CCFrameBufferObject bind with clear.

Author: slembcke

CCRendererGLSupport.m

@@ -365,11 +365,18 @@ -(void)dealloc
 	});
 }
 
--(void)bind
+-(void)bindWithClear:(GLbitfield)mask color:(GLKVector4)color4 depth:(GLclampf)depth stencil:(GLint)stencil
 {
+	glBindFramebuffer(GL_FRAMEBUFFER, _fbo);
+	
 	CGSize size = self.sizeInPixels;
 	glViewport(0, 0, size.width, size.height);
-	glBindFramebuffer(GL_FRAMEBUFFER, _fbo);
+	
+	if(mask & GL_COLOR_BUFFER_BIT) glClearColor(color4.r, color4.g, color4.b, color4.a);
+	if(mask & GL_DEPTH_BUFFER_BIT) glClearDepth(depth);
+	if(mask & GL_STENCIL_BUFFER_BIT) glClearStencil(stencil);
+	
+	glClear(mask);
 }
 
 -(void)syncWithView:(CC_VIEW<CCDirectorView> *)view;

cocos2d/CCRenderer.m

@@ -336,14 +336,23 @@ -(void)prepareWithProjection:(const GLKMatrix4 *)projection framebuffer:(CCFrame
 
 -(void)enqueueClear:(GLbitfield)mask color:(GLKVector4)color4 depth:(GLclampf)depth stencil:(GLint)stencil globalSortOrder:(NSInteger)globalSortOrder
 {
-	#warning GL code.
-	[self enqueueBlock:^{
-		if(mask & GL_COLOR_BUFFER_BIT) glClearColor(color4.r, color4.g, color4.b, color4.a);
-		if(mask & GL_DEPTH_BUFFER_BIT) glClearDepth(depth);
-		if(mask & GL_STENCIL_BUFFER_BIT) glClearStencil(stencil);
+	// If a clear is the very first command, then handle it specially.
+	if(globalSortOrder == NSIntegerMin && _queue.count == 0 && _queueStack.count == 0){
+		_clearMask = mask;
+		_clearColor = color4;
+		_clearDepth = depth;
+		_clearStencil = stencil;
+	} else {
+		NSAssert([CCConfiguration sharedConfiguration].graphicsAPI == CCGraphicsAPIGL, @"Clear commands must be the first command in the queue unless using GL.");
 
-		glClear(mask);
-	} globalSortOrder:globalSortOrder debugLabel:@"CCRenderer: Clear" threadSafe:YES];
+		[self enqueueBlock:^{
+			if(mask & GL_COLOR_BUFFER_BIT) glClearColor(color4.r, color4.g, color4.b, color4.a);
+			if(mask & GL_DEPTH_BUFFER_BIT) glClearDepth(depth);
+			if(mask & GL_STENCIL_BUFFER_BIT) glClearStencil(stencil);
+			
+			glClear(mask);
+		} globalSortOrder:globalSortOrder debugLabel:@"CCRenderer: Clear" threadSafe:YES];
+	}
 }
 
 -(void)enqueueBlock:(void (^)())block globalSortOrder:(NSInteger)globalSortOrder debugLabel:(NSString *)debugLabel threadSafe:(BOOL)threadsafe
@@ -397,7 +406,7 @@ -(void)flush
 {
 	CCRENDERER_DEBUG_PUSH_GROUP_MARKER(@"CCRenderer: Flush");
 
-	[_framebuffer bind];
+	[_framebuffer bindWithClear:_clearMask color:_clearColor depth:_clearDepth stencil:_clearStencil];
 
 	// Commit the buffers.
 	[_buffers commit];

cocos2d/CCRendererBasicTypes_Private.h

@@ -128,7 +128,8 @@ CCGraphicsBufferPushElements(CCGraphicsBuffer *buffer, size_t requestedCount)
 
 -(void)syncWithView:(CC_VIEW<CCDirectorView> *)view;
 
-#warning TODO bind with clear.
--(void)bind;
+// Not ideal to use GL enumerations here.
+// It's out of convenience, and it's a private API.
+-(void)bindWithClear:(GLbitfield)mask color:(GLKVector4)color4 depth:(GLclampf)depth stencil:(GLint)stencil;
 
 @end

cocos2d/CCRenderer_Private.h

@@ -119,6 +119,12 @@ typedef NS_ENUM(NSUInteger, CCRenderCommandDrawMode){
 	NSMutableArray *_queue;
 	NSMutableArray *_queueStack;
 
+	// Handle clearing specially if it's the very first command.
+	GLbitfield _clearMask;
+	GLKVector4 _clearColor;
+	GLclampf _clearDepth;
+	GLint _clearStencil;
+	
 	// Current renderer bindings for fast state checking.
 	// Invalidated at the end of each frame.
 	__unsafe_unretained CCRenderState *_renderState;

cocos2d/Platforms/iOS/CCMetalSupport.m

@@ -69,16 +69,23 @@ -(void)endRenderPass
 	_currentRenderCommandEncoder = nil;
 }
 
--(void)beginRenderPass:(id<MTLTexture>)destinationTexture;
+-(void)beginRenderPass:(id<MTLTexture>)destinationTexture clearMask:(GLbitfield)mask color:(GLKVector4)color4 depth:(GLclampf)depth stencil:(GLint)stencil;
 {
 	// End the previous render pass.
 	[self endRenderPass];
 
 	MTLRenderPassColorAttachmentDescriptor *colorAttachment = [MTLRenderPassColorAttachmentDescriptor new];
 	colorAttachment.texture = destinationTexture;
-	colorAttachment.loadAction = MTLLoadActionClear;
-	colorAttachment.clearColor = MTLClearColorMake(0, 0, 0, 0);
-	colorAttachment.storeAction = MTLStoreActionStore;
+	if(mask & GL_COLOR_BUFFER_BIT){
+		colorAttachment.loadAction = MTLLoadActionClear;
+		colorAttachment.clearColor = MTLClearColorMake(color4.r, color4.g, color4.b, color4.a);
+		colorAttachment.storeAction = MTLStoreActionStore;
+	} else {
+		colorAttachment.loadAction = MTLLoadActionDontCare;
+		colorAttachment.storeAction = MTLStoreActionStore;
+	}
+	
+	// TODO depth and stencil.
 
 	MTLRenderPassDescriptor *renderPassDescriptor = [MTLRenderPassDescriptor renderPassDescriptor];
 	renderPassDescriptor.colorAttachments[0] = colorAttachment;
@@ -175,9 +182,9 @@ -(instancetype)initWithTexture:(CCTexture *)texture depthStencilFormat:(GLuint)d
 	return self;
 }
 
--(void)bind
+-(void)bindWithClear:(GLbitfield)mask color:(GLKVector4)color4 depth:(GLclampf)depth stencil:(GLint)stencil
 {
-	[[CCMetalContext currentContext] beginRenderPass:_frameBufferTexture];
+	[[CCMetalContext currentContext] beginRenderPass:_frameBufferTexture clearMask:mask color:color4 depth:depth stencil:stencil];
 }
 
 -(void)syncWithView:(CC_VIEW<CCDirectorView> *)view;

cocos2d/Platforms/iOS/CCMetalSupport_Private.h

@@ -71,7 +71,7 @@
 +(instancetype)currentContext;
 +(void)setCurrentContext:(CCMetalContext *)context;
 
--(void)beginRenderPass:(id<MTLTexture>)destinationTexture;
+-(void)beginRenderPass:(id<MTLTexture>)destinationTexture clearMask:(GLbitfield)mask color:(GLKVector4)color4 depth:(GLclampf)depth stencil:(GLint)stencil;
 
 -(void)flushCommandBuffer;