Cocos2D-X 3.xでGLSLの使い方法

新しいサンプルのプロジェクト

GameScene.cpp

bool GameLayer::init()
{
    ...
    // sourceSprite
    _sourceSprite = Sprite::create("HelloWorld.png");
    _sourceSprite->setPosition(Vec2(_screenWidth/2, _screenHeight/2));
    this->addChild(_sourceSprite);

    // apply gray effect to sprite
    this->greySprite(_sourceSprite);
}

GameScene.cpp

void GameLayer::graySprite(Sprite * sprite)
{
    if(sprite)
    {
        GLProgram * p = new GLProgram();
        p->initWithFilenames("gray.vsh", "gray.fsh");
        p->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_POSITION, GLProgram::VERTEX_ATTRIB_POSITION);
        p->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_COLOR, GLProgram::VERTEX_ATTRIB_COLOR);
        p->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_TEX_COORD, GLProgram::VERTEX_ATTRIB_TEX_COORDS);
        p->link();
        p->updateUniforms();
        sprite->setGLProgram(p);
    }
}

Resourcesのファイルに　gray.vshとgray.fsh　を入れます

gray.vsh

varying vec4 v_fragmentColor;   
varying vec2 v_texCoord;    

void main()         
{
    vec4 v_orColor = v_fragmentColor * texture2D(CC_Texture0, v_texCoord);
    float gray = dot(v_orColor.rgb, vec3(0.299, 0.587, 0.114));
    gl_FragColor = vec4(gray, gray, gray, v_orColor.a);
}               

gray.fsh

attribute vec4 a_position;
attribute vec2 a_texCoord;
attribute vec4 a_color;


varying vec4 v_fragmentColor;
varying vec2 v_texCoord;

void main() 
{                           
    gl_Position = CC_PMatrix * a_position;  // not CC_MVPMatrix
    v_fragmentColor = a_color;
    v_texCoord = a_texCoord;
}