src/video/x11/SDL_x11gamma.c
author Sam Lantinga <slouken@libsdl.org>
Wed, 06 Mar 2002 11:23:08 +0000
changeset 297 f6ffac90895c
parent 292 eadc0746dfaf
child 445 98d778ed4abf
permissions -rw-r--r--
Updated copyright information for 2002
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 #ifdef SAVE_RCSID
    24 static char rcsid =
    25  "@(#) $Id$";
    26 #endif
    27 
    28 #include "SDL.h"
    29 #include "SDL_events.h"
    30 #include "SDL_events_c.h"
    31 #include "SDL_x11video.h"
    32 
    33 /* From the X server sources... */
    34 #define MAX_GAMMA 10.0
    35 #define MIN_GAMMA (1.0/MAX_GAMMA)
    36 
    37 static int X11_SetGammaNoLock(_THIS, float red, float green, float blue)
    38 {
    39 #ifdef XFREE86_VMGAMMA
    40     if (use_vidmode >= 200) {
    41         SDL_NAME(XF86VidModeGamma) gamma;
    42         Bool succeeded;
    43 
    44 	/* Clamp the gamma values */
    45 	if ( red < MIN_GAMMA ) {
    46 		gamma.red = MIN_GAMMA;
    47 	} else
    48 	if ( red > MAX_GAMMA ) {
    49 		gamma.red = MAX_GAMMA;
    50 	} else {
    51         	gamma.red = red;
    52 	}
    53 	if ( green < MIN_GAMMA ) {
    54 		gamma.green = MIN_GAMMA;
    55 	} else
    56 	if ( green > MAX_GAMMA ) {
    57 		gamma.green = MAX_GAMMA;
    58 	} else {
    59         	gamma.green = green;
    60 	}
    61 	if ( blue < MIN_GAMMA ) {
    62 		gamma.blue = MIN_GAMMA;
    63 	} else
    64 	if ( blue > MAX_GAMMA ) {
    65 		gamma.blue = MAX_GAMMA;
    66 	} else {
    67         	gamma.blue = blue;
    68 	}
    69         if ( SDL_GetAppState() & SDL_APPACTIVE ) {
    70             succeeded = SDL_NAME(XF86VidModeSetGamma)(SDL_Display, SDL_Screen, &gamma);
    71             XSync(SDL_Display, False);
    72         } else {
    73             gamma_saved[0] = gamma.red;
    74             gamma_saved[1] = gamma.green;
    75             gamma_saved[2] = gamma.blue;
    76             succeeded = True;
    77         }
    78         if ( succeeded ) {
    79             ++gamma_changed;
    80         }
    81         return succeeded ? 0 : -1;
    82     }
    83 #endif
    84     SDL_SetError("Gamma correction not supported");
    85     return -1;
    86 }
    87 int X11_SetVidModeGamma(_THIS, float red, float green, float blue)
    88 {
    89     int result;
    90 
    91     SDL_Lock_EventThread();
    92     result = X11_SetGammaNoLock(this, red, green, blue);
    93     SDL_Unlock_EventThread();
    94 
    95     return(result);
    96 }
    97 
    98 static int X11_GetGammaNoLock(_THIS, float *red, float *green, float *blue)
    99 {
   100 #ifdef XFREE86_VMGAMMA
   101     if (use_vidmode >= 2) {
   102         SDL_NAME(XF86VidModeGamma) gamma;
   103         if (SDL_NAME(XF86VidModeGetGamma)(SDL_Display, SDL_Screen, &gamma)) {
   104             *red   = gamma.red;
   105             *green = gamma.green;
   106             *blue  = gamma.blue;
   107             return 0;
   108         }
   109         return -1;
   110     }
   111 #endif
   112     return -1;
   113 }
   114 int X11_GetVidModeGamma(_THIS, float *red, float *green, float *blue)
   115 {
   116     int result;
   117 
   118     SDL_Lock_EventThread();
   119     result = X11_GetGammaNoLock(this, red, green, blue);
   120     SDL_Unlock_EventThread();
   121 
   122     return(result);
   123 }
   124 
   125 void X11_SaveVidModeGamma(_THIS)
   126 {
   127     /* Try to save the current gamma, otherwise disable gamma control */
   128     if ( X11_GetGammaNoLock(this,
   129               &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]) < 0 ) {
   130         this->SetGamma = 0;
   131         this->GetGamma = 0;
   132     }
   133     gamma_changed = 0;
   134 }
   135 void X11_SwapVidModeGamma(_THIS)
   136 {
   137     float new_gamma[3];
   138 
   139     if ( gamma_changed ) {
   140         new_gamma[0] = gamma_saved[0];
   141         new_gamma[1] = gamma_saved[1];
   142         new_gamma[2] = gamma_saved[2];
   143         X11_GetGammaNoLock(this, &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]);
   144         X11_SetGammaNoLock(this, new_gamma[0], new_gamma[1], new_gamma[2]);
   145     }
   146 }