Spine深入学习———— 渲染

数据有了之后，就开始渲染

渲染相关

绘制顺序

骨架的绘制顺序就是一个插槽列表，在插槽列表中上方的附件在下方之上绘制，绘制顺序可以在层级树中的骨架下查看。

基础流程

渲染实现

以下按照cocos2dx的实现来 （cocos2dx 3.7 spine3.6）

SkeletonRenderer

本身继承于Node，所以渲染部分看draw函数。

void SkeletonRenderer::draw (Renderer* renderer, const Mat4& transform, uint32_t transformFlags) {
	SkeletonBatch* batch = SkeletonBatch::getInstance();
	SkeletonTwoColorBatch* twoColorBatch = SkeletonTwoColorBatch::getInstance();
	bool isTwoColorTint = this->isTwoColorTint();
	
	if (_effect) _effect->begin(_effect, _skeleton);

	Color4F nodeColor;
	nodeColor.r = getDisplayedColor().r / (float)255;
	nodeColor.g = getDisplayedColor().g / (float)255;
	nodeColor.b = getDisplayedColor().b / (float)255;
	nodeColor.a = getDisplayedOpacity() / (float)255;
	
    Color4F color;
	Color4F darkColor;
	AttachmentVertices* attachmentVertices = nullptr;
	TwoColorTrianglesCommand* lastTwoColorTrianglesCommand = nullptr;
	for (int i = 0, n = _skeleton->slotsCount; i < n; ++i) {
		spSlot* slot = _skeleton->drawOrder[i];
		if (!slot->attachment) {
			spSkeletonClipping_clipEnd(_clipper, slot);
			continue;
		}
		
		cocos2d::TrianglesCommand::Triangles triangles;
		TwoColorTriangles trianglesTwoColor;
		
		switch (slot->attachment->type) {
		case SP_ATTACHMENT_REGION: {
			spRegionAttachment* attachment = (spRegionAttachment*)slot->attachment;
			attachmentVertices = getAttachmentVertices(attachment);
			
			if (!isTwoColorTint) {
				triangles.indices = attachmentVertices->_triangles->indices;
				triangles.indexCount = attachmentVertices->_triangles->indexCount;
				triangles.verts = batch->allocateVertices(attachmentVertices->_triangles->vertCount);
				triangles.vertCount = attachmentVertices->_triangles->vertCount;
				memcpy(triangles.verts, attachmentVertices->_triangles->verts, sizeof(cocos2d::V3F_C4B_T2F) * attachmentVertices->_triangles->vertCount);
				spRegionAttachment_computeWorldVertices(attachment, slot->bone, (float*)triangles.verts, 0, 6);
			} else {
				trianglesTwoColor.indices = attachmentVertices->_triangles->indices;
				trianglesTwoColor.indexCount = attachmentVertices->_triangles->indexCount;
				trianglesTwoColor.verts = twoColorBatch->allocateVertices(attachmentVertices->_triangles->vertCount);
				trianglesTwoColor.vertCount = attachmentVertices->_triangles->vertCount;
				for (int ii = 0; ii < trianglesTwoColor.vertCount; ii++) {
					trianglesTwoColor.verts[ii].texCoords = attachmentVertices->_triangles->verts[ii].texCoords;
				}
				spRegionAttachment_computeWorldVertices(attachment, slot->bone, (float*)trianglesTwoColor.verts, 0, 7);
			}
			
            color.r = attachment->color.r;
			color.g = attachment->color.g;
			color.b = attachment->color.b;
			color.a = attachment->color.a;
			
			break;
		}
		case SP_ATTACHMENT_MESH: {
			spMeshAttachment* attachment = (spMeshAttachment*)slot->attachment;
			attachmentVertices = getAttachmentVertices(attachment);
			
			if (!isTwoColorTint) {
				triangles.indices = attachmentVertices->_triangles->indices;
				triangles.indexCount = attachmentVertices->_triangles->indexCount;
				triangles.verts = batch->allocateVertices(attachmentVertices->_triangles->vertCount);
				triangles.vertCount = attachmentVertices->_triangles->vertCount;
				memcpy(triangles.verts, attachmentVertices->_triangles->verts, sizeof(cocos2d::V3F_C4B_T2F) * attachmentVertices->_triangles->vertCount);
				spVertexAttachment_computeWorldVertices(SUPER(attachment), slot, 0, triangles.vertCount * sizeof(cocos2d::V3F_C4B_T2F) / 4, (float*)triangles.verts, 0, 6);
			} else {
				trianglesTwoColor.indices = attachmentVertices->_triangles->indices;
				trianglesTwoColor.indexCount = attachmentVertices->_triangles->indexCount;
				trianglesTwoColor.verts = twoColorBatch->allocateVertices(attachmentVertices->_triangles->vertCount);
				trianglesTwoColor.vertCount = attachmentVertices->_triangles->vertCount;
				for (int ii = 0; ii < trianglesTwoColor.vertCount; ii++) {
					trianglesTwoColor.verts[ii].texCoords = attachmentVertices->_triangles->verts[ii].texCoords;
				}
				spVertexAttachment_computeWorldVertices(SUPER(attachment), slot, 0, trianglesTwoColor.vertCount * sizeof(V3F_C4B_C4B_T2F) / 4, (float*)trianglesTwoColor.verts, 0, 7);
			}
			
			color.r = attachment->color.r;
			color.g = attachment->color.g;
			color.b = attachment->color.b;
			color.a = attachment->color.a;
			
			break;
		}
		case SP_ATTACHMENT_CLIPPING: {
			spClippingAttachment* clip = (spClippingAttachment*)slot->attachment;
			spSkeletonClipping_clipStart(_clipper, slot, clip);
		}
		default:
			spSkeletonClipping_clipEnd(_clipper, slot);
			continue;
		}
		
		if (slot->darkColor) {
			darkColor.r = slot->darkColor->r * 255;
			darkColor.g = slot->darkColor->g * 255;
			darkColor.b = slot->darkColor->b * 255;
		} else {
			darkColor.r = 0;
			darkColor.g = 0;
			darkColor.b = 0;
		}
		
		color.a *= nodeColor.a * _skeleton->color.a * slot->color.a * 255;
		// skip rendering if the color of this attachment is 0
		if (color.a == 0){
			spSkeletonClipping_clipEnd(_clipper, slot);
			continue;
		}
		float multiplier = _premultipliedAlpha ? color.a : 255;
		color.r *= nodeColor.r * _skeleton->color.r * slot->color.r * multiplier;
		color.g *= nodeColor.g * _skeleton->color.g * slot->color.g * multiplier;
		color.b *= nodeColor.b * _skeleton->color.b * slot->color.b * multiplier;
		
		BlendFunc blendFunc;
		switch (slot->data->blendMode) {
			case SP_BLEND_MODE_ADDITIVE:
				blendFunc.src = _premultipliedAlpha ? GL_ONE : GL_SRC_ALPHA;
				blendFunc.dst = GL_ONE;
				break;
			case SP_BLEND_MODE_MULTIPLY:
				blendFunc.src = GL_DST_COLOR;
				blendFunc.dst = GL_ONE_MINUS_SRC_ALPHA;
				break;
			case SP_BLEND_MODE_SCREEN:
				blendFunc.src = GL_ONE;
				blendFunc.dst = GL_ONE_MINUS_SRC_COLOR;
				break;
			default:
				blendFunc.src = _premultipliedAlpha ? GL_ONE : GL_SRC_ALPHA;
				blendFunc.dst = GL_ONE_MINUS_SRC_ALPHA;
		}
		
		if (!isTwoColorTint) {
			if (spSkeletonClipping_isClipping(_clipper)) {
				spSkeletonClipping_clipTriangles(_clipper, (float*)&triangles.verts[0].vertices, triangles.vertCount * sizeof(cocos2d::V3F_C4B_T2F) / 4, triangles.indices, triangles.indexCount, (float*)&triangles.verts[0].texCoords, 6);
				batch->deallocateVertices(triangles.vertCount);
				
				if (_clipper->clippedTriangles->size == 0){
					spSkeletonClipping_clipEnd(_clipper, slot);
					continue;
				}
				
				triangles.vertCount = _clipper->clippedVertices->size >> 1;
				triangles.verts = batch->allocateVertices(triangles.vertCount);
				triangles.indexCount = _clipper->clippedTriangles->size;
				triangles.indices = batch->allocateIndices(triangles.indexCount);
				memcpy(triangles.indices, _clipper->clippedTriangles->items, sizeof(unsigned short) * _clipper->clippedTriangles->size);
				
				cocos2d::TrianglesCommand* batchedTriangles = batch->addCommand(renderer, _globalZOrder, attachmentVertices->_texture, _glProgramState, blendFunc, triangles, transform, transformFlags);
				
				float* verts = _clipper->clippedVertices->items;
				float* uvs = _clipper->clippedUVs->items;
				if (_effect) {
					spColor light;
					spColor dark;
					light.r = color.r / 255.0f;
					light.g = color.g / 255.0f;
					light.b = color.b / 255.0f;
					light.a = color.a / 255.0f;
					dark.r = dark.g = dark.b = dark.a = 0;
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount, vv = 0; v < vn; ++v, vv+=2) {
						V3F_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						spColor lightCopy = light;
						spColor darkCopy = dark;
						vertex->vertices.x = verts[vv];
						vertex->vertices.y = verts[vv + 1];
						vertex->texCoords.u = uvs[vv];
						vertex->texCoords.v = uvs[vv + 1];
						_effect->transform(_effect, &vertex->vertices.x, &vertex->vertices.y, &vertex->texCoords.u, &vertex->texCoords.v, &lightCopy, &darkCopy);
						vertex->colors.r = (GLubyte)(lightCopy.r * 255);
						vertex->colors.g = (GLubyte)(lightCopy.g * 255);
						vertex->colors.b = (GLubyte)(lightCopy.b * 255);
						vertex->colors.a = (GLubyte)(lightCopy.a * 255);
					}
				} else {
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount, vv = 0; v < vn; ++v, vv+=2) {
						V3F_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						vertex->vertices.x = verts[vv];
						vertex->vertices.y = verts[vv + 1];
						vertex->texCoords.u = uvs[vv];
						vertex->texCoords.v = uvs[vv + 1];
						vertex->colors.r = (GLubyte)color.r;
						vertex->colors.g = (GLubyte)color.g;
						vertex->colors.b = (GLubyte)color.b;
						vertex->colors.a = (GLubyte)color.a;
					}
				}
			} else {
				cocos2d::TrianglesCommand* batchedTriangles = batch->addCommand(renderer, _globalZOrder, attachmentVertices->_texture, _glProgramState, blendFunc, triangles, transform, transformFlags);
				
				if (_effect) {
					spColor light;
					spColor dark;
					light.r = color.r / 255.0f;
					light.g = color.g / 255.0f;
					light.b = color.b / 255.0f;
					light.a = color.a / 255.0f;
					dark.r = dark.g = dark.b = dark.a = 0;
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount; v < vn; ++v) {
						V3F_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						spColor lightCopy = light;
						spColor darkCopy = dark;
						_effect->transform(_effect, &vertex->vertices.x, &vertex->vertices.y, &vertex->texCoords.u, &vertex->texCoords.v, &lightCopy, &darkCopy);
						vertex->colors.r = (GLubyte)(lightCopy.r * 255);
						vertex->colors.g = (GLubyte)(lightCopy.g * 255);
						vertex->colors.b = (GLubyte)(lightCopy.b * 255);
						vertex->colors.a = (GLubyte)(lightCopy.a * 255);
					}
				} else {
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount; v < vn; ++v) {
						V3F_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						vertex->colors.r = (GLubyte)color.r;
						vertex->colors.g = (GLubyte)color.g;
						vertex->colors.b = (GLubyte)color.b;
						vertex->colors.a = (GLubyte)color.a;
					}
				}
			}
		} else {
			if (spSkeletonClipping_isClipping(_clipper)) {
				spSkeletonClipping_clipTriangles(_clipper, (float*)&trianglesTwoColor.verts[0].position, trianglesTwoColor.vertCount * sizeof(V3F_C4B_C4B_T2F) / 4, trianglesTwoColor.indices, trianglesTwoColor.indexCount, (float*)&trianglesTwoColor.verts[0].texCoords, 7);
				twoColorBatch->deallocateVertices(trianglesTwoColor.vertCount);
				
				if (_clipper->clippedTriangles->size == 0){
					spSkeletonClipping_clipEnd(_clipper, slot);
					continue;
				}
				
				trianglesTwoColor.vertCount = _clipper->clippedVertices->size >> 1;
				trianglesTwoColor.verts = twoColorBatch->allocateVertices(trianglesTwoColor.vertCount);
				trianglesTwoColor.indexCount = _clipper->clippedTriangles->size;
				trianglesTwoColor.indices = twoColorBatch->allocateIndices(trianglesTwoColor.indexCount);
				memcpy(trianglesTwoColor.indices, _clipper->clippedTriangles->items, sizeof(unsigned short) * _clipper->clippedTriangles->size);
				
				TwoColorTrianglesCommand* batchedTriangles = lastTwoColorTrianglesCommand = twoColorBatch->addCommand(renderer, _globalZOrder, attachmentVertices->_texture->getName(), _glProgramState, blendFunc, trianglesTwoColor, transform, transformFlags);
				
				float* verts = _clipper->clippedVertices->items;
				float* uvs = _clipper->clippedUVs->items;
				
				if (_effect) {
					spColor light;
					spColor dark;
					light.r = color.r / 255.0f;
					light.g = color.g / 255.0f;
					light.b = color.b / 255.0f;
					light.a = color.a / 255.0f;
					dark.r = darkColor.r / 255.0f;
					dark.g = darkColor.g / 255.0f;
					dark.b = darkColor.b / 255.0f;
					dark.a = darkColor.a / 255.0f;
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount, vv = 0; v < vn; ++v, vv += 2) {
						V3F_C4B_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						spColor lightCopy = light;
						spColor darkCopy = dark;
						vertex->position.x = verts[vv];
						vertex->position.y = verts[vv + 1];
						vertex->texCoords.u = uvs[vv];
						vertex->texCoords.v = uvs[vv + 1];
						_effect->transform(_effect, &vertex->position.x, &vertex->position.y, &vertex->texCoords.u, &vertex->texCoords.v, &lightCopy, &darkCopy);
						vertex->color.r = (GLubyte)(lightCopy.r * 255);
						vertex->color.g = (GLubyte)(lightCopy.g * 255);
						vertex->color.b = (GLubyte)(lightCopy.b * 255);
						vertex->color.a = (GLubyte)(lightCopy.a * 255);
						vertex->color2.r = (GLubyte)(darkCopy.r * 255);
						vertex->color2.g = (GLubyte)(darkCopy.g * 255);
						vertex->color2.b = (GLubyte)(darkCopy.b * 255);
						vertex->color2.a = 1;
					}
				} else {
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount, vv = 0; v < vn; ++v, vv += 2) {
						V3F_C4B_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						vertex->position.x = verts[vv];
						vertex->position.y = verts[vv + 1];
						vertex->texCoords.u = uvs[vv];
						vertex->texCoords.v = uvs[vv + 1];
						vertex->color.r = (GLubyte)color.r;
						vertex->color.g = (GLubyte)color.g;
						vertex->color.b = (GLubyte)color.b;
						vertex->color.a = (GLubyte)color.a;
						vertex->color2.r = (GLubyte)darkColor.r;
						vertex->color2.g = (GLubyte)darkColor.g;
						vertex->color2.b = (GLubyte)darkColor.b;
						vertex->color2.a = 1;
					}
				}
			} else {
				TwoColorTrianglesCommand* batchedTriangles = lastTwoColorTrianglesCommand = twoColorBatch->addCommand(renderer, _globalZOrder, attachmentVertices->_texture->getName(), _glProgramState, blendFunc, trianglesTwoColor, transform, transformFlags);
				
				if (_effect) {
					spColor light;
					spColor dark;
					light.r = color.r / 255.0f;
					light.g = color.g / 255.0f;
					light.b = color.b / 255.0f;
					light.a = color.a / 255.0f;
					dark.r = darkColor.r / 255.0f;
					dark.g = darkColor.g / 255.0f;
					dark.b = darkColor.b / 255.0f;
					dark.a = darkColor.a / 255.0f;
					
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount; v < vn; ++v) {
						V3F_C4B_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						spColor lightCopy = light;
						spColor darkCopy = dark;
						_effect->transform(_effect, &vertex->position.x, &vertex->position.y, &vertex->texCoords.u, &vertex->texCoords.v, &lightCopy, &darkCopy);
						vertex->color.r = (GLubyte)(lightCopy.r * 255);
						vertex->color.g = (GLubyte)(lightCopy.g * 255);
						vertex->color.b = (GLubyte)(lightCopy.b * 255);
						vertex->color.a = (GLubyte)(lightCopy.a * 255);
						vertex->color2.r = (GLubyte)(darkCopy.r * 255);
						vertex->color2.g = (GLubyte)(darkCopy.g * 255);
						vertex->color2.b = (GLubyte)(darkCopy.b * 255);
						vertex->color2.a = 1;
					}
				} else {
					for (int v = 0, vn = batchedTriangles->getTriangles().vertCount; v < vn; ++v) {
						V3F_C4B_C4B_T2F* vertex = batchedTriangles->getTriangles().verts + v;
						vertex->color.r = (GLubyte)color.r;
						vertex->color.g = (GLubyte)color.g;
						vertex->color.b = (GLubyte)color.b;
						vertex->color.a = (GLubyte)color.a;
						vertex->color2.r = (GLubyte)darkColor.r;
						vertex->color2.g = (GLubyte)darkColor.g;
						vertex->color2.b = (GLubyte)darkColor.b;
						vertex->color2.a = 1;
					}
				}
			}
		}
		spSkeletonClipping_clipEnd(_clipper, slot);
	}
	spSkeletonClipping_clipEnd2(_clipper);
	
	if (lastTwoColorTrianglesCommand) {
		Node* parent = this->getParent();
		
		// We need to decide if we can postpone flushing the current
		// batch. We can postpone if the next sibling node is a
		// two color tinted skeleton with the same global-z.
		// The parent->getChildrenCount() > 100 check is a hack
		// as checking for a sibling is an O(n) operation, and if
		// all children of this nodes parent are skeletons, we
		// are in O(n2) territory.
		if (!parent || parent->getChildrenCount() > 100 || getChildrenCount() != 0) {
			lastTwoColorTrianglesCommand->setForceFlush(true);
		} else {
			Vector<Node*>& children = parent->getChildren();
			Node* sibling = nullptr;
			for (ssize_t i = 0; i < children.size(); i++) {
				if (children.at(i) == this) {
					if (i < children.size() - 1) {
						sibling = children.at(i+1);
						break;
					}
				}
			}
			if (!sibling) {
				lastTwoColorTrianglesCommand->setForceFlush(true);
			} else {
				SkeletonRenderer* siblingSkeleton = dynamic_cast<SkeletonRenderer*>(sibling);
				if (!siblingSkeleton || // flush is next sibling isn't a SkeletonRenderer
					!siblingSkeleton->isTwoColorTint() || // flush if next sibling isn't two color tinted
					!siblingSkeleton->isVisible() || // flush if next sibling is two color tinted but not visible
					(siblingSkeleton->getGlobalZOrder() != this->getGlobalZOrder())) { // flush if next sibling is two color tinted but z-order differs
					lastTwoColorTrianglesCommand->setForceFlush(true);
				}
			}
		}
	}
	
	if (_effect) _effect->end(_effect);

	if (_debugSlots || _debugBones || _debugMeshes) {
        drawDebug(renderer, transform, transformFlags);
	}
}

实现有点长，一点一点分析。

SkeletonBatch* batch = SkeletonBatch::getInstance();
	SkeletonTwoColorBatch* twoColorBatch = SkeletonTwoColorBatch::getInstance();

SkeletonBatch：骨骼合批，将所有骨骼放入合批指令中，本质上是TrianglesCommand指令。

cocos2d::TrianglesCommand* SkeletonBatch::addCommand(cocos2d::Renderer* renderer, float globalOrder, cocos2d::Texture2D* texture, cocos2d::GLProgramState* glProgramState, cocos2d::BlendFunc blendType, const cocos2d::TrianglesCommand::Triangles& triangles, const cocos2d::Mat4& mv, uint32_t flags) {
	TrianglesCommand* command = nextFreeCommand();
	command->init(globalOrder, texture, glProgramState, blendType, triangles, mv, flags);
	renderer->addCommand(command);
	return command;
}

SkeletonTwoColorBatch：双色着色合批。是TwoColorTrianglesCommand指令。

双色着色：TwoColorTint

    //是否双色着色
	bool isTwoColorTint = this->isTwoColorTint();
	//顶点动画
	if (_effect) _effect->begin(_effect, _skeleton);
    
    //计算附加着色颜色
    //用skeleton乘上(multiplying)槽位颜色来计算附件的着色颜色, 每通道的RGBA范围均为[0-1]
	Color4F nodeColor;
	nodeColor.r = getDisplayedColor().r / (float)255;
	nodeColor.g = getDisplayedColor().g / (float)255;
	nodeColor.b = getDisplayedColor().b / (float)255;
	nodeColor.a = getDisplayedOpacity() / (float)255;
	
	//双色着色使用
    Color4F color;
	Color4F darkColor;
	
	//附件顶点
	AttachmentVertices* attachmentVertices = nullptr;
	TwoColorTrianglesCommand* lastTwoColorTrianglesCommand = nullptr;

接下来遍历所有骨骼。

for (int i = 0, n = _skeleton->slotsCount; i < n; ++i)

取的时候是根据drawOrder去取的，简单说就是渲染顺序（插槽列表）。

spSlot* slot = _skeleton->drawOrder[i];
if (!slot->attachment) {
	spSkeletonClipping_clipEnd(_clipper, slot);
	continue;
}

如果插槽没有附件，那么就选择不渲染。

接下来，根据插槽附加的类型进行分别处理

SP_ATTACHMENT_REGION ： 一个textured矩形

//强制转换为spRegionAttachment结构体
spRegionAttachment* attachment = (spRegionAttachment*)slot->attachment;
//从附件的渲染对象中获取atlas页texture（纹理坐标）
attachmentVertices = getAttachmentVertices(attachment);

//如果不是双色着色
if (!isTwoColorTint) {
  //创建一个TrianglesCommand指令
	triangles.indices = attachmentVertices->_triangles->indices; //data索引 index指针
	triangles.indexCount = attachmentVertices->_triangles->indexCount; //索引index的数量
	triangles.verts = batch->allocateVertices(attachmentVertices->_triangles->vertCount); //初始化顶点数据
	triangles.vertCount = attachmentVertices->_triangles->vertCount; //顶点个数
	//填充顶点数据
	memcpy(triangles.verts, attachmentVertices->_triangles->verts, sizeof(cocos2d::V3F_C4B_T2F) * attachmentVertices->_triangles->vertCount);
	//调用RegionAttachment::computeWorldVertices计算其世界顶点
	spRegionAttachment_computeWorldVertices(attachment, slot->bone, (float*)triangles.verts, 0, 6);
} else {
//如果是双色着色，那么用TwoColorTriangles去构建顶点信息
	trianglesTwoColor.indices = attachmentVertices->_triangles->indices;
	trianglesTwoColor.indexCount = attachmentVertices->_triangles->indexCount;
	trianglesTwoColor.verts = twoColorBatch->allocateVertices(attachmentVertices->_triangles->vertCount);
	trianglesTwoColor.vertCount = attachmentVertices->_triangles->vertCount;
	for (int ii = 0; ii < trianglesTwoColor.vertCount; ii++) {
		trianglesTwoColor.verts[ii].texCoords = attachmentVertices->_triangles->verts[ii].texCoords;
	}
	spRegionAttachment_computeWorldVertices(attachment, slot->bone, (float*)trianglesTwoColor.verts, 0, 7);
}

//计算的颜色就是附件的颜色	
color.r = attachment->color.r;
color.g = attachment->color.g;
color.b = attachment->color.b;
color.a = attachment->color.a;

上面的流程就是

SP_ATTACHMENT_MESH ：一个textured网格，其顶点受到多个有权重骨詻的影响

spMeshAttachment* attachment = (spMeshAttachment*)slot->attachment;
attachmentVertices = getAttachmentVertices(attachment);
	
if (!isTwoColorTint) {
	triangles.indices = attachmentVertices->_triangles->indices;
	triangles.indexCount = attachmentVertices->_triangles->indexCount;
	triangles.verts = batch->allocateVertices(attachmentVertices->_triangles->vertCount);
	triangles.vertCount = attachmentVertices->_triangles->vertCount;
	memcpy(triangles.verts, attachmentVertices->_triangles->verts, sizeof(cocos2d::V3F_C4B_T2F) * attachmentVertices->_triangles->vertCount);
	//不同的是这里 计算世界顶点的方式
	spVertexAttachment_computeWorldVertices(SUPER(attachment), slot, 0, triangles.vertCount * sizeof(cocos2d::V3F_C4B_T2F) / 4, (float*)triangles.verts, 0, 6);
} else {
	trianglesTwoColor.indices = attachmentVertices->_triangles->indices;
	trianglesTwoColor.indexCount = attachmentVertices->_triangles->indexCount;
	trianglesTwoColor.verts = twoColorBatch->allocateVertices(attachmentVertices->_triangles->vertCount);
	trianglesTwoColor.vertCount = attachmentVertices->_triangles->vertCount;
	for (int ii = 0; ii < trianglesTwoColor.vertCount; ii++) {
		trianglesTwoColor.verts[ii].texCoords = attachmentVertices->_triangles->verts[ii].texCoords;
	}
	spVertexAttachment_computeWorldVertices(SUPER(attachment), slot, 0, trianglesTwoColor.vertCount * sizeof(V3F_C4B_C4B_T2F) / 4, (float*)trianglesTwoColor.verts, 0, 7);
}
	
color.r = attachment->color.r;
color.g = attachment->color.g;
color.b = attachment->color.b;
color.a = attachment->color.a;
	
break;

SP_ATTACHMENT_CLIPPING：一个多边形，用于在绘制中裁剪其他附件

case SP_ATTACHMENT_CLIPPING: {
	spClippingAttachment* clip = (spClippingAttachment*)slot->attachment;
	spSkeletonClipping_clipStart(_clipper, slot, clip);
}
default:
	spSkeletonClipping_clipEnd(_clipper, slot);
	continue;
}

计算附件颜色值

用skeleton乘上(multiplying)槽位颜色来计算附件的着色颜色, 每通道的RGBA范围均为[0-1]

color.a *= nodeColor.a * _skeleton->color.a * slot->color.a * 255;
// skip rendering if the color of this attachment is 0
if (color.a == 0){
	spSkeletonClipping_clipEnd(_clipper, slot);
	continue;
}
float multiplier = _premultipliedAlpha ? color.a : 255;
color.r *= nodeColor.r * _skeleton->color.r * slot->color.r * multiplier;
color.g *= nodeColor.g * _skeleton->color.g * slot->color.g * multiplier;
color.b *= nodeColor.b * _skeleton->color.b * slot->color.b * multiplier;

接下来颜色混合

BlendFunc blendFunc;
switch (slot->data->blendMode) {
	case SP_BLEND_MODE_ADDITIVE:
		blendFunc.src = _premultipliedAlpha ? GL_ONE : GL_SRC_ALPHA;
		blendFunc.dst = GL_ONE;
		break;
	case SP_BLEND_MODE_MULTIPLY:
		blendFunc.src = GL_DST_COLOR;
		blendFunc.dst = GL_ONE_MINUS_SRC_ALPHA;
		break;
	case SP_BLEND_MODE_SCREEN:
		blendFunc.src = GL_ONE;
		blendFunc.dst = GL_ONE_MINUS_SRC_COLOR;
		break;
	default:
		blendFunc.src = _premultipliedAlpha ? GL_ONE : GL_SRC_ALPHA;
		blendFunc.dst = GL_ONE_MINUS_SRC_ALPHA;
}

根据是否有裁剪附件，来添加batch渲染指令

如果有裁剪，优先处理裁剪，剔除掉裁剪区域外的纹理和顶点坐标。

然后在判断是否有顶点动画