cocos2d-x 获取图片的某像素点的RGBA颜色

原文:https://www.cnblogs.com/jaoye/archive/2013/02/19/2916501.html

        ccColor4B c = {0, 0, 0, 0};
        CCPoint pt = ccp(240,160);//要获取的点
        unsigned int x = pt.x, y = pt.y;

        CCImage * myimg = new CCImage();
        //加载 图片
        myimg->initWithImageFileThreadSafe("HelloWorld1.png");
        unsigned char *data_=myimg->getData();
        unsigned int *pixel = (unsigned int *)data_;
        pixel = pixel + (y * 480) + x;        //480 是图片的宽
        c.r = *pixel & 0xff;
        c.g = (*pixel >> 8) & 0xff;
        c.b = (*pixel >> 16) & 0xff;
        c.a = (*pixel >> 24) & 0xff;        //这个值  就是透明度