Vertex paging for GL.

Author: slembcke

CCRendererGLSupport.m

@@ -189,6 +189,26 @@ -(void)commit
 @interface CCGraphicsBufferBindingsGL : CCGraphicsBufferBindings @end
 @implementation CCGraphicsBufferBindingsGL {
 	GLuint _vao;
+	
+	// Cache the currently bound page to avoid switching it if possible
+	NSUInteger _currentPage;
+}
+
+static inline void
+BindVertexPage(CCGraphicsBufferBindingsGL *self, NSUInteger page)
+{
+	if(page != self->_currentPage){
+		size_t pageOffset = page*(1<<16)*sizeof(CCVertex);
+		
+		glBindBuffer(GL_ARRAY_BUFFER, ((CCGraphicsBufferGLBasic *)self->_vertexBuffer)->_buffer);
+		glVertexAttribPointer(CCShaderAttributePosition, 4, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)(pageOffset + offsetof(CCVertex, position)));
+		glVertexAttribPointer(CCShaderAttributeTexCoord1, 2, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)(pageOffset + offsetof(CCVertex, texCoord1)));
+		glVertexAttribPointer(CCShaderAttributeTexCoord2, 2, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)(pageOffset + offsetof(CCVertex, texCoord2)));
+		glVertexAttribPointer(CCShaderAttributeColor, 4, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)(pageOffset + offsetof(CCVertex, color)));
+		glBindBuffer(GL_ARRAY_BUFFER, 0);
+		
+		self->_currentPage = page;
+	}
 }
 
 -(instancetype)init
@@ -212,16 +232,12 @@ -(instancetype)init
 			glEnableVertexAttribArray(CCShaderAttributeTexCoord2);
 			glEnableVertexAttribArray(CCShaderAttributeColor);
 
-			glBindBuffer(GL_ARRAY_BUFFER, ((CCGraphicsBufferGLBasic *)_vertexBuffer)->_buffer);
-			glVertexAttribPointer(CCShaderAttributePosition, 4, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)offsetof(CCVertex, position));
-			glVertexAttribPointer(CCShaderAttributeTexCoord1, 2, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)offsetof(CCVertex, texCoord1));
-			glVertexAttribPointer(CCShaderAttributeTexCoord2, 2, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)offsetof(CCVertex, texCoord2));
-			glVertexAttribPointer(CCShaderAttributeColor, 4, GL_FLOAT, GL_FALSE, sizeof(CCVertex), (void *)offsetof(CCVertex, color));
+			_currentPage = NSUIntegerMax; // Start with an invalid value.
+			BindVertexPage(self, 0);
 
 			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ((CCGraphicsBufferGLBasic *)_indexBuffer)->_buffer);
 
 			glBindVertexArray(0);
-			glBindBuffer(GL_ARRAY_BUFFER, 0);
 			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 
 			CCGL_DEBUG_POP_GROUP_MARKER();
@@ -237,10 +253,16 @@ -(void)dealloc
 	CCRenderDispatch(YES, ^{glDeleteVertexArrays(1, &vao);});
 }
 
--(void)bind:(BOOL)bind
+-(void)bind:(BOOL)bind vertexPage:(NSUInteger)vertexPage
 {
 	CCGL_DEBUG_INSERT_EVENT_MARKER("CCGraphicsBufferBindingsGL: Bind VAO");
-	glBindVertexArray(bind ? _vao : 0);
+	
+	if(bind){
+		glBindVertexArray(_vao);
+		BindVertexPage(self, vertexPage);
+	} else {
+		glBindVertexArray(0);
+	}
 }
 
 @end

cocos2d-ui-tests/tests/CCRendererTest.m

@@ -135,6 +135,35 @@ -(id)init
 //	[self.contentNode addChild:sprite];
 //}
 
+-(void)setupVertexPagingTest
+{
+	self.subTitle = @"Should draw a bird.";
+	
+	CCSprite *sprite = [CCSprite spriteWithImageNamed:@"Sprites/bird.png"];
+	sprite.position = ccp(50, 50);
+	
+	CCRenderTexture *rt = [CCRenderTexture renderTextureWithWidth:100 height:100];
+	rt.positionType = CCPositionTypeNormalized;
+	rt.position = ccp(0.5, 0.5);
+	
+	// Wrap the drawing in a render texture since this will give it a unique renderer. (undefined, but currently true)
+	CCRenderer *renderer = [rt beginWithClear:0 g:0 b:0 a:0];
+		// Artificially use up all of the vertex indices.
+		// You can fit 2^16 vertexes per page. So 66*1000 will use slightly more than a page worth of vertexes.
+		// I'm specifically avoiding POT sized allocations of vertexes below.
+		// If paging is not working, it will skip drawing the sprite.
+		for(int i=0; i<66; i++){
+			CCRenderBuffer buffer = [renderer enqueueTriangles:1 andVertexes:1000 withState:[CCRenderState debugColor] globalSortOrder:0];
+			// Tell it to draw a degerenate triangle for the entire batch of vertices.
+			CCRenderBufferSetTriangle(buffer, 0, 0, 0, 0);
+		}
+		
+		[sprite visit];
+	[rt end];
+	
+	[self.contentNode addChild:rt];
+}
+
 #if !__CC_METAL_SUPPORTED_AND_ENABLED
 -(void)setupClippingNodeTest
 {

cocos2d/CCNoARC.m

@@ -124,30 +124,55 @@ -(void)enqueueTriangles:(CCRenderer *)renderer transform:(const GLKMatrix4 *)tra
 
 @implementation CCRenderer(NoARC)
 
+// Positive offset of the vertex allocation to prevent overlapping a boundary.
+static inline NSUInteger
+PageOffset(NSUInteger firstVertex, NSUInteger vertexCount)
+{
+	NSCAssert(vertexCount < UINT16_MAX + 1, @"Too many vertexes for a single draw count.");
+	
+	// Space remaining on the current vertex page.
+	NSUInteger remain = (firstVertex | UINT16_MAX) - firstVertex + 1;
+	
+	if(remain >= vertexCount){
+		// Allocation will not overlap a page boundary. 
+		return 0;
+	} else {
+		return remain;
+	}
+}
+
 -(CCRenderBuffer)enqueueTriangles:(NSUInteger)triangleCount andVertexes:(NSUInteger)vertexCount withState:(CCRenderState *)renderState globalSortOrder:(NSInteger)globalSortOrder;
 {
 	// Need to record the first vertex or element index before pushing more vertexes.
 	NSUInteger firstVertex = _buffers->_vertexBuffer->_count;
 	NSUInteger firstIndex = _buffers->_indexBuffer->_count;
 
+	// Value is 0 unless there a page boundary overlap would occur.
+	NSUInteger vertexPageOffset = PageOffset(firstVertex, vertexCount);
+	
+	// Split vertexes into pages of 2^16 vertexes since GLES2 requires indexing with shorts.
+	NSUInteger vertexPage = (firstVertex + vertexPageOffset) >> 16;
+	NSUInteger vertexPageIndex = (firstVertex + vertexPageOffset) & 0xFFFF;
+	
+	// Ensure that the buffers have enough storage space.
 	NSUInteger indexCount = 3*triangleCount;
-	CCVertex *vertexes = CCGraphicsBufferPushElements(_buffers->_vertexBuffer, vertexCount);
+	CCVertex *vertexes = CCGraphicsBufferPushElements(_buffers->_vertexBuffer, vertexCount + vertexPageOffset);
 	uint16_t *elements = CCGraphicsBufferPushElements(_buffers->_indexBuffer, indexCount);
 
 	CCRenderCommandDraw *previous = _lastDrawCommand;
-	if(previous && previous->_renderState == renderState && previous->_globalSortOrder == globalSortOrder){
+	if(previous && previous->_renderState == renderState && previous->_globalSortOrder == globalSortOrder && previous->_vertexPage == vertexPage){
 		// Batch with the previous command.
 		[previous batch:indexCount];
 	} else {
 		// Start a new command.
-		CCRenderCommandDraw *command = [[CCRenderCommandDrawClass alloc] initWithMode:CCRenderCommandDrawTriangles renderState:renderState first:firstIndex count:indexCount globalSortOrder:globalSortOrder];
+		CCRenderCommandDraw *command = [[CCRenderCommandDrawClass alloc] initWithMode:CCRenderCommandDrawTriangles renderState:renderState firstIndex:firstIndex vertexPage:vertexPage count:indexCount globalSortOrder:globalSortOrder];
 		[_queue addObject:command];
 		[command release];
 
 		_lastDrawCommand = command;
 	}
 
-	return (CCRenderBuffer){vertexes, elements, firstVertex};
+	return (CCRenderBuffer){vertexes, elements, vertexPageIndex};
 }
 
 -(CCRenderBuffer)enqueueLines:(NSUInteger)lineCount andVertexes:(NSUInteger)vertexCount withState:(CCRenderState *)renderState globalSortOrder:(NSInteger)globalSortOrder;
@@ -156,32 +181,41 @@ -(CCRenderBuffer)enqueueLines:(NSUInteger)lineCount andVertexes:(NSUInteger)vert
 	NSUInteger firstVertex = _buffers->_vertexBuffer->_count;
 	NSUInteger firstIndex = _buffers->_indexBuffer->_count;
 
+	// Value is 0 unless there a page boundary overlap would occur.
+	NSUInteger vertexPageOffset = PageOffset(firstVertex, vertexCount);
+	
+	// Split vertexes into pages of 2^16 vertexes since GLES2 requires indexing with shorts.
+	NSUInteger vertexPage = (firstVertex + vertexPageOffset) >> 16;
+	NSUInteger vertexPageIndex = (firstVertex + vertexPageOffset) & 0xFFFF;
+	
+	// Ensure that the buffers have enough storage space.
 	NSUInteger indexCount = 2*lineCount;
-	CCVertex *vertexes = CCGraphicsBufferPushElements(_buffers->_vertexBuffer, vertexCount);
+	CCVertex *vertexes = CCGraphicsBufferPushElements(_buffers->_vertexBuffer, vertexCount + vertexPageOffset);
 	uint16_t *elements = CCGraphicsBufferPushElements(_buffers->_indexBuffer, indexCount);
 
-	CCRenderCommandDraw *command = [[CCRenderCommandDrawClass alloc] initWithMode:CCRenderCommandDrawLines renderState:renderState first:firstIndex count:indexCount globalSortOrder:globalSortOrder];
+	CCRenderCommandDraw *command = [[CCRenderCommandDrawClass alloc] initWithMode:CCRenderCommandDrawLines renderState:renderState firstIndex:firstIndex vertexPage:vertexPage count:indexCount globalSortOrder:globalSortOrder];
 	[_queue addObject:command];
 	[command release];
 
 	// Line drawing commands are currently intended for debugging and cannot be batched.
 	_lastDrawCommand = nil;
 
-	return(CCRenderBuffer){vertexes, elements, firstVertex};
+	return(CCRenderBuffer){vertexes, elements, vertexPageIndex};
 }
 
 static inline void
-CCRendererBindBuffers(CCRenderer *self, BOOL bind)
+CCRendererBindBuffers(CCRenderer *self, BOOL bind, NSUInteger vertexPage)
 {
- 	if(bind != self->_buffersBound){
-		[self->_buffers bind:bind];
+ 	if(bind != self->_buffersBound || vertexPage != self->_vertexPageBound){
+		[self->_buffers bind:bind vertexPage:vertexPage];
 		self->_buffersBound = bind;
+		self->_vertexPageBound = vertexPage;
 	}
 }
 
--(void)bindBuffers:(BOOL)bind
+-(void)bindBuffers:(BOOL)bind vertexPage:(NSUInteger)vertexPage
 {
-	CCRendererBindBuffers(self, bind);
+	CCRendererBindBuffers(self, bind, vertexPage);
 }
 
 
@@ -270,11 +304,11 @@ -(void)invokeOnRenderer:(CCRenderer *)renderer
 {
 	CCGL_DEBUG_PUSH_GROUP_MARKER("CCRendererCommandDraw: Invoke");
 
-	CCRendererBindBuffers(renderer, YES);
+	CCRendererBindBuffers(renderer, YES, _vertexPage);
 	CCRenderStateGLTransition((CCRenderStateGL *)_renderState, renderer, (CCRenderStateGL *)renderer->_renderState);
 	renderer->_renderState = _renderState;
 
-	glDrawElements(GLDrawModes[_mode], (GLsizei)_count, GL_UNSIGNED_SHORT, (GLvoid *)(_first*sizeof(GLushort)));
+	glDrawElements(GLDrawModes[_mode], (GLsizei)_count, GL_UNSIGNED_SHORT, (GLvoid *)(_firstIndex*sizeof(GLushort)));
 	CC_INCREMENT_GL_DRAWS(1);
 
 	CCGL_DEBUG_POP_GROUP_MARKER();

cocos2d/CCRenderTexture.h

@@ -158,7 +158,7 @@ typedef NS_ENUM(NSInteger, CCRenderTextureImageFormat)
  *  @param b Blue color.
  *  @param a Alpha.
  */
--(void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a;
+-(CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a;
 
 /**
  *  starts rendering to the texture while clearing the texture first.
@@ -170,7 +170,7 @@ typedef NS_ENUM(NSInteger, CCRenderTextureImageFormat)
  *  @param a Alpha.
  *  @param depthValue Depth value.
  */
-- (void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue;
+- (CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue;
 
 /**
  *  starts rendering to the texture while clearing the texture first.
@@ -183,7 +183,7 @@ typedef NS_ENUM(NSInteger, CCRenderTextureImageFormat)
  *  @param depthValue Depth value.
  *  @param stencilValue Stencil value.
  */
-- (void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue stencil:(int)stencilValue;
+- (CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue stencil:(int)stencilValue;
 
 /** 
  *  Ends grabbing 

cocos2d/CCRenderTexture.m

@@ -272,25 +272,27 @@ -(CCRenderer *)begin
 	return renderer;
 }
 
--(void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue stencil:(int)stencilValue flags:(GLbitfield)flags
+-(CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue stencil:(int)stencilValue flags:(GLbitfield)flags
 {
 	CCRenderer *renderer = [self begin];
 	[renderer enqueueClear:flags color:GLKVector4Make(r, g, b, a) depth:depthValue stencil:stencilValue globalSortOrder:NSIntegerMin];
+	
+	return renderer;
 }
 
--(void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a
+-(CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a
 {
-	[self beginWithClear:r g:g b:b a:a depth:0 stencil:0 flags:GL_COLOR_BUFFER_BIT];
+	return [self beginWithClear:r g:g b:b a:a depth:0 stencil:0 flags:GL_COLOR_BUFFER_BIT];
 }
 
--(void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue
+-(CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue
 {
-	[self beginWithClear:r g:g b:b a:a depth:depthValue stencil:0 flags:GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT];
+	return [self beginWithClear:r g:g b:b a:a depth:depthValue stencil:0 flags:GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT];
 }
 
--(void)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue stencil:(int)stencilValue
+-(CCRenderer *)beginWithClear:(float)r g:(float)g b:(float)b a:(float)a depth:(float)depthValue stencil:(int)stencilValue
 {
-	[self beginWithClear:r g:g b:b a:a depth:depthValue stencil:stencilValue flags:GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT];
+	return [self beginWithClear:r g:g b:b a:a depth:depthValue stencil:stencilValue flags:GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT];
 }
 
 -(void)end

cocos2d/CCRenderer.m

@@ -99,7 +99,7 @@ void CCRENDERER_DEBUG_CHECK_ERRORS(void){
 
 @implementation CCRenderCommandDraw
 
--(instancetype)initWithMode:(CCRenderCommandDrawMode)mode renderState:(CCRenderState *)renderState first:(NSUInteger)first count:(size_t)count globalSortOrder:(NSInteger)globalSortOrder
+-(instancetype)initWithMode:(CCRenderCommandDrawMode)mode renderState:(CCRenderState *)renderState firstIndex:(NSUInteger)firstIndex vertexPage:(NSUInteger)vertexPage count:(size_t)count globalSortOrder:(NSInteger)globalSortOrder;
 {
 	if((self = [super init])){
 		_mode = mode;
@@ -108,7 +108,8 @@ -(instancetype)initWithMode:(CCRenderCommandDrawMode)mode renderState:(CCRenderS
 #else
 		_renderState = renderState;
 #endif
-		_first = first;
+		_firstIndex = firstIndex;
+		_vertexPage = vertexPage;
 		_count = count;
 		_globalSortOrder = globalSortOrder;
 	}
@@ -166,7 +167,7 @@ -(void)invokeOnRenderer:(CCRenderer *)renderer
 {
 	CCRENDERER_DEBUG_PUSH_GROUP_MARKER(_debugLabel);
 
-	[renderer bindBuffers:NO];
+	[renderer bindBuffers:NO vertexPage:0];
 	_block();
 
 	CCRENDERER_DEBUG_POP_GROUP_MARKER();
@@ -421,7 +422,7 @@ -(void)flush
 	// Execute the rendering commands.
 	SortQueue(_queue);
 	for(id<CCRenderCommand> command in _queue) [command invokeOnRenderer:self];
-	[self bindBuffers:NO];
+	[self bindBuffers:NO vertexPage:0];
 
 	[_queue removeAllObjects];
 

cocos2d/CCRendererBasicTypes.m

@@ -402,8 +402,8 @@ -(void)dealloc
 
 @implementation CCGraphicsBufferBindings
 
-// Base implementations does nothing.
--(void)bind:(BOOL)bind {}
+// Base implementation does nothing.
+-(void)bind:(BOOL)bind vertexPage:(NSUInteger)vertexPage {}
 
 -(void)prepare
 {

cocos2d/CCRendererBasicTypes_Private.h

@@ -105,7 +105,7 @@ CCGraphicsBufferPushElements(CCGraphicsBuffer *buffer, size_t requestedCount)
 }
 
 /// Make the buffers ready to use by drawing commands.
--(void)bind:(BOOL)bind;
+-(void)bind:(BOOL)bind vertexPage:(NSUInteger)vertexPage;
 
 /// Prepare buffers for changes.
 -(void)prepare;

cocos2d/CCRenderer_Private.h

@@ -80,14 +80,14 @@ typedef NS_ENUM(NSUInteger, CCRenderCommandDrawMode){
 	CCRenderState *_renderState;
 	NSInteger _globalSortOrder;
 
-	NSUInteger _first;
+	NSUInteger _firstIndex, _vertexPage;
 	size_t _count;
 }
 
 @property(nonatomic, readonly) NSUInteger first;
 @property(nonatomic, readonly) size_t count;
 
--(instancetype)initWithMode:(CCRenderCommandDrawMode)mode renderState:(CCRenderState *)renderState first:(NSUInteger)first count:(size_t)count globalSortOrder:(NSInteger)globalSortOrder;
+-(instancetype)initWithMode:(CCRenderCommandDrawMode)mode renderState:(CCRenderState *)renderState firstIndex:(NSUInteger)firstIndex vertexPage:(NSUInteger)vertexPage count:(size_t)count globalSortOrder:(NSInteger)globalSortOrder;
 
 -(void)batch:(NSUInteger)count;
 
@@ -117,6 +117,7 @@ typedef NS_ENUM(NSUInteger, CCRenderCommandDrawMode){
 	__unsafe_unretained CCRenderState *_renderState;
 	__unsafe_unretained CCRenderCommandDraw *_lastDrawCommand;
 	BOOL _buffersBound;
+	NSUInteger _vertexPageBound;
 }
 
 /// Current global shader uniform values.
@@ -144,7 +145,7 @@ typedef NS_ENUM(NSUInteger, CCRenderCommandDrawMode){
 -(void)setRenderState:(CCRenderState *)renderState;
 
 /// Bind the renderer's VAO if it is not currently bound.
--(void)bindBuffers:(BOOL)bind;
+-(void)bindBuffers:(BOOL)bind vertexPage:(NSUInteger)vertexPage;
 
 @end