From 3c8f67c3c66a86fc9e45469ce2fed4222d486c9f Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Tue, 17 Nov 2009 04:03:57 -0500
Subject: [PATCH] Force a double-buffered GL context.

---
 Source/OpenGL_Windows.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Source/OpenGL_Windows.cpp b/Source/OpenGL_Windows.cpp
index 244e135..64fce39 100644
--- a/Source/OpenGL_Windows.cpp
+++ b/Source/OpenGL_Windows.cpp
@@ -928,6 +928,8 @@ Boolean SetUp (Game & game)
 
     SDL_ShowCursor(0);
 
+    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+
     if (SDL_SetVideoMode(kContextWidth, kContextHeight, 0, sdlflags) == NULL)
     {
         fprintf(stderr, "SDL_SetVideoMode() failed: %s\n", SDL_GetError());
@@ -947,6 +949,14 @@ Boolean SetUp (Game & game)
         }
     }
 
+    int dblbuf = 0;
+    if ((SDL_GL_GetAttribute(SDL_GL_DOUBLEBUFFER, &dblbuf) == -1) || (!dblbuf))
+    {
+        fprintf(stderr, "Failed to get double buffered GL context!\n");
+        SDL_Quit();
+        return false;
+    }
+
     if (!lookup_all_glsyms())
     {
         SDL_Quit();
-- 
2.39.2