OpenGLRenderer: Implement texture blit/copy if glCopyImageSubData is not supported

include/Nazara/OpenGLRenderer/Wrapper/Context.hpp

@@ -26,6 +26,8 @@ namespace Nz
 
 namespace Nz::GL
 {
+	class Texture;
+
 	enum class BufferTarget
 	{
 		Array,
@@ -107,7 +109,9 @@ namespace Nz::GL
 		friend SymbolLoader;
 
 		public:
-			inline Context(const OpenGLDevice* device);
+			Context(const OpenGLDevice* device);
+			Context(const Context&) = delete;
+			Context(Context&&) = delete;
 			virtual ~Context();
 
 			void BindBuffer(BufferTarget target, GLuint buffer, bool force = false) const;
@@ -120,8 +124,14 @@ namespace Nz::GL
 			void BindUniformBuffer(UInt32 uboUnit, GLuint buffer, GLintptr offset, GLsizeiptr size) const;
 			void BindVertexArray(GLuint vertexArray, bool force = false) const;
 
+			bool BlitTexture(const Texture& source, const Texture& destination, const Boxui& srcBox, const Vector3ui& dstPos, SamplerFilter filter) const;
+
 			bool ClearErrorStack() const;
 
+			bool CopyTexture(const Texture& source, const Texture& destination, const Boxui& srcBox, const Vector3ui& dstPos) const;
+
+			inline bool DidLastCallSucceed() const;
+
 			virtual void EnableVerticalSync(bool enabled) = 0;
 
 			inline const OpenGLDevice* GetDevice() const;
@@ -160,6 +170,9 @@ namespace Nz::GL
 			NAZARA_OPENGLRENDERER_FOREACH_GLES_FUNC(NAZARA_OPENGLRENDERER_FUNC, NAZARA_OPENGLRENDERER_FUNC)
 #undef NAZARA_OPENGLRENDERER_FUNC
 
+			Context& operator=(const Context&) = delete;
+			Context& operator=(Context&&) = delete;
+
 			static const Context* GetCurrentContext();
 			static bool SetCurrentContext(const Context* context);
 
@@ -176,7 +189,8 @@ namespace Nz::GL
 			ContextParams m_params;
 
 		private:
-			void GL_APIENTRY HandleDebugMessage(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message) const;
+			void HandleDebugMessage(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar* message) const;
+			bool InitializeBlitFramebuffers() const;
 
 			enum class FunctionIndex
 			{
@@ -187,6 +201,8 @@ namespace Nz::GL
 				Count
 			};
 
+			struct BlitFramebuffers;
+
 			struct State
 			{
 				struct Box
@@ -223,10 +239,13 @@ namespace Nz::GL
 
 			std::array<ExtensionStatus, UnderlyingCast(Extension::Max) + 1> m_extensionStatus;
 			std::array<GLFunction, UnderlyingCast(FunctionIndex::Count)> m_originalFunctionPointer;
+			mutable std::unique_ptr<BlitFramebuffers> m_blitFramebuffers;
 			std::unordered_set<std::string> m_supportedExtensions;
 			OpenGLVaoCache m_vaoCache;
 			const OpenGLDevice* m_device;
 			mutable State m_state;
+			mutable bool m_didCollectErrors;
+			mutable bool m_hadAnyError;
 	};
 }
 

include/Nazara/OpenGLRenderer/Wrapper/Context.inl

@@ -7,10 +7,12 @@
 
 namespace Nz::GL
 {
-	inline Context::Context(const OpenGLDevice* device) :
+	inline bool Context::DidLastCallSucceed() const
-	m_vaoCache(*this),
-	m_device(device)
 	{
+		if (!m_didCollectErrors)
+			ProcessErrorStack();
+
+		return !m_hadAnyError;
 	}
 
 	inline const OpenGLDevice* Context::GetDevice() const

src/Nazara/OpenGLRenderer/OpenGLTexture.cpp

@@ -64,25 +64,7 @@ namespace Nz
 		const OpenGLTexture& glTexture = static_cast<const OpenGLTexture&>(source);
 
 		const GL::Context& context = m_texture.EnsureDeviceContext();
-
+		return context.CopyTexture(glTexture.GetTexture(), m_texture, srcBox, dstPos);
-		// Use glCopyImageSubData if available
-		if (context.glCopyImageSubData)
-		{
-			GLuint srcImage = glTexture.GetTexture().GetObjectId();
-			GLenum srcTarget = ToOpenGL(ToTextureTarget(glTexture.GetType()));
-
-			GLuint dstImage = m_texture.GetObjectId();
-			GLenum dstTarget = ToOpenGL(ToTextureTarget(m_params.type));
-
-			context.glCopyImageSubData(srcImage, srcTarget, 0, GLint(srcBox.x), GLint(srcBox.y), GLint(srcBox.z), dstImage, dstTarget, 0, GLint(dstPos.x), GLint(dstPos.y), GLint(dstPos.z), GLsizei(srcBox.width), GLsizei(srcBox.height), GLsizei(srcBox.depth));
-			return true;
-		}
-		else
-		{
-			//TODO: Blit using framebuffers
-		}
-
-		return false;
 	}
 
 	PixelFormat OpenGLTexture::GetFormat() const

src/Nazara/OpenGLRenderer/Wrapper/Context.cpp

@@ -3,12 +3,14 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/OpenGLRenderer/Wrapper/Context.hpp>
+#include <Nazara/Core/CallOnExit.hpp>
 #include <Nazara/Core/Error.hpp>
 #include <Nazara/Core/Log.hpp>
 #include <Nazara/Core/StringExt.hpp>
 #include <Nazara/OpenGLRenderer/OpenGLDevice.hpp>
+#include <Nazara/OpenGLRenderer/OpenGLTexture.hpp>
 #include <Nazara/OpenGLRenderer/Utils.hpp>
-#include <Nazara/OpenGLRenderer/Wrapper/Loader.hpp>
+#include <Nazara/OpenGLRenderer/Wrapper/Framebuffer.hpp>
 #include <cstring>
 #include <sstream>
 #include <stdexcept>
@@ -56,6 +58,12 @@ namespace Nz::GL
 		};
 	}
 
+	struct Context::BlitFramebuffers
+	{
+		GL::Framebuffer drawFBO;
+		GL::Framebuffer readFBO;
+	};
+
 	struct Context::SymbolLoader
 	{
 		SymbolLoader(Context& parent) :
@@ -99,6 +107,15 @@ namespace Nz::GL
 		Context& context;
 	};
 
+
+	Context::Context(const OpenGLDevice* device) :
+	m_vaoCache(*this),
+	m_device(device),
+	m_didCollectErrors(false),
+	m_hadAnyError(false)
+	{
+	}
+
 	Context::~Context()
 	{
 		if (m_device)
@@ -235,15 +252,71 @@ namespace Nz::GL
 		}
 	}
 
+	bool Context::BlitTexture(const Texture& source, const Texture& destination, const Boxui& srcBox, const Vector3ui& dstPos, SamplerFilter filter) const
+	{
+		if (!m_blitFramebuffers && !InitializeBlitFramebuffers())
+			return false;
+
+		//TODO: handle other textures types
+		assert(source.GetTarget() == TextureTarget::Target2D);
+		assert(destination.GetTarget() == TextureTarget::Target2D);
+
+		// Bind framebuffers before configuring them (so they won't override each other)
+		BindFramebuffer(FramebufferTarget::Draw, m_blitFramebuffers->drawFBO.GetObjectId());
+		BindFramebuffer(FramebufferTarget::Read, m_blitFramebuffers->readFBO.GetObjectId());
+
+		// Attach textures to color attachment
+		m_blitFramebuffers->drawFBO.Texture2D(GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, destination.GetObjectId());
+		if (GLenum checkResult = m_blitFramebuffers->drawFBO.Check(); checkResult != GL_FRAMEBUFFER_COMPLETE)
+		{
+			NazaraError("Blit draw FBO is incomplete: " + TranslateOpenGLError(checkResult));
+			return false;
+		}
+
+		m_blitFramebuffers->readFBO.Texture2D(GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, source.GetObjectId());
+		if (GLenum checkResult = m_blitFramebuffers->readFBO.Check(); checkResult != GL_FRAMEBUFFER_COMPLETE)
+		{
+			NazaraError("Blit read FBO is incomplete: " + TranslateOpenGLError(checkResult));
+			return false;
+		}
+
+		glBlitFramebuffer(srcBox.x, srcBox.y, srcBox.x + srcBox.width, srcBox.y + srcBox.height, dstPos.x, dstPos.y, dstPos.x + srcBox.width, dstPos.y + srcBox.height, GL_COLOR_BUFFER_BIT, ToOpenGL(filter));
+		return true;
+	}
+
 	bool Context::ClearErrorStack() const
 	{
 		assert(GetCurrentContext() == this);
 
 		while (glGetError() != GL_NO_ERROR);
 
+		m_didCollectErrors = false;
+		m_hadAnyError = false;
+
 		return true;
 	}
 
+	bool Context::CopyTexture(const Texture& source, const Texture& destination, const Boxui& srcBox, const Vector3ui& dstPos) const
+	{
+		// Use glCopyImageSubData if available
+		if (glCopyImageSubData && false)
+		{
+			GLuint srcImage = source.GetObjectId();
+			GLenum srcTarget = ToOpenGL(source.GetTarget());
+
+			GLuint dstImage = destination.GetObjectId();
+			GLenum dstTarget = ToOpenGL(destination.GetTarget());
+
+			glCopyImageSubData(srcImage, srcTarget, 0, GLint(srcBox.x), GLint(srcBox.y), GLint(srcBox.z), dstImage, dstTarget, 0, GLint(dstPos.x), GLint(dstPos.y), GLint(dstPos.z), GLsizei(srcBox.width), GLsizei(srcBox.height), GLsizei(srcBox.depth));
+			return true;
+		}
+		else
+		{
+			// If glCopyImageSubData is not available, fallback to framebuffer blit
+			return BlitTexture(source, destination, srcBox, dstPos, SamplerFilter::Nearest);
+		}
+	}
+
 	bool Context::Initialize(const ContextParams& params)
 	{
 		if (!SetCurrentContext(this))
@@ -397,8 +470,8 @@ namespace Nz::GL
 		glGetIntegerv(GL_VIEWPORT, res.data());
 		m_state.viewport = { res[0], res[1], res[2], res[3] };
 
-		m_state.renderStates.frontFace = FrontFace::CounterClockwise; //< OpenGL default front face is counter-clockwise
 		m_state.renderStates.depthCompare = RendererComparison::Less; //< OpenGL default depth mode is GL_LESS
+		m_state.renderStates.frontFace = FrontFace::CounterClockwise; //< OpenGL default front face is counter-clockwise
 
 		EnableVerticalSync(false);
 
@@ -419,6 +492,9 @@ namespace Nz::GL
 			NazaraError("OpenGL error: " + TranslateOpenGLError(lastError));
 		}
 
+		m_didCollectErrors = true;
+		m_hadAnyError = hasAnyError;
+
 		return hasAnyError;
 	}
 
@@ -707,6 +783,7 @@ namespace Nz::GL
 
 	void Context::OnContextRelease()
 	{
+		m_blitFramebuffers.reset();
 		m_vaoCache.Clear();
 	}
 
@@ -840,4 +917,22 @@ namespace Nz::GL
 
 		NazaraNotice(ss.str());
 	}
+
+	bool Context::InitializeBlitFramebuffers() const
+	{
+		m_blitFramebuffers = std::make_unique<BlitFramebuffers>();
+		if (!m_blitFramebuffers->drawFBO.Create(*this))
+		{
+			NazaraError("failed to initialize draw FBO");
+			return false;
+		}
+
+		if (!m_blitFramebuffers->readFBO.Create(*this))
+		{
+			NazaraError("failed to initialize read FBO");
+			return false;
+		}
+
+		return true;
+	}
 }