RTCEAGLVideoView: Fix GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT error.

talk/app/webrtc/objc/RTCEAGLVideoView.m

Index: talk/app/webrtc/objc/RTCEAGLVideoView.m
diff --git a/talk/app/webrtc/objc/RTCEAGLVideoView.m b/talk/app/webrtc/objc/RTCEAGLVideoView.m
index 61040ba1025c2f23eed07f916df93d36b2955d76..961d809b47fc016866ca744492851a958a5d266c 100644
--- a/talk/app/webrtc/objc/RTCEAGLVideoView.m
+++ b/talk/app/webrtc/objc/RTCEAGLVideoView.m
@@ -137,6 +137,7 @@
   _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
@@ -158,13 +159,7 @@
   __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];
 }
@@ -213,6 +208,21 @@
 
 #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];