--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/video/x11/SDL_x11gamma.c	Thu Apr 26 16:45:43 2001 +0000
@@ -0,0 +1,147 @@
+/*
+    SDL - Simple DirectMedia Layer
+    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library 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
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+    Sam Lantinga
+    slouken@devolution.com
+*/
+
+#ifdef SAVE_RCSID
+static char rcsid =
+ "@(#) $Id$";
+#endif
+
+#include "SDL.h"
+#include "SDL_events.h"
+#include "SDL_events_c.h"
+#include "SDL_x11video.h"
+
+/* From the X server sources... */
+#define MAX_GAMMA 10.0
+#define MIN_GAMMA (1.0/MAX_GAMMA)
+
+static int X11_SetGammaNoLock(_THIS, float red, float green, float blue)
+{
+#ifdef XFREE86_VMGAMMA
+    if (use_vidmode) {
+        XF86VidModeGamma gamma;
+        Bool succeeded;
+
+	/* Clamp the gamma values */
+	if ( red < MIN_GAMMA ) {
+		gamma.red = MIN_GAMMA;
+	} else
+	if ( red > MAX_GAMMA ) {
+		gamma.red = MAX_GAMMA;
+	} else {
+        	gamma.red = red;
+	}
+	if ( green < MIN_GAMMA ) {
+		gamma.green = MIN_GAMMA;
+	} else
+	if ( green > MAX_GAMMA ) {
+		gamma.green = MAX_GAMMA;
+	} else {
+        	gamma.green = green;
+	}
+	if ( blue < MIN_GAMMA ) {
+		gamma.blue = MIN_GAMMA;
+	} else
+	if ( blue > MAX_GAMMA ) {
+		gamma.blue = MAX_GAMMA;
+	} else {
+        	gamma.blue = blue;
+	}
+        if ( SDL_GetAppState() & SDL_APPACTIVE ) {
+            succeeded = XVidMode(SetGamma, (SDL_Display, SDL_Screen, &gamma));
+            XSync(SDL_Display, False);
+        } else {
+            gamma_saved[0] = gamma.red;
+            gamma_saved[1] = gamma.green;
+            gamma_saved[2] = gamma.blue;
+            succeeded = True;
+        }
+        if ( succeeded ) {
+            ++gamma_changed;
+        }
+        return succeeded ? 0 : -1;
+    }
+#endif
+    SDL_SetError("Gamma correction not supported");
+    return -1;
+}
+int X11_SetVidModeGamma(_THIS, float red, float green, float blue)
+{
+    int result;
+
+    SDL_Lock_EventThread();
+    result = X11_SetGammaNoLock(this, red, green, blue);
+    SDL_Unlock_EventThread();
+
+    return(result);
+}
+
+static int X11_GetGammaNoLock(_THIS, float *red, float *green, float *blue)
+{
+#ifdef XFREE86_VMGAMMA
+    if (use_vidmode) {
+        XF86VidModeGamma gamma;
+        if (XVidMode(GetGamma, (SDL_Display, SDL_Screen, &gamma))) {
+            *red   = gamma.red;
+            *green = gamma.green;
+            *blue  = gamma.blue;
+            return 0;
+        }
+        return -1;
+    }
+#endif
+    SDL_SetError("Gamma correction not supported");
+    return -1;
+}
+int X11_GetVidModeGamma(_THIS, float *red, float *green, float *blue)
+{
+    int result;
+
+    SDL_Lock_EventThread();
+    result = X11_GetGammaNoLock(this, red, green, blue);
+    SDL_Unlock_EventThread();
+
+    return(result);
+}
+
+void X11_SaveVidModeGamma(_THIS)
+{
+    /* Try to save the current gamma, otherwise disable gamma control */
+    if ( X11_GetGammaNoLock(this,
+              &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]) < 0 ) {
+        this->SetGamma = 0;
+        this->GetGamma = 0;
+    }
+    gamma_changed = 0;
+}
+void X11_SwapVidModeGamma(_THIS)
+{
+    float new_gamma[3];
+
+    if ( gamma_changed ) {
+        new_gamma[0] = gamma_saved[0];
+        new_gamma[1] = gamma_saved[1];
+        new_gamma[2] = gamma_saved[2];
+        X11_GetGammaNoLock(this, &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]);
+        X11_SetGammaNoLock(this, new_gamma[0], new_gamma[1], new_gamma[2]);
+    }
+}