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OpenGL ES、iPhone和间歇性错误:GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_OES(0x8CD6)

opengl-es iphone

westsider · 技术社区 · 14 年前

我在iPhone 4上看到这个错误,但在iPad上没有,这可能是很重要的。

大多数情况下,这很有效。但是,我从createFrameBuffer方法中的glCheckFramebufferStatusOES()获取GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_OES。原因是backingWidth和backingHeight都是0。

这是我的createFrameBuffer方法-它大部分时间都在工作。

- (BOOL)createFramebuffer
 { 
 // Generate IDs for a framebuffer object and a color renderbuffer
 glGenFramebuffersOES(1, &viewFramebuffer);
 glGenRenderbuffersOES(1, &viewRenderbuffer);

 glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

 glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

 // This call associates the storage for the current render buffer with the EAGLDrawable (our CAEAGLLayer)
 // allowing us to draw into a buffer that will later be rendered to screen wherever the layer is (which corresponds with our view).
 [context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:(id<EAGLDrawable>)self.layer];

 glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer);

 //DLog(@" backing size = (%d, %d)", backingWidth, backingHeight);
 glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
 glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);
 DLog(@" backing size = (%d, %d)", backingWidth, backingHeight);


 err = glGetError();
 if (err != GL_NO_ERROR)
  DLog(@"Error. glError: 0x%04X", err);

 // For this sample, we also need a depth buffer, so we'll create and attach one via another renderbuffer.
 glGenRenderbuffersOES(1, &depthRenderbuffer);
 glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
 glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);

 glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);

 if(glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES)
  {
  NSLog(@"failed to make complete framebuffer object 0x%X", glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));
  return NO;
  }

 return YES;
 }

2 回复 | 直到 14 年前

Tom Andersen 14 年前

我也有同样的问题。对我来说,修复方法是在去年的opengl示例代码中,苹果在每次layoutSubviews调用中重建renderbuffer。现在,如果您创建一个iPhone模板opengl项目,您将看到layoutSubviews只会破坏renderbuffer。然后在每次绘制时,如果渲染缓冲区为零,则创建它。这是更好的,因为当你要画所有的炉等都应该是发光和准备去。

我认为,在我的例子中,渲染缓冲区是在EagleView层不可用时(即处于某种可拆卸状态)尝试构建的。在任何情况下,当我改变我的代码,以匹配它的工作。

此外,对这段代码的调用更少,这可能更快。启动时会有很多场景加载和移动,这会用我的应用程序生成1/2打布局子视图调用。

由于苹果代码中的注释很少,layoutsubviews调用中有一个注释非常重要:

// The framebuffer will be re-created at the beginning of the next 
   setFramebuffer method call.

--汤姆

gulchrider 14 年前

您要做的是在drawView调用中创建帧缓冲区,正如Tom上面所说,但是,您还需要将对drawView的调用推迟到layoutSubviews函数返回。我这样做的方式是:

- (void) layoutSubviews
{
 [EAGLContext setCurrentContext:context];

 [self destroyFramebuffer];

 // Create the framebuffer in drawView instead as needed, as before create 
 // would occasionally happen when the view wasn't servicable (?) and cause 
 // a crash. Additionally, send the drawView call to the main UI thread 
 // (ALA PostMessage in Win32) so that it is deferred until this function 
 // returns and the message loop has a chance to process other stuff, etc 
 // so the EAGLView will be ready to use when createFramebuffer is finally 
 // called and the glGetRenderbufferParameterivOES calls to get the backing 
 // width and height for the render buffer will always work (occasionally I 
 // would see them come back as zero on my old first gen phone, and this 
 // crashes OpenGL.)
 //
 // Also, using this original method, I would see memory warnings in the 
 // debugger console window with my iPad when rotating (not all the time, 
 // but pretty frequently.)  These seem to have gone away using this new 
 // deferred method...
 [self performSelectorOnMainThread:@selector(drawView) 
                        withObject:nil 
                     waitUntilDone:NO];
}

罗斯