cocos2dx 图片变灰及正常显示实现(lua可以调用)

图片变灰, 采用shader就可以实现,  

有2中方法,

1,  像CCSprite一样create

2.  把CCSprite传进来, 并把图片要不要变灰的flag传进来, 具体实现看代码和后面的使用方法

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GraySprite.h

////  GraySprite.h//  goddess////  Created by rekoo on 13-7-23.////#ifndef __goddess__GraySprite__#define __goddess__GraySprite__#include "cocos2d.h"#include "cocos-ext.h"USING_NS_CC;USING_NS_CC_EXT;class GraySprite : public CCSprite{public:    GraySprite();    ~GraySprite();                                               bool initWithTexture(CCTexture2D* texture, const CCRect&  rect);    void draw();    void initProgram();    void listenBackToForeground(CCObject *obj);                                               static GraySprite* create(const char *pszFileName);                                           };#endif /* defined(__goddess__GraySprite__) */

GraySprite.cpp

////  GraySprite.cpp//  goddess////  Created by rekoo on 13-7-23.////// 用shader创建灰度图， 用法跟sprite一样//  lua用法： local sprite = GraySprite:create("pic.png")#include "GraySprite.h"GraySprite::GraySprite(){}GraySprite::~GraySprite(){}GraySprite* GraySprite::create(const char *pszFileName){    GraySprite* pRet = new GraySprite();    if (pRet && pRet->initWithFile(pszFileName))    {        pRet->autorelease();    }    else    {        CC_SAFE_DELETE(pRet);    }                                           return pRet;}void GraySprite::listenBackToForeground(CCObject *obj){    setShaderProgram(NULL);    initProgram();}bool GraySprite::initWithTexture(CCTexture2D* texture, const CCRect& rect){    if( CCSprite::initWithTexture(texture, rect) )    {                                                           CCSize s = getTexture()->getContentSizeInPixels();                                                this->initProgram();                                                   return true;    }                                           return false;}void GraySprite::initProgram(){//    GLchar * fragSource = (GLchar*) CCString::createWithContentsOfFile(//                                                                       CCFileUtils::sharedFileUtils()->fullPathForFilename("Shaders/example_Blur.fsh").c_str())->getCString();                                         const  GLchar * pfrag =    "#ifdef GL_ES \n \    precision mediump float; \n \    #endif \n\    uniform sampler2D u_texture; \n \    varying vec2 v_texCoord; \n \    varying vec4 v_fragmentColor; \n \    void main(void) \n \    { \n \    float alpha = texture2D(u_texture, v_texCoord).a; \n \    float grey = dot(texture2D(u_texture, v_texCoord).rgb, vec3(0.299,0.587,0.114)); \n \    gl_FragColor = vec4(grey, grey, grey,alpha); \n \    } ";                                                                               CCGLProgram* pProgram = new CCGLProgram();    pProgram->initWithVertexShaderByteArray(ccPositionTextureColor_vert, pfrag);    setShaderProgram(pProgram);    pProgram->release();                                           CHECK_GL_ERROR_DEBUG();                                           getShaderProgram()->addAttribute(kCCAttributeNamePosition, kCCVertexAttrib_Position);    getShaderProgram()->addAttribute(kCCAttributeNameColor, kCCVertexAttrib_Color);    getShaderProgram()->addAttribute(kCCAttributeNameTexCoord, kCCVertexAttrib_TexCoords);                                           CHECK_GL_ERROR_DEBUG();                                           getShaderProgram()->link();                                           CHECK_GL_ERROR_DEBUG();                                           getShaderProgram()->updateUniforms();                                       }void GraySprite::draw(){    ccGLEnableVertexAttribs(kCCVertexAttribFlag_PosColorTex );    ccBlendFunc blend = getBlendFunc();    ccGLBlendFunc(blend.src, blend.dst);                                           getShaderProgram()->use();    getShaderProgram()->setUniformsForBuiltins();                                                                                  ccGLBindTexture2D( getTexture()->getName());                                           //    // Attributes    //#define kQuadSize sizeof(m_sQuad.bl)    long offset = (long)&m_sQuad;                                           // vertex    int diff = offsetof( ccV3F_C4B_T2F, vertices);    glVertexAttribPointer(kCCVertexAttrib_Position, 3, GL_FLOAT, GL_FALSE, kQuadSize, (void*) (offset + diff));                                           // texCoods    diff = offsetof( ccV3F_C4B_T2F, texCoords);    glVertexAttribPointer(kCCVertexAttrib_TexCoords, 2, GL_FLOAT, GL_FALSE, kQuadSize, (void*)(offset + diff));                                           // color    diff = offsetof( ccV3F_C4B_T2F, colors);    glVertexAttribPointer(kCCVertexAttrib_Color, 4, GL_UNSIGNED_BYTE, GL_TRUE, kQuadSize, (void*)(offset + diff));                                                                                  glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);                                           CC_INCREMENT_GL_DRAWS(1);}

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使用例子:

1.  GraySprite * gs = GraySprite::create("01.png");

剩下跟CCSprite一样, 设置位置, addChild等等

2. CCSprite * cs = CCSprite::create("02.png");

GraySprite::setGray(cs, 1);   //变灰

GraySprite::setGray(cs, 0);  //原色

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把GraySprte暴露出去, lua就可以调用, 很方便