From ecc7d2913e73fffb5786d5d812245a370d6e9bb5 Mon Sep 17 00:00:00 2001
From: vladislavbelov <vladislavbelov@wildfiregames.com>
Date: Wed, 29 Jan 2020 22:03:44 +0000
Subject: [PATCH] Moves GL error check after SwapBuffers to decrease a possible
 synchronization during rendering process.

Comments By: Stan, elexis
Differential Revision: https://code.wildfiregames.com/D2600
This was SVN commit r23462.
---
 source/main.cpp                           |  4 +++-
 source/renderer/Renderer.cpp              | 17 ++++++++---------
 source/renderer/Renderer.h                |  7 ++++++-
 source/tools/atlas/GameInterface/View.cpp |  3 ++-
 4 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/source/main.cpp b/source/main.cpp
index d8553dcc40..eaf7d70942 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2020 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -420,6 +420,8 @@ static void Frame()
 			SDL_GL_SwapWindow(g_VideoMode.GetWindow());
 			ogl_WarnIfError();
 		}
+
+		g_Renderer.OnSwapBuffers();
 	}
 
 	g_Profiler.Frame();
diff --git a/source/renderer/Renderer.cpp b/source/renderer/Renderer.cpp
index 59da4544b6..df866d3fc9 100644
--- a/source/renderer/Renderer.cpp
+++ b/source/renderer/Renderer.cpp
@@ -1456,17 +1456,16 @@ void CRenderer::EndFrame()
 		m->Model.TranspUnskinned->EndFrame();
 
 	ogl_tex_bind(0, 0);
-
-	{
-		PROFILE3("error check");
-		int err = glGetError();
-		if (err)
-		{
-			ONCE(LOGERROR("CRenderer::EndFrame: GL errors %s (%04x) occurred", ogl_GetErrorName(err), err));
-		}
-	}
 }
 
+void CRenderer::OnSwapBuffers()
+{
+	PROFILE3("error check");
+	// We have to check GL errors after SwapBuffer to avoid possible
+	// synchronizations during rendering.
+	//if (GLenum  err = glGetError())
+	//	ONCE(LOGERROR("GL error %s (0x%04x) occurred", ogl_GetErrorName(err), err));
+}
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 // DisplayFrustum: debug displays
diff --git a/source/renderer/Renderer.h b/source/renderer/Renderer.h
index 7c3161e494..7f349f67ec 100644
--- a/source/renderer/Renderer.h
+++ b/source/renderer/Renderer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2020 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -137,6 +137,11 @@ public:
 	// signal frame end
 	void EndFrame();
 
+	/**
+	 * Should be called after each SwapBuffers call.
+	 */
+	void OnSwapBuffers();
+
 	/**
 	 * Set simulation context for rendering purposes.
 	 * Must be called at least once when the game has started and before
diff --git a/source/tools/atlas/GameInterface/View.cpp b/source/tools/atlas/GameInterface/View.cpp
index 928da509f8..ef3776443a 100644
--- a/source/tools/atlas/GameInterface/View.cpp
+++ b/source/tools/atlas/GameInterface/View.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2020 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -231,6 +231,7 @@ void AtlasViewGame::Render()
 
 	::Render();
 	Atlas_GLSwapBuffers((void*)g_AtlasGameLoop->glCanvas);
+	g_Renderer.OnSwapBuffers();
 }
 
 void AtlasViewGame::DrawCinemaPathTool()