Merge pull request #1650 from unknownbrackets/attributeless-fix

OGL: Unbind the active VAO before attributeless rendering

Source/Core/VideoBackends/OGL/FramebufferManager.cpp

@@ -373,6 +373,8 @@ void FramebufferManager::ReinterpretPixelData(unsigned int convtype)
 {
 	g_renderer->ResetAPIState();
 
+	OpenGL_BindAttributelessVAO();
+
 	GLuint src_texture = 0;
 
 	// We aren't allowed to render and sample the same texture in one draw call,

Source/Core/VideoBackends/OGL/GLUtil.cpp

@@ -16,6 +16,8 @@
 #include "VideoCommon/VideoConfig.h"
 
 cInterfaceBase *GLInterface;
+static GLuint attributelessVAO = 0;
+static GLuint attributelessVBO = 0;
 
 namespace OGL
 {
@@ -113,3 +115,38 @@ GLuint OpenGL_CompileProgram(const char* vertexShader, const char* fragmentShade
 	return programID;
 }
 
+void OpenGL_CreateAttributelessVAO()
+{
+	glGenVertexArrays(1, &attributelessVAO);
+	_dbg_assert_msg_(VIDEO, attributelessVAO != 0, "Attributeless VAO should have been created successfully.")
+
+	// In a compatibility context, we require a valid, bound array buffer.
+	glGenBuffers(1, &attributelessVBO);
+	_dbg_assert_msg_(VIDEO, attributelessVBO != 0, "Attributeless VBO should have been created successfully.")
+
+	// Initialize the buffer with nothing.
+	glBindBuffer(GL_ARRAY_BUFFER, attributelessVBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat), nullptr, GL_STATIC_DRAW);
+
+	// We must also define vertex attribute 0.
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, nullptr);
+}
+
+void OpenGL_BindAttributelessVAO()
+{
+	_dbg_assert_msg_(VIDEO, attributelessVAO != 0, "Attributeless VAO should have already been created.")
+	glBindVertexArray(attributelessVAO);
+}
+
+void OpenGL_DeleteAttributelessVAO()
+{
+	_dbg_assert_msg_(VIDEO, attributelessVAO != 0, "Attributeless VAO should have already been created.")
+	if (attributelessVAO != 0)
+	{
+		glDeleteVertexArrays(1, &attributelessVAO);
+		glDeleteBuffers(1, &attributelessVBO);
+
+		attributelessVAO = 0;
+		attributelessVBO = 0;
+	}
+}

Source/Core/VideoBackends/OGL/GLUtil.h

@@ -18,6 +18,14 @@ void InitInterface();
 // Helpers
 GLuint OpenGL_CompileProgram(const char *vertexShader, const char *fragmentShader);
 
+// Creates and deletes a VAO and VBO suitable for attributeless rendering.
+// Called by the Renderer.
+void OpenGL_CreateAttributelessVAO();
+void OpenGL_DeleteAttributelessVAO();
+
+// Binds the VAO suitable for attributeless rendering.
+void OpenGL_BindAttributelessVAO();
+
 // this should be removed in future, but as long as glsl is unstable, we should really read this messages
 #if defined(_DEBUG) || defined(DEBUGFAST)
 #define DEBUG_GLSL 1

Source/Core/VideoBackends/OGL/PostProcessing.cpp

@@ -72,6 +72,8 @@ void OpenGLPostProcessing::BlitFromTexture(TargetRectangle src, TargetRectangle
 
 	if (m_attribute_workaround)
 		glBindVertexArray(m_attribute_vao);
+	else
+		OpenGL_BindAttributelessVAO();
 
 	m_shader.Bind();
 

Source/Core/VideoBackends/OGL/Render.cpp

@@ -691,6 +691,8 @@ void Renderer::Shutdown()
 
 	delete m_post_processor;
 	m_post_processor = nullptr;
+
+	OpenGL_DeleteAttributelessVAO();
 }
 
 void Renderer::Init()
@@ -717,6 +719,8 @@ void Renderer::Init()
 		"	ocol0 = c;\n"
 		"}\n");
 
+	OpenGL_CreateAttributelessVAO();
+
 	// creating buffers
 	glGenBuffers(1, &s_ShowEFBCopyRegions_VBO);
 	glGenVertexArrays(1, &s_ShowEFBCopyRegions_VAO);

Source/Core/VideoBackends/OGL/TextureCache.cpp

@@ -249,6 +249,8 @@ void TextureCache::TCacheEntry::FromRenderTarget(u32 dstAddr, unsigned int dstFo
 	{
 		FramebufferManager::SetFramebuffer(framebuffer);
 
+		OpenGL_BindAttributelessVAO();
+
 		glActiveTexture(GL_TEXTURE0+9);
 		glBindTexture(GL_TEXTURE_2D_ARRAY, read_texture);
 

Source/Core/VideoBackends/OGL/TextureConverter.cpp

@@ -222,6 +222,8 @@ static void EncodeToRamUsingShader(GLuint srcTexture,
 	// attach render buffer as color destination
 	FramebufferManager::SetFramebuffer(s_texConvFrameBuffer[0]);
 
+	OpenGL_BindAttributelessVAO();
+
 	// set source texture
 	glActiveTexture(GL_TEXTURE0+9);
 	glBindTexture(GL_TEXTURE_2D_ARRAY, srcTexture);
@@ -362,6 +364,8 @@ void DecodeToTexture(u32 xfbAddr, int srcWidth, int srcHeight, GLuint destTextur
 
 	g_renderer->ResetAPIState(); // reset any game specific settings
 
+	OpenGL_BindAttributelessVAO();
+
 	// switch to texture converter frame buffer
 	// attach destTexture as color destination
 	FramebufferManager::SetFramebuffer(s_texConvFrameBuffer[1]);