src/video/x11/SDL_x11gamma.c
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FUNCTIONS
This source file includes following functions.
- X11_SetGammaNoLock
- X11_SetVidModeGamma
- X11_GetGammaNoLock
- X11_GetVidModeGamma
- X11_SaveVidModeGamma
- X11_SwapVidModeGamma
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997, 1998, 1999, 2000, 2001 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@devolution.com
21 */
22
23 #ifdef SAVE_RCSID
24 static char rcsid =
25 "@(#) $Id: SDL_x11gamma.c,v 1.1.2.13 2001/02/10 07:20:13 hercules Exp $";
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)
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38 {
39 #ifdef XFREE86_VMGAMMA
40 if (use_vidmode) {
41 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 = XVidMode(SetGamma, (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)
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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)
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99 {
100 #ifdef XFREE86_VMGAMMA
101 if (use_vidmode) {
102 XF86VidModeGamma gamma;
103 if (XVidMode(GetGamma, (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 SDL_SetError("Gamma correction not supported");
113 return -1;
114 }
115 int X11_GetVidModeGamma(_THIS, float *red, float *green, float *blue)
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116 {
117 int result;
118
119 SDL_Lock_EventThread();
120 result = X11_GetGammaNoLock(this, red, green, blue);
121 SDL_Unlock_EventThread();
122
123 return(result);
124 }
125
126 void X11_SaveVidModeGamma(_THIS)
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127 {
128 /* Try to save the current gamma, otherwise disable gamma control */
129 if ( X11_GetGammaNoLock(this,
130 &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]) < 0 ) {
131 this->SetGamma = 0;
132 this->GetGamma = 0;
133 }
134 gamma_changed = 0;
135 }
136 void X11_SwapVidModeGamma(_THIS)
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137 {
138 float new_gamma[3];
139
140 if ( gamma_changed ) {
141 new_gamma[0] = gamma_saved[0];
142 new_gamma[1] = gamma_saved[1];
143 new_gamma[2] = gamma_saved[2];
144 X11_GetGammaNoLock(this, &gamma_saved[0], &gamma_saved[1], &gamma_saved[2]);
145 X11_SetGammaNoLock(this, new_gamma[0], new_gamma[1], new_gamma[2]);
146 }
147 }