cocos2d-x ccsprite 使用 shader生成自己想要的颜色的图片

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1. class BYGraySprite : public CCSprite{  
2.       
3. public:  
4.     BYGraySprite();  
5.     virtual ~BYGraySprite();  
6.     static BYGraySprite* create(const char* pszFileName);  
7.     bool initWithTexture(CCTexture2D* pTexture, const CCRect& tRect);  
8.     virtual void draw();  
9. };  

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1. #include "BYGraySprite.h"  
2. BYGraySprite::BYGraySprite(){  
3.       
4. }  
5.   
6. BYGraySprite::~BYGraySprite(){  
7.       
8. }  
9.   
10. BYGraySprite* BYGraySprite::create( const char* pszFileName ){  
11.     BYGraySprite* graySprite = new BYGraySprite;  
12.     if (graySprite && graySprite->initWithFile(pszFileName)){  
13.         graySprite->autorelease();  
14.         return graySprite;  
15.     }else{  
16.         CC_SAFE_RELEASE(graySprite);  
17.         return NULL;  
18.     }  
19. }  
20.   
21. bool BYGraySprite::initWithTexture(CCTexture2D* pTexture, const CCRect& tRect ){  
22.     do{  
23.         CC_BREAK_IF(!CCSprite::initWithTexture(pTexture, tRect));  
24.           
25.         GLchar* pszFragSource =  
26.         "#ifdef GL_ES \n \  
27.         precision mediump float; \n \  
28.         #endif \n \  
29.         uniform sampler2D u_texture; \n \  
30.         varying vec2 v_texCoord; \n \  
31.         varying vec4 v_fragmentColor; \n \  
32.         void main(void) \n \  
33.         { \n \  
34.         // Convert to greyscale using NTSC weightings \n \  
35.         float grey = dot(texture2D(u_texture, v_texCoord).rgba, vec4(0.5, 0.0, 0.0,0.7)); \n \  
36.         gl_FragColor = vec4(grey, 0.0, 0.0, 0.0); \n \  
37.         }";  
38.           
39.         CCGLProgram* pProgram = new CCGLProgram();  
40.         pProgram->initWithVertexShaderByteArray(ccPositionTextureColor_vert, pszFragSource);  
41.         this->setShaderProgram(pProgram);  
42.         pProgram->release();  
43.         CHECK_GL_ERROR_DEBUG();  
44.           
45.         this->getShaderProgram()->addAttribute(kCCAttributeNamePosition, kCCVertexAttrib_Position);  
46.         this->getShaderProgram()->addAttribute(kCCAttributeNameColor, kCCVertexAttrib_Color);  
47.         this->getShaderProgram()->addAttribute(kCCAttributeNameTexCoord, kCCVertexAttrib_TexCoords);  
48.         CHECK_GL_ERROR_DEBUG();  
49.           
50.         this->getShaderProgram()->link();  
51.         CHECK_GL_ERROR_DEBUG();  
52.           
53.         this->getShaderProgram()->updateUniforms();  
54.         CHECK_GL_ERROR_DEBUG();  
55.           
56.         return true;  
57.     } while (0);  
58.     return false;  
59. }  
60.   
61. void BYGraySprite::draw(){  
62.     ccGLEnableVertexAttribs(kCCVertexAttribFlag_PosColorTex );  
63.     ccGLBlendFunc( m_sBlendFunc.src, m_sBlendFunc.dst );  
64.       
65.     this->getShaderProgram()->use();  
66.     this->getShaderProgram()->setUniformForModelViewProjectionMatrix();  
67.       
68.     ccGLBindTexture2D( this->getTexture()->getName() );  
69.       
70. #define kQuadSize sizeof(m_sQuad.bl)  
71.     long offset = (long)&m_sQuad;  
72.       
73.     // vertex  
74.     int diff = offsetof( ccV3F_C4B_T2F, vertices);  
75.     glVertexAttribPointer(kCCVertexAttrib_Position, 3, GL_FLOAT, GL_FALSE, kQuadSize, (void*) (offset + diff));  
76.       
77.     // texCoods  
78.     diff = offsetof( ccV3F_C4B_T2F, texCoords);  
79.     glVertexAttribPointer(kCCVertexAttrib_TexCoords, 2, GL_FLOAT, GL_FALSE, kQuadSize, (void*)(offset + diff));  
80.       
81.     // color  
82.     diff = offsetof( ccV3F_C4B_T2F, colors);  
83.     glVertexAttribPointer(kCCVertexAttrib_Color, 4, GL_UNSIGNED_BYTE, GL_TRUE, kQuadSize, (void*)(offset + diff));  
84.     glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);  
85.     CC_INCREMENT_GL_DRAWS(1);  
86. }  

使用

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1. BYGraySprite* graySprite = BYGraySprite::create("boss.png");  
2. graySprite->setPosition(ccp(480,320) );  
3. addChild(graySprite);