#include "ltpch.h"
#include "dxShader.h"
#include "dxSharedContext.h"

#include <d3dcompiler.h>

namespace Light {

	dxShader::dxShader(BasicFileHandle vertexFile, BasicFileHandle pixelFile, Ref<dxSharedContext> sharedContext)
		: m_Context(sharedContext),
		  m_VertexShader(nullptr),
		  m_PixelShader(nullptr),
		  m_VertexBlob(nullptr)
	{
		Microsoft::WRL::ComPtr<ID3DBlob> ps = nullptr, vsErr = nullptr, psErr = nullptr;

		// compile shaders (we don't use DXC here because if D3DCompile fails it throws a dxException without logging the vsErr/psErr
		D3DCompile(vertexFile.GetData(), vertexFile.GetSize(), NULL, nullptr, nullptr, "main", "vs_4_0", NULL, NULL, &m_VertexBlob, &vsErr);
		D3DCompile(pixelFile.GetData(), pixelFile.GetSize(), NULL, nullptr, nullptr, "main", "ps_4_0", NULL, NULL, &ps, &psErr);

		// check
		LT_ENGINE_ASSERT(!vsErr.Get(), "dxShader::dxShader: vertex shader compile error: {}", (char*)vsErr->GetBufferPointer());
		LT_ENGINE_ASSERT(!psErr.Get(), "dxShader::dxShader: pixels shader compile error: {}", (char*)psErr->GetBufferPointer());

		// create shaders
		HRESULT hr;
		DXC(m_Context->GetDevice()->CreateVertexShader(m_VertexBlob->GetBufferPointer(), m_VertexBlob->GetBufferSize(), NULL, &m_VertexShader));
		DXC(m_Context->GetDevice()->CreatePixelShader(ps->GetBufferPointer(), ps->GetBufferSize(), NULL, &m_PixelShader));
	}

	dxShader::~dxShader()
	{
		UnBind();
	}

	void dxShader::Bind()
	{
		m_Context->GetDeviceContext()->VSSetShader(m_VertexShader.Get(), nullptr, 0u);
		m_Context->GetDeviceContext()->PSSetShader(m_PixelShader.Get(), nullptr, 0u);
	}

	void dxShader::UnBind()
	{
		m_Context->GetDeviceContext()->VSSetShader(nullptr, nullptr, 0u);
		m_Context->GetDeviceContext()->PSSetShader(nullptr, nullptr, 0u);
	}

}