1 files changed, 100 insertions, 0 deletions
diff --git a/src/sdl/sdl_gamma.cpp b/src/sdl/sdl_gamma.cpp
new file mode 100644
index 0000000..372fdf2
--- /dev/null
+++ b/src/sdl/sdl_gamma.cpp
@@ -0,0 +1,100 @@
+/*
+===========================================================================
+Copyright (C) 1999-2005 Id Software, Inc.
+Copyright (C) 2000-2013 Darklegion Development
+Copyright (C) 2015-2019 GrangerHub
+
+This file is part of Tremulous.
+
+Tremulous is free software; you can redistribute it
+and/or modify it under the terms of the GNU General Public License as
+published by the Free Software Foundation; either version 3 of the License,
+or (at your option) any later version.
+
+Tremulous is distributed in the hope that it will be
+useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Tremulous; if not, see <https://www.gnu.org/licenses/>
+
+===========================================================================
+*/
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+#ifdef USE_LOCAL_HEADERS
+# include "SDL.h"
+#else
+# include <SDL.h>
+#endif
+
+#include "qcommon/cvar.h"
+#include "qcommon/qcommon.h"
+#include "renderercommon/tr_common.h"
+
+extern SDL_Window *SDL_window;
+
+/*
+=================
+GLimp_SetGamma
+=================
+*/
+void GLimp_SetGamma( unsigned char red[256], unsigned char green[256], unsigned char blue[256] )
+{
+	Uint16 table[3][256];
+	int i, j;
+
+	if( !glConfig.deviceSupportsGamma || r_ignorehwgamma->integer > 0 )
+		return;
+
+	for (i = 0; i < 256; i++)
+	{
+		table[0][i] = ( ( ( Uint16 ) red[i] ) << 8 ) | red[i];
+		table[1][i] = ( ( ( Uint16 ) green[i] ) << 8 ) | green[i];
+		table[2][i] = ( ( ( Uint16 ) blue[i] ) << 8 ) | blue[i];
+	}
+
+#ifdef _WIN32
+	// Win2K and newer put this odd restriction on gamma ramps...
+	{
+		OSVERSIONINFO	vinfo;
+
+		vinfo.dwOSVersionInfoSize = sizeof( vinfo );
+		GetVersionEx( &vinfo );
+		if( vinfo.dwMajorVersion >= 5 && vinfo.dwPlatformId == VER_PLATFORM_WIN32_NT )
+		{
+			ri.Printf( PRINT_DEVELOPER, "performing gamma clamp.\n" );
+			for( j = 0 ; j < 3 ; j++ )
+			{
+				for( i = 0 ; i < 128 ; i++ )
+				{
+					if( table[ j ] [ i] > ( ( 128 + i ) << 8 ) )
+						table[ j ][ i ] = ( 128 + i ) << 8;
+				}
+
+				if( table[ j ] [127 ] > 254 << 8 )
+					table[ j ][ 127 ] = 254 << 8;
+			}
+		}
+	}
+#endif
+
+	// enforce constantly increasing
+	for (j = 0; j < 3; j++)
+	{
+		for (i = 1; i < 256; i++)
+		{
+			if (table[j][i] < table[j][i-1])
+				table[j][i] = table[j][i-1];
+		}
+	}
+
+	if (SDL_SetWindowGammaRamp(SDL_window, table[0], table[1], table[2]) < 0)
+	{
+		ri.Printf( PRINT_DEVELOPER, "SDL_SetWindowGammaRamp() failed: %s\n", SDL_GetError() );
+	}
+}