Cocos2dx内的坐标系(Coordinate Systems In Cocos2dx)

窗口坐标系：即openGL坐标系，左下角为原点，向右是x正方向，向上是y正方向。

纹理坐标系：左上角为原点，向右是x正方向，向下是y正方向。在使用图集时，例如截取其中的某个矩形块来创建一个sprite会用到此坐标系。

Window Coordinate System: which uses the openGL coordinate system, has an origin at the left bottom corner, x increases towards the rightside and y increases towards the upside.

Texture Coordinate System: which has an origin at the top left corner, with x increasing towards the rightside and y increasing towards the downside.This coordinate system will be used when you use a tileset, like using a rect from it to create a sprite.

code example:

CCSpriteBatchNode* batchnode = CCSpriteBatchNode::create("data/tileset/grass.png");
CCSprite* sprite= CCSprite::createWithTexture(batchnode->getTexture(), CCRectMake(0,0,48,32));
batchnode->addChild(bnsprite);
this->addChild(batchnode);

The second line in this code fragment, created an sprite,using a 48*32 rect on the top left corner of the texture.