cocos2dx 使用glsl

<pre name="code" class="cpp">class ShaderNode : public Node
{
public:
    static ShaderNode* shaderNodeWithVertex(const std::string &vert,const std::string &frag);
    
    virtual void update(float dt);
    virtual void draw(Renderer *renderer,const Mat4 &transform,uint32_t flags) override;
    
protected:
    ShaderNode();
    ~ShaderNode();
    
    bool initWithVertex(const std::string &vert,const std::string &frag);
    void loadShaderVertex(const std::string &vert,const std::string &frag);
    
    void onDraw(const Mat4 &transform,uint32_t flags);
    
    Vec2 _center;
    Vec2 _resolution;
    float      _time;
    std::string _vertFileName;
    std::string _fragFileName;
    CustomCommand _customCommand;
};

<pre name="code" class="cpp">enum
{
    SIZE_X = 256,SIZE_Y = 256,};

ShaderNode::ShaderNode()
:_center(Vec2(0.0f,0.0f)),_resolution(Vec2(0.0f,_time(0.0f)
{
}

ShaderNode::~ShaderNode()
{
}

ShaderNode* ShaderNode::shaderNodeWithVertex(const std::string &vert,const std::string& frag)
{
    auto node = new (std::nothrow) ShaderNode();
    node->initWithVertex(vert,frag);
    node->autorelease();
    
    return node;
}

bool ShaderNode::initWithVertex(const std::string &vert,const std::string &frag)
{
#if CC_ENABLE_CACHE_TEXTURE_DATA
    auto listener = EventListenerCustom::create(EVENT_RENDERER_RECREATED,[this](EventCustom* event){
        this->setGLProgramState(nullptr);
        loadShaderVertex(_vertFileName,_fragFileName);
    });
    
    _eventdispatcher->addEventListenerWithSceneGraPHPriority(listener,this);
#endif
    
    _vertFileName = vert;
    _fragFileName = frag;
    
    loadShaderVertex(vert,frag);
    
    _time = 0;
    _resolution = Vec2(SIZE_X,SIZE_Y)*2.5 ;
    getGLProgramState()->setUniformVec2("resolution",_resolution);
    
    scheduleUpdate();
    
    setContentSize(Size(SIZE_X,SIZE_Y)*5 );
    setAnchorPoint(Vec2(0.5f,0.5f));
    
    
    return true;
}

void ShaderNode::loadShaderVertex(const std::string &vert,const std::string &frag)
{
    auto fileUtiles = FileUtils::getInstance();
    
    // frag
    auto fragmentFilePath = fileUtiles->fullPathForFilename(frag);
    auto fragSource = fileUtiles->getStringFromFile(fragmentFilePath);
    
    // vert
    std::string vertSource;
    if (vert.empty()) {
        vertSource = ccPositionTextureColor_vert;
    } else {
        std::string vertexFilePath = fileUtiles->fullPathForFilename(vert);
        vertSource = fileUtiles->getStringFromFile(vertexFilePath);
    }
    
    auto glprogram = GLProgram::createWithByteArrays(vertSource.c_str(),fragSource.c_str());
    auto glprogramstate = GLProgramState::getorCreateWithGLProgram(glprogram);
    setGLProgramState(glprogramstate);
}

void ShaderNode::update(float dt)
{
    _time += dt;
}

void ShaderNode::draw(Renderer *renderer,uint32_t flags)
{
    _customCommand.init(_globalZOrder);
    _customCommand.func = CC_CALLBACK_0(ShaderNode::onDraw,this,transform,flags);
    renderer->addCommand(&_customCommand);
}

void ShaderNode::onDraw(const Mat4 &transform,uint32_t flags)
{
    float w = SIZE_X*5,h = SIZE_Y*5;
    GLfloat vertices[12] = {0,w,h,h};
    
    auto glProgramState = getGLProgramState();
    glProgramState->setVertexAttribPointer("a_position",2,GL_FLOAT,GL_FALSE,vertices);
    glProgramState->apply(transform);
    
    glDrawArrays(GL_TRIANGLES,6);
    
    CC_INCREMENT_GL_DRAWN_BATCHES_AND_VERTICES(1,6);
}

<pre name="code" class="cpp">auto s = Director::getInstance()->getWinSize()/2;
    s.height = Director::getInstance()->getWinSize().height * 0.62;
    sn->setPosition(Vec2(0,0));
    sn->getGLProgramState()->setUniformVec2("center",s);//设置的是世界坐标
    m_effctNode->addChild(sn);