iOS中多个UIView如何绑定EAGLContext

razer751

大家好，

    最近在开发一个OpenGLES2.0的应用，涉及到多个UIView绑定多个EAGLContext的问题，参考了网上的讨论发现仍然有问题，以下是drawFrame的关键代码（使用了多重采样），

- (void)setupRenderBuffer {

    glGenRenderbuffers(1, &colorRenderBuffer);

    glBindRenderbuffer(GL_RENDERBUFFER, colorRenderBuffer);

    [_context renderbufferStorage:GL_RENDERBUFFER fromDrawable:_eaglLayer];

}

- (void)setupFrameBuffer {

    GLint backingWidth_;

    GLint backingHeight_;

    glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &backingWidth_);

    glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &backingHeight_);

   

    glGenFramebuffers(1, &defaultFrameBuffer);

    glBindFramebuffer(GL_FRAMEBUFFER, defaultFrameBuffer);

    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,

                              GL_RENDERBUFFER, colorRenderBuffer);

   

    glGenFramebuffers(1, &sampleFramebuffer);

    glBindFramebuffer(GL_FRAMEBUFFER, sampleFramebuffer);

   

    glGenRenderbuffers(1, &sampleColorRenderbuffer);

    glBindRenderbuffer(GL_RENDERBUFFER, sampleColorRenderbuffer);

    glRenderbufferStorageMultisampleAPPLE(GL_RENDERBUFFER, 4, GL_RGBA8_OES, backingWidth_, backingHeight_);

    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, sampleColorRenderbuffer);

   

    glGenRenderbuffers(1, &sampleDepthRenderbuffer);

    glBindRenderbuffer(GL_RENDERBUFFER, sampleDepthRenderbuffer);

    glRenderbufferStorageMultisampleAPPLE(GL_RENDERBUFFER, 4, GL_DEPTH_COMPONENT16, backingWidth_, backingHeight_);

    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, sampleDepthRenderbuffer);

   

    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){

        NSLog(@"Failed to make complete framebuffer object %x", glCheckFramebufferStatus(GL_FRAMEBUFFER));

    }

}

- (void)drawFrame: (CADisplayLink*)displayLink {

    [EAGLContext setCurrentContext:_context];

    _fcDirector->mainLoop();

    glBindFramebuffer(GL_READ_FRAMEBUFFER_APPLE, sampleFramebuffer);

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_APPLE, defaultFrameBuffer);

    glResolveMultisampleFramebufferAPPLE();

    glBindRenderbuffer(GL_RENDERBUFFER, colorRenderBuffer);

    const GLenum discards[]  = {GL_COLOR_ATTACHMENT0,GL_DEPTH_ATTACHMENT};

    glDiscardFramebufferEXT(GL_READ_FRAMEBUFFER_APPLE,2,discards);

    glBindFramebuffer(GL_FRAMEBUFFER, sampleFramebuffer);

    [_context presentRenderbuffer:GL_RENDERBUFFER];

    glFlush();

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glBindFramebuffer(GL_RENDERBUFFER, 0);

    glBindFramebuffer(GL_READ_FRAMEBUFFER_APPLE, 0);

    glBindFramebuffer(GL_DRAW_FRAMEBUFFER_APPLE, 0);

}

以上代码在多个View切换的时候会报0X500的错误，求指导！