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http://galoisplusplus.coding....
之前曾经在cocos2d-x V3.x不规则按钮探讨过在cocos2d-x 3.x版本实现不规则按钮的方法,后来本渣又琢磨了下仿照RenderTexture类调用OpenGL ES API来获取图片像素信息的方式。这种方式由于按钮图片的Texture已在内存中,且不需要解析图片文件格式,因此相比之前用Image::initWithImageFile还是要快一些的。
重写的loadNormalTransparentInfo
函数如下:
void IrregularButton::loadNormalTransparentInfo() { #ifdef DEBUG auto start = std::chrono::steady_clock::now(); #endif Sprite* normalRenderer = static_cast<Sprite*>(_buttonNormalRenderer); auto normalTexture = normalRenderer->getTexture(); const Size& s = normalTexture->getContentSizeInPixels(); int savedBufferWidth = (int)s.width; int savedBufferHeight = (int)s.height; GLubyte *buffer = nullptr; // the FBO which cocos2dx used is not window-system-provided (non-zero id) GLint oldFBO; glGetIntegerv(GL_FRAMEBUFFER_BINDING,&oldFBO); GLuint framebuffer; glGenFramebuffers(1,&framebuffer); glBindFramebuffer(GL_FRAMEBUFFER,framebuffer); glBindTexture(GL_TEXTURE_2D,normalTexture->getName()); glTexImage2D(GL_TEXTURE_2D,GL_RGBA4,savedBufferWidth,savedBufferHeight,GL_RGBA,GL_UNSIGNED_BYTE,0); glFramebufferTexture2D(GL_FRAMEBUFFER,GL_COLOR_ATTACHMENT0,GL_TEXTURE_2D,normalTexture->getName(),0); CCASSERT(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE,"Could not attach texture to framebuffer"); buffer = new (std::nothrow) GLubyte[savedBufferWidth * savedBufferHeight * 4]; glPixelStorei(GL_PACK_ALIGNMENT,1); glReadPixels(0,buffer); glBindFramebuffer(GL_FRAMEBUFFER,oldFBO); auto dataLen = savedBufferWidth * savedBufferHeight * 4; if (normalTransparent_ != nullptr) { delete[] normalTransparent_; } normalImageWidth_ = savedBufferWidth; normalImageHeight_ = savedBufferHeight; normalTransparent_ = new bool[dataLen / (sizeof(unsigned char) * 4)]; for (auto i = 0; i < normalImageHeight_; i++) { for (auto j = 0; j < normalImageWidth_; j++) { normalTransparent_[i * normalImageWidth_ + j] = (buffer[(i * normalImageWidth_ + j) * 4 + 3] == 0); } } CC_SAFE_DELETE_ARRAY(buffer); #ifdef DEBUG auto end = std::chrono::steady_clock::now(); auto totalTime = std::chrono::duration_cast<std::chrono::milliseconds>(end - start); printf("load from memory: %lld ms\n",totalTime.count()); #endif }