visit区域剪裁

游戏主城比较大，支持拖动与缩放，m_touchLayer变量内取得位置偏移量与scale比例。

void testLayer::visit(void)

{

    glEnable(GL_SCISSOR_TEST);

    CCPoint    selfPos = ccpAdd(this->getParent()->getPosition(), m_touchLayer->getPosition());

    

    CCSize     selfContentSize =  this->getContentSize();

    

    CCLOG("selfPos = %f,%f, selfContentSize =%f,%f", selfPos.x, selfPos.y ,selfContentSize.width, selfContentSize.height );

    

    float   scaleX = CCEGLView::sharedOpenGLView()->getScaleX() * m_touchLayer->getScaleX();

    float   scaleY = CCEGLView::sharedOpenGLView()->getScaleY() * m_touchLayer->getScaleY();

    

    CCLOG("scale = %f,%f,m_bg->scale = %f,%f",scaleX,scaleY,m_touchLayer->getScaleX(),m_touchLayer->getScaleY());

    

    CCRect   viewPortRect =  CCEGLView::sharedOpenGLView()->getViewPortRect();

    

    glScissor(selfPos.x *scaleX  +  viewPortRect.origin.x  ,

              selfPos.y * scaleY  +  viewPortRect.origin.y ,

              selfContentSize.width*scaleX,

              selfContentSize.height*scaleY);

    

    

    CCNode::visit();//显示父类的内容

    glDisable(GL_SCISSOR_TEST);

}