Question

我正在iPhone上创建3D OpenGL ES视图，并且想要设置深度缓冲区，所以我可以使用它。我正在调用glEnable(GL_DEPTH_TEST)等等，但由于我没有设置z缓冲区，它什么也没做。

我正在寻找一个等效的电话 glutInitDisplayMode(GLUT_DEPTH)

任何帮助都是最受欢迎的。谢谢！

Answer 1

正如您所怀疑的那样，您没有深度缓冲区。您需要在您创建的使用CAEAGLLayer作为其图层的任何UIView子类中将深度缓冲区附加到帧缓冲区。

假设您正在使用Apple的OpenGL ES Xcode模板，相关的UIView子类是EAGLView。其中有一个方法createFramebuffer，它负责创建帧缓冲区。最初它会说：

- (void)createFramebuffer
{
    if (context && !defaultFramebuffer)
    {
        [EAGLContext setCurrentContext:context];

        // Create default framebuffer object.
        glGenFramebuffers(1, &defaultFramebuffer);
        glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);

        // Create color render buffer and allocate backing store.
        glGenRenderbuffers(1, &colorRenderbuffer);
        glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
        [context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer *)self.layer];
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &framebufferWidth);
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &framebufferHeight);

        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderbuffer);

        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
            NSLog(@"Failed to make complete framebuffer object %x", glCheckFramebufferStatus(GL_FRAMEBUFFER));
    }
}

它的作用是生成并绑定帧缓冲区，然后生成并绑定颜色渲染缓冲区，为颜色缓冲区提供CAEAGLLayer附带的固有存储，抓取帧尺寸以供日后使用，并将颜色缓冲区附加到渲染缓冲区。

您还需要创建和附加深度缓冲区。哪个应该一样简单（为depthRenderbuffer添加一个合适的实例变量;直接在这里输入）：

glGenRenderbuffers(1, &depthRenderbuffer);
glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);

glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, framebufferWidth, framebufferHeight);

glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthRenderbuffer);

它看起来像是什么 - 生成并绑定渲染缓冲区，将其存储分配为与颜色缓冲区相同尺寸的16位深度缓冲区，然后将其附加到帧缓冲区。

所以，总的来说（未经测试）：

- (void)createFramebuffer
{
    if (context && !defaultFramebuffer)
    {
        [EAGLContext setCurrentContext:context];

        // Create default framebuffer object.
        glGenFramebuffers(1, &defaultFramebuffer);
        glBindFramebuffer(GL_FRAMEBUFFER, defaultFramebuffer);

        // Create color render buffer and allocate backing store.
        glGenRenderbuffers(1, &colorRenderbuffer);
        glBindRenderbuffer(GL_RENDERBUFFER, colorRenderbuffer);
        [context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer *)self.layer];
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &framebufferWidth);
        glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &framebufferHeight);

        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, colorRenderbuffer);

        // Create depth render buffer and allocate backing store.
        glGenRenderbuffers(1, &depthRenderbuffer);
        glBindRenderbuffer(GL_RENDERBUFFER, depthRenderbuffer);

        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, framebufferWidth, framebufferHeight);

        glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthRenderbuffer);

        if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
            NSLog(@"Failed to make complete framebuffer object %x", glCheckFramebufferStatus(GL_FRAMEBUFFER));
    }
}

在OpenGL ES for iPhone中请求DepthBuffer

1 个答案: