axmol/cocos2dx/effects/CCGrabber.cpp

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Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2009      On-Core
 
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#include "CCGrabber.h"
#include "ccMacros.h"
#include "textures/CCTexture2D.h"
#include "platform/platform.h"

NS_CC_BEGIN

CCGrabber::CCGrabber(void)
    : m_fbo(0)
    , m_oldFBO(0)
{
    memset(m_oldClearColor, 0, sizeof(m_oldClearColor));

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

void CCGrabber::grab(CCTexture2D *pTexture)
{
    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &m_oldFBO);

    // bind
    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);

    // associate texture with FBO
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, pTexture->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, m_oldFBO);
}

void CCGrabber::beforeRender(CCTexture2D *pTexture)
{
    CC_UNUSED_PARAM(pTexture);

    glGetIntegerv(GL_FRAMEBUFFER_BINDING, &m_oldFBO);
    glBindFramebuffer(GL_FRAMEBUFFER, m_fbo);
    
    // save clear color
    glGetFloatv(GL_COLOR_CLEAR_VALUE, m_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 CCGrabber 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 CCGrabber::afterRender(cocos2d::CCTexture2D *pTexture)
{
    CC_UNUSED_PARAM(pTexture);

    glBindFramebuffer(GL_FRAMEBUFFER, m_oldFBO);
//  glColorMask(true, true, true, true);    // #631
    
    // Restore clear color
    glClearColor(m_oldClearColor[0], m_oldClearColor[1], m_oldClearColor[2], m_oldClearColor[3]);
}

CCGrabber::~CCGrabber()
{
    CCLOGINFO("cocos2d: deallocing %p", this);
    glDeleteFramebuffers(1, &m_fbo);
}

NS_CC_END