From a0519dc37d580d21f6190dc47e739d99ada09b71 Mon Sep 17 00:00:00 2001
From: pouillot <pouillot@30fe4595-0a0c-4342-8851-515496e4dcbd>
Date: Tue, 3 May 2011 13:07:30 +0000
Subject: [PATCH] Re #320 Fixes the detection of max multi-sampling level under
 Windows

git-svn-id: https://svn.code.sf.net/p/speed-dreams/code/trunk@3537 30fe4595-0a0c-4342-8851-515496e4dcbd

Former-commit-id: f650456ced9d536359cc929b87430418e1c2823b
Former-commit-id: 207c34a230730a56612c1bb1891b6ba065d3b6cf
---
 src/libs/tgfclient/glfeatures.cpp | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/libs/tgfclient/glfeatures.cpp b/src/libs/tgfclient/glfeatures.cpp
index 98964b3d4..841c7dfbd 100644
--- a/src/libs/tgfclient/glfeatures.cpp
+++ b/src/libs/tgfclient/glfeatures.cpp
@@ -16,18 +16,17 @@
  *                                                                         *
  ***************************************************************************/
 
-
 #include <sstream>
 #include <limits>
 
 #include <SDL/SDL.h>
 
-//#include "guiscreen.h"
 #include "glfeatures.h"
 
 // Avoid C lib <cstdlib> "max" to overload <limits> ones.
 #undef min
 
+
 static const char* pszNoUnit = 0;
 
 
@@ -204,12 +203,33 @@ bool GfglFeatures::detectBestSupport(int& nWidth, int& nHeight, int& nDepth,
 		
 				// Anti-aliasing : detect the max supported number of samples
 				// (assumed to be <= 32).
+#ifndef WIN32
 				SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
+#endif
 				int nMaxMultiSamples = 32; // Hard coded max value for the moment.
 				while (!pWinSurface && nMaxMultiSamples > 1)
 				{
+					// Set the anti-aliasing attributes and setup the video mode.
+#ifdef WIN32
+					SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
+#endif
 					SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, nMaxMultiSamples);
 					pWinSurface = SDL_SetVideoMode(nWidth, nHeight, nCurrDepth, bfVideoMode);
+
+					// Now check if we have a video mode, and if it actually features
+					// what we specified.
+#ifdef WIN32
+					int nActualSampleBuffers = 0;
+					SDL_GL_GetAttribute(SDL_GL_MULTISAMPLEBUFFERS, &nActualSampleBuffers);
+					int nActualMultiSamples = 0;
+					SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &nActualMultiSamples);
+// 					GfLogDebug("nMaxMultiSamples=%d : nActualSampleBuffers=%d, nActualMultiSamples=%d\n",
+// 							   nMaxMultiSamples, nActualSampleBuffers, nActualMultiSamples);
+
+					// If not, try a lower number of samples.
+					if (nActualSampleBuffers == 0 || nActualMultiSamples != nMaxMultiSamples)
+						pWinSurface = 0;
+#endif
 					if (!pWinSurface)
 					{
 						GfLogTrace("%d+%d bit %dx anti-aliased double-buffer not supported\n",
@@ -269,9 +289,11 @@ bool GfglFeatures::detectBestSupport(int& nWidth, int& nHeight, int& nDepth,
 	int nValue;
 	SDL_GL_GetAttribute(SDL_GL_MULTISAMPLEBUFFERS, &nValue);
 	_mapSupportedBool[MultiSampling] = nValue != 0;
+	//GfLogDebug("SDL_GL_GetAttribute(SDL_GL_MULTISAMPLEBUFFERS) = %d\n", nValue);
 	if (nValue)
 	{
 		SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &nValue);
+		//GfLogDebug("SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES) = %d\n", nValue);
 		if (nValue > 1)
 			_mapSupportedInt[MultiSamplingSamples] = nValue;
 		else