RTCEAGLVideoView: Fix GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT error.

talk/app/webrtc/objc/RTCEAGLVideoView.m

 /*
  * libjingle
  * Copyright 2014 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 119 matching lines @@
 
   // GLKView manages a framebuffer for us.
   _glkView = [[GLKView alloc] initWithFrame:CGRectZero
                                     context:glContext];
   _glkView.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
   _glkView.drawableDepthFormat = GLKViewDrawableDepthFormatNone;
   _glkView.drawableStencilFormat = GLKViewDrawableStencilFormatNone;
   _glkView.drawableMultisample = GLKViewDrawableMultisampleNone;
   _glkView.delegate = self;
   _glkView.layer.masksToBounds = YES;
+  _glkView.enableSetNeedsDisplay = NO;
   [self addSubview:_glkView];
 
   // Listen to application state in order to clean up OpenGL before app goes
   // away.
   NSNotificationCenter* notificationCenter =
     [NSNotificationCenter defaultCenter];
   [notificationCenter addObserver:self
                          selector:@selector(willResignActive)
                              name:UIApplicationWillResignActiveNotification
                            object:nil];
   [notificationCenter addObserver:self
                          selector:@selector(didBecomeActive)
                              name:UIApplicationDidBecomeActiveNotification
                            object:nil];
 
   // Frames are received on a separate thread, so we poll for current frame
   // using a refresh rate proportional to screen refresh frequency. This
   // occurs on the main thread.
   __weak RTCEAGLVideoView* weakSelf = self;
   _timer = [[RTCDisplayLinkTimer alloc] initWithTimerHandler:^{
       RTCEAGLVideoView* strongSelf = weakSelf;
-      // Don't render if frame hasn't changed.
-      if (strongSelf.glRenderer.lastDrawnFrame == strongSelf.i420Frame) {
-        return;
-      }
-      // This tells the GLKView that it's dirty, which will then call the
-      // GLKViewDelegate method implemented below.
-      [strongSelf.glkView setNeedsDisplay];
+      [strongSelf displayLinkTimerDidFire];
     }];
   [self setupGL];
 }
 
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   UIApplicationState appState =
       [UIApplication sharedApplication].applicationState;
   if (appState == UIApplicationStateActive) {
     [self teardownGL];
@@ skipping 28 matching lines @@
     [strongSelf.delegate videoView:strongSelf didChangeVideoSize:size];
   });
 }
 
 - (void)renderFrame:(RTCI420Frame*)frame {
   self.i420Frame = frame;
 }
 
 #pragma mark - Private
 
+- (void)displayLinkTimerDidFire {
+  // Don't render if frame hasn't changed.
+  if (_glRenderer.lastDrawnFrame == self.i420Frame) {
+    return;
+  }
+
+  // Only call -[GLKView display] if the drawable size is
+  // non-empty. Calling display will make the GLKView setup it's

[magjed_webrtc, 2015/09/18 09:24:14]

nit: s/it's/its/g

+  // render buffer if necessary, but that will fail with error
+  // GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT if size is empty.
+  if (self.bounds.size.width > 0 && self.bounds.size.height > 0) {
+    [_glkView display];

[magjed_webrtc, 2015/09/18 09:24:14]

It looks like you changed setNeedsDisplay to display? What's the difference?

+  }
+}
+
 - (void)setupGL {
   self.i420Frame = nil;
   [_glRenderer setupGL];
   _timer.isPaused = NO;
 }
 
 - (void)teardownGL {
   self.i420Frame = nil;
   _timer.isPaused = YES;
   [_glkView deleteDrawable];
   [_glRenderer teardownGL];
 }
 
 - (void)didBecomeActive {
   [self setupGL];
 }
 
 - (void)willResignActive {
   [self teardownGL];
 }
 
 @end