裁切区域

新建工程testClip

添加类ClipLayer

ClipLayer.h

//

//  ClipLayer.h

//  testClip

//

//  Created by cloud on 13-4-11.

//

//

#ifndef __testClip__ClipLayer__

#define __testClip__ClipLayer__

#include "cocos2d.h"

using namespace cocos2d;

class ClipLayer:public CCLayer

{

public:

    static ClipLayer *create(CCSize size);

    void clipLayerInit(CCSize size);

    void visit();

    CCSize mSize;

};

#endif /* defined(__testClip__ClipLayer__) */

ClipLayer.cpp

//

//  ClipLayer.cpp

//  testClip

//

//  Created by cloud on 13-4-11.

//

//

#include "ClipLayer.h"

ClipLayer *ClipLayer::create(CCSize size)

{

    ClipLayer *nCLayer=new ClipLayer();

    if (nCLayer&&nCLayer->init()) {

        nCLayer->autorelease();

        nCLayer->clipLayerInit(size);

        return nCLayer;

    }

    CC_SAFE_DELETE(nCLayer);

    return NULL;

}

void ClipLayer::clipLayerInit(CCSize size)

{

    mSize=size;   

    

}

void ClipLayer::visit()

{

    kmGLPushMatrix();

    

    if (m_pGrid&&m_pGrid->isActive()) {

        m_pGrid->beforeDraw();

        this->transformAncestors();

    }

    this->transform();

    

    //默认情况，剪裁是禁用的

    glEnable(GL_SCISSOR_TEST);//启用剪裁测试

    

    float s= this->getScale();//当前layer缩放的倍数

    //获取缩放倍率

    s *=CCDirector::sharedDirector()->getContentScaleFactor();

    CCPoint screenPos=this->convertToWorldSpace(this->getParent()->getPosition());

    //默认不设置Scissor的大小是整个视图的大小

    glScissor((GLint)screenPos.x, (GLint)screenPos.y, (GLsizei)(mSize.width*s), (GLsizei)(mSize.height*s));

    

    if (m_pChildren) {

        ccArray *arrayData=m_pChildren->data;

        unsigned int i=0;

        for (; i<arrayData->num; i++)

        {

            CCNode *child=(CCNode *)arrayData->arr[i];

            if(child->getZOrder()<0)

            {                

                child->visit();                

            }

            else

            {

                break;

            }

        }

        this->draw();

        for (;i<arrayData->num; i++) {

            CCNode *child=(CCNode*)arrayData->arr[i];

            child->visit();

        }

    }

    else

    {

        this->draw();

    }

    glDisable(GL_SCISSOR_TEST);//禁用剪裁

    if (m_pGrid&&m_pGrid->isActive()) {

        m_pGrid->afterDraw(this);

    }

    kmGLPopMatrix();

    

}

修改HelloWorldScene.cpp

#include "HelloWorldScene.h"

#include "SimpleAudioEngine.h"

#include "ClipLayer.h"

using namespace cocos2d;

using namespace CocosDenshion;

CCScene* HelloWorld::scene()

{

    // 'scene' is an autorelease object

    CCScene *scene = CCScene::create();

    

    // 'layer' is an autorelease object

    HelloWorld *layer = HelloWorld::create();

    // add layer as a child to scene

    scene->addChild(layer);

    // return the scene

    return scene;

}

// on "init" you need to initialize your instance

bool HelloWorld::init()

{

    //////////////////////////////

    // 1. super init first

    if ( !CCLayer::init() )

    {

        return false;

    }

#define clipMacro 3

    switch (clipMacro) {

        case 1:

        {

            CCLabelTTF *label=CCLabelTTF::create("正常精灵", "Helvetica", 24);

            label->setPosition(ccp(100,260));

            addChild(label);

            CCLabelTTF *clipLabel=CCLabelTTF::create("剪裁后的精灵", "Helvetica",24);

            clipLabel->setPosition(ccp(300,260));

            addChild(clipLabel);

            

            CCSprite *sprite=CCSprite::create("Icon.png");

            sprite->setPosition(ccpAdd(label->getPosition(), ccp(0,-100)));

            addChild(sprite);

            

            CCSprite *clipSprite=CCSprite::create("Icon.png");

            clipSprite->setPosition(ccpAdd(clipLabel->getPosition(), ccp(0,-100)));

            clipSprite->setTextureRect(CCRectMake(0, 0, 30, 30));

            addChild(clipSprite);

        }

            break;

        case 2:

        {

            CCLayer *layer=CCLayer::create();

            layer->setPosition(ccp(190,110));//Icon不应该显示全，但它显示全了，说明没剪裁

            layer->addChild(CCSprite::create("Icon.png"));

            addChild(layer);

        }

            break;

        case 3:

        {

            CCSize size = CCDirector::sharedDirector()->getWinSize();

            CCLayerColor* colorBg = CCLayerColor::create(ccc4(255, 127, 0, 255), size.width,size.height);

            addChild(colorBg);

            

            ClipLayer *clipLayer=ClipLayer::create(CCSizeMake(100, 100));

            clipLayer->setPosition(ccp(190,110));

            clipLayer->addChild(CCSprite::create("Icon.png"));

            addChild(clipLayer);

        }

            break;

        default:

            break;

    }

    

    

    return true;

}