Cocos2dx 像素判断碰撞检测

最近研究了一下透明图片的点击事件即png图片中透明区域的点击。当时用j2me的时候，记得设置个值就可以处理是像素点击还是图片点击，不对，是碰撞检测。看了看jdk，它处理了像素，处理如下： public void handlesinglepixel(int x, int y, int pixel) { int alpha = (pixel >> 24) & 0xff; int red = (pixel >> 16) & 0xff; int green = (pixel >> 8) & 0xff; int blue = (pixel ) & 0xff; // Deal with the pixel as necessary... } 复制代码 这时候使用的像素格式是ARGB。 bool CCTexture2D::initPremultipliedATextureWithImage(CCImage *image, unsigned int width, unsigned int height) { unsigned char* tempData = image->getData(); this->setFDImageData(tempData); unsigned int* inPixel32 = NULL; unsigned char* inPixel8 = NULL; unsigned short* outPixel16 = NULL; bool hasAlpha = image->hasAlpha(); CCSize imageSize = CCSizeMake((float)(image->getWidth()), (float)(image->getHeight())); CCTexture2DPixelFormat pixelFormat; size_t bpp = image->getBitsPerComponent(); // compute pixel format if(hasAlpha) { pixelFormat = g_defaultAlphaPixelFormat; } else { if (bpp >= 8) { pixelFormat = kCCTexture2DPixelFormat_RGB888; } else { pixelFormat = kCCTexture2DPixelFormat_RGB565; } } // Repack the pixel data into the right format unsigned int length = width * height; if (pixelFormat == kCCTexture2DPixelFormat_RGB565) { if (hasAlpha) { // Convert "RRRRRRRRRGGGGGGGGBBBBBBBBAAAAAAAA" to "RRRRRGGGGGGBBBBB" tempData = new unsigned char[width * height * 2]; outPixel16 = (unsigned short*)tempData; inPixel32 = (unsigned int*)image->getData(); for(unsigned int i = 0; i < length; ++i, ++inPixel32) { *outPixel16++ = ((((*inPixel32 >> 0) & 0xFF) >> 3) << 11) | // R ((((*inPixel32 >> 8) & 0xFF) >> 2) << 5) | // G ((((*inPixel32 >> 16) & 0xFF) >> 3) << 0); // B } } else { // Convert "RRRRRRRRRGGGGGGGGBBBBBBBB" to "RRRRRGGGGGGBBBBB" tempData = new unsigned char[width * height * 2]; outPixel16 = (unsigned short*)tempData; inPixel8 = (unsigned char*)image->getData(); for(unsigned int i = 0; i < length; ++i) { *outPixel16++ = (((*inPixel8++ & 0xFF) >> 3) << 11) | // R (((*inPixel8++ & 0xFF) >> 2) << 5) | // G (((*inPixel8++ & 0xFF) >> 3) << 0); // B } } } else if (pixelFormat == kCCTexture2DPixelFormat_RGBA4444) { // Convert "RRRRRRRRRGGGGGGGGBBBBBBBBAAAAAAAA" to "RRRRGGGGBBBBAAAA" inPixel32 = (unsigned int*)image->getData(); tempData = new unsigned char[width * height * 2]; outPixel16 = (unsigned short*)tempData; for(unsigned int i = 0; i < length; ++i, ++inPixel32) { *outPixel16++ = ((((*inPixel32 >> 0) & 0xFF) >> 4) << 12) | // R ((((*inPixel32 >> 8) & 0xFF) >> 4) << 8) | // G ((((*inPixel32 >> 16) & 0xFF) >> 4) << 4) | // B ((((*inPixel32 >> 24) & 0xFF) >> 4) << 0); // A } } else if (pixelFormat == kCCTexture2DPixelFormat_RGB5A1) { // Convert "RRRRRRRRRGGGGGGGGBBBBBBBBAAAAAAAA" to "RRRRRGGGGGBBBBBA" inPixel32 = (unsigned int*)image->getData(); tempData = new unsigned char[width * height * 2]; outPixel16 = (unsigned short*)tempData; for(unsigned int i = 0; i < length; ++i, ++inPixel32) { *outPixel16++ = ((((*inPixel32 >> 0) & 0xFF) >> 3) << 11) | // R ((((*inPixel32 >> 8) & 0xFF) >> 3) << 6) | // G ((((*inPixel32 >> 16) & 0xFF) >> 3) << 1) | // B ((((*inPixel32 >> 24) & 0xFF) >> 7) << 0); // A } } else if (pixelFormat == kCCTexture2DPixelFormat_A8) { // Convert "RRRRRRRRRGGGGGGGGBBBBBBBBAAAAAAAA" to "AAAAAAAA" inPixel32 = (unsigned int*)image->getData(); tempData = new unsigned char[width * height]; unsigned char *outPixel8 = tempData; for(unsigned int i = 0; i < length; ++i, ++inPixel32) { *outPixel8++ = (*inPixel32 >> 24) & 0xFF; // A } } if (hasAlpha && pixelFormat == kCCTexture2DPixelFormat_RGB888) { // Convert "RRRRRRRRRGGGGGGGGBBBBBBBBAAAAAAAA" to "RRRRRRRRGGGGGGGGBBBBBBBB" inPixel32 = (unsigned int*)image->getData(); tempData = new unsigned char[width * height * 3]; unsigned char *outPixel8 = tempData; for(unsigned int i = 0; i < length; ++i, ++inPixel32) { *outPixel8++ = (*inPixel32 >> 0) & 0xFF; // R *outPixel8++ = (*inPixel32 >> 8) & 0xFF; // G *outPixel8++ = (*inPixel32 >> 16) & 0xFF; // B } } initWithData(tempData, pixelFormat, width, height, imageSize); if (tempData != image->getData()) { delete [] tempData; } m_bHasPremultipliedAlpha = image->isPremultipliedAlpha(); return true; } 复制代码 那么，在2dx中，我们也是可以这么处理的，首先看纹理中的一个函数： 这里面针对kCCTexture2DPixelFormat_RGB888像素格式的图片进行了这么的处理： *outPixel8++ = (*inPixel32 >> 0) & 0xFF; // R *outPixel8++ = (*inPixel32 >> 8) & 0xFF; // G *outPixel8++ = (*inPixel32 >> 16) & 0xFF; // B 复制代码 那么，我们就可以考虑在点击事件中处理这个透明区域的问题了，began事件如下： bool FDPixelSprite::ccTouchBegan(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent) { if (this->isContainTouchLocation(pTouch) ) { ccColor4B c = {0, 0, 0, 0}; CCSize winSize = CCDirector::sharedDirector()->getWinSize(); CCPoint touchPoint = pTouch->getLocationInView(); CCSize cSize = this->getContentSize(); CCPoint pos(this->getPositionX() - cSize.width/2,winSize.height-this->getPositionY()- cSize.height/2); CCPoint localPoint = ccp(touchPoint.x - pos.x, touchPoint.y -pos.y); unsigned int x = localPoint.x, y = localPoint.y; unsigned char *data_ = this->getTexture()->getFDImageData(); unsigned int *pixel = (unsigned int *)data_; pixel = pixel + (y * (int)this->getContentSize().width)* 1 + x * 1; c.r = *pixel & 0xff; c.g = (*pixel >> 8) & 0xff; c.b = (*pixel >> 16) & 0xff; c.a = (*pixel >> 24) & 0xff; if (c.a == 0) { CCLog("firedragonpzy:ccTouchBegan"); return false; }else { return true; } } return false; } 复制代码 处理原理： 获取点击的像素，判断当前的a值是否为0，若为0，则是透明区域。 注意点： 图片的坐标原点在图片的左上角，这里大家需要做一下坐标的转化，把点击屏幕的坐标转化为相对于图像左上角的坐标即可。 关于图像，它的颜色表示分为：R、G、B、A四部分，各占八位。 代码中：*pixel >> (n)bit，为了得到单独的red,green,blue,alpha值，具体得到什么，目前不是很清楚，貌似什么进制【时间原因，改日谈……】不过可以给大家提供个例子。 网上例子(jdk)： 比如大红色用整数表示就是00 FF 00 00 pixel >> somebits是为了得到单独的alpha,red,green,blue值 右移24与255与操作得到alpha 16位得到red…… 如果不& 0xff的话，上面的int green = (pixel >>  8) & 0xff; 得到的green值是FF 00 也就是65280，当然就不是我们要得到值 与操作是为了把高位削去!!!! 【因为pixel是一个整数 图像的表示分四部分：alpha值，red,green,blue 每一个值占一个字节，一个字节有8位二进制】 求解释……欢迎拍砖…… 推荐阅读：http://www.cocos2d-x.org/boards/6/topics/3472 注意啦，注意啦，下面还有个赠送篇、、、、【产生赠送篇的缘由：一群友说如果设置了锚点，怎么处理啊，那代码起不是不对了，所以我又产生了赠送篇，不过使用精灵的时候，基本都是以(0.5,0.5)为锚点，我开始没考虑这问题是源于这，呵呵，假设你锚点不是(0.5,0.5)旋转什么的可能就……效果不好。不过既然有不是CCPointZero的需求，我就写了支持不同锚点的FDPixelSprite,不过建议大家使用针对锚点为(0.5,0.5)的，效率高……】 现在贴出我的FDPixelSprite，大家可以直接使用此精灵处理含有透明区域图片的点击问题： FDPixelSprite.h // // FDPixelSprite.h // PixelDemo // // Created by firedragonpzy on 13-2-19. // // #ifndef __PixelDemo__FDPixelSprite__ #define __PixelDemo__FDPixelSprite__ #include "cocos2d.h" USING_NS_CC; class FDPixelSprite : public CCSprite, public CCTargetedTouchDelegate { public: FDPixelSprite(); virtual ~FDPixelSprite(); void onEnter(); void onExit(); static FDPixelSprite* create( const char *pszFileName ); CCRect atlasRect(); bool isContainTouchLocation(CCTouch *pTouch); bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent); void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent); void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent); CC_SYNTHESIZE(const char*, m_pName,Name); }; #endif /* defined(__PixelDemo__FDPixelSprite__) */ 复制代码 FDPixelSprite.cpp // // FDPixelSprite.cpp // PixelDemo // // Created by firedragonpzy on 13-2-19. // // #include "FDPixelSprite.h" FDPixelSprite::FDPixelSprite() {} FDPixelSprite::~FDPixelSprite() {} FDPixelSprite* FDPixelSprite::create(const char *pszFileName) { FDPixelSprite *sprite = new FDPixelSprite(); if (sprite && sprite->initWithFile(pszFileName)) { sprite->setName(pszFileName); sprite->autorelease(); return sprite; } CC_SAFE_DELETE(sprite); sprite = NULL; return NULL; } void FDPixelSprite::onEnter() { CCSprite::onEnter(); CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, 0, true); } void FDPixelSprite::onExit() { CCSprite::onExit(); CCDirector::sharedDirector()->getTouchDispatcher()->removeDelegate(this); } bool FDPixelSprite::ccTouchBegan(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent) { if (this->isContainTouchLocation(pTouch) ) { ccColor4B c = {0, 0, 0, 0}; CCSize winSize = CCDirector::sharedDirector()->getWinSize(); CCPoint touchPoint = pTouch->getLocationInView(); CCSize cSize = this->getContentSize(); CCPoint pos(this->getPositionX() - cSize.width/2,winSize.height-this->getPositionY()- cSize.height/2); CCPoint localPoint = ccp(touchPoint.x - pos.x, touchPoint.y -pos.y); unsigned int x = localPoint.x, y = localPoint.y; unsigned char *data_ = this->getTexture()->getFDImageData(); unsigned int *pixel = (unsigned int *)data_; pixel = pixel + (y * (int)this->getContentSize().width)* 1 + x * 1; c.r = *pixel & 0xff; c.g = (*pixel >> 8) & 0xff; c.b = (*pixel >> 16) & 0xff; c.a = (*pixel >> 24) & 0xff; if (c.a == 0) { CCLog("firedragonpzy:ccTouchBegan"); return false; }else { return true; } } return false; } void FDPixelSprite::ccTouchMoved(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent) { CCPoint pos = this->getPosition(); CCPoint sub = pTouch->getDelta(); this->setPosition(ccpAdd(pos, sub)); } void FDPixelSprite::ccTouchEnded(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent) { CCLog("firedragonpzy:ccTouchEnded"); } CCRect FDPixelSprite::atlasRect() { CCSize cSize = this->getContentSize(); return CCRectMake(-cSize.width/2, -cSize.height/2, cSize.width, cSize.height); } bool FDPixelSprite::isContainTouchLocation(cocos2d::CCTouch *pTouch) { return this->atlasRect().containsPoint(convertTouchToNodeSpaceAR(pTouch)); } 复制代码 ————————————–赠送篇———————————————- 为什么产生赠送篇 ，上面已经解释的很清楚了，不废话了，开门见山： 改为适配不同锚点需要改动两个地方： （一）：区域的判断： CCRect FDPixelSprite::atlasRect() { CCSize cSize = this->getContentSize(); CCPoint point = this->getAnchorPointInPoints(); return CCRectMake( -point.x, -point.y, cSize.width,cSize.height); } 复制代码 （二）相对于图片像素的转化 复制代码 bool FDPixelSprite::ccTouchBegan(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent) { if (this->isContainTouchLocation(pTouch) ) { ccColor4B c = {0, 0, 0, 0}; CCSize winSize = CCDirector::sharedDirector()->getWinSize(); CCPoint touchPoint = pTouch->getLocationInView(); CCSize cSize = this->getContentSize(); CCPoint point =this->getAnchorPointInPoints(); point = ccp(cSize.width - point.x,cSize.height- point.y); CCPoint pos(this->getPositionX() - point.x,winSize.height-this->getPositionY()- point.y); CCPoint localPoint = ccp(touchPoint.x - pos.x, touchPoint.y -pos.y); unsigned int x = localPoint.x, y = localPoint.y; unsigned char *data_ = this->getTexture()->getFDImageData(); unsigned int *pixel = (unsigned int *)data_; pixel = pixel + (y * (int)this->getContentSize().width)* 1 + x * 1; c.r = *pixel & 0xff; c.g = (*pixel >> 8) & 0xff; c.b = (*pixel >> 16) & 0xff; c.a = (*pixel >> 24) & 0xff; if (c.a == 0) { CCLog("firedragonpzy:ccTouchBegan----------"); return false; }else { return true; } } return false; }