RedCore/cocos2d/cocos/2d/CCGrabber.cpp

/****************************************************************************
Copyright (c) 2009      On-Core
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2013-2017 Chukong Technologies Inc.
 
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#include "2d/CCGrabber.h"
#include "base/ccMacros.h"
#include "renderer/CCTexture2D.h"

NS_CC_BEGIN

Grabber::Grabber(void)
    : _FBO(0)
    , _oldFBO(0)
{
    memset(_oldClearColor, 0, sizeof(_oldClearColor));

    // generate FBO
    glGenFramebuffers(1, &_FBO);
}

void Grabber::grab(Texture2D *texture)
{
    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &_oldFBO);

    // bind
    glBindFramebuffer(GL_FRAMEBUFFER, _FBO);

    // associate texture with FBO
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture->getName(), 0);

    // check if it worked (probably worth doing :) )
    GLuint status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (status != GL_FRAMEBUFFER_COMPLETE)
    {
        CCASSERT(0, "Frame Grabber: could not attach texture to framebuffer");
    }

    glBindFramebuffer(GL_FRAMEBUFFER, _oldFBO);
}

void Grabber::beforeRender(Texture2D* /*texture*/)
{
    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &_oldFBO);
    glBindFramebuffer(GL_FRAMEBUFFER, _FBO);
    
    // save clear color
    glGetFloatv(GL_COLOR_CLEAR_VALUE, _oldClearColor);
    // FIXME: doesn't work with RGB565.

    glClearColor(0, 0, 0, 0);

    // BUG #631: To fix #631, uncomment the lines with #631
    // Warning: But it Grabber won't work with 2 effects at the same time
//  glClearColor(0.0f,0.0f,0.0f,1.0f);    // #631

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

//  glColorMask(true, true, true, false);    // #631
}

void Grabber::afterRender(cocos2d::Texture2D* /*texture*/)
{
    glBindFramebuffer(GL_FRAMEBUFFER, _oldFBO);
//  glColorMask(true, true, true, true);    // #631
    
    // Restore clear color
    glClearColor(_oldClearColor[0], _oldClearColor[1], _oldClearColor[2], _oldClearColor[3]);
}

Grabber::~Grabber()
{
    CCLOGINFO("deallocing Grabber: %p", this);
    glDeleteFramebuffers(1, &_FBO);
}

NS_CC_END