[cocos2d-x]对CCSprite进行高斯模糊

摘要  cocos2d-x 2.2.1 中没有直接用于模糊精灵的类，但是在TestCpp里面的ShaderTest实现了高斯模糊。于是直接搬过来用就行了。

cocos2d-x  高斯模糊  精灵  blur

你可以从下面的目录找到示例的源代码：

cocos2d-x-2.2.1\samples\Cpp\TestCpp\Classes\ShaderTest

SpriteBlur类用于实现高斯模糊，但并没有定义在ShaderTest.h中，打开ShaderTest.cpp，大概在488行有这个类的定义和实现：

01 // ShaderBlur
02
03 class SpriteBlur : public CCSprite
04 {
05 public:
06     ~SpriteBlur();
07     void setBlurSize(float f);
08     bool initWithTexture(CCTexture2D* texture, const CCRect&  rect);
09     void draw();
10     void initProgram();
11     void listenBackToForeground(CCObject *obj);
12
13     static SpriteBlur* create(const char *pszFileName);
14
15     CCPoint blur_;
16     GLfloat    sub_[4];
17
18     GLuint    blurLocation;
19     GLuint    subLocation;
20 };

实现：

001 SpriteBlur::~SpriteBlur()
002 {
003     CCNotificationCenter::sharedNotificationCenter()->removeObserver(this, EVENT_COME_TO_FOREGROUND);
004 }
005
006 SpriteBlur* SpriteBlur::create(const char *pszFileName)
007 {
008     SpriteBlur* pRet = new SpriteBlur();
009     if (pRet && pRet->initWithFile(pszFileName))
010     {
011         pRet->autorelease();
012     }
013     else
014     {
015         CC_SAFE_DELETE(pRet);
016     }
017
018     return pRet;
019 }
020
021 void SpriteBlur::listenBackToForeground(CCObject *obj)
022 {
023     setShaderProgram(NULL);
024     initProgram();
025 }
026
027 bool SpriteBlur::initWithTexture(CCTexture2D* texture, const CCRect& rect)
028 {
029     if( CCSprite::initWithTexture(texture, rect) )
030     {
031         CCNotificationCenter::sharedNotificationCenter()->addObserver(this,
032                                                                       callfuncO_selector(SpriteBlur::listenBackToForeground),
033                                                                       EVENT_COME_TO_FOREGROUND,
034                                                                       NULL);
035
036         CCSize s = getTexture()->getContentSizeInPixels();
037
038         blur_ = ccp(1/s.width, 1/s.height);
039         sub_[0] = sub_[1] = sub_[2] = sub_[3] = 0;
040
041         this->initProgram();
042
043         return true;
044     }
045
046     return false;
047 }
048
049 void SpriteBlur::initProgram()
050 {
051     GLchar * fragSource = (GLchar*) CCString::createWithContentsOfFile(
052                                 CCFileUtils::sharedFileUtils()->fullPathForFilename("Shaders/example_Blur.fsh").c_str())->getCString();
053     CCGLProgram* pProgram = new CCGLProgram();
054     pProgram->initWithVertexShaderByteArray(ccPositionTextureColor_vert, fragSource);
055     setShaderProgram(pProgram);
056     pProgram->release();
057
058     CHECK_GL_ERROR_DEBUG();
059
060     getShaderProgram()->addAttribute(kCCAttributeNamePosition, kCCVertexAttrib_Position);
061     getShaderProgram()->addAttribute(kCCAttributeNameColor, kCCVertexAttrib_Color);
062     getShaderProgram()->addAttribute(kCCAttributeNameTexCoord, kCCVertexAttrib_TexCoords);
063
064     CHECK_GL_ERROR_DEBUG();
065
066     getShaderProgram()->link();
067
068     CHECK_GL_ERROR_DEBUG();
069
070     getShaderProgram()->updateUniforms();
071
072     CHECK_GL_ERROR_DEBUG();
073
074     subLocation = glGetUniformLocation( getShaderProgram()->getProgram(), "substract");
075     blurLocation = glGetUniformLocation( getShaderProgram()->getProgram(), "blurSize");
076
077     CHECK_GL_ERROR_DEBUG();
078 }
079
080 void SpriteBlur::draw()
081 {
082     ccGLEnableVertexAttribs(kCCVertexAttribFlag_PosColorTex );
083     ccBlendFunc blend = getBlendFunc();
084     ccGLBlendFunc(blend.src, blend.dst);
085
086     getShaderProgram()->use();
087     getShaderProgram()->setUniformsForBuiltins();
088     getShaderProgram()->setUniformLocationWith2f(blurLocation, blur_.x, blur_.y);
089     getShaderProgram()->setUniformLocationWith4fv(subLocation, sub_, 1);
090
091     ccGLBindTexture2D( getTexture()->getName());
092
093     //
094     // Attributes
095     //
096 #define kQuadSize sizeof(m_sQuad.bl)
097     long offset = (long)&m_sQuad;
098
099     // vertex
100     int diff = offsetof( ccV3F_C4B_T2F, vertices);
101     glVertexAttribPointer(kCCVertexAttrib_Position, 3, GL_FLOAT, GL_FALSE, kQuadSize, (void*) (offset + diff));
102
103     // texCoods
104     diff = offsetof( ccV3F_C4B_T2F, texCoords);
105     glVertexAttribPointer(kCCVertexAttrib_TexCoords, 2, GL_FLOAT, GL_FALSE, kQuadSize, (void*)(offset + diff));
106
107     // color
108     diff = offsetof( ccV3F_C4B_T2F, colors);
109     glVertexAttribPointer(kCCVertexAttrib_Color, 4, GL_UNSIGNED_BYTE, GL_TRUE, kQuadSize, (void*)(offset + diff));
110
111
112     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
113
114     CC_INCREMENT_GL_DRAWS(1);
115 }
116
117 void SpriteBlur::setBlurSize(float f)
118 {
119     CCSize s = getTexture()->getContentSizeInPixels();
120
121     blur_ = ccp(1/s.width, 1/s.height);
122     blur_ = ccpMult(blur_,f);
123 }

好了，直接copy到你的program里面，不过有一点需要注意，就是他这个只能用一个文件(图片)create，如果需要用一个Texture初始化(因为有时候需要模糊即时的sprite)，可以稍微改装一下，加一个函数：

1 static SpriteBlur* createWithTexture(CCTexture2D *pTexture);

实现：

01 SpriteBlur* SpriteBlur::createWithTexture(CCTexture2D *pTexture)
02 {
03     CCAssert(pTexture != NULL, "Invalid texture for sprite");
04
05     CCRect rect = CCRectZero;
06     rect.size = pTexture->getContentSize();
07
08     SpriteBlur* pRet = new SpriteBlur();
09     if (pRet && pRet->initWithTexture(pTexture,rect))
10     {
11         pRet->autorelease();
12     }
13     else
14     {
15         CC_SAFE_DELETE(pRet);
16     }
17
18     return pRet;
19 }

用法：

1 SpriteBlur *bluredSpr = SpriteBlur::createWithTexture(tex);
2 bluredSpr->setPosition(ccp(sz.width/2,sz.height/2));
3 bluredSpr->setBlurSize(0.9f); // 这里稍微设小一点
4 addChild(bluredSpr);

效果：

注意：

他需要一个fsh文件（具体看它的实现），似乎是叠texture用的，找到example_Blur.fsh放到你的Resources\Shaders目录下