axmol/cocos/2d/CCGrabber.cpp

/****************************************************************************
Copyright (c) 2009      On-Core
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (C) 2013-2014 Chukong Technologies Inc.
 
http://www.cocos2d-x.org

Permission is hereby granted, free of charge, to any person obtaining a copy
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/
#include "CCGrabber.h"
#include "2d/ccMacros.h"
#include "2d/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)
{
    CC_UNUSED_PARAM(texture);

    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &_oldFBO);
    glBindFramebuffer(GL_FRAMEBUFFER, _FBO);
    
    // save clear color
    glGetFloatv(GL_COLOR_CLEAR_VALUE, _oldClearColor);
    // BUG XXX: 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)
{
    CC_UNUSED_PARAM(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