src/video/x11/SDL_x11gamma.c
author Ryan C. Gordon <icculus@icculus.org>
Wed, 22 Mar 2006 05:00:59 +0000
changeset 1575 3ba88cb7eb1b
parent 1402 d910939febfa
child 1662 782fd950bd46
child 1895 c121d94672cb
child 4159 a1b03ba2fcd0
permissions -rw-r--r--
Updated dynamic X11 code. See details in Bugzilla #170.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 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     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 #include "SDL_config.h"
    23 
    24 #include "SDL.h"
    25 #include "SDL_events.h"
    26 #include "../../events/SDL_events_c.h"
    27 #include "SDL_x11video.h"
    28 
    29 /* From the X server sources... */
    30 #define MAX_GAMMA 10.0
    31 #define MIN_GAMMA (1.0/MAX_GAMMA)
    32 
    33 static int X11_SetGammaNoLock(_THIS, float red, float green, float blue)
    34 {
    35 #if SDL_VIDEO_DRIVER_X11_VIDMODE
    36     if (use_vidmode >= 200) {
    37         SDL_NAME(XF86VidModeGamma) gamma;
    38         Bool succeeded;
    39 
    40 	/* Clamp the gamma values */
    41 	if ( red < MIN_GAMMA ) {
    42 		gamma.red = MIN_GAMMA;
    43 	} else
    44 	if ( red > MAX_GAMMA ) {
    45 		gamma.red = MAX_GAMMA;
    46 	} else {
    47         	gamma.red = red;
    48 	}
    49 	if ( green < MIN_GAMMA ) {
    50 		gamma.green = MIN_GAMMA;
    51 	} else
    52 	if ( green > MAX_GAMMA ) {
    53 		gamma.green = MAX_GAMMA;
    54 	} else {
    55         	gamma.green = green;
    56 	}
    57 	if ( blue < MIN_GAMMA ) {
    58 		gamma.blue = MIN_GAMMA;
    59 	} else
    60 	if ( blue > MAX_GAMMA ) {
    61 		gamma.blue = MAX_GAMMA;
    62 	} else {
    63         	gamma.blue = blue;
    64 	}
    65         if ( SDL_GetAppState() & SDL_APPACTIVE ) {
    66             succeeded = SDL_NAME(XF86VidModeSetGamma)(SDL_Display, SDL_Screen, &gamma);
    67             XSync(SDL_Display, False);
    68         } else {
    69             gamma_saved[0] = gamma.red;
    70             gamma_saved[1] = gamma.green;
    71             gamma_saved[2] = gamma.blue;
    72             succeeded = True;
    73         }
    74         if ( succeeded ) {
    75             ++gamma_changed;
    76         }
    77         return succeeded ? 0 : -1;
    78     }
    79 #endif
    80     SDL_SetError("Gamma correction not supported");
    81     return -1;
    82 }
    83 int X11_SetVidModeGamma(_THIS, float red, float green, float blue)
    84 {
    85     int result;
    86 
    87     SDL_Lock_EventThread();
    88     result = X11_SetGammaNoLock(this, red, green, blue);
    89     SDL_Unlock_EventThread();
    90 
    91     return(result);
    92 }
    93 
    94 static int X11_GetGammaNoLock(_THIS, float *red, float *green, float *blue)
    95 {
    96 #if SDL_VIDEO_DRIVER_X11_VIDMODE
    97     if (use_vidmode >= 200) {
    98         SDL_NAME(XF86VidModeGamma) gamma;
    99         if (SDL_NAME(XF86VidModeGetGamma)(SDL_Display, SDL_Screen, &gamma)) {
   100             *red   = gamma.red;
   101             *green = gamma.green;
   102             *blue  = gamma.blue;
   103             return 0;
   104         }
   105         return -1;
   106     }
   107 #endif
   108     return -1;
   109 }
   110 int X11_GetVidModeGamma(_THIS, float *red, float *green, float *blue)
   111 {
   112     int result;
   113 
   114     SDL_Lock_EventThread();
   115     result = X11_GetGammaNoLock(this, red, green, blue);
   116     SDL_Unlock_EventThread();
   117 
   118     return(result);
   119 }
   120 
   121 void X11_SaveVidModeGamma(_THIS)
   122 {
   123     /* Try to save the current gamma, otherwise disable gamma control */
   124     if ( X11_GetGammaNoLock(this,
   125               &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]) < 0 ) {
   126         this->SetGamma = 0;
   127         this->GetGamma = 0;
   128     }
   129     gamma_changed = 0;
   130 }
   131 void X11_SwapVidModeGamma(_THIS)
   132 {
   133     float new_gamma[3];
   134 
   135     if ( gamma_changed ) {
   136         new_gamma[0] = gamma_saved[0];
   137         new_gamma[1] = gamma_saved[1];
   138         new_gamma[2] = gamma_saved[2];
   139         X11_GetGammaNoLock(this, &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]);
   140         X11_SetGammaNoLock(this, new_gamma[0], new_gamma[1], new_gamma[2]);
   141     }
   142 }