Several renderer fixes for 3dfx hardware:

- Try to determine which 3dfx card we are using
- Use GL_CLAMP for 3dfx instead, fixes dynamic lights/skyboxes/etc. (GL_CLAMP_TO_EDGE becomes GL_REPEAT on older 3dfx drivers)
- Support for 3dfx gamma control and overbrights restored
- Indexed w/ alpha color is now forced GL_RGBA on Voodoo Graphics (v1)
- attempt at silencing the 3dfx splash

code/sdl/sdl_gamma.c

@@ -29,6 +29,11 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "../renderercommon/tr_common.h"
 #include "../qcommon/qcommon.h"
 
+#ifdef _WIN32
+// leilei - 3dfx gamma fix
+BOOL  ( WINAPI * qwglGetDeviceGammaRamp3DFX)( HDC, LPVOID );
+BOOL  ( WINAPI * qwglSetDeviceGammaRamp3DFX)( HDC, LPVOID );
+#endif
 /*
 =================
 GLimp_SetGamma
@@ -86,6 +91,19 @@ void GLimp_SetGamma( unsigned char red[256], unsigned char green[256], unsigned
 		}
 	}
 
+	// leilei - 3dfx gamma support
+#ifdef _WIN32
+	if ( qwglSetDeviceGammaRamp3DFX )
+	{
+		HDC hDC;// = GetDC( hWnd );
+		hDC = GetDC( GetForegroundWindow() );
+		qwglSetDeviceGammaRamp3DFX( hDC, table );
+		ReleaseDC( GetForegroundWindow(), hDC );
+	}
+	else
+#endif
+	{
 	SDL_SetGammaRamp(table[0], table[1], table[2]);
+	}
 }
 

code/sdl/sdl_glimp.c

@@ -845,6 +845,15 @@ success:
 	// http://bugzilla.icculus.org/show_bug.cgi?id=4316
 	glConfig.deviceSupportsGamma = SDL_SetGamma( 1.0f, 1.0f, 1.0f ) >= 0;
 
+
+#ifdef _WIN32
+	// leilei - 3dfx gamma 
+	if ( qwglSetDeviceGammaRamp3DFX )
+	{
+		glConfig.deviceSupportsGamma = 1; // force it
+	}
+#endif
+
 	if ( -1 == r_ignorehwgamma->integer)
 		glConfig.deviceSupportsGamma = 1;