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 103 matching lines @@
 }
 
 - (instancetype)initWithCoder:(NSCoder *)aDecoder {
   if (self = [super initWithCoder:aDecoder]) {
     [self configure];
   }
   return self;
 }
 
 - (void)configure {
-  EAGLContext* glContext =
-    [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3];
-  if (!glContext) {
-    glContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
-  }
-  _glRenderer = [[RTCOpenGLVideoRenderer alloc] initWithContext:glContext];

[magjed_webrtc, 2015/09/17 08:59:46]

Why can't _glRenderer alloc stay in this function?

-
-  // 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;
-  [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];
     }];
+}
+
+- (BOOL)isGLConfigured {
+  return (_glkView != nil) && (_glRenderer != nil);
+}
+
+- (void)configureGLIfApplicable {
+  NSAssert([NSThread isMainThread], @"should only configure on main thread");
+  if ((![self isGLConfigured]) && (!CGRectIsEmpty(self.bounds))) {
+    [self configureGL];
+    NSAssert([self isGLConfigured], @"GL components should have been configured");
+  }
+}
+
+- (void)configureGL {
+  NSAssert((self.bounds.size.width > 0) && (self.bounds.size.height > 0),
+           @"Don't attempt to configure GLKView and renderer until a size is specified");
+  EAGLContext *glContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3];
+  if (!glContext) {
+    glContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
+  }
+  _glRenderer = [[RTCOpenGLVideoRenderer alloc] initWithContext:glContext];
+
+  // GLKView manages a framebuffer for us.
+  _glkView = [[GLKView alloc] initWithFrame:self.bounds context:glContext];
+  _glkView.drawableColorFormat = GLKViewDrawableColorFormatRGBA8888;
+  _glkView.drawableDepthFormat = GLKViewDrawableDepthFormatNone;
+  _glkView.drawableStencilFormat = GLKViewDrawableStencilFormatNone;
+  _glkView.drawableMultisample = GLKViewDrawableMultisampleNone;
+  _glkView.delegate = self;
+  _glkView.layer.masksToBounds = YES;
+  [self addSubview:_glkView];
+
   [self setupGL];
 }
 
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   UIApplicationState appState =
       [UIApplication sharedApplication].applicationState;
   if (appState == UIApplicationStateActive) {
     [self teardownGL];
   }
   [_timer invalidate];
 }
 
 #pragma mark - UIView
 
+- (void)setFrame:(CGRect)frame {
+  [super setFrame:frame];
+  [self configureGLIfApplicable];
+}
+
+- (void)setBounds:(CGRect)bounds {
+  [super setBounds:bounds];
+  [self configureGLIfApplicable];
+}
+
 - (void)layoutSubviews {
   [super layoutSubviews];
   _glkView.frame = self.bounds;
 }
 
 #pragma mark - GLKViewDelegate
 
 // This method is called when the GLKView's content is dirty and needs to be
 // redrawn. This occurs on main thread.
 - (void)glkView:(GLKView*)view drawInRect:(CGRect)rect {
   // The renderer will draw the frame to the framebuffer corresponding to the
   // one used by |view|.
   [_glRenderer drawFrame:self.i420Frame];

[magjed_webrtc, 2015/09/17 08:59:46]

Maybe drop frames here if framebuffer is not complete yet?

 }
 
 #pragma mark - RTCVideoRenderer
 
 // These methods may be called on non-main thread.
 - (void)setSize:(CGSize)size {
   __weak RTCEAGLVideoView* weakSelf = self;
   dispatch_async(dispatch_get_main_queue(), ^{
     RTCEAGLVideoView* strongSelf = weakSelf;
     [strongSelf.delegate videoView:strongSelf didChangeVideoSize:size];
@@ skipping 21 matching lines @@
 
 - (void)didBecomeActive {
   [self setupGL];
 }
 
 - (void)willResignActive {
   [self teardownGL];
 }
 
 @end