灰色图片

// 第一种

void HelloWorld::spriteToGrey(Sprite* sprite_chess)

{

Point point = sprite_chess->getPosition();

sprite_chess->setPosition(sprite_chess->getContentSize().width / 2, sprite_chess->getContentSize().height / 2);

RenderTexture *render = RenderTexture::create(sprite_chess->getContentSize().width, sprite_chess->getContentSize().height, Texture2D::PixelFormat::RGBA8888);

render->beginWithClear(0.0f, 0.0f, 0.0f, 0.0f);

sprite_chess->visit();

render->end();

Director::getInstance()->getRenderer()->render();

Image *finalImage = render->newImage();

unsigned char *pData = finalImage->getData();

int iIndex = 0;

for (int i = 0; i < finalImage->getHeight(); i++)

{

for (int j = 0; j < finalImage->getWidth(); j++)

    {

// gray

int iBPos = iIndex;

unsigned int iB = pData[iIndex];

iIndex++;

unsigned int iG = pData[iIndex];

iIndex++;

unsigned int iR = pData[iIndex];

iIndex++;

iIndex++;

unsigned int iGray = 0.3 * iR + 0.6 * iG + 0.1 * iB;

pData[iBPos] = pData[iBPos + 1] = pData[iBPos + 2] = (unsigned char)iGray;

}

}

Texture2D *texture = new Texture2D;

texture->initWithImage(finalImage);

delete finalImage;

sprite_chess->setTexture(texture);

texture->release();

sprite_chess->setPosition(point);

}

//实现Sprite或者ImageView类型的图片变灰（已修正位置偏移问题）

void HelloWorld::spriteToGrey2(Node* tempSp)

{

ImageView* imgView = dynamic_cast<ImageView*>(tempSp);

Sprite* imgView2 = dynamic_cast<Sprite*>(tempSp);

Sprite* sp = nullptr;

if (imgView) {

Scale9Sprite* scale9sp = dynamic_cast<Scale9Sprite*>(imgView->getVirtualRenderer());

if (scale9sp) {

sp = scale9sp->getSprite();

}

}

else if (imgView2) {

sp = imgView2;

}

if (!sp) {

return;

}

const GLchar* pszFragSource =

"#ifdef GL_ES \n\

precision mediump float; \n\

#endif \n\

varying vec2 v_texCoord; \n\

varying vec4 v_fragmentColor; \n\

void main(void) \n\

{ \n\

// Convert to greyscale using NTSC weightings \n\

vec4 col = v_fragmentColor * texture2D(CC_Texture0, v_texCoord); \n\

float grey = dot(col.rgb, vec3(0.299, 0.587, 0.114)); \n\

gl_FragColor = vec4(grey, grey, grey, col.a); \n\

}";

GLProgram* pProgram = new GLProgram();

pProgram->initWithByteArrays(ccPositionTextureColor_noMVP_vert, pszFragSource);

sp->setGLProgram(pProgram);

pProgram->release();

CHECK_GL_ERROR_DEBUG();

sp->getGLProgram()->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_POSITION, GLProgram::VERTEX_ATTRIB_POSITION);

sp->getGLProgram()->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_COLOR, GLProgram::VERTEX_ATTRIB_COLOR);

sp->getGLProgram()->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_TEX_COORD, GLProgram::VERTEX_ATTRIB_TEX_COORD);

CHECK_GL_ERROR_DEBUG();

sp->getGLProgram()->link();

CHECK_GL_ERROR_DEBUG();

sp->getGLProgram()->updateUniforms();

CHECK_GL_ERROR_DEBUG();

}