stbi__cleanup_jpeg(z); return NULL; }
// determine actual number of components to generate
n = req_comp ? req_comp : z->s->img_n >= 3 ? 3 : 1;
is_rgb = z->s->img_n == 3 && (z->rgb == 3 || (z->app14_color_transform == 0 && !z->jfif));
if (z->s->img_n == 3 && n < 3 && !is_rgb)
decode_n = 1;
else
decode_n = z->s->img_n;
// resample and color-convert
{
int k;
unsigned int i, j;
stbi_uc* output;
stbi_uc* coutput[4] = { NULL, NULL, NULL, NULL };
stbi__resample res_comp[4];
for (k = 0; k < decode_n; ++k) {
stbi__resample* r = &res_comp[k];
// allocate line buffer big enough for upsampling off the edges
// with upsample factor of 4
z->img_comp[k].linebuf = (stbi_uc*)stbi__malloc(z->s->img_x + 3);
if (!z->img_comp[k].linebuf) { stbi__cleanup_jpeg(z); return stbi__errpuc("outofmem", "Out of memory"); }
r->hs = z->img_h_max / z->img_comp[k].h;
r->vs = z->img_v_max / z->img_comp[k].v;
r->ystep = r->vs >> 1;
r->w_lores = (z->s->img_x + r->hs - 1) / r->hs;
r->ypos = 0;
r->line0 = r->line1 = z->img_comp[k].data;
if (r->hs == 1 && r->vs == 1) r->resample = resample_row_1;
else if (r->hs == 1 && r->vs == 2) r->resample = stbi__resample_row_v_2;
else if (r->hs == 2 && r->vs == 1) r->resample = stbi__resample_row_h_2;
else if (r->hs == 2 && r->vs == 2) r->resample = z->resample_row_hv_2_kernel;
else r->resample = stbi__resample_row_generic;
}
// can't error after this so, this is safe
output = (stbi_uc*)stbi__malloc_mad3(n, z->s->img_x, z->s->img_y, 1);
if (!output) { stbi__cleanup_jpeg(z); return stbi__errpuc("outofmem", "Out of memory"); }
// now go ahead and resample
for (j = 0; j < z->s->img_y; ++j) {
stbi_uc* out = output + n * z->s->img_x * j;
for (k = 0; k < decode_n; ++k) {
stbi__resample* r = &res_comp[k];
int y_bot = r->ystep >= (r->vs >> 1);
coutput[k] = r->resample(z->img_comp[k].linebuf,
y_bot ? r->line1 : r->line0,
y_bot ? r->line0 : r->line1,
r->w_lores, r->hs);
if (++r->ystep >= r->vs) {
r->ystep = 0;
r->line0 = r->line1;
if (++r->ypos < z->img_comp[k].y)
r->line1 += z->img_comp[k].w2;
}
}
if (n >= 3) {
stbi_uc* y = coutput[0];
if (z->s->img_n == 3) {
if (is_rgb) {
for (i = 0; i < z->s->img_x; ++i) {
out[0] = y[i];
out[1] = coutput[1][i];
out[2] = coutput[2][i];
out[3] = 255;
out += n;
}
}
else {
z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n);
}
}
else if (z->s->img_n == 4) {
if (z->app14_color_transform == 0) { // CMYK
for (i = 0; i < z->s->img_x; ++i) {
stbi_uc m = coutput[3][i];
out[0] = stbi__blinn_8x8(coutput[0][i], m);
out[1] = stbi__blinn_8x8(coutput[1][i], m);
out[2] = stbi__blinn_8x8(coutput[2][i], m);
out[3] = 255;
out += n;
}
}
else if (z->app14_color_transform == 2) { // YCCK
z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n);
for (i = 0; i < z->s->img_x; ++i) {
stbi_uc m = coutput[3][i];
out[0] = stbi__blinn_8x8(255 - out[0], m);
out[1] = stbi__blinn_8x8(255 - out[1], m);
out[2] = stbi__blinn_8x8(255 - out[2], m);
out += n;
}
}
else { // YCbCr + alpha? Ignore the fourth channel for now
z->YCbCr_to_RGB_kernel(out, y, coutput[1], coutput[2], z->s->img_x, n);
}
}
else
for (i = 0; i < z->s->img_x; ++i) {
out[0] = out[1] = out[2] = y[i];
out[3] = 255; // not used if n==3
out += n;
}
}
else {
if (is_rgb) {
if (n == 1)
for (i = 0; i < z->s->img_x; ++i)
*out++ = stbi__compute_y(coutput[0][i], coutput[1][i], coutput[2][i]);
else {
for (i = 0; i < z->s->img_x; ++i, out += 2) {
out[0] = stbi__compute_y(coutput[0][i], coutput[1][i], coutput[2][i]);
out[1] = 255;
}
}
}
else if (z->s->img_n == 4 && z->app14_color_transform == 0) {
for (i = 0; i < z->s->img_x; ++i) {
stbi_uc m = coutput[3][i];
stbi_uc r = stbi__blinn_8x8(coutput[0][i], m);
stbi_uc g = stbi__blinn_8x8(coutput[1][i], m);
stbi_uc b = stbi__blinn_8x8(coutput[2][i], m);
out[0] = stbi__compute_y(r, g, b);
out[1] = 255;
out += n;
}
}
else if (z->s->img_n == 4 && z->app14_color_transform == 2) {
for (i = 0; i < z->s->img_x; ++i) {
out[0] = stbi__blinn_8x8(255 - coutput[0][i], coutput[3][i]);
out[1] = 255;
out += n;
}
}
else {
stbi_uc* y = coutput[0];
if (n == 1)
for (i = 0; i < z->s->img_x; ++i) out[i] = y[i];
else
for (i = 0; i < z->s->img_x; ++i) { *out++ = y[i]; *out++ = 255; }
}
}
}
stbi__cleanup_jpeg(z);
*out_x = z->s->img_x;
*out_y = z->s->img_y;
if (comp) *comp = z->s->img_n >= 3 ? 3 : 1; // report original components, not output
return output;
}
}
static void* stbi__jpeg_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
unsigned char* result;
stbi__jpeg* j = (stbi__jpeg*)stbi__malloc(sizeof(stbi__jpeg));
STBI_NOTUSED(ri);
j->s = s;
stbi__setup_jpeg(j);
result = load_jpeg_image(j, x, y, comp, req_comp);
STBI_FREE(j);
return result;
}
static int stbi__jpeg_test(stbi__context* s)
{
int r;
stbi__jpeg* j = (stbi__jpeg*)stbi__malloc(sizeof(stbi__jpeg));
j->s = s;
stbi__setup_jpeg(j);
r = stbi__decode_jpeg_header(j, STBI__SCAN_type);
stbi__rewind(s);
STBI_FREE(j);
return r;
}
static int stbi__jpeg_info_raw(stbi__jpeg* j, int* x, int* y, int* comp)
{
if (!stbi__decode_jpeg_header(j, STBI__SCAN_header)) {
stbi__rewind(j->s);
return 0;
}
if (x) *x = j->s->img_x;
if (y) *y = j->s->img_y;
if (comp) *comp = j->s->img_n >= 3 ? 3 : 1;
return 1;
}
static int stbi__jpeg_info(stbi__context* s, int* x, int* y, int* comp)
{
int result;
stbi__jpeg* j = (stbi__jpeg*)(stbi__malloc(sizeof(stbi__jpeg)));
j->s = s;
result = stbi__jpeg_info_raw(j, x, y, comp);
STBI_FREE(j);
return result;
}
#endif
// public domain zlib decode v0.2 Sean Barrett 2006-11-18
// simple implementation
// - all input must be provided in an upfront buffer
// - all output is written to a single output buffer (can malloc/realloc)
// performance
// - fast huffman
#ifndef STBI_NO_ZLIB
// fast-way is faster to check than jpeg huffman, but slow way is slower
#define STBI__ZFAST_BITS 9 // accelerate all cases in default tables
#define STBI__ZFAST_MASK ((1 << STBI__ZFAST_BITS) - 1)
// zlib-style huffman encoding
// (jpegs packs from left, zlib from right, so can't share code)
typedef struct
{
stbi__uint16 fast[1 << STBI__ZFAST_BITS];
stbi__uint16 firstcode[16];
int maxcode[17];
stbi__uint16 firstsymbol[16];
stbi_uc size[288];
stbi__uint16 value[288];
} stbi__zhuffman;
stbi_inline static int stbi__bitreverse16(int n)
{
n = ((n & 0xAAAA) >> 1) | ((n & 0x5555) << 1);
n = ((n & 0xCCCC) >> 2) | ((n & 0x3333) << 2);
n = ((n & 0xF0F0) >> 4) | ((n & 0x0F0F) << 4);
n = ((n & 0xFF00) >> 8) | ((n & 0x00FF) << 8);
return n;
}
stbi_inline static int stbi__bit_reverse(int v, int bits)
{
STBI_ASSERT(bits <= 16);
// to bit reverse n bits, reverse 16 and shift
// e.g. 11 bits, bit reverse and shift away 5
return stbi__bitreverse16(v) >> (16 - bits);
}
static int stbi__zbuild_huffman(stbi__zhuffman* z, const stbi_uc* sizelist, int num)
{
int i, k = 0;
int code, next_code[16], sizes[17];
// DEFLATE spec for generating codes
memset(sizes, 0, sizeof(sizes));
memset(z->fast, 0, sizeof(z->fast));
for (i = 0; i < num; ++i)
++sizes[sizelist[i]];
sizes[0] = 0;
for (i = 1; i < 16; ++i)
if (sizes[i] > (1 << i))
return stbi__err("bad sizes", "Corrupt PNG");
code = 0;
for (i = 1; i < 16; ++i) {
next_code[i] = code;
z->firstcode[i] = (stbi__uint16)code;
z->firstsymbol[i] = (stbi__uint16)k;
code = (code + sizes[i]);
if (sizes[i])
if (code - 1 >= (1 << i)) return stbi__err("bad codelengths", "Corrupt PNG");
z->maxcode[i] = code << (16 - i); // preshift for inner loop
code <<= 1;
k += sizes[i];
}
z->maxcode[16] = 0x10000; // sentinel
for (i = 0; i < num; ++i) {
int s = sizelist[i];
if (s) {
int c = next_code[s] - z->firstcode[s] + z->firstsymbol[s];
stbi__uint16 fastv = (stbi__uint16)((s << 9) | i);
z->size[c] = (stbi_uc)s;
z->value[c] = (stbi__uint16)i;
if (s <= STBI__ZFAST_BITS) {
int j = stbi__bit_reverse(next_code[s], s);
while (j < (1 << STBI__ZFAST_BITS)) {
z->fast[j] = fastv;
j += (1 << s);
}
}
++next_code[s];
}
}
return 1;
}
// zlib-from-memory implementation for PNG reading
// because PNG allows splitting the zlib stream arbitrarily,
// and it's annoying structurally to have PNG call ZLIB call PNG,
// we require PNG read all the IDATs and combine them into a single
// memory buffer
typedef struct
{
stbi_uc* zbuffer, * zbuffer_end;
int num_bits;
stbi__uint32 code_buffer;
char* zout;
char* zout_start;
char* zout_end;
int z_expandable;
stbi__zhuffman z_length, z_distance;
} stbi__zbuf;
stbi_inline static int stbi__zeof(stbi__zbuf* z)
{
return (z->zbuffer >= z->zbuffer_end);
}
stbi_inline static stbi_uc stbi__zget8(stbi__zbuf* z)
{
return stbi__zeof(z) ? 0 : *z->zbuffer++;
}
static void stbi__fill_bits(stbi__zbuf* z)
{
do {
if (z->code_buffer >= (1U << z->num_bits)) {
z->zbuffer = z->zbuffer_end; /* treat this as EOF so we fail. */
return;
}
z->code_buffer |= (unsigned int)stbi__zget8(z) << z->num_bits;
z->num_bits += 8;
} while (z->num_bits <= 24);
}
stbi_inline static unsigned int stbi__zreceive(stbi__zbuf* z, int n)
{
unsigned int k;
if (z->num_bits < n) stbi__fill_bits(z);
k = z->code_buffer & ((1 << n) - 1);
z->code_buffer >>= n;
z->num_bits -= n;
return k;
}
static int stbi__zhuffman_decode_slowpath(stbi__zbuf* a, stbi__zhuffman* z)
{
int b, s, k;
// not resolved by fast table, so compute it the slow way
// use jpeg approach, which requires MSbits at top
k = stbi__bit_reverse(a->code_buffer, 16);
for (s = STBI__ZFAST_BITS + 1; ; ++s)
if (k < z->maxcode[s])
break;
if (s >= 16) return -1; // invalid code!
// code size is s, so:
b = (k >> (16 - s)) - z->firstcode[s] + z->firstsymbol[s];
if (b >= sizeof(z->size)) return -1; // some data was corrupt somewhere!
if (z->size[b] != s) return -1; // was originally an assert, but report failure instead.
a->code_buffer >>= s;
a->num_bits -= s;
return z->value[b];
}
stbi_inline static int stbi__zhuffman_decode(stbi__zbuf* a, stbi__zhuffman* z)
{
int b, s;
if (a->num_bits < 16) {
if (stbi__zeof(a)) {
return -1; /* report error for unexpected end of data. */
}
stbi__fill_bits(a);
}
b = z->fast[a->code_buffer & STBI__ZFAST_MASK];
if (b) {
s = b >> 9;
a->code_buffer >>= s;
a->num_bits -= s;
return b & 511;
}
return stbi__zhuffman_decode_slowpath(a, z);
}
static int stbi__zexpand(stbi__zbuf* z, char* zout, int n) // need to make room for n bytes
{
char* q;
unsigned int cur, limit, old_limit;
z->zout = zout;
if (!z->z_expandable) return stbi__err("output buffer limit", "Corrupt PNG");
cur = (unsigned int)(z->zout - z->zout_start);
limit = old_limit = (unsigned)(z->zout_end - z->zout_start);
if (UINT_MAX - cur < (unsigned)n) return stbi__err("outofmem", "Out of memory");
while (cur + n > limit) {
if (limit > UINT_MAX / 2) return stbi__err("outofmem", "Out of memory");
limit *= 2;
}
q = (char*)STBI_REALLOC_SIZED(z->zout_start, old_limit, limit);
STBI_NOTUSED(old_limit);
if (q == NULL) return stbi__err("outofmem", "Out of memory");
z->zout_start = q;
z->zout = q + cur;
z->zout_end = q + limit;
return 1;
}
static const int stbi__zlength_base[31] = {
3,4,5,6,7,8,9,10,11,13,
15,17,19,23,27,31,35,43,51,59,
67,83,99,115,131,163,195,227,258,0,0 };
static const int stbi__zlength_extra[31] =
{ 0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0,0,0 };
static const int stbi__zdist_base[32] = { 1,2,3,4,5,7,9,13,17,25,33,49,65,97,129,193,
257,385,513,769,1025,1537,2049,3073,4097,6145,8193,12289,16385,24577,0,0 };
static const int stbi__zdist_extra[32] =
{ 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13 };
static int stbi__parse_huffman_block(stbi__zbuf* a)
{
char* zout = a->zout;
for (;;) {
int z = stbi__zhuffman_decode(a, &a->z_length);
if (z < 256) {
if (z < 0) return stbi__err("bad huffman code", "Corrupt PNG"); // error in huffman codes
if (zout >= a->zout_end) {
if (!stbi__zexpand(a, zout, 1)) return 0;
zout = a->zout;
}
*zout++ = (char)z;
}
else {
stbi_uc* p;
int len, dist;
if (z == 256) {
a->zout = zout;
return 1;
}
z -= 257;
len = stbi__zlength_base[z];
if (stbi__zlength_extra[z]) len += stbi__zreceive(a, stbi__zlength_extra[z]);
z = stbi__zhuffman_decode(a, &a->z_distance);
if (z < 0) return stbi__err("bad huffman code", "Corrupt PNG");
dist = stbi__zdist_base[z];
if (stbi__zdist_extra[z]) dist += stbi__zreceive(a, stbi__zdist_extra[z]);
if (zout - a->zout_start < dist) return stbi__err("bad dist", "Corrupt PNG");
if (zout + len > a->zout_end) {
if (!stbi__zexpand(a, zout, len)) return 0;
zout = a->zout;
}
p = (stbi_uc*)(zout - dist);
if (dist == 1) { // run of one byte; common in images.
stbi_uc v = *p;
if (len) { do *zout++ = v; while (--len); }
}
else {
if (len) { do *zout++ = *p++; while (--len); }
}
}
}
}
static int stbi__compute_huffman_codes(stbi__zbuf* a)
{
static const stbi_uc length_dezigzag[19] = { 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15 };
stbi__zhuffman z_codelength;
stbi_uc lencodes[286 + 32 + 137];//padding for maximum single op
stbi_uc codelength_sizes[19];
int i, n;
int hlit = stbi__zreceive(a, 5) + 257;
int hdist = stbi__zreceive(a, 5) + 1;
int hclen = stbi__zreceive(a, 4) + 4;
int ntot = hlit + hdist;
memset(codelength_sizes, 0, sizeof(codelength_sizes));
for (i = 0; i < hclen; ++i) {
int s = stbi__zreceive(a, 3);
codelength_sizes[length_dezigzag[i]] = (stbi_uc)s;
}
if (!stbi__zbuild_huffman(&z_codelength, codelength_sizes, 19)) return 0;
n = 0;
while (n < ntot) {
int c = stbi__zhuffman_decode(a, &z_codelength);
if (c < 0 || c >= 19) return stbi__err("bad codelengths", "Corrupt PNG");
if (c < 16)
lencodes[n++] = (stbi_uc)c;
else {
stbi_uc fill = 0;
if (c == 16) {
c = stbi__zreceive(a, 2) + 3;
if (n == 0) return stbi__err("bad codelengths", "Corrupt PNG");
fill = lencodes[n - 1];
}
else if (c == 17) {
c = stbi__zreceive(a, 3) + 3;
}
else if (c == 18) {
c = stbi__zreceive(a, 7) + 11;
}
else {
return stbi__err("bad codelengths", "Corrupt PNG");
}
if (ntot - n < c) return stbi__err("bad codelengths", "Corrupt PNG");
memset(lencodes + n, fill, c);
n += c;
}
}
if (n != ntot) return stbi__err("bad codelengths", "Corrupt PNG");
if (!stbi__zbuild_huffman(&a->z_length, lencodes, hlit)) return 0;
if (!stbi__zbuild_huffman(&a->z_distance, lencodes + hlit, hdist)) return 0;
return 1;
}
static int stbi__parse_uncompressed_block(stbi__zbuf* a)
{
stbi_uc header[4];
int len, nlen, k;
if (a->num_bits & 7)
stbi__zreceive(a, a->num_bits & 7); // discard
// drain the bit-packed data into header
k = 0;
while (a->num_bits > 0) {
header[k++] = (stbi_uc)(a->code_buffer & 255); // suppress MSVC run-time check
a->code_buffer >>= 8;
a->num_bits -= 8;
}
if (a->num_bits < 0) return stbi__err("zlib corrupt", "Corrupt PNG");
// now fill header the normal way
while (k < 4)
header[k++] = stbi__zget8(a);
len = header[1] * 256 + header[0];
nlen = header[3] * 256 + header[2];
if (nlen != (len ^ 0xffff)) return stbi__err("zlib corrupt", "Corrupt PNG");
if (a->zbuffer + len > a->zbuffer_end) return stbi__err("read past buffer", "Corrupt PNG");
if (a->zout + len > a->zout_end)
if (!stbi__zexpand(a, a->zout, len)) return 0;
memcpy(a->zout, a->zbuffer, len);
a->zbuffer += len;
a->zout += len;
return 1;
}
static int stbi__parse_zlib_header(stbi__zbuf* a)
{
int cmf = stbi__zget8(a);
int cm = cmf & 15;
/* int cinfo = cmf >> 4; */
int flg = stbi__zget8(a);
if (stbi__zeof(a)) return stbi__err("bad zlib header", "Corrupt PNG"); // zlib spec
if ((cmf * 256 + flg) % 31 != 0) return stbi__err("bad zlib header", "Corrupt PNG"); // zlib spec
if (flg & 32) return stbi__err("no preset dict", "Corrupt PNG"); // preset dictionary not allowed in png
if (cm != 8) return stbi__err("bad compression", "Corrupt PNG"); // DEFLATE required for png
// window = 1 << (8 + cinfo)... but who cares, we fully buffer output
return 1;
}
static const stbi_uc stbi__zdefault_length[288] =
{
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,8,8,8,8,8,8,8,8
};
static const stbi_uc stbi__zdefault_distance[32] =
{
5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5
};
/*
Init algorithm:
{
int i; // use <= to match clearly with spec
for (i=0; i <= 143; ++i) stbi__zdefault_length[i] = 8;
for ( ; i <= 255; ++i) stbi__zdefault_length[i] = 9;
for ( ; i <= 279; ++i) stbi__zdefault_length[i] = 7;
for ( ; i <= 287; ++i) stbi__zdefault_length[i] = 8;
for (i=0; i <= 31; ++i) stbi__zdefault_distance[i] = 5;
}
*/
static int stbi__parse_zlib(stbi__zbuf* a, int parse_header)
{
int final, type;
if (parse_header)
if (!stbi__parse_zlib_header(a)) return 0;
a->num_bits = 0;
a->code_buffer = 0;
do {
final = stbi__zreceive(a, 1);
type = stbi__zreceive(a, 2);
if (type == 0) {
if (!stbi__parse_uncompressed_block(a)) return 0;
}
else if (type == 3) {
return 0;
}
else {
if (type == 1) {
// use fixed code lengths
if (!stbi__zbuild_huffman(&a->z_length, stbi__zdefault_length, 288)) return 0;
if (!stbi__zbuild_huffman(&a->z_distance, stbi__zdefault_distance, 32)) return 0;
}
else {
if (!stbi__compute_huffman_codes(a)) return 0;
}
if (!stbi__parse_huffman_block(a)) return 0;
}
} while (!final);
return 1;
}
static int stbi__do_zlib(stbi__zbuf* a, char* obuf, int olen, int exp, int parse_header)
{
a->zout_start = obuf;
a->zout = obuf;
a->zout_end = obuf + olen;
a->z_expandable = exp;
return stbi__parse_zlib(a, parse_header);
}
STBIDEF char* stbi_zlib_decode_malloc_guesssize(const char* buffer, int len, int initial_size, int* outlen)
{
stbi__zbuf a;
char* p = (char*)stbi__malloc(initial_size);
if (p == NULL) return NULL;
a.zbuffer = (stbi_uc*)buffer;
a.zbuffer_end = (stbi_uc*)buffer + len;
if (stbi__do_zlib(&a, p, initial_size, 1, 1)) {
if (outlen) *outlen = (int)(a.zout - a.zout_start);
return a.zout_start;
}
else {
STBI_FREE(a.zout_start);
return NULL;
}
}
STBIDEF char* stbi_zlib_decode_malloc(char const* buffer, int len, int* outlen)
{
return stbi_zlib_decode_malloc_guesssize(buffer, len, 16384, outlen);
}
STBIDEF char* stbi_zlib_decode_malloc_guesssize_headerflag(const char* buffer, int len, int initial_size, int* outlen, int parse_header)
{
stbi__zbuf a;
char* p = (char*)stbi__malloc(initial_size);
if (p == NULL) return NULL;
a.zbuffer = (stbi_uc*)buffer;
a.zbuffer_end = (stbi_uc*)buffer + len;
if (stbi__do_zlib(&a, p, initial_size, 1, parse_header)) {
if (outlen) *outlen = (int)(a.zout - a.zout_start);
return a.zout_start;
}
else {
STBI_FREE(a.zout_start);
return NULL;
}
}
STBIDEF int stbi_zlib_decode_buffer(char* obuffer, int olen, char const* ibuffer, int ilen)
{
stbi__zbuf a;
a.zbuffer = (stbi_uc*)ibuffer;
a.zbuffer_end = (stbi_uc*)ibuffer + ilen;
if (stbi__do_zlib(&a, obuffer, olen, 0, 1))
return (int)(a.zout - a.zout_start);
else
return -1;
}
STBIDEF char* stbi_zlib_decode_noheader_malloc(char const* buffer, int len, int* outlen)
{
stbi__zbuf a;
char* p = (char*)stbi__malloc(16384);
if (p == NULL) return NULL;
a.zbuffer = (stbi_uc*)buffer;
a.zbuffer_end = (stbi_uc*)buffer + len;
if (stbi__do_zlib(&a, p, 16384, 1, 0)) {
if (outlen) *outlen = (int)(a.zout - a.zout_start);
return a.zout_start;
}
else {
STBI_FREE(a.zout_start);
return NULL;
}
}
STBIDEF int stbi_zlib_decode_noheader_buffer(char* obuffer, int olen, const char* ibuffer, int ilen)
{
stbi__zbuf a;
a.zbuffer = (stbi_uc*)ibuffer;
a.zbuffer_end = (stbi_uc*)ibuffer + ilen;
if (stbi__do_zlib(&a, obuffer, olen, 0, 0))
return (int)(a.zout - a.zout_start);
else
return -1;
}
#endif
// public domain "baseline" PNG decoder v0.10 Sean Barrett 2006-11-18
// simple implementation
// - only 8-bit samples
// - no CRC checking
// - allocates lots of intermediate memory
// - avoids problem of streaming data between subsystems
// - avoids explicit window management
// performance
// - uses stb_zlib, a PD zlib implementation with fast huffman decoding
#ifndef STBI_NO_PNG
typedef struct
{
stbi__uint32 length;
stbi__uint32 type;
} stbi__pngchunk;
static stbi__pngchunk stbi__get_chunk_header(stbi__context* s)
{
stbi__pngchunk c;
c.length = stbi__get32be(s);
c.type = stbi__get32be(s);
return c;
}
static int stbi__check_png_header(stbi__context* s)
{
static const stbi_uc png_sig[8] = { 137,80,78,71,13,10,26,10 };
int i;
for (i = 0; i < 8; ++i)
if (stbi__get8(s) != png_sig[i]) return stbi__err("bad png sig", "Not a PNG");
return 1;
}
typedef struct
{
stbi__context* s;
stbi_uc* idata, * expanded, * out;
int depth;
} stbi__png;
enum {
STBI__F_none = 0,
STBI__F_sub = 1,
STBI__F_up = 2,
STBI__F_avg = 3,
STBI__F_paeth = 4,
// synthetic filters used for first scanline to avoid needing a dummy row of 0s
STBI__F_avg_first,
STBI__F_paeth_first
};
static stbi_uc first_row_filter[5] =
{
STBI__F_none,
STBI__F_sub,
STBI__F_none,
STBI__F_avg_first,
STBI__F_paeth_first
};
static int stbi__paeth(int a, int b, int c)
{
int p = a + b - c;
int pa = abs(p - a);
int pb = abs(p - b);
int pc = abs(p - c);
if (pa <= pb && pa <= pc) return a;
if (pb <= pc) return b;
return c;
}
static const stbi_uc stbi__depth_scale_table[9] = { 0, 0xff, 0x55, 0, 0x11, 0,0,0, 0x01 };
// create the png data from post-deflated data
static int stbi__create_png_image_raw(stbi__png* a, stbi_uc* raw, stbi__uint32 raw_len, int out_n, stbi__uint32 x, stbi__uint32 y, int depth, int color)
{
int bytes = (depth == 16 ? 2 : 1);
stbi__context* s = a->s;
stbi__uint32 i, j, stride = x * out_n * bytes;
stbi__uint32 img_len, img_width_bytes;
int k;
int img_n = s->img_n; // copy it into a local for later
int output_bytes = out_n * bytes;
int filter_bytes = img_n * bytes;
int width = x;
STBI_ASSERT(out_n == s->img_n || out_n == s->img_n + 1);
a->out = (stbi_uc*)stbi__malloc_mad3(x, y, output_bytes, 0); // extra bytes to write off the end into
if (!a->out) return stbi__err("outofmem", "Out of memory");
if (!stbi__mad3sizes_valid(img_n, x, depth, 7)) return stbi__err("too large", "Corrupt PNG");
img_width_bytes = (((img_n * x * depth) + 7) >> 3);
img_len = (img_width_bytes + 1) * y;
// we used to check for exact match between raw_len and img_len on non-interlaced PNGs,
// but issue #276 reported a PNG in the wild that had extra data at the end (all zeros),
// so just check for raw_len < img_len always.
if (raw_len < img_len) return stbi__err("not enough pixels", "Corrupt PNG");
for (j = 0; j < y; ++j) {
stbi_uc* cur = a->out + stride * j;
stbi_uc* prior;
int filter = *raw++;
if (filter > 4)
return stbi__err("invalid filter", "Corrupt PNG");
if (depth < 8) {
if (img_width_bytes > x) return stbi__err("invalid width", "Corrupt PNG");
cur += x * out_n - img_width_bytes; // store output to the rightmost img_len bytes, so we can decode in place
filter_bytes = 1;
width = img_width_bytes;
}
prior = cur - stride; // bugfix: need to compute this after 'cur +=' computation above
// if first row, use special filter that doesn't sample previous row
if (j == 0) filter = first_row_filter[filter];
// handle first byte explicitly
for (k = 0; k < filter_bytes; ++k) {
switch (filter) {
case STBI__F_none: cur[k] = raw[k]; break;
case STBI__F_sub: cur[k] = raw[k]; break;
case STBI__F_up: cur[k] = STBI__BYTECAST(raw[k] + prior[k]); break;
case STBI__F_avg: cur[k] = STBI__BYTECAST(raw[k] + (prior[k] >> 1)); break;
case STBI__F_paeth: cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(0, prior[k], 0)); break;
case STBI__F_avg_first: cur[k] = raw[k]; break;
case STBI__F_paeth_first: cur[k] = raw[k]; break;
}
}
if (depth == 8) {
if (img_n != out_n)
cur[img_n] = 255; // first pixel
raw += img_n;
cur += out_n;
prior += out_n;
}
else if (depth == 16) {
if (img_n != out_n) {
cur[filter_bytes] = 255; // first pixel top byte
cur[filter_bytes + 1] = 255; // first pixel bottom byte
}
raw += filter_bytes;
cur += output_bytes;
prior += output_bytes;
}
else {
raw += 1;
cur += 1;
prior += 1;
}
// this is a little gross, so that we don't switch per-pixel or per-component
if (depth < 8 || img_n == out_n) {
int nk = (width - 1) * filter_bytes;
#define STBI__CASE(f) \
case f: \
for (k=0; k < nk; ++k)
switch (filter) {
// "none" filter turns into a memcpy here; make that explicit.
case STBI__F_none: memcpy(cur, raw, nk); break;
STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k - filter_bytes]); } break;
STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break;
STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k - filter_bytes]) >> 1)); } break;
STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k - filter_bytes], prior[k], prior[k - filter_bytes])); } break;
STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k - filter_bytes] >> 1)); } break;
STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k - filter_bytes], 0, 0)); } break;
}
#undef STBI__CASE
raw += nk;
}
else {
STBI_ASSERT(img_n + 1 == out_n);
#define STBI__CASE(f) \
case f: \
for (i=x-1; i >= 1; --i, cur[filter_bytes]=255,raw+=filter_bytes,cur+=output_bytes,prior+=output_bytes) \
for (k=0; k < filter_bytes; ++k)
switch (filter) {
STBI__CASE(STBI__F_none) { cur[k] = raw[k]; } break;
STBI__CASE(STBI__F_sub) { cur[k] = STBI__BYTECAST(raw[k] + cur[k - output_bytes]); } break;
STBI__CASE(STBI__F_up) { cur[k] = STBI__BYTECAST(raw[k] + prior[k]); } break;
STBI__CASE(STBI__F_avg) { cur[k] = STBI__BYTECAST(raw[k] + ((prior[k] + cur[k - output_bytes]) >> 1)); } break;
STBI__CASE(STBI__F_paeth) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k - output_bytes], prior[k], prior[k - output_bytes])); } break;
STBI__CASE(STBI__F_avg_first) { cur[k] = STBI__BYTECAST(raw[k] + (cur[k - output_bytes] >> 1)); } break;
STBI__CASE(STBI__F_paeth_first) { cur[k] = STBI__BYTECAST(raw[k] + stbi__paeth(cur[k - output_bytes], 0, 0)); } break;
}
#undef STBI__CASE
// the loop above sets the high byte of the pixels' alpha, but for
// 16 bit png files we also need the low byte set. we'll do that here.
if (depth == 16) {
cur = a->out + stride * j; // start at the beginning of the row again
for (i = 0; i < x; ++i, cur += output_bytes) {
cur[filter_bytes + 1] = 255;
}
}
}
}
// we make a separate pass to expand bits to pixels; for performance,
// this could run two scanlines behind the above code, so it won't
// intefere with filtering but will still be in the cache.
if (depth < 8) {
for (j = 0; j < y; ++j) {
stbi_uc* cur = a->out + stride * j;
stbi_uc* in = a->out + stride * j + x * out_n - img_width_bytes;
// unpack 1/2/4-bit into a 8-bit buffer. allows us to keep the common 8-bit path optimal at minimal cost for 1/2/4-bit
// png guarante byte alignment, if width is not multiple of 8/4/2 we'll decode dummy trailing data that will be skipped in the later loop
stbi_uc scale = (color == 0) ? stbi__depth_scale_table[depth] : 1; // scale grayscale values to 0..255 range
// note that the final byte might overshoot and write more data than desired.
// we can allocate enough data that this never writes out of memory, but it
// could also overwrite the next scanline. can it overwrite non-empty data
// on the next scanline? yes, consider 1-pixel-wide scanlines with 1-bit-per-pixel.
// so we need to explicitly clamp the final ones
if (depth == 4) {
for (k = x * img_n; k >= 2; k -= 2, ++in) {
*cur++ = scale * ((*in >> 4));
*cur++ = scale * ((*in) & 0x0f);
}
if (k > 0) *cur++ = scale * ((*in >> 4));
}
else if (depth == 2) {
for (k = x * img_n; k >= 4; k -= 4, ++in) {
*cur++ = scale * ((*in >> 6));
*cur++ = scale * ((*in >> 4) & 0x03);
*cur++ = scale * ((*in >> 2) & 0x03);
*cur++ = scale * ((*in) & 0x03);
}
if (k > 0) *cur++ = scale * ((*in >> 6));
if (k > 1) *cur++ = scale * ((*in >> 4) & 0x03);
if (k > 2) *cur++ = scale * ((*in >> 2) & 0x03);
}
else if (depth == 1) {
for (k = x * img_n; k >= 8; k -= 8, ++in) {
*cur++ = scale * ((*in >> 7));
*cur++ = scale * ((*in >> 6) & 0x01);
*cur++ = scale * ((*in >> 5) & 0x01);
*cur++ = scale * ((*in >> 4) & 0x01);
*cur++ = scale * ((*in >> 3) & 0x01);
*cur++ = scale * ((*in >> 2) & 0x01);
*cur++ = scale * ((*in >> 1) & 0x01);
*cur++ = scale * ((*in) & 0x01);
}
if (k > 0) *cur++ = scale * ((*in >> 7));
if (k > 1) *cur++ = scale * ((*in >> 6) & 0x01);
if (k > 2) *cur++ = scale * ((*in >> 5) & 0x01);
if (k > 3) *cur++ = scale * ((*in >> 4) & 0x01);
if (k > 4) *cur++ = scale * ((*in >> 3) & 0x01);
if (k > 5) *cur++ = scale * ((*in >> 2) & 0x01);
if (k > 6) *cur++ = scale * ((*in >> 1) & 0x01);
}
if (img_n != out_n) {
int q;
// insert alpha = 255
cur = a->out + stride * j;
if (img_n == 1) {
for (q = x - 1; q >= 0; --q) {
cur[q * 2 + 1] = 255;
cur[q * 2 + 0] = cur[q];
}
}
else {
STBI_ASSERT(img_n == 3);
for (q = x - 1; q >= 0; --q) {
cur[q * 4 + 3] = 255;
cur[q * 4 + 2] = cur[q * 3 + 2];
cur[q * 4 + 1] = cur[q * 3 + 1];
cur[q * 4 + 0] = cur[q * 3 + 0];
}
}
}
}
}
else if (depth == 16) {
// force the image data from big-endian to platform-native.
// this is done in a separate pass due to the decoding relying
// on the data being untouched, but could probably be done
// per-line during decode if care is taken.
stbi_uc* cur = a->out;
stbi__uint16* cur16 = (stbi__uint16*)cur;
for (i = 0; i < x * y * out_n; ++i, cur16++, cur += 2) {
*cur16 = (cur[0] << 8) | cur[1];
}
}
return 1;
}
static int stbi__create_png_image(stbi__png* a, stbi_uc* image_data, stbi__uint32 image_data_len, int out_n, int depth, int color, int interlaced)
{
int bytes = (depth == 16 ? 2 : 1);
int out_bytes = out_n * bytes;
stbi_uc* final;
int p;
if (!interlaced)
return stbi__create_png_image_raw(a, image_data, image_data_len, out_n, a->s->img_x, a->s->img_y, depth, color);
// de-interlacing
final = (stbi_uc*)stbi__malloc_mad3(a->s->img_x, a->s->img_y, out_bytes, 0);
for (p = 0; p < 7; ++p) {
int xorig[] = { 0,4,0,2,0,1,0 };
int yorig[] = { 0,0,4,0,2,0,1 };
int xspc[] = { 8,8,4,4,2,2,1 };
int yspc[] = { 8,8,8,4,4,2,2 };
int i, j, x, y;
// pass1_x[4] = 0, pass1_x[5] = 1, pass1_x[12] = 1
x = (a->s->img_x - xorig[p] + xspc[p] - 1) / xspc[p];
y = (a->s->img_y - yorig[p] + yspc[p] - 1) / yspc[p];
if (x && y) {
stbi__uint32 img_len = ((((a->s->img_n * x * depth) + 7) >> 3) + 1) * y;
if (!stbi__create_png_image_raw(a, image_data, image_data_len, out_n, x, y, depth, color)) {
STBI_FREE(final);
return 0;
}
for (j = 0; j < y; ++j) {
for (i = 0; i < x; ++i) {
int out_y = j * yspc[p] + yorig[p];
int out_x = i * xspc[p] + xorig[p];
memcpy(final + out_y * a->s->img_x * out_bytes + out_x * out_bytes,
a->out + (j * x + i) * out_bytes, out_bytes);
}
}
STBI_FREE(a->out);
image_data += img_len;
image_data_len -= img_len;
}
}
a->out = final;
return 1;
}
static int stbi__compute_transparency(stbi__png* z, stbi_uc tc[3], int out_n)
{
stbi__context* s = z->s;
stbi__uint32 i, pixel_count = s->img_x * s->img_y;
stbi_uc* p = z->out;
// compute color-based transparency, assuming we've
// already got 255 as the alpha value in the output
STBI_ASSERT(out_n == 2 || out_n == 4);
if (out_n == 2) {
for (i = 0; i < pixel_count; ++i) {
p[1] = (p[0] == tc[0] ? 0 : 255);
p += 2;
}
}
else {
for (i = 0; i < pixel_count; ++i) {
if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2])
p[3] = 0;
p += 4;
}
}
return 1;
}
static int stbi__compute_transparency16(stbi__png* z, stbi__uint16 tc[3], int out_n)
{
stbi__context* s = z->s;
stbi__uint32 i, pixel_count = s->img_x * s->img_y;
stbi__uint16* p = (stbi__uint16*)z->out;
// compute color-based transparency, assuming we've
// already got 65535 as the alpha value in the output
STBI_ASSERT(out_n == 2 || out_n == 4);
if (out_n == 2) {
for (i = 0; i < pixel_count; ++i) {
p[1] = (p[0] == tc[0] ? 0 : 65535);
p += 2;
}
}
else {
for (i = 0; i < pixel_count; ++i) {
if (p[0] == tc[0] && p[1] == tc[1] && p[2] == tc[2])
p[3] = 0;
p += 4;
}
}
return 1;
}
static int stbi__expand_png_palette(stbi__png* a, stbi_uc* palette, int len, int pal_img_n)
{
stbi__uint32 i, pixel_count = a->s->img_x * a->s->img_y;
stbi_uc* p, * temp_out, * orig = a->out;
p = (stbi_uc*)stbi__malloc_mad2(pixel_count, pal_img_n, 0);
if (p == NULL) return stbi__err("outofmem", "Out of memory");
// between here and free(out) below, exitting would leak
temp_out = p;
if (pal_img_n == 3) {
for (i = 0; i < pixel_count; ++i) {
int n = orig[i] * 4;
p[0] = palette[n];
p[1] = palette[n + 1];
p[2] = palette[n + 2];
p += 3;
}
}
else {
for (i = 0; i < pixel_count; ++i) {
int n = orig[i] * 4;
p[0] = palette[n];
p[1] = palette[n + 1];
p[2] = palette[n + 2];
p[3] = palette[n + 3];
p += 4;
}
}
STBI_FREE(a->out);
a->out = temp_out;
STBI_NOTUSED(len);
return 1;
}
static int stbi__unpremultiply_on_load = 0;
static int stbi__de_iphone_flag = 0;
STBIDEF void stbi_set_unpremultiply_on_load(int flag_true_if_should_unpremultiply)
{
stbi__unpremultiply_on_load = flag_true_if_should_unpremultiply;
}
STBIDEF void stbi_convert_iphone_png_to_rgb(int flag_true_if_should_convert)
{
stbi__de_iphone_flag = flag_true_if_should_convert;
}
static void stbi__de_iphone(stbi__png* z)
{
stbi__context* s = z->s;
stbi__uint32 i, pixel_count = s->img_x * s->img_y;
stbi_uc* p = z->out;
if (s->img_out_n == 3) { // convert bgr to rgb
for (i = 0; i < pixel_count; ++i) {
stbi_uc t = p[0];
p[0] = p[2];
p[2] = t;
p += 3;
}
}
else {
STBI_ASSERT(s->img_out_n == 4);
if (stbi__unpremultiply_on_load) {
// convert bgr to rgb and unpremultiply
for (i = 0; i < pixel_count; ++i) {
stbi_uc a = p[3];
stbi_uc t = p[0];
if (a) {
stbi_uc half = a / 2;
p[0] = (p[2] * 255 + half) / a;
p[1] = (p[1] * 255 + half) / a;
p[2] = (t * 255 + half) / a;
}
else {
p[0] = p[2];
p[2] = t;
}
p += 4;
}
}
else {
// convert bgr to rgb
for (i = 0; i < pixel_count; ++i) {
stbi_uc t = p[0];
p[0] = p[2];
p[2] = t;
p += 4;
}
}
}
}
#define STBI__PNG_TYPE(a,b,c,d) (((unsigned) (a) << 24) + ((unsigned) (b) << 16) + ((unsigned) (c) << 8) + (unsigned) (d))
static int stbi__parse_png_file(stbi__png* z, int scan, int req_comp)
{
stbi_uc palette[1024], pal_img_n = 0;
stbi_uc has_trans = 0, tc[3] = { 0 };
stbi__uint16 tc16[3];
stbi__uint32 ioff = 0, idata_limit = 0, i, pal_len = 0;
int first = 1, k, interlace = 0, color = 0, is_iphone = 0;
stbi__context* s = z->s;
z->expanded = NULL;
z->idata = NULL;
z->out = NULL;
if (!stbi__check_png_header(s)) return 0;
if (scan == STBI__SCAN_type) return 1;
for (;;) {
stbi__pngchunk c = stbi__get_chunk_header(s);
switch (c.type) {
case STBI__PNG_TYPE('C', 'g', 'B', 'I'):
is_iphone = 1;
stbi__skip(s, c.length);
break;
case STBI__PNG_TYPE('I', 'H', 'D', 'R'): {
int comp, filter;
if (!first) return stbi__err("multiple IHDR", "Corrupt PNG");
first = 0;
if (c.length != 13) return stbi__err("bad IHDR len", "Corrupt PNG");
s->img_x = stbi__get32be(s);
s->img_y = stbi__get32be(s);
if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__err("too large", "Very large image (corrupt?)");
if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__err("too large", "Very large image (corrupt?)");
z->depth = stbi__get8(s); if (z->depth != 1 && z->depth != 2 && z->depth != 4 && z->depth != 8 && z->depth != 16) return stbi__err("1/2/4/8/16-bit only", "PNG not supported: 1/2/4/8/16-bit only");
color = stbi__get8(s); if (color > 6) return stbi__err("bad ctype", "Corrupt PNG");
if (color == 3 && z->depth == 16) return stbi__err("bad ctype", "Corrupt PNG");
if (color == 3) pal_img_n = 3; else if (color & 1) return stbi__err("bad ctype", "Corrupt PNG");
comp = stbi__get8(s); if (comp) return stbi__err("bad comp method", "Corrupt PNG");
filter = stbi__get8(s); if (filter) return stbi__err("bad filter method", "Corrupt PNG");
interlace = stbi__get8(s); if (interlace > 1) return stbi__err("bad interlace method", "Corrupt PNG");
if (!s->img_x || !s->img_y) return stbi__err("0-pixel image", "Corrupt PNG");
if (!pal_img_n) {
s->img_n = (color & 2 ? 3 : 1) + (color & 4 ? 1 : 0);
if ((1 << 30) / s->img_x / s->img_n < s->img_y) return stbi__err("too large", "Image too large to decode");
if (scan == STBI__SCAN_header) return 1;
}
else {
// if paletted, then pal_n is our final components, and
// img_n is # components to decompress/filter.
s->img_n = 1;
if ((1 << 30) / s->img_x / 4 < s->img_y) return stbi__err("too large", "Corrupt PNG");
// if SCAN_header, have to scan to see if we have a tRNS
}
break;
}
case STBI__PNG_TYPE('P', 'L', 'T', 'E'): {
if (first) return stbi__err("first not IHDR", "Corrupt PNG");
if (c.length > 256 * 3) return stbi__err("invalid PLTE", "Corrupt PNG");
pal_len = c.length / 3;
if (pal_len * 3 != c.length) return stbi__err("invalid PLTE", "Corrupt PNG");
for (i = 0; i < pal_len; ++i) {
palette[i * 4 + 0] = stbi__get8(s);
palette[i * 4 + 1] = stbi__get8(s);
palette[i * 4 + 2] = stbi__get8(s);
palette[i * 4 + 3] = 255;
}
break;
}
case STBI__PNG_TYPE('t', 'R', 'N', 'S'): {
if (first) return stbi__err("first not IHDR", "Corrupt PNG");
if (z->idata) return stbi__err("tRNS after IDAT", "Corrupt PNG");
if (pal_img_n) {
if (scan == STBI__SCAN_header) { s->img_n = 4; return 1; }
if (pal_len == 0) return stbi__err("tRNS before PLTE", "Corrupt PNG");
if (c.length > pal_len) return stbi__err("bad tRNS len", "Corrupt PNG");
pal_img_n = 4;
for (i = 0; i < c.length; ++i)
palette[i * 4 + 3] = stbi__get8(s);
}
else {
if (!(s->img_n & 1)) return stbi__err("tRNS with alpha", "Corrupt PNG");
if (c.length != (stbi__uint32)s->img_n * 2) return stbi__err("bad tRNS len", "Corrupt PNG");
has_trans = 1;
if (z->depth == 16) {
for (k = 0; k < s->img_n; ++k) tc16[k] = (stbi__uint16)stbi__get16be(s); // copy the values as-is
}
else {
for (k = 0; k < s->img_n; ++k) tc[k] = (stbi_uc)(stbi__get16be(s) & 255) * stbi__depth_scale_table[z->depth]; // non 8-bit images will be larger
}
}
break;
}
case STBI__PNG_TYPE('I', 'D', 'A', 'T'): {
if (first) return stbi__err("first not IHDR", "Corrupt PNG");
if (pal_img_n && !pal_len) return stbi__err("no PLTE", "Corrupt PNG");
if (scan == STBI__SCAN_header) { s->img_n = pal_img_n; return 1; }
if ((int)(ioff + c.length) < (int)ioff) return 0;
if (ioff + c.length > idata_limit) {
stbi__uint32 idata_limit_old = idata_limit;
stbi_uc* p;
if (idata_limit == 0) idata_limit = c.length > 4096 ? c.length : 4096;
while (ioff + c.length > idata_limit)
idata_limit *= 2;
STBI_NOTUSED(idata_limit_old);
p = (stbi_uc*)STBI_REALLOC_SIZED(z->idata, idata_limit_old, idata_limit); if (p == NULL) return stbi__err("outofmem", "Out of memory");
z->idata = p;
}
if (!stbi__getn(s, z->idata + ioff, c.length)) return stbi__err("outofdata", "Corrupt PNG");
ioff += c.length;
break;
}
case STBI__PNG_TYPE('I', 'E', 'N', 'D'): {
stbi__uint32 raw_len, bpl;
if (first) return stbi__err("first not IHDR", "Corrupt PNG");
if (scan != STBI__SCAN_load) return 1;
if (z->idata == NULL) return stbi__err("no IDAT", "Corrupt PNG");
// initial guess for decoded data size to avoid unnecessary reallocs
bpl = (s->img_x * z->depth + 7) / 8; // bytes per line, per component
raw_len = bpl * s->img_y * s->img_n /* pixels */ + s->img_y /* filter mode per row */;
z->expanded = (stbi_uc*)stbi_zlib_decode_malloc_guesssize_headerflag((char*)z->idata, ioff, raw_len, (int*)&raw_len, !is_iphone);
if (z->expanded == NULL) return 0; // zlib should set error
STBI_FREE(z->idata); z->idata = NULL;
if ((req_comp == s->img_n + 1 && req_comp != 3 && !pal_img_n) || has_trans)
s->img_out_n = s->img_n + 1;
else
s->img_out_n = s->img_n;
if (!stbi__create_png_image(z, z->expanded, raw_len, s->img_out_n, z->depth, color, interlace)) return 0;
if (has_trans) {
if (z->depth == 16) {
if (!stbi__compute_transparency16(z, tc16, s->img_out_n)) return 0;
}
else {
if (!stbi__compute_transparency(z, tc, s->img_out_n)) return 0;
}
}
if (is_iphone && stbi__de_iphone_flag && s->img_out_n > 2)
stbi__de_iphone(z);
if (pal_img_n) {
// pal_img_n == 3 or 4
s->img_n = pal_img_n; // record the actual colors we had
s->img_out_n = pal_img_n;
if (req_comp >= 3) s->img_out_n = req_comp;
if (!stbi__expand_png_palette(z, palette, pal_len, s->img_out_n))
return 0;
}
else if (has_trans) {
// non-paletted image with tRNS -> source image has (constant) alpha
++s->img_n;
}
STBI_FREE(z->expanded); z->expanded = NULL;
// end of PNG chunk, read and skip CRC
stbi__get32be(s);
return 1;
}
default:
// if critical, fail
if (first) return stbi__err("first not IHDR", "Corrupt PNG");
if ((c.type & (1 << 29)) == 0) {
#ifndef STBI_NO_FAILURE_STRINGS
// not threadsafe
static char invalid_chunk[] = "XXXX PNG chunk not known";
invalid_chunk[0] = STBI__BYTECAST(c.type >> 24);
invalid_chunk[1] = STBI__BYTECAST(c.type >> 16);
invalid_chunk[2] = STBI__BYTECAST(c.type >> 8);
invalid_chunk[3] = STBI__BYTECAST(c.type >> 0);
#endif
return stbi__err(invalid_chunk, "PNG not supported: unknown PNG chunk type");
}
stbi__skip(s, c.length);
break;
}
// end of PNG chunk, read and skip CRC
stbi__get32be(s);
}
}
static void* stbi__do_png(stbi__png* p, int* x, int* y, int* n, int req_comp, stbi__result_info* ri)
{
void* result = NULL;
if (req_comp < 0 || req_comp > 4) return stbi__errpuc("bad req_comp", "Internal error");
if (stbi__parse_png_file(p, STBI__SCAN_load, req_comp)) {
if (p->depth <= 8)
ri->bits_per_channel = 8;
else if (p->depth == 16)
ri->bits_per_channel = 16;
else
return stbi__errpuc("bad bits_per_channel", "PNG not supported: unsupported color depth");
result = p->out;
p->out = NULL;
if (req_comp && req_comp != p->s->img_out_n) {
if (ri->bits_per_channel == 8)
result = stbi__convert_format((unsigned char*)result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y);
else
result = stbi__convert_format16((stbi__uint16*)result, p->s->img_out_n, req_comp, p->s->img_x, p->s->img_y);
p->s->img_out_n = req_comp;
if (result == NULL) return result;
}
*x = p->s->img_x;
*y = p->s->img_y;
if (n) *n = p->s->img_n;
}
STBI_FREE(p->out); p->out = NULL;
STBI_FREE(p->expanded); p->expanded = NULL;
STBI_FREE(p->idata); p->idata = NULL;
return result;
}
static void* stbi__png_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
stbi__png p;
p.s = s;
return stbi__do_png(&p, x, y, comp, req_comp, ri);
}
static int stbi__png_test(stbi__context* s)
{
int r;
r = stbi__check_png_header(s);
stbi__rewind(s);
return r;
}
static int stbi__png_info_raw(stbi__png* p, int* x, int* y, int* comp)
{
if (!stbi__parse_png_file(p, STBI__SCAN_header, 0)) {
stbi__rewind(p->s);
return 0;
}
if (x) *x = p->s->img_x;
if (y) *y = p->s->img_y;
if (comp) *comp = p->s->img_n;
return 1;
}
static int stbi__png_info(stbi__context* s, int* x, int* y, int* comp)
{
stbi__png p;
p.s = s;
return stbi__png_info_raw(&p, x, y, comp);
}
static int stbi__png_is16(stbi__context* s)
{
stbi__png p;
p.s = s;
if (!stbi__png_info_raw(&p, NULL, NULL, NULL))
return 0;
if (p.depth != 16) {
stbi__rewind(p.s);
return 0;
}
return 1;
}
#endif
// Microsoft/Windows BMP image
#ifndef STBI_NO_BMP
static int stbi__bmp_test_raw(stbi__context* s)
{
int r;
int sz;
if (stbi__get8(s) != 'B') return 0;
if (stbi__get8(s) != 'M') return 0;
stbi__get32le(s); // discard filesize
stbi__get16le(s); // discard reserved
stbi__get16le(s); // discard reserved
stbi__get32le(s); // discard data offset
sz = stbi__get32le(s);
r = (sz == 12 || sz == 40 || sz == 56 || sz == 108 || sz == 124);
return r;
}
static int stbi__bmp_test(stbi__context* s)
{
int r = stbi__bmp_test_raw(s);
stbi__rewind(s);
return r;
}
// returns 0..31 for the highest set bit
static int stbi__high_bit(unsigned int z)
{
int n = 0;
if (z == 0) return -1;
if (z >= 0x10000) { n += 16; z >>= 16; }
if (z >= 0x00100) { n += 8; z >>= 8; }
if (z >= 0x00010) { n += 4; z >>= 4; }
if (z >= 0x00004) { n += 2; z >>= 2; }
if (z >= 0x00002) { n += 1;/* >>= 1;*/ }
return n;
}
static int stbi__bitcount(unsigned int a)
{
a = (a & 0x55555555) + ((a >> 1) & 0x55555555); // max 2
a = (a & 0x33333333) + ((a >> 2) & 0x33333333); // max 4
a = (a + (a >> 4)) & 0x0f0f0f0f; // max 8 per 4, now 8 bits
a = (a + (a >> 8)); // max 16 per 8 bits
a = (a + (a >> 16)); // max 32 per 8 bits
return a & 0xff;
}
// extract an arbitrarily-aligned N-bit value (N=bits)
// from v, and then make it 8-bits long and fractionally
// extend it to full full range.
static int stbi__shiftsigned(unsigned int v, int shift, int bits)
{
static unsigned int mul_table[9] = {
0,
0xff/*0b11111111*/, 0x55/*0b01010101*/, 0x49/*0b01001001*/, 0x11/*0b00010001*/,
0x21/*0b00100001*/, 0x41/*0b01000001*/, 0x81/*0b10000001*/, 0x01/*0b00000001*/,
};
static unsigned int shift_table[9] = {
0, 0,0,1,0,2,4,6,0,
};
if (shift < 0)
v <<= -shift;
else
v >>= shift;
STBI_ASSERT(v < 256);
v >>= (8 - bits);
STBI_ASSERT(bits >= 0 && bits <= 8);
return (int)((unsigned)v * mul_table[bits]) >> shift_table[bits];
}
typedef struct
{
int bpp, offset, hsz;
unsigned int mr, mg, mb, ma, all_a;
int extra_read;
} stbi__bmp_data;
static void* stbi__bmp_parse_header(stbi__context* s, stbi__bmp_data* info)
{
int hsz;
if (stbi__get8(s) != 'B' || stbi__get8(s) != 'M') return stbi__errpuc("not BMP", "Corrupt BMP");
stbi__get32le(s); // discard filesize
stbi__get16le(s); // discard reserved
stbi__get16le(s); // discard reserved
info->offset = stbi__get32le(s);
info->hsz = hsz = stbi__get32le(s);
info->mr = info->mg = info->mb = info->ma = 0;
info->extra_read = 14;
if (info->offset < 0) return stbi__errpuc("bad BMP", "bad BMP");
if (hsz != 12 && hsz != 40 && hsz != 56 && hsz != 108 && hsz != 124) return stbi__errpuc("unknown BMP", "BMP type not supported: unknown");
if (hsz == 12) {
s->img_x = stbi__get16le(s);
s->img_y = stbi__get16le(s);
}
else {
s->img_x = stbi__get32le(s);
s->img_y = stbi__get32le(s);
}
if (stbi__get16le(s) != 1) return stbi__errpuc("bad BMP", "bad BMP");
info->bpp = stbi__get16le(s);
if (hsz != 12) {
int compress = stbi__get32le(s);
if (compress == 1 || compress == 2) return stbi__errpuc("BMP RLE", "BMP type not supported: RLE");
stbi__get32le(s); // discard sizeof
stbi__get32le(s); // discard hres
stbi__get32le(s); // discard vres
stbi__get32le(s); // discard colorsused
stbi__get32le(s); // discard max important
if (hsz == 40 || hsz == 56) {
if (hsz == 56) {
stbi__get32le(s);
stbi__get32le(s);
stbi__get32le(s);
stbi__get32le(s);
}
if (info->bpp == 16 || info->bpp == 32) {
if (compress == 0) {
if (info->bpp == 32) {
info->mr = 0xffu << 16;
info->mg = 0xffu << 8;
info->mb = 0xffu << 0;
info->ma = 0xffu << 24;
info->all_a = 0; // if all_a is 0 at end, then we loaded alpha channel but it was all 0
}
else {
info->mr = 31u << 10;
info->mg = 31u << 5;
info->mb = 31u << 0;
}
}
else if (compress == 3) {
info->mr = stbi__get32le(s);
info->mg = stbi__get32le(s);
info->mb = stbi__get32le(s);
info->extra_read += 12;
// not documented, but generated by photoshop and handled by mspaint
if (info->mr == info->mg && info->mg == info->mb) {
// ?!?!?
return stbi__errpuc("bad BMP", "bad BMP");
}
}
else
return stbi__errpuc("bad BMP", "bad BMP");
}
}
else {
int i;
if (hsz != 108 && hsz != 124)
return stbi__errpuc("bad BMP", "bad BMP");
info->mr = stbi__get32le(s);
info->mg = stbi__get32le(s);
info->mb = stbi__get32le(s);
info->ma = stbi__get32le(s);
stbi__get32le(s); // discard color space
for (i = 0; i < 12; ++i)
stbi__get32le(s); // discard color space parameters
if (hsz == 124) {
stbi__get32le(s); // discard rendering intent
stbi__get32le(s); // discard offset of profile data
stbi__get32le(s); // discard size of profile data
stbi__get32le(s); // discard reserved
}
}
}
return (void*)1;
}
static void* stbi__bmp_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
stbi_uc* out;
unsigned int mr = 0, mg = 0, mb = 0, ma = 0, all_a;
stbi_uc pal[256][4];
int psize = 0, i, j, width;
int flip_vertically, pad, target;
stbi__bmp_data info;
STBI_NOTUSED(ri);
info.all_a = 255;
if (stbi__bmp_parse_header(s, &info) == NULL)
return NULL; // error code already set
flip_vertically = ((int)s->img_y) > 0;
s->img_y = abs((int)s->img_y);
if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
mr = info.mr;
mg = info.mg;
mb = info.mb;
ma = info.ma;
all_a = info.all_a;
if (info.hsz == 12) {
if (info.bpp < 24)
psize = (info.offset - info.extra_read - 24) / 3;
}
else {
if (info.bpp < 16)
psize = (info.offset - info.extra_read - info.hsz) >> 2;
}
if (psize == 0) {
STBI_ASSERT(info.offset == s->callback_already_read + (int)(s->img_buffer - s->img_buffer_original));
if (info.offset != s->callback_already_read + (s->img_buffer - s->buffer_start)) {
return stbi__errpuc("bad offset", "Corrupt BMP");
}
}
if (info.bpp == 24 && ma == 0xff000000)
s->img_n = 3;
else
s->img_n = ma ? 4 : 3;
if (req_comp && req_comp >= 3) // we can directly decode 3 or 4
target = req_comp;
else
target = s->img_n; // if they want monochrome, we'll post-convert
// sanity-check size
if (!stbi__mad3sizes_valid(target, s->img_x, s->img_y, 0))
return stbi__errpuc("too large", "Corrupt BMP");
out = (stbi_uc*)stbi__malloc_mad3(target, s->img_x, s->img_y, 0);
if (!out) return stbi__errpuc("outofmem", "Out of memory");
if (info.bpp < 16) {
int z = 0;
if (psize == 0 || psize > 256) { STBI_FREE(out); return stbi__errpuc("invalid", "Corrupt BMP"); }
for (i = 0; i < psize; ++i) {
pal[i][2] = stbi__get8(s);
pal[i][1] = stbi__get8(s);
pal[i][0] = stbi__get8(s);
if (info.hsz != 12) stbi__get8(s);
pal[i][3] = 255;
}
stbi__skip(s, info.offset - info.extra_read - info.hsz - psize * (info.hsz == 12 ? 3 : 4));
if (info.bpp == 1) width = (s->img_x + 7) >> 3;
else if (info.bpp == 4) width = (s->img_x + 1) >> 1;
else if (info.bpp == 8) width = s->img_x;
else { STBI_FREE(out); return stbi__errpuc("bad bpp", "Corrupt BMP"); }
pad = (-width) & 3;
if (info.bpp == 1) {
for (j = 0; j < (int)s->img_y; ++j) {
int bit_offset = 7, v = stbi__get8(s);
for (i = 0; i < (int)s->img_x; ++i) {
int color = (v >> bit_offset) & 0x1;
out[z++] = pal[color][0];
out[z++] = pal[color][1];
out[z++] = pal[color][2];
if (target == 4) out[z++] = 255;
if (i + 1 == (int)s->img_x) break;
if ((--bit_offset) < 0) {
bit_offset = 7;
v = stbi__get8(s);
}
}
stbi__skip(s, pad);
}
}
else {
for (j = 0; j < (int)s->img_y; ++j) {
for (i = 0; i < (int)s->img_x; i += 2) {
int v = stbi__get8(s), v2 = 0;
if (info.bpp == 4) {
v2 = v & 15;
v >>= 4;
}
out[z++] = pal[v][0];
out[z++] = pal[v][1];
out[z++] = pal[v][2];
if (target == 4) out[z++] = 255;
if (i + 1 == (int)s->img_x) break;
v = (info.bpp == 8) ? stbi__get8(s) : v2;
out[z++] = pal[v][0];
out[z++] = pal[v][1];
out[z++] = pal[v][2];
if (target == 4) out[z++] = 255;
}
stbi__skip(s, pad);
}
}
}
else {
int rshift = 0, gshift = 0, bshift = 0, ashift = 0, rcount = 0, gcount = 0, bcount = 0, acount = 0;
int z = 0;
int easy = 0;
stbi__skip(s, info.offset - info.extra_read - info.hsz);
if (info.bpp == 24) width = 3 * s->img_x;
else if (info.bpp == 16) width = 2 * s->img_x;
else /* bpp = 32 and pad = 0 */ width = 0;
pad = (-width) & 3;
if (info.bpp == 24) {
easy = 1;
}
else if (info.bpp == 32) {
if (mb == 0xff && mg == 0xff00 && mr == 0x00ff0000 && ma == 0xff000000)
easy = 2;
}
if (!easy) {
if (!mr || !mg || !mb) { STBI_FREE(out); return stbi__errpuc("bad masks", "Corrupt BMP"); }
// right shift amt to put high bit in position #7
rshift = stbi__high_bit(mr) - 7; rcount = stbi__bitcount(mr);
gshift = stbi__high_bit(mg) - 7; gcount = stbi__bitcount(mg);
bshift = stbi__high_bit(mb) - 7; bcount = stbi__bitcount(mb);
ashift = stbi__high_bit(ma) - 7; acount = stbi__bitcount(ma);
if (rcount > 8 || gcount > 8 || bcount > 8 || acount > 8) { STBI_FREE(out); return stbi__errpuc("bad masks", "Corrupt BMP"); }
}
for (j = 0; j < (int)s->img_y; ++j) {
if (easy) {
for (i = 0; i < (int)s->img_x; ++i) {
unsigned char a;
out[z + 2] = stbi__get8(s);
out[z + 1] = stbi__get8(s);
out[z + 0] = stbi__get8(s);
z += 3;
a = (easy == 2 ? stbi__get8(s) : 255);
all_a |= a;
if (target == 4) out[z++] = a;
}
}
else {
int bpp = info.bpp;
for (i = 0; i < (int)s->img_x; ++i) {
stbi__uint32 v = (bpp == 16 ? (stbi__uint32)stbi__get16le(s) : stbi__get32le(s));
unsigned int a;
out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mr, rshift, rcount));
out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mg, gshift, gcount));
out[z++] = STBI__BYTECAST(stbi__shiftsigned(v & mb, bshift, bcount));
a = (ma ? stbi__shiftsigned(v & ma, ashift, acount) : 255);
all_a |= a;
if (target == 4) out[z++] = STBI__BYTECAST(a);
}
}
stbi__skip(s, pad);
}
}
// if alpha channel is all 0s, replace with all 255s
if (target == 4 && all_a == 0)
for (i = 4 * s->img_x * s->img_y - 1; i >= 0; i -= 4)
out[i] = 255;
if (flip_vertically) {
stbi_uc t;
for (j = 0; j < (int)s->img_y >> 1; ++j) {
stbi_uc* p1 = out + j * s->img_x * target;
stbi_uc* p2 = out + (s->img_y - 1 - j) * s->img_x * target;
for (i = 0; i < (int)s->img_x * target; ++i) {
t = p1[i]; p1[i] = p2[i]; p2[i] = t;
}
}
}
if (req_comp && req_comp != target) {
out = stbi__convert_format(out, target, req_comp, s->img_x, s->img_y);
if (out == NULL) return out; // stbi__convert_format frees input on failure
}
*x = s->img_x;
*y = s->img_y;
if (comp) *comp = s->img_n;
return out;
}
#endif
// Targa Truevision - TGA
// by Jonathan Dummer
#ifndef STBI_NO_TGA
// returns STBI_rgb or whatever, 0 on error
static int stbi__tga_get_comp(int bits_per_pixel, int is_grey, int* is_rgb16)
{
// only RGB or RGBA (incl. 16bit) or grey allowed
if (is_rgb16) *is_rgb16 = 0;
switch (bits_per_pixel) {
case 8: return STBI_grey;
case 16: if (is_grey) return STBI_grey_alpha;
// fallthrough
case 15: if (is_rgb16) *is_rgb16 = 1;
return STBI_rgb;
case 24: // fallthrough
case 32: return bits_per_pixel / 8;
default: return 0;
}
}
static int stbi__tga_info(stbi__context* s, int* x, int* y, int* comp)
{
int tga_w, tga_h, tga_comp, tga_image_type, tga_bits_per_pixel, tga_colormap_bpp;
int sz, tga_colormap_type;
stbi__get8(s); // discard Offset
tga_colormap_type = stbi__get8(s); // colormap type
if (tga_colormap_type > 1) {
stbi__rewind(s);
return 0; // only RGB or indexed allowed
}
tga_image_type = stbi__get8(s); // image type
if (tga_colormap_type == 1) { // colormapped (paletted) image
if (tga_image_type != 1 && tga_image_type != 9) {
stbi__rewind(s);
return 0;
}
stbi__skip(s, 4); // skip index of first colormap entry and number of entries
sz = stbi__get8(s); // check bits per palette color entry
if ((sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32)) {
stbi__rewind(s);
return 0;
}
stbi__skip(s, 4); // skip image x and y origin
tga_colormap_bpp = sz;
}
else { // "normal" image w/o colormap - only RGB or grey allowed, +/- RLE
if ((tga_image_type != 2) && (tga_image_type != 3) && (tga_image_type != 10) && (tga_image_type != 11)) {
stbi__rewind(s);
return 0; // only RGB or grey allowed, +/- RLE
}
stbi__skip(s, 9); // skip colormap specification and image x/y origin
tga_colormap_bpp = 0;
}
tga_w = stbi__get16le(s);
if (tga_w < 1) {
stbi__rewind(s);
return 0; // test width
}
tga_h = stbi__get16le(s);
if (tga_h < 1) {
stbi__rewind(s);
return 0; // test height
}
tga_bits_per_pixel = stbi__get8(s); // bits per pixel
stbi__get8(s); // ignore alpha bits
if (tga_colormap_bpp != 0) {
if ((tga_bits_per_pixel != 8) && (tga_bits_per_pixel != 16)) {
// when using a colormap, tga_bits_per_pixel is the size of the indexes
// I don't think anything but 8 or 16bit indexes makes sense
stbi__rewind(s);
return 0;
}
tga_comp = stbi__tga_get_comp(tga_colormap_bpp, 0, NULL);
}
else {
tga_comp = stbi__tga_get_comp(tga_bits_per_pixel, (tga_image_type == 3) || (tga_image_type == 11), NULL);
}
if (!tga_comp) {
stbi__rewind(s);
return 0;
}
if (x) *x = tga_w;
if (y) *y = tga_h;
if (comp) *comp = tga_comp;
return 1; // seems to have passed everything
}
static int stbi__tga_test(stbi__context* s)
{
int res = 0;
int sz, tga_color_type;
stbi__get8(s); // discard Offset
tga_color_type = stbi__get8(s); // color type
if (tga_color_type > 1) goto errorEnd; // only RGB or indexed allowed
sz = stbi__get8(s); // image type
if (tga_color_type == 1) { // colormapped (paletted) image
if (sz != 1 && sz != 9) goto errorEnd; // colortype 1 demands image type 1 or 9
stbi__skip(s, 4); // skip index of first colormap entry and number of entries
sz = stbi__get8(s); // check bits per palette color entry
if ((sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32)) goto errorEnd;
stbi__skip(s, 4); // skip image x and y origin
}
else { // "normal" image w/o colormap
if ((sz != 2) && (sz != 3) && (sz != 10) && (sz != 11)) goto errorEnd; // only RGB or grey allowed, +/- RLE
stbi__skip(s, 9); // skip colormap specification and image x/y origin
}
if (stbi__get16le(s) < 1) goto errorEnd; // test width
if (stbi__get16le(s) < 1) goto errorEnd; // test height
sz = stbi__get8(s); // bits per pixel
if ((tga_color_type == 1) && (sz != 8) && (sz != 16)) goto errorEnd; // for colormapped images, bpp is size of an index
if ((sz != 8) && (sz != 15) && (sz != 16) && (sz != 24) && (sz != 32)) goto errorEnd;
res = 1; // if we got this far, everything's good and we can return 1 instead of 0
errorEnd:
stbi__rewind(s);
return res;
}
// read 16bit value and convert to 24bit RGB
static void stbi__tga_read_rgb16(stbi__context* s, stbi_uc* out)
{
stbi__uint16 px = (stbi__uint16)stbi__get16le(s);
stbi__uint16 fiveBitMask = 31;
// we have 3 channels with 5bits each
int r = (px >> 10) & fiveBitMask;
int g = (px >> 5) & fiveBitMask;
int b = px & fiveBitMask;
// Note that this saves the data in RGB(A) order, so it doesn't need to be swapped later
out[0] = (stbi_uc)((r * 255) / 31);
out[1] = (stbi_uc)((g * 255) / 31);
out[2] = (stbi_uc)((b * 255) / 31);
// some people claim that the most significant bit might be used for alpha
// (possibly if an alpha-bit is set in the "image descriptor byte")
// but that only made 16bit test images completely translucent..
// so let's treat all 15 and 16bit TGAs as RGB with no alpha.
}
static void* stbi__tga_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
// read in the TGA header stuff
int tga_offset = stbi__get8(s);
int tga_indexed = stbi__get8(s);
int tga_image_type = stbi__get8(s);
int tga_is_RLE = 0;
int tga_palette_start = stbi__get16le(s);
int tga_palette_len = stbi__get16le(s);
int tga_palette_bits = stbi__get8(s);
int tga_x_origin = stbi__get16le(s);
int tga_y_origin = stbi__get16le(s);
int tga_width = stbi__get16le(s);
int tga_height = stbi__get16le(s);
int tga_bits_per_pixel = stbi__get8(s);
int tga_comp, tga_rgb16 = 0;
int tga_inverted = stbi__get8(s);
// int tga_alpha_bits = tga_inverted & 15; // the 4 lowest bits - unused (useless?)
// image data
unsigned char* tga_data;
unsigned char* tga_palette = NULL;
int i, j;
unsigned char raw_data[4] = { 0 };
int RLE_count = 0;
int RLE_repeating = 0;
int read_next_pixel = 1;
STBI_NOTUSED(ri);
STBI_NOTUSED(tga_x_origin); // @TODO
STBI_NOTUSED(tga_y_origin); // @TODO
if (tga_height > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
if (tga_width > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
// do a tiny bit of precessing
if (tga_image_type >= 8)
{
tga_image_type -= 8;
tga_is_RLE = 1;
}
tga_inverted = 1 - ((tga_inverted >> 5) & 1);
// If I'm paletted, then I'll use the number of bits from the palette
if (tga_indexed) tga_comp = stbi__tga_get_comp(tga_palette_bits, 0, &tga_rgb16);
else tga_comp = stbi__tga_get_comp(tga_bits_per_pixel, (tga_image_type == 3), &tga_rgb16);
if (!tga_comp) // shouldn't really happen, stbi__tga_test() should have ensured basic consistency
return stbi__errpuc("bad format", "Can't find out TGA pixelformat");
// tga info
*x = tga_width;
*y = tga_height;
if (comp) *comp = tga_comp;
if (!stbi__mad3sizes_valid(tga_width, tga_height, tga_comp, 0))
return stbi__errpuc("too large", "Corrupt TGA");
tga_data = (unsigned char*)stbi__malloc_mad3(tga_width, tga_height, tga_comp, 0);
if (!tga_data) return stbi__errpuc("outofmem", "Out of memory");
// skip to the data's starting position (offset usually = 0)
stbi__skip(s, tga_offset);
if (!tga_indexed && !tga_is_RLE && !tga_rgb16) {
for (i = 0; i < tga_height; ++i) {
int row = tga_inverted ? tga_height - i - 1 : i;
stbi_uc* tga_row = tga_data + row * tga_width * tga_comp;
stbi__getn(s, tga_row, tga_width * tga_comp);
}
}
else {
// do I need to load a palette?
if (tga_indexed)
{
if (tga_palette_len == 0) { /* you have to have at least one entry! */
STBI_FREE(tga_data);
return stbi__errpuc("bad palette", "Corrupt TGA");
}
// any data to skip? (offset usually = 0)
stbi__skip(s, tga_palette_start);
// load the palette
tga_palette = (unsigned char*)stbi__malloc_mad2(tga_palette_len, tga_comp, 0);
if (!tga_palette) {
STBI_FREE(tga_data);
return stbi__errpuc("outofmem", "Out of memory");
}
if (tga_rgb16) {
stbi_uc* pal_entry = tga_palette;
STBI_ASSERT(tga_comp == STBI_rgb);
for (i = 0; i < tga_palette_len; ++i) {
stbi__tga_read_rgb16(s, pal_entry);
pal_entry += tga_comp;
}
}
else if (!stbi__getn(s, tga_palette, tga_palette_len * tga_comp)) {
STBI_FREE(tga_data);
STBI_FREE(tga_palette);
return stbi__errpuc("bad palette", "Corrupt TGA");
}
}
// load the data
for (i = 0; i < tga_width * tga_height; ++i)
{
// if I'm in RLE mode, do I need to get a RLE stbi__pngchunk?
if (tga_is_RLE)
{
if (RLE_count == 0)
{
// yep, get the next byte as a RLE command
int RLE_cmd = stbi__get8(s);
RLE_count = 1 + (RLE_cmd & 127);
RLE_repeating = RLE_cmd >> 7;
read_next_pixel = 1;
}
else if (!RLE_repeating)
{
read_next_pixel = 1;
}
}
else
{
read_next_pixel = 1;
}
// OK, if I need to read a pixel, do it now
if (read_next_pixel)
{
// load however much data we did have
if (tga_indexed)
{
// read in index, then perform the lookup
int pal_idx = (tga_bits_per_pixel == 8) ? stbi__get8(s) : stbi__get16le(s);
if (pal_idx >= tga_palette_len) {
// invalid index
pal_idx = 0;
}
pal_idx *= tga_comp;
for (j = 0; j < tga_comp; ++j) {
raw_data[j] = tga_palette[pal_idx + j];
}
}
else if (tga_rgb16) {
STBI_ASSERT(tga_comp == STBI_rgb);
stbi__tga_read_rgb16(s, raw_data);
}
else {
// read in the data raw
for (j = 0; j < tga_comp; ++j) {
raw_data[j] = stbi__get8(s);
}
}
// clear the reading flag for the next pixel
read_next_pixel = 0;
} // end of reading a pixel
// copy data
for (j = 0; j < tga_comp; ++j)
tga_data[i * tga_comp + j] = raw_data[j];
// in case we're in RLE mode, keep counting down
--RLE_count;
}
// do I need to invert the image?
if (tga_inverted)
{
for (j = 0; j * 2 < tga_height; ++j)
{
int index1 = j * tga_width * tga_comp;
int index2 = (tga_height - 1 - j) * tga_width * tga_comp;
for (i = tga_width * tga_comp; i > 0; --i)
{
unsigned char temp = tga_data[index1];
tga_data[index1] = tga_data[index2];
tga_data[index2] = temp;
++index1;
++index2;
}
}
}
// clear my palette, if I had one
if (tga_palette != NULL)
{
STBI_FREE(tga_palette);
}
}
// swap RGB - if the source data was RGB16, it already is in the right order
if (tga_comp >= 3 && !tga_rgb16)
{
unsigned char* tga_pixel = tga_data;
for (i = 0; i < tga_width * tga_height; ++i)
{
unsigned char temp = tga_pixel[0];
tga_pixel[0] = tga_pixel[2];
tga_pixel[2] = temp;
tga_pixel += tga_comp;
}
}
// convert to target component count
if (req_comp && req_comp != tga_comp)
tga_data = stbi__convert_format(tga_data, tga_comp, req_comp, tga_width, tga_height);
// the things I do to get rid of an error message, and yet keep
// Microsoft's C compilers happy... [8^(
tga_palette_start = tga_palette_len = tga_palette_bits =
tga_x_origin = tga_y_origin = 0;
STBI_NOTUSED(tga_palette_start);
// OK, done
return tga_data;
}
#endif
// *************************************************************************************************
// Photoshop PSD loader -- PD by Thatcher Ulrich, integration by Nicolas Schulz, tweaked by STB
#ifndef STBI_NO_PSD
static int stbi__psd_test(stbi__context* s)
{
int r = (stbi__get32be(s) == 0x38425053);
stbi__rewind(s);
return r;
}
static int stbi__psd_decode_rle(stbi__context* s, stbi_uc* p, int pixelCount)
{
int count, nleft, len;
count = 0;
while ((nleft = pixelCount - count) > 0) {
len = stbi__get8(s);
if (len == 128) {
// No-op.
}
else if (len < 128) {
// Copy next len+1 bytes literally.
len++;
if (len > nleft) return 0; // corrupt data
count += len;
while (len) {
*p = stbi__get8(s);
p += 4;
len--;
}
}
else if (len > 128) {
stbi_uc val;
// Next -len+1 bytes in the dest are replicated from next source byte.
// (Interpret len as a negative 8-bit int.)
len = 257 - len;
if (len > nleft) return 0; // corrupt data
val = stbi__get8(s);
count += len;
while (len) {
*p = val;
p += 4;
len--;
}
}
}
return 1;
}
static void* stbi__psd_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri, int bpc)
{
int pixelCount;
int channelCount, compression;
int channel, i;
int bitdepth;
int w, h;
stbi_uc* out;
STBI_NOTUSED(ri);
// Check identifier
if (stbi__get32be(s) != 0x38425053) // "8BPS"
return stbi__errpuc("not PSD", "Corrupt PSD image");
// Check file type version.
if (stbi__get16be(s) != 1)
return stbi__errpuc("wrong version", "Unsupported version of PSD image");
// Skip 6 reserved bytes.
stbi__skip(s, 6);
// Read the number of channels (R, G, B, A, etc).
channelCount = stbi__get16be(s);
if (channelCount < 0 || channelCount > 16)
return stbi__errpuc("wrong channel count", "Unsupported number of channels in PSD image");
// Read the rows and columns of the image.
h = stbi__get32be(s);
w = stbi__get32be(s);
if (h > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
if (w > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
// Make sure the depth is 8 bits.
bitdepth = stbi__get16be(s);
if (bitdepth != 8 && bitdepth != 16)
return stbi__errpuc("unsupported bit depth", "PSD bit depth is not 8 or 16 bit");
// Make sure the color mode is RGB.
// Valid options are:
// 0: Bitmap
// 1: Grayscale
// 2: Indexed color
// 3: RGB color
// 4: CMYK color
// 7: Multichannel
// 8: Duotone
// 9: Lab color
if (stbi__get16be(s) != 3)
return stbi__errpuc("wrong color format", "PSD is not in RGB color format");
// Skip the Mode Data. (It's the palette for indexed color; other info for other modes.)
stbi__skip(s, stbi__get32be(s));
// Skip the image resources. (resolution, pen tool paths, etc)
stbi__skip(s, stbi__get32be(s));
// Skip the reserved data.
stbi__skip(s, stbi__get32be(s));
// Find out if the data is compressed.
// Known values:
// 0: no compression
// 1: RLE compressed
compression = stbi__get16be(s);
if (compression > 1)
return stbi__errpuc("bad compression", "PSD has an unknown compression format");
// Check size
if (!stbi__mad3sizes_valid(4, w, h, 0))
return stbi__errpuc("too large", "Corrupt PSD");
// Create the destination image.
if (!compression && bitdepth == 16 && bpc == 16) {
out = (stbi_uc*)stbi__malloc_mad3(8, w, h, 0);
ri->bits_per_channel = 16;
}
else
out = (stbi_uc*)stbi__malloc(4 * w * h);
if (!out) return stbi__errpuc("outofmem", "Out of memory");
pixelCount = w * h;
// Initialize the data to zero.
//memset( out, 0, pixelCount * 4 );
// Finally, the image data.
if (compression) {
// RLE as used by .PSD and .TIFF
// Loop until you get the number of unpacked bytes you are expecting:
// Read the next source byte into n.
// If n is between 0 and 127 inclusive, copy the next n+1 bytes literally.
// Else if n is between -127 and -1 inclusive, copy the next byte -n+1 times.
// Else if n is 128, noop.
// Endloop
// The RLE-compressed data is preceded by a 2-byte data count for each row in the data,
// which we're going to just skip.
stbi__skip(s, h * channelCount * 2);
// Read the RLE data by channel.
for (channel = 0; channel < 4; channel++) {
stbi_uc* p;
p = out + channel;
if (channel >= channelCount) {
// Fill this channel with default data.
for (i = 0; i < pixelCount; i++, p += 4)
*p = (channel == 3 ? 255 : 0);
}
else {
// Read the RLE data.
if (!stbi__psd_decode_rle(s, p, pixelCount)) {
STBI_FREE(out);
return stbi__errpuc("corrupt", "bad RLE data");
}
}
}
}
else {
// We're at the raw image data. It's each channel in order (Red, Green, Blue, Alpha, ...)
// where each channel consists of an 8-bit (or 16-bit) value for each pixel in the image.
// Read the data by channel.
for (channel = 0; channel < 4; channel++) {
if (channel >= channelCount) {
// Fill this channel with default data.
if (bitdepth == 16 && bpc == 16) {
stbi__uint16* q = ((stbi__uint16*)out) + channel;
stbi__uint16 val = channel == 3 ? 65535 : 0;
for (i = 0; i < pixelCount; i++, q += 4)
*q = val;
}
else {
stbi_uc* p = out + channel;
stbi_uc val = channel == 3 ? 255 : 0;
for (i = 0; i < pixelCount; i++, p += 4)
*p = val;
}
}
else {
if (ri->bits_per_channel == 16) { // output bpc
stbi__uint16* q = ((stbi__uint16*)out) + channel;
for (i = 0; i < pixelCount; i++, q += 4)
*q = (stbi__uint16)stbi__get16be(s);
}
else {
stbi_uc* p = out + channel;
if (bitdepth == 16) { // input bpc
for (i = 0; i < pixelCount; i++, p += 4)
*p = (stbi_uc)(stbi__get16be(s) >> 8);
}
else {
for (i = 0; i < pixelCount; i++, p += 4)
*p = stbi__get8(s);
}
}
}
}
}
// remove weird white matte from PSD
if (channelCount >= 4) {
if (ri->bits_per_channel == 16) {
for (i = 0; i < w * h; ++i) {
stbi__uint16* pixel = (stbi__uint16*)out + 4 * i;
if (pixel[3] != 0 && pixel[3] != 65535) {
float a = pixel[3] / 65535.0f;
float ra = 1.0f / a;
float inv_a = 65535.0f * (1 - ra);
pixel[0] = (stbi__uint16)(pixel[0] * ra + inv_a);
pixel[1] = (stbi__uint16)(pixel[1] * ra + inv_a);
pixel[2] = (stbi__uint16)(pixel[2] * ra + inv_a);
}
}
}
else {
for (i = 0; i < w * h; ++i) {
unsigned char* pixel = out + 4 * i;
if (pixel[3] != 0 && pixel[3] != 255) {
float a = pixel[3] / 255.0f;
float ra = 1.0f / a;
float inv_a = 255.0f * (1 - ra);
pixel[0] = (unsigned char)(pixel[0] * ra + inv_a);
pixel[1] = (unsigned char)(pixel[1] * ra + inv_a);
pixel[2] = (unsigned char)(pixel[2] * ra + inv_a);
}
}
}
}
// convert to desired output format
if (req_comp && req_comp != 4) {
if (ri->bits_per_channel == 16)
out = (stbi_uc*)stbi__convert_format16((stbi__uint16*)out, 4, req_comp, w, h);
else
out = stbi__convert_format(out, 4, req_comp, w, h);
if (out == NULL) return out; // stbi__convert_format frees input on failure
}
if (comp) *comp = 4;
*y = h;
*x = w;
return out;
}
#endif
// *************************************************************************************************
// Softimage PIC loader
// by Tom Seddon
//
// See http://softimage.wiki.softimage.com/index.php/INFO:_PIC_file_format
// See http://ozviz.wasp.uwa.edu.au/~pbourke/dataformats/softimagepic/
#ifndef STBI_NO_PIC
static int stbi__pic_is4(stbi__context* s, const char* str)
{
int i;
for (i = 0; i < 4; ++i)
if (stbi__get8(s) != (stbi_uc)str[i])
return 0;
return 1;
}
static int stbi__pic_test_core(stbi__context* s)
{
int i;
if (!stbi__pic_is4(s, "\x53\x80\xF6\x34"))
return 0;
for (i = 0; i < 84; ++i)
stbi__get8(s);
if (!stbi__pic_is4(s, "PICT"))
return 0;
return 1;
}
typedef struct
{
stbi_uc size, type, channel;
} stbi__pic_packet;
static stbi_uc* stbi__readval(stbi__context* s, int channel, stbi_uc* dest)
{
int mask = 0x80, i;
for (i = 0; i < 4; ++i, mask >>= 1) {
if (channel & mask) {
if (stbi__at_eof(s)) return stbi__errpuc("bad file", "PIC file too short");
dest[i] = stbi__get8(s);
}
}
return dest;
}
static void stbi__copyval(int channel, stbi_uc* dest, const stbi_uc* src)
{
int mask = 0x80, i;
for (i = 0; i < 4; ++i, mask >>= 1)
if (channel & mask)
dest[i] = src[i];
}
static stbi_uc* stbi__pic_load_core(stbi__context* s, int width, int height, int* comp, stbi_uc* result)
{
int act_comp = 0, num_packets = 0, y, chained;
stbi__pic_packet packets[10];
// this will (should...) cater for even some bizarre stuff like having data
// for the same channel in multiple packets.
do {
stbi__pic_packet* packet;
if (num_packets == sizeof(packets) / sizeof(packets[0]))
return stbi__errpuc("bad format", "too many packets");
packet = &packets[num_packets++];
chained = stbi__get8(s);
packet->size = stbi__get8(s);
packet->type = stbi__get8(s);
packet->channel = stbi__get8(s);
act_comp |= packet->channel;
if (stbi__at_eof(s)) return stbi__errpuc("bad file", "file too short (reading packets)");
if (packet->size != 8) return stbi__errpuc("bad format", "packet isn't 8bpp");
} while (chained);
*comp = (act_comp & 0x10 ? 4 : 3); // has alpha channel?
for (y = 0; y < height; ++y) {
int packet_idx;
for (packet_idx = 0; packet_idx < num_packets; ++packet_idx) {
stbi__pic_packet* packet = &packets[packet_idx];
stbi_uc* dest = result + y * width * 4;
switch (packet->type) {
default:
return stbi__errpuc("bad format", "packet has bad compression type");
case 0: {//uncompressed
int x;
for (x = 0; x < width; ++x, dest += 4)
if (!stbi__readval(s, packet->channel, dest))
return 0;
break;
}
case 1://Pure RLE
{
int left = width, i;
while (left > 0) {
stbi_uc count, value[4];
count = stbi__get8(s);
if (stbi__at_eof(s)) return stbi__errpuc("bad file", "file too short (pure read count)");
if (count > left)
count = (stbi_uc)left;
if (!stbi__readval(s, packet->channel, value)) return 0;
for (i = 0; i < count; ++i, dest += 4)
stbi__copyval(packet->channel, dest, value);
left -= count;
}
}
break;
case 2: {//Mixed RLE
int left = width;
while (left > 0) {
int count = stbi__get8(s), i;
if (stbi__at_eof(s)) return stbi__errpuc("bad file", "file too short (mixed read count)");
if (count >= 128) { // Repeated
stbi_uc value[4];
if (count == 128)
count = stbi__get16be(s);
else
count -= 127;
if (count > left)
return stbi__errpuc("bad file", "scanline overrun");
if (!stbi__readval(s, packet->channel, value))
return 0;
for (i = 0; i < count; ++i, dest += 4)
stbi__copyval(packet->channel, dest, value);
}
else { // Raw
++count;
if (count > left) return stbi__errpuc("bad file", "scanline overrun");
for (i = 0; i < count; ++i, dest += 4)
if (!stbi__readval(s, packet->channel, dest))
return 0;
}
left -= count;
}
break;
}
}
}
}
return result;
}
static void* stbi__pic_load(stbi__context* s, int* px, int* py, int* comp, int req_comp, stbi__result_info* ri)
{
stbi_uc* result;
int i, x, y, internal_comp;
STBI_NOTUSED(ri);
if (!comp) comp = &internal_comp;
for (i = 0; i < 92; ++i)
stbi__get8(s);
x = stbi__get16be(s);
y = stbi__get16be(s);
if (y > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
if (x > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
if (stbi__at_eof(s)) return stbi__errpuc("bad file", "file too short (pic header)");
if (!stbi__mad3sizes_valid(x, y, 4, 0)) return stbi__errpuc("too large", "PIC image too large to decode");
stbi__get32be(s); //skip `ratio'
stbi__get16be(s); //skip `fields'
stbi__get16be(s); //skip `pad'
// intermediate buffer is RGBA
result = (stbi_uc*)stbi__malloc_mad3(x, y, 4, 0);
memset(result, 0xff, x * y * 4);
if (!stbi__pic_load_core(s, x, y, comp, result)) {
STBI_FREE(result);
result = 0;
}
*px = x;
*py = y;
if (req_comp == 0) req_comp = *comp;
result = stbi__convert_format(result, 4, req_comp, x, y);
return result;
}
static int stbi__pic_test(stbi__context* s)
{
int r = stbi__pic_test_core(s);
stbi__rewind(s);
return r;
}
#endif
// *************************************************************************************************
// GIF loader -- public domain by Jean-Marc Lienher -- simplified/shrunk by stb
#ifndef STBI_NO_GIF
typedef struct
{
stbi__int16 prefix;
stbi_uc first;
stbi_uc suffix;
} stbi__gif_lzw;
typedef struct
{
int w, h;
stbi_uc* out; // output buffer (always 4 components)
stbi_uc* background; // The current "background" as far as a gif is concerned
stbi_uc* history;
int flags, bgindex, ratio, transparent, eflags;
stbi_uc pal[256][4];
stbi_uc lpal[256][4];
stbi__gif_lzw codes[8192];
stbi_uc* color_table;
int parse, step;
int lflags;
int start_x, start_y;
int max_x, max_y;
int cur_x, cur_y;
int line_size;
int delay;
} stbi__gif;
static int stbi__gif_test_raw(stbi__context* s)
{
int sz;
if (stbi__get8(s) != 'G' || stbi__get8(s) != 'I' || stbi__get8(s) != 'F' || stbi__get8(s) != '8') return 0;
sz = stbi__get8(s);
if (sz != '9' && sz != '7') return 0;
if (stbi__get8(s) != 'a') return 0;
return 1;
}
static int stbi__gif_test(stbi__context* s)
{
int r = stbi__gif_test_raw(s);
stbi__rewind(s);
return r;
}
static void stbi__gif_parse_colortable(stbi__context* s, stbi_uc pal[256][4], int num_entries, int transp)
{
int i;
for (i = 0; i < num_entries; ++i) {
pal[i][2] = stbi__get8(s);
pal[i][1] = stbi__get8(s);
pal[i][0] = stbi__get8(s);
pal[i][3] = transp == i ? 0 : 255;
}
}
static int stbi__gif_header(stbi__context* s, stbi__gif* g, int* comp, int is_info)
{
stbi_uc version;
if (stbi__get8(s) != 'G' || stbi__get8(s) != 'I' || stbi__get8(s) != 'F' || stbi__get8(s) != '8')
return stbi__err("not GIF", "Corrupt GIF");
version = stbi__get8(s);
if (version != '7' && version != '9') return stbi__err("not GIF", "Corrupt GIF");
if (stbi__get8(s) != 'a') return stbi__err("not GIF", "Corrupt GIF");
stbi__g_failure_reason = "";
g->w = stbi__get16le(s);
g->h = stbi__get16le(s);
g->flags = stbi__get8(s);
g->bgindex = stbi__get8(s);
g->ratio = stbi__get8(s);
g->transparent = -1;
if (g->w > STBI_MAX_DIMENSIONS) return stbi__err("too large", "Very large image (corrupt?)");
if (g->h > STBI_MAX_DIMENSIONS) return stbi__err("too large", "Very large image (corrupt?)");
if (comp != 0) *comp = 4; // can't actually tell whether it's 3 or 4 until we parse the comments
if (is_info) return 1;
if (g->flags & 0x80)
stbi__gif_parse_colortable(s, g->pal, 2 << (g->flags & 7), -1);
return 1;
}
static int stbi__gif_info_raw(stbi__context* s, int* x, int* y, int* comp)
{
stbi__gif* g = (stbi__gif*)stbi__malloc(sizeof(stbi__gif));
if (!stbi__gif_header(s, g, comp, 1)) {
STBI_FREE(g);
stbi__rewind(s);
return 0;
}
if (x) *x = g->w;
if (y) *y = g->h;
STBI_FREE(g);
return 1;
}
static void stbi__out_gif_code(stbi__gif* g, stbi__uint16 code)
{
stbi_uc* p, * c;
int idx;
// recurse to decode the prefixes, since the linked-list is backwards,
// and working backwards through an interleaved image would be nasty
if (g->codes[code].prefix >= 0)
stbi__out_gif_code(g, g->codes[code].prefix);
if (g->cur_y >= g->max_y) return;
idx = g->cur_x + g->cur_y;
p = &g->out[idx];
g->history[idx / 4] = 1;
c = &g->color_table[g->codes[code].suffix * 4];
if (c[3] > 128) { // don't render transparent pixels;
p[0] = c[2];
p[1] = c[1];
p[2] = c[0];
p[3] = c[3];
}
g->cur_x += 4;
if (g->cur_x >= g->max_x) {
g->cur_x = g->start_x;
g->cur_y += g->step;
while (g->cur_y >= g->max_y && g->parse > 0) {
g->step = (1 << g->parse) * g->line_size;
g->cur_y = g->start_y + (g->step >> 1);
--g->parse;
}
}
}
static stbi_uc* stbi__process_gif_raster(stbi__context* s, stbi__gif* g)
{
stbi_uc lzw_cs;
stbi__int32 len, init_code;
stbi__uint32 first;
stbi__int32 codesize, codemask, avail, oldcode, bits, valid_bits, clear;
stbi__gif_lzw* p;
lzw_cs = stbi__get8(s);
if (lzw_cs > 12) return NULL;
clear = 1 << lzw_cs;
first = 1;
codesize = lzw_cs + 1;
codemask = (1 << codesize) - 1;
bits = 0;
valid_bits = 0;
for (init_code = 0; init_code < clear; init_code++) {
g->codes[init_code].prefix = -1;
g->codes[init_code].first = (stbi_uc)init_code;
g->codes[init_code].suffix = (stbi_uc)init_code;
}
// support no starting clear code
avail = clear + 2;
oldcode = -1;
len = 0;
for (;;) {
if (valid_bits < codesize) {
if (len == 0) {
len = stbi__get8(s); // start new block
if (len == 0)
return g->out;
}
--len;
bits |= (stbi__int32)stbi__get8(s) << valid_bits;
valid_bits += 8;
}
else {
stbi__int32 code = bits & codemask;
bits >>= codesize;
valid_bits -= codesize;
// @OPTIMIZE: is there some way we can accelerate the non-clear path?
if (code == clear) { // clear code
codesize = lzw_cs + 1;
codemask = (1 << codesize) - 1;
avail = clear + 2;
oldcode = -1;
first = 0;
}
else if (code == clear + 1) { // end of stream code
stbi__skip(s, len);
while ((len = stbi__get8(s)) > 0)
stbi__skip(s, len);
return g->out;
}
else if (code <= avail) {
if (first) {
return stbi__errpuc("no clear code", "Corrupt GIF");
}
if (oldcode >= 0) {
p = &g->codes[avail++];
if (avail > 8192) {
return stbi__errpuc("too many codes", "Corrupt GIF");
}
p->prefix = (stbi__int16)oldcode;
p->first = g->codes[oldcode].first;
p->suffix = (code == avail) ? p->first : g->codes[code].first;
}
else if (code == avail)
return stbi__errpuc("illegal code in raster", "Corrupt GIF");
stbi__out_gif_code(g, (stbi__uint16)code);
if ((avail & codemask) == 0 && avail <= 0x0FFF) {
codesize++;
codemask = (1 << codesize) - 1;
}
oldcode = code;
}
else {
return stbi__errpuc("illegal code in raster", "Corrupt GIF");
}
}
}
}
// this function is designed to support animated gifs, although stb_image doesn't support it
// two back is the image from two frames ago, used for a very specific disposal format
static stbi_uc* stbi__gif_load_next(stbi__context* s, stbi__gif* g, int* comp, int req_comp, stbi_uc* two_back)
{
int dispose;
int first_frame;
int pi;
int pcount;
STBI_NOTUSED(req_comp);
// on first frame, any non-written pixels get the background colour (non-transparent)
first_frame = 0;
if (g->out == 0) {
if (!stbi__gif_header(s, g, comp, 0)) return 0; // stbi__g_failure_reason set by stbi__gif_header
if (!stbi__mad3sizes_valid(4, g->w, g->h, 0))
return stbi__errpuc("too large", "GIF image is too large");
pcount = g->w * g->h;
g->out = (stbi_uc*)stbi__malloc(4 * pcount);
g->background = (stbi_uc*)stbi__malloc(4 * pcount);
g->history = (stbi_uc*)stbi__malloc(pcount);
if (!g->out || !g->background || !g->history)
return stbi__errpuc("outofmem", "Out of memory");
// image is treated as "transparent" at the start - ie, nothing overwrites the current background;
// background colour is only used for pixels that are not rendered first frame, after that "background"
// color refers to the color that was there the previous frame.
memset(g->out, 0x00, 4 * pcount);
memset(g->background, 0x00, 4 * pcount); // state of the background (starts transparent)
memset(g->history, 0x00, pcount); // pixels that were affected previous frame
first_frame = 1;
}
else {
// second frame - how do we dispose of the previous one?
dispose = (g->eflags & 0x1C) >> 2;
pcount = g->w * g->h;
if ((dispose == 3) && (two_back == 0)) {
dispose = 2; // if I don't have an image to revert back to, default to the old background
}
if (dispose == 3) { // use previous graphic
for (pi = 0; pi < pcount; ++pi) {
if (g->history[pi]) {
memcpy(&g->out[pi * 4], &two_back[pi * 4], 4);
}
}
}
else if (dispose == 2) {
// restore what was changed last frame to background before that frame;
for (pi = 0; pi < pcount; ++pi) {
if (g->history[pi]) {
memcpy(&g->out[pi * 4], &g->background[pi * 4], 4);
}
}
}
else {
// This is a non-disposal case eithe way, so just
// leave the pixels as is, and they will become the new background
// 1: do not dispose
// 0: not specified.
}
// background is what out is after the undoing of the previou frame;
memcpy(g->background, g->out, 4 * g->w * g->h);
}
// clear my history;
memset(g->history, 0x00, g->w * g->h); // pixels that were affected previous frame
for (;;) {
int tag = stbi__get8(s);
switch (tag) {
case 0x2C: /* Image Descriptor */
{
stbi__int32 x, y, w, h;
stbi_uc* o;
x = stbi__get16le(s);
y = stbi__get16le(s);
w = stbi__get16le(s);
h = stbi__get16le(s);
if (((x + w) > (g->w)) || ((y + h) > (g->h)))
return stbi__errpuc("bad Image Descriptor", "Corrupt GIF");
g->line_size = g->w * 4;
g->start_x = x * 4;
g->start_y = y * g->line_size;
g->max_x = g->start_x + w * 4;
g->max_y = g->start_y + h * g->line_size;
g->cur_x = g->start_x;
g->cur_y = g->start_y;
// if the width of the specified rectangle is 0, that means
// we may not see *any* pixels or the image is malformed;
// to make sure this is caught, move the current y down to
// max_y (which is what out_gif_code checks).
if (w == 0)
g->cur_y = g->max_y;
g->lflags = stbi__get8(s);
if (g->lflags & 0x40) {
g->step = 8 * g->line_size; // first interlaced spacing
g->parse = 3;
}
else {
g->step = g->line_size;
g->parse = 0;
}
if (g->lflags & 0x80) {
stbi__gif_parse_colortable(s, g->lpal, 2 << (g->lflags & 7), g->eflags & 0x01 ? g->transparent : -1);
g->color_table = (stbi_uc*)g->lpal;
}
else if (g->flags & 0x80) {
g->color_table = (stbi_uc*)g->pal;
}
else
return stbi__errpuc("missing color table", "Corrupt GIF");
o = stbi__process_gif_raster(s, g);
if (!o) return NULL;
// if this was the first frame,
pcount = g->w * g->h;
if (first_frame && (g->bgindex > 0)) {
// if first frame, any pixel not drawn to gets the background color
for (pi = 0; pi < pcount; ++pi) {
if (g->history[pi] == 0) {
g->pal[g->bgindex][3] = 255; // just in case it was made transparent, undo that; It will be reset next frame if need be;
memcpy(&g->out[pi * 4], &g->pal[g->bgindex], 4);
}
}
}
return o;
}
case 0x21: // Comment Extension.
{
int len;
int ext = stbi__get8(s);
if (ext == 0xF9) { // Graphic Control Extension.
len = stbi__get8(s);
if (len == 4) {
g->eflags = stbi__get8(s);
g->delay = 10 * stbi__get16le(s); // delay - 1/100th of a second, saving as 1/1000ths.
// unset old transparent
if (g->transparent >= 0) {
g->pal[g->transparent][3] = 255;
}
if (g->eflags & 0x01) {
g->transparent = stbi__get8(s);
if (g->transparent >= 0) {
g->pal[g->transparent][3] = 0;
}
}
else {
// don't need transparent
stbi__skip(s, 1);
g->transparent = -1;
}
}
else {
stbi__skip(s, len);
break;
}
}
while ((len = stbi__get8(s)) != 0) {
stbi__skip(s, len);
}
break;
}
case 0x3B: // gif stream termination code
return (stbi_uc*)s; // using '1' causes warning on some compilers
default:
return stbi__errpuc("unknown code", "Corrupt GIF");
}
}
}
static void* stbi__load_gif_main(stbi__context* s, int** delays, int* x, int* y, int* z, int* comp, int req_comp)
{
if (stbi__gif_test(s)) {
int layers = 0;
stbi_uc* u = 0;
stbi_uc* out = 0;
stbi_uc* two_back = 0;
stbi__gif g;
int stride;
int out_size = 0;
int delays_size = 0;
memset(&g, 0, sizeof(g));
if (delays) {
*delays = 0;
}
do {
u = stbi__gif_load_next(s, &g, comp, req_comp, two_back);
if (u == (stbi_uc*)s) u = 0; // end of animated gif marker
if (u) {
*x = g.w;
*y = g.h;
++layers;
stride = g.w * g.h * 4;
if (out) {
void* tmp = (stbi_uc*)STBI_REALLOC_SIZED(out, out_size, layers * stride);
if (NULL == tmp) {
STBI_FREE(g.out);
STBI_FREE(g.history);
STBI_FREE(g.background);
return stbi__errpuc("outofmem", "Out of memory");
}
else {
out = (stbi_uc*)tmp;
out_size = layers * stride;
}
if (delays) {
*delays = (int*)STBI_REALLOC_SIZED(*delays, delays_size, sizeof(int) * layers);
delays_size = layers * sizeof(int);
}
}
else {
out = (stbi_uc*)stbi__malloc(layers * stride);
out_size = layers * stride;
if (delays) {
*delays = (int*)stbi__malloc(layers * sizeof(int));
delays_size = layers * sizeof(int);
}
}
memcpy(out + ((layers - 1) * stride), u, stride);
if (layers >= 2) {
two_back = out - 2 * stride;
}
if (delays) {
(*delays)[layers - 1U] = g.delay;
}
}
} while (u != 0);
// free temp buffer;
STBI_FREE(g.out);
STBI_FREE(g.history);
STBI_FREE(g.background);
// do the final conversion after loading everything;
if (req_comp && req_comp != 4)
out = stbi__convert_format(out, 4, req_comp, layers * g.w, g.h);
*z = layers;
return out;
}
else {
return stbi__errpuc("not GIF", "Image was not as a gif type.");
}
}
static void* stbi__gif_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
stbi_uc* u = 0;
stbi__gif g;
memset(&g, 0, sizeof(g));
STBI_NOTUSED(ri);
u = stbi__gif_load_next(s, &g, comp, req_comp, 0);
if (u == (stbi_uc*)s) u = 0; // end of animated gif marker
if (u) {
*x = g.w;
*y = g.h;
// moved conversion to after successful load so that the same
// can be done for multiple frames.
if (req_comp && req_comp != 4)
u = stbi__convert_format(u, 4, req_comp, g.w, g.h);
}
else if (g.out) {
// if there was an error and we allocated an image buffer, free it!
STBI_FREE(g.out);
}
// free buffers needed for multiple frame loading;
STBI_FREE(g.history);
STBI_FREE(g.background);
return u;
}
static int stbi__gif_info(stbi__context* s, int* x, int* y, int* comp)
{
return stbi__gif_info_raw(s, x, y, comp);
}
#endif
// *************************************************************************************************
// Radiance RGBE HDR loader
// originally by Nicolas Schulz
#ifndef STBI_NO_HDR
static int stbi__hdr_test_core(stbi__context* s, const char* signature)
{
int i;
for (i = 0; signature[i]; ++i)
if (stbi__get8(s) != signature[i])
return 0;
stbi__rewind(s);
return 1;
}
static int stbi__hdr_test(stbi__context* s)
{
int r = stbi__hdr_test_core(s, "#?RADIANCE\n");
stbi__rewind(s);
if (!r) {
r = stbi__hdr_test_core(s, "#?RGBE\n");
stbi__rewind(s);
}
return r;
}
#define STBI__HDR_BUFLEN 1024
static char* stbi__hdr_gettoken(stbi__context* z, char* buffer)
{
int len = 0;
char c = '\0';
c = (char)stbi__get8(z);
while (!stbi__at_eof(z) && c != '\n') {
buffer[len++] = c;
if (len == STBI__HDR_BUFLEN - 1) {
// flush to end of line
while (!stbi__at_eof(z) && stbi__get8(z) != '\n')
;
break;
}
c = (char)stbi__get8(z);
}
buffer[len] = 0;
return buffer;
}
static void stbi__hdr_convert(float* output, stbi_uc* input, int req_comp)
{
if (input[3] != 0) {
float f1;
// Exponent
f1 = (float)ldexp(1.0f, input[3] - (int)(128 + 8));
if (req_comp <= 2)
output[0] = (input[0] + input[1] + input[2]) * f1 / 3;
else {
output[0] = input[0] * f1;
output[1] = input[1] * f1;
output[2] = input[2] * f1;
}
if (req_comp == 2) output[1] = 1;
if (req_comp == 4) output[3] = 1;
}
else {
switch (req_comp) {
case 4: output[3] = 1; /* fallthrough */
case 3: output[0] = output[1] = output[2] = 0;
break;
case 2: output[1] = 1; /* fallthrough */
case 1: output[0] = 0;
break;
}
}
}
static float* stbi__hdr_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
char buffer[STBI__HDR_BUFLEN];
char* token;
int valid = 0;
int width, height;
stbi_uc* scanline;
float* hdr_data;
int len;
unsigned char count, value;
int i, j, k, c1, c2, z;
const char* headerToken;
STBI_NOTUSED(ri);
// Check identifier
headerToken = stbi__hdr_gettoken(s, buffer);
if (strcmp(headerToken, "#?RADIANCE") != 0 && strcmp(headerToken, "#?RGBE") != 0)
return stbi__errpf("not HDR", "Corrupt HDR image");
// Parse header
for (;;) {
token = stbi__hdr_gettoken(s, buffer);
if (token[0] == 0) break;
if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
}
if (!valid) return stbi__errpf("unsupported format", "Unsupported HDR format");
// Parse width and height
// can't use sscanf() if we're not using stdio!
token = stbi__hdr_gettoken(s, buffer);
if (strncmp(token, "-Y ", 3)) return stbi__errpf("unsupported data layout", "Unsupported HDR format");
token += 3;
height = (int)strtol(token, &token, 10);
while (*token == ' ') ++token;
if (strncmp(token, "+X ", 3)) return stbi__errpf("unsupported data layout", "Unsupported HDR format");
token += 3;
width = (int)strtol(token, NULL, 10);
if (height > STBI_MAX_DIMENSIONS) return stbi__errpf("too large", "Very large image (corrupt?)");
if (width > STBI_MAX_DIMENSIONS) return stbi__errpf("too large", "Very large image (corrupt?)");
*x = width;
*y = height;
if (comp) *comp = 3;
if (req_comp == 0) req_comp = 3;
if (!stbi__mad4sizes_valid(width, height, req_comp, sizeof(float), 0))
return stbi__errpf("too large", "HDR image is too large");
// Read data
hdr_data = (float*)stbi__malloc_mad4(width, height, req_comp, sizeof(float), 0);
if (!hdr_data)
return stbi__errpf("outofmem", "Out of memory");
// Load image data
// image data is stored as some number of sca
if (width < 8 || width >= 32768) {
// Read flat data
for (j = 0; j < height; ++j) {
for (i = 0; i < width; ++i) {
stbi_uc rgbe[4];
main_decode_loop:
stbi__getn(s, rgbe, 4);
stbi__hdr_convert(hdr_data + j * width * req_comp + i * req_comp, rgbe, req_comp);
}
}
}
else {
// Read RLE-encoded data
scanline = NULL;
for (j = 0; j < height; ++j) {
c1 = stbi__get8(s);
c2 = stbi__get8(s);
len = stbi__get8(s);
if (c1 != 2 || c2 != 2 || (len & 0x80)) {
// not run-length encoded, so we have to actually use THIS data as a decoded
// pixel (note this can't be a valid pixel--one of RGB must be >= 128)
stbi_uc rgbe[4];
rgbe[0] = (stbi_uc)c1;
rgbe[1] = (stbi_uc)c2;
rgbe[2] = (stbi_uc)len;
rgbe[3] = (stbi_uc)stbi__get8(s);
stbi__hdr_convert(hdr_data, rgbe, req_comp);
i = 1;
j = 0;
STBI_FREE(scanline);
goto main_decode_loop; // yes, this makes no sense
}
len <<= 8;
len |= stbi__get8(s);
if (len != width) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("invalid decoded scanline length", "corrupt HDR"); }
if (scanline == NULL) {
scanline = (stbi_uc*)stbi__malloc_mad2(width, 4, 0);
if (!scanline) {
STBI_FREE(hdr_data);
return stbi__errpf("outofmem", "Out of memory");
}
}
for (k = 0; k < 4; ++k) {
int nleft;
i = 0;
while ((nleft = width - i) > 0) {
count = stbi__get8(s);
if (count > 128) {
// Run
value = stbi__get8(s);
count -= 128;
if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
for (z = 0; z < count; ++z)
scanline[i++ * 4 + k] = value;
}
else {
// Dump
if (count > nleft) { STBI_FREE(hdr_data); STBI_FREE(scanline); return stbi__errpf("corrupt", "bad RLE data in HDR"); }
for (z = 0; z < count; ++z)
scanline[i++ * 4 + k] = stbi__get8(s);
}
}
}
for (i = 0; i < width; ++i)
stbi__hdr_convert(hdr_data + (j * width + i) * req_comp, scanline + i * 4, req_comp);
}
if (scanline)
STBI_FREE(scanline);
}
return hdr_data;
}
static int stbi__hdr_info(stbi__context* s, int* x, int* y, int* comp)
{
char buffer[STBI__HDR_BUFLEN];
char* token;
int valid = 0;
int dummy;
if (!x) x = &dummy;
if (!y) y = &dummy;
if (!comp) comp = &dummy;
if (stbi__hdr_test(s) == 0) {
stbi__rewind(s);
return 0;
}
for (;;) {
token = stbi__hdr_gettoken(s, buffer);
if (token[0] == 0) break;
if (strcmp(token, "FORMAT=32-bit_rle_rgbe") == 0) valid = 1;
}
if (!valid) {
stbi__rewind(s);
return 0;
}
token = stbi__hdr_gettoken(s, buffer);
if (strncmp(token, "-Y ", 3)) {
stbi__rewind(s);
return 0;
}
token += 3;
*y = (int)strtol(token, &token, 10);
while (*token == ' ') ++token;
if (strncmp(token, "+X ", 3)) {
stbi__rewind(s);
return 0;
}
token += 3;
*x = (int)strtol(token, NULL, 10);
*comp = 3;
return 1;
}
#endif // STBI_NO_HDR
#ifndef STBI_NO_BMP
static int stbi__bmp_info(stbi__context* s, int* x, int* y, int* comp)
{
void* p;
stbi__bmp_data info;
info.all_a = 255;
p = stbi__bmp_parse_header(s, &info);
stbi__rewind(s);
if (p == NULL)
return 0;
if (x) *x = s->img_x;
if (y) *y = s->img_y;
if (comp) {
if (info.bpp == 24 && info.ma == 0xff000000)
*comp = 3;
else
*comp = info.ma ? 4 : 3;
}
return 1;
}
#endif
#ifndef STBI_NO_PSD
static int stbi__psd_info(stbi__context* s, int* x, int* y, int* comp)
{
int channelCount, dummy, depth;
if (!x) x = &dummy;
if (!y) y = &dummy;
if (!comp) comp = &dummy;
if (stbi__get32be(s) != 0x38425053) {
stbi__rewind(s);
return 0;
}
if (stbi__get16be(s) != 1) {
stbi__rewind(s);
return 0;
}
stbi__skip(s, 6);
channelCount = stbi__get16be(s);
if (channelCount < 0 || channelCount > 16) {
stbi__rewind(s);
return 0;
}
*y = stbi__get32be(s);
*x = stbi__get32be(s);
depth = stbi__get16be(s);
if (depth != 8 && depth != 16) {
stbi__rewind(s);
return 0;
}
if (stbi__get16be(s) != 3) {
stbi__rewind(s);
return 0;
}
*comp = 4;
return 1;
}
static int stbi__psd_is16(stbi__context* s)
{
int channelCount, depth;
if (stbi__get32be(s) != 0x38425053) {
stbi__rewind(s);
return 0;
}
if (stbi__get16be(s) != 1) {
stbi__rewind(s);
return 0;
}
stbi__skip(s, 6);
channelCount = stbi__get16be(s);
if (channelCount < 0 || channelCount > 16) {
stbi__rewind(s);
return 0;
}
(void)stbi__get32be(s);
(void)stbi__get32be(s);
depth = stbi__get16be(s);
if (depth != 16) {
stbi__rewind(s);
return 0;
}
return 1;
}
#endif
#ifndef STBI_NO_PIC
static int stbi__pic_info(stbi__context* s, int* x, int* y, int* comp)
{
int act_comp = 0, num_packets = 0, chained, dummy;
stbi__pic_packet packets[10];
if (!x) x = &dummy;
if (!y) y = &dummy;
if (!comp) comp = &dummy;
if (!stbi__pic_is4(s, "\x53\x80\xF6\x34")) {
stbi__rewind(s);
return 0;
}
stbi__skip(s, 88);
*x = stbi__get16be(s);
*y = stbi__get16be(s);
if (stbi__at_eof(s)) {
stbi__rewind(s);
return 0;
}
if ((*x) != 0 && (1 << 28) / (*x) < (*y)) {
stbi__rewind(s);
return 0;
}
stbi__skip(s, 8);
do {
stbi__pic_packet* packet;
if (num_packets == sizeof(packets) / sizeof(packets[0]))
return 0;
packet = &packets[num_packets++];
chained = stbi__get8(s);
packet->size = stbi__get8(s);
packet->type = stbi__get8(s);
packet->channel = stbi__get8(s);
act_comp |= packet->channel;
if (stbi__at_eof(s)) {
stbi__rewind(s);
return 0;
}
if (packet->size != 8) {
stbi__rewind(s);
return 0;
}
} while (chained);
*comp = (act_comp & 0x10 ? 4 : 3);
return 1;
}
#endif
// *************************************************************************************************
// Portable Gray Map and Portable Pixel Map loader
// by Ken Miller
//
// PGM: http://netpbm.sourceforge.net/doc/pgm.html
// PPM: http://netpbm.sourceforge.net/doc/ppm.html
//
// Known limitations:
// Does not support comments in the header section
// Does not support ASCII image data (formats P2 and P3)
// Does not support 16-bit-per-channel
#ifndef STBI_NO_PNM
static int stbi__pnm_test(stbi__context* s)
{
char p, t;
p = (char)stbi__get8(s);
t = (char)stbi__get8(s);
if (p != 'P' || (t != '5' && t != '6')) {
stbi__rewind(s);
return 0;
}
return 1;
}
static void* stbi__pnm_load(stbi__context* s, int* x, int* y, int* comp, int req_comp, stbi__result_info* ri)
{
stbi_uc* out;
STBI_NOTUSED(ri);
if (!stbi__pnm_info(s, (int*)&s->img_x, (int*)&s->img_y, (int*)&s->img_n))
return 0;
if (s->img_y > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
if (s->img_x > STBI_MAX_DIMENSIONS) return stbi__errpuc("too large", "Very large image (corrupt?)");
*x = s->img_x;
*y = s->img_y;
if (comp) *comp = s->img_n;
if (!stbi__mad3sizes_valid(s->img_n, s->img_x, s->img_y, 0))
return stbi__errpuc("too large", "PNM too large");
out = (stbi_uc*)stbi__malloc_mad3(s->img_n, s->img_x, s->img_y, 0);
if (!out) return stbi__errpuc("outofmem", "Out of memory");
stbi__getn(s, out, s->img_n * s->img_x * s->img_y);
if (req_comp && req_comp != s->img_n) {
out = stbi__convert_format(out, s->img_n, req_comp, s->img_x, s->img_y);
if (out == NULL) return out; // stbi__convert_format frees input on failure
}
return out;
}
static int stbi__pnm_isspace(char c)
{
return c == ' ' || c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r';
}
static void stbi__pnm_skip_whitespace(stbi__context* s, char* c)
{
for (;;) {
while (!stbi__at_eof(s) && stbi__pnm_isspace(*c))
*c = (char)stbi__get8(s);
if (stbi__at_eof(s) || *c != '#')
break;
while (!stbi__at_eof(s) && *c != '\n' && *c != '\r')
*c = (char)stbi__get8(s);
}
}
static int stbi__pnm_isdigit(char c)
{
return c >= '0' && c <= '9';
}
static int stbi__pnm_getinteger(stbi__context* s, char* c)
{
int value = 0;
while (!stbi__at_eof(s) && stbi__pnm_isdigit(*c)) {
value = value * 10 + (*c - '0');
*c = (char)stbi__get8(s);
}
return value;
}
static int stbi__pnm_info(stbi__context* s, int* x, int* y, int* comp)
{
int maxv, dummy;
char c, p, t;
if (!x) x = &dummy;
if (!y) y = &dummy;
if (!comp) comp = &dummy;
stbi__rewind(s);
// Get identifier
p = (char)stbi__get8(s);
t = (char)stbi__get8(s);
if (p != 'P' || (t != '5' && t != '6')) {
stbi__rewind(s);
return 0;
}
*comp = (t == '6') ? 3 : 1; // '5' is 1-component .pgm; '6' is 3-component .ppm
c = (char)stbi__get8(s);
stbi__pnm_skip_whitespace(s, &c);
*x = stbi__pnm_getinteger(s, &c); // read width
stbi__pnm_skip_whitespace(s, &c);
*y = stbi__pnm_getinteger(s, &c); // read height
stbi__pnm_skip_whitespace(s, &c);
maxv = stbi__pnm_getinteger(s, &c); // read max value
if (maxv > 255)
return stbi__err("max value > 255", "PPM image not 8-bit");
else
return 1;
}
#endif
static int stbi__info_main(stbi__context* s, int* x, int* y, int* comp)
{
#ifndef STBI_NO_JPEG
if (stbi__jpeg_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_PNG
if (stbi__png_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_GIF
if (stbi__gif_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_BMP
if (stbi__bmp_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_PSD
if (stbi__psd_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_PIC
if (stbi__pic_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_PNM
if (stbi__pnm_info(s, x, y, comp)) return 1;
#endif
#ifndef STBI_NO_HDR
if (stbi__hdr_info(s, x, y, comp)) return 1;
#endif
// test tga last because it's a crappy test!
#ifndef STBI_NO_TGA
if (stbi__tga_info(s, x, y, comp))
return 1;
#endif
return stbi__err("unknown image type", "Image not of any known type, or corrupt");
}
static int stbi__is_16_main(stbi__context* s)
{
#ifndef STBI_NO_PNG
if (stbi__png_is16(s)) return 1;
#endif
#ifndef STBI_NO_PSD
if (stbi__psd_is16(s)) return 1;
#endif
return 0;
}
#ifndef STBI_NO_STDIO
STBIDEF int stbi_info(char const* filename, int* x, int* y, int* comp)
{
FILE* f = stbi__fopen(filename, "rb");
int result;
if (!f) return stbi__err("can't fopen", "Unable to open file");
result = stbi_info_from_file(f, x, y, comp);
fclose(f);
return result;
}
STBIDEF int stbi_info_from_file(FILE* f, int* x, int* y, int* comp)
{
int r;
stbi__context s;
long pos = ftell(f);
stbi__start_file(&s, f);
r = stbi__info_main(&s, x, y, comp);
fseek(f, pos, SEEK_SET);
return r;
}
STBIDEF int stbi_is_16_bit(char const* filename)
{
FILE* f = stbi__fopen(filename, "rb");
int result;
if (!f) return stbi__err("can't fopen", "Unable to open file");
result = stbi_is_16_bit_from_file(f);
fclose(f);
return result;
}
STBIDEF int stbi_is_16_bit_from_file(FILE* f)
{
int r;
stbi__context s;
long pos = ftell(f);
stbi__start_file(&s, f);
r = stbi__is_16_main(&s);
fseek(f, pos, SEEK_SET);
return r;
}
#endif // !STBI_NO_STDIO
STBIDEF int stbi_info_from_memory(stbi_uc const* buffer, int len, int* x, int* y, int* comp)
{
stbi__context s;
stbi__start_mem(&s, buffer, len);
return stbi__info_main(&s, x, y, comp);
}
STBIDEF int stbi_info_from_callbacks(stbi_io_callbacks const* c, void* user, int* x, int* y, int* comp)
{
stbi__context s;
stbi__start_callbacks(&s, (stbi_io_callbacks*)c, user);
return stbi__info_main(&s, x, y, comp);
}
STBIDEF int stbi_is_16_bit_from_memory(stbi_uc const* buffer, int len)
{
stbi__context s;
stbi__start_mem(&s, buffer, len);
return stbi__is_16_main(&s);
}
STBIDEF int stbi_is_16_bit_from_callbacks(stbi_io_callbacks const* c, void* user)
{
stbi__context s;
stbi__start_callbacks(&s, (stbi_io_callbacks*)c, user);
return stbi__is_16_main(&s);
}
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