Framebuffer resizing

- Added 'Camera::OnResize()' for keeping the aspect ratio updated to
      prevent streching/squashing the scene

- Added 'FrameBuffe::Resize()'

- Enabled ImGui docking and viewport

- 'MirrorLayer::m_Camera' & 'MirrorLayer::m_Framebuffer' now adjust their properties
      when ImGui's available region changes

Engine/src/Engine/Camera/Camera.cpp

@@ -25,6 +25,12 @@ namespace Light {
 		                           FLT_MAX, FLT_MIN);
 	}
 
+	void Camera::OnResize(const glm::vec2& size)
+	{
+		m_AspectRatio = size.x / size.y;
+		CalculateProjection();
+	}
+
 	void Camera::Move(const glm::vec2& position)
 	{
 		m_Position += position;

Engine/src/Engine/Camera/Camera.h

@@ -25,6 +25,8 @@ namespace Light {
 		void CalculateView();
 		void CalculateProjection();
 
+		void OnResize(const glm::vec2& size);
+
 		inline const glm::mat4& GetView() const { return m_View; }
 		inline const glm::mat4& GetProjection() const { return m_Projection; }
 

Engine/src/Engine/Graphics/Framebuffer.h

@@ -28,6 +28,8 @@ namespace Light {
 		virtual void BindAsTarget() = 0;
 		virtual void BindAsResource() = 0;
 
+		virtual void Resize(const glm::vec2& size) = 0;
+
 	protected:
 		Framebuffer() = default;
 	};

Engine/src/Platform/GraphicsAPI/DirectX/dxFramebuffer.cpp

@@ -54,4 +54,20 @@ namespace Light {
 		LT_ENGINE_ERROR("dxFramebuffer::BindAsResource: NO_IMPLEMENT");
 	}
 
+	void dxFramebuffer::Resize(const glm::vec2& size)
+	{
+		D3D11_TEXTURE2D_DESC textureDesc;
+		D3D11_RENDER_TARGET_VIEW_DESC rtvDesc;
+		D3D11_SHADER_RESOURCE_VIEW_DESC srvDesc;
+
+		m_ColorAttachment->GetDesc(&textureDesc);
+		m_RenderTargetView->GetDesc(&rtvDesc);
+		m_ResourceView->GetDesc(&srvDesc);
+
+		HRESULT hr;
+		DXC(m_Context->GetDevice()->CreateTexture2D(&textureDesc, nullptr, &m_ColorAttachment));
+		DXC(m_Context->GetDevice()->CreateRenderTargetView(m_ColorAttachment.Get(), &rtvDesc, &m_RenderTargetView));
+		DXC(m_Context->GetDevice()->CreateShaderResourceView(m_ColorAttachment.Get(), &srvDesc, &m_ResourceView));
+	}
+
 }	

Engine/src/Platform/GraphicsAPI/DirectX/dxFramebuffer.h

@@ -31,6 +31,7 @@ namespace Light {
 		void BindAsTarget() override;
 		void BindAsResource() override;
 
+		void Resize(const glm::vec2& size) override;
 	};
 
 }

Engine/src/Platform/GraphicsAPI/DirectX/dxUserInterface.cpp

@@ -22,6 +22,12 @@ namespace Light {
 		ImGuiIO& io = ImGui::GetIO();
 		io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
 
+		io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+		io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;
+
+		io.ConfigFlags |= ImGuiBackendFlags_PlatformHasViewports;
+		io.ConfigFlags |= ImGuiBackendFlags_RendererHasViewports;
+
 		// style
 		ImGui::StyleColorsDark();
 
@@ -51,6 +57,9 @@ namespace Light {
 	{
 		ImGui::Render();
 		ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
+
+		ImGui::UpdatePlatformWindows();
+		ImGui::RenderPlatformWindowsDefault();
 	}
 
 	void dxUserInterface::LogDebugData()

Engine/src/Platform/GraphicsAPI/OpenGL/glFramebuffer.cpp

@@ -1,13 +1,48 @@
 #include "ltpch.h"
 #include "glFramebuffer.h"
 
+#include <glm/glm.hpp>
+
 #include <glad/glad.h>
 
 namespace Light {
 
 	glFramebuffer::glFramebuffer(const FramebufferSpecification& specification)
-		: m_Specification(specification)
+		: m_Specification(specification), m_BufferID(0u), m_ColorAttachment(0u), m_DepthStencilAttachment(0u)
 	{
+		Resize({ specification.width, specification.height });
+	}
+
+	glFramebuffer::~glFramebuffer()
+	{
+		glDeleteFramebuffers(1, &m_BufferID);
+		glDeleteTextures(1, &m_ColorAttachment);
+		// glDeleteTextures(1, &m_DepthStencilAttachment);
+	}
+
+	void glFramebuffer::BindAsTarget()
+	{
+		glBindFramebuffer(GL_FRAMEBUFFER, m_BufferID);
+		glViewport(0, 0, m_Specification.width, m_Specification.height);
+
+		glClearColor(m_Specification.defaultColor.r, m_Specification.defaultColor.g, m_Specification.defaultColor.b, m_Specification.defaultColor.a);
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
+
+	void glFramebuffer::BindAsResource()
+	{
+		LT_ENGINE_ERROR("glFramebuffer::BindAsResource: NO_IMPLEMENT!");
+	}
+
+	void glFramebuffer::Resize(const glm::vec2& size)
+	{
+		if (m_BufferID)
+		{
+			glDeleteFramebuffers(1, &m_BufferID);
+			glDeleteTextures(1, &m_ColorAttachment);
+			// glDeleteTextures(1, &m_DepthStencilAttachment);
+		}
+
 		glCreateFramebuffers(1, &m_BufferID);
 		glBindFramebuffer(GL_FRAMEBUFFER, m_BufferID);
 
@@ -32,21 +67,4 @@ namespace Light {
 		glBindFramebuffer(GL_FRAMEBUFFER, 0);
 	}
 
-	glFramebuffer::~glFramebuffer()
-	{
-		glDeleteFramebuffers(1, &m_BufferID);
-	}
-
-	void glFramebuffer::BindAsTarget()
-	{
-		glBindFramebuffer(GL_FRAMEBUFFER, m_BufferID);
-		glClearColor(m_Specification.defaultColor.r, m_Specification.defaultColor.g, m_Specification.defaultColor.b, m_Specification.defaultColor.a);
-		glClear(GL_COLOR_BUFFER_BIT);
-	}
-
-	void glFramebuffer::BindAsResource()
-	{
-		LT_ENGINE_ERROR("glFramebuffer::BindAsResource: NO_IMPLEMENT!");
-	}
-
 }

Engine/src/Platform/GraphicsAPI/OpenGL/glFramebuffer.h

@@ -20,6 +20,8 @@ namespace Light {
 
 		void BindAsTarget() override;
 		void BindAsResource() override;
+
+		void Resize(const glm::vec2& size) override;
 	};
 
 }

Engine/src/Platform/GraphicsAPI/OpenGL/glUserInterface.cpp

@@ -5,9 +5,12 @@
 #include <imgui_impl_glfw.h>
 #include <imgui_impl_opengl3.h>
 
+#include <GLFW/glfw3.h>
+
 namespace Light {
 
 	glUserInterface::glUserInterface(GLFWwindow* windowHandle)
+		: m_WindowHandle(windowHandle)
 	{
 		// create context
 		IMGUI_CHECKVERSION();
@@ -16,6 +19,11 @@ namespace Light {
 		// configure  io
 		ImGuiIO& io = ImGui::GetIO();
 		io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
+		io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+		io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;
+
+		io.ConfigFlags |= ImGuiBackendFlags_PlatformHasViewports;
+		io.ConfigFlags |= ImGuiBackendFlags_RendererHasViewports;
 
 		// style color
 		ImGui::StyleColorsDark();
@@ -46,6 +54,10 @@ namespace Light {
 	{
 		ImGui::Render();
 		ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+		ImGui::UpdatePlatformWindows();
+		ImGui::RenderPlatformWindowsDefault();
+		glfwMakeContextCurrent(m_WindowHandle);
 	}
 
 	void glUserInterface::LogDebugData()

Engine/src/Platform/GraphicsAPI/OpenGL/glUserInterface.h

@@ -3,10 +3,15 @@
 #include "Base.h"
 #include "UserInterface/UserInterface.h"
 
+class GLFWwindow;
+
 namespace Light {
 
 	class glUserInterface : public UserInterface
 	{
+	private:
+		GLFWwindow* m_WindowHandle;
+
 	public:
 		glUserInterface(GLFWwindow* windowHandle);
 		~glUserInterface();

Mirror/src/MirrorLayer.h

@@ -53,10 +53,20 @@ public:
 	{
 		ImGui::Begin("GameView");
 
+		static ImVec2 regionAvailPrev = {0, 0};
+		ImVec2 regionAvail = ImGui::GetContentRegionAvail();
+
+		if (regionAvail.x != regionAvailPrev.x || regionAvail.y != regionAvailPrev.y)
+		{
+			m_Framebuffer->Resize({ regionAvail.x, regionAvail.y });
+			m_Camera->OnResize({ regionAvail.x, regionAvail.y });
+			regionAvailPrev = regionAvail;
+		}
+
 		if(Light::GraphicsContext::GetGraphicsAPI() == Light::GraphicsAPI::DirectX)
-			ImGui::Image(m_Framebuffer->GetColorAttachment(), ImVec2(400, 300));
+			ImGui::Image(m_Framebuffer->GetColorAttachment(), regionAvail);
 		else
-			ImGui::Image(m_Framebuffer->GetColorAttachment(), ImVec2(400, 300), ImVec2(0, 1), ImVec2(1, 0));
+			ImGui::Image(m_Framebuffer->GetColorAttachment(), regionAvail, ImVec2(0, 1), ImVec2(1, 0));
 
 		ImGui::End();
 	}