2 /* Bring up a window and manipulate the gamma on it */
11 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
12 static void quit(int rc)
18 /* Turn a normal gamma value into an appropriate gamma ramp */
19 void CalculateGamma(double gamma, Uint16 *ramp)
24 for ( i=0; i<256; ++i ) {
25 value = (int)(pow((double)i/256.0, gamma)*65535.0 + 0.5);
26 if ( value > 65535 ) {
29 ramp[i] = (Uint16)value;
33 /* This can be used as a general routine for all of the test programs */
34 int get_video_args(char *argv[], int *w, int *h, int *bpp, Uint32 *flags)
41 *flags = SDL_SWSURFACE;
43 for ( i=1; argv[i]; ++i ) {
44 if ( strcmp(argv[i], "-width") == 0 ) {
49 if ( strcmp(argv[i], "-height") == 0 ) {
54 if ( strcmp(argv[i], "-bpp") == 0 ) {
56 *bpp = atoi(argv[++i]);
59 if ( strcmp(argv[i], "-fullscreen") == 0 ) {
60 *flags |= SDL_FULLSCREEN;
62 if ( strcmp(argv[i], "-hw") == 0 ) {
63 *flags |= SDL_HWSURFACE;
65 if ( strcmp(argv[i], "-hwpalette") == 0 ) {
66 *flags |= SDL_HWPALETTE;
73 int main(int argc, char *argv[])
85 /* Check command line arguments */
86 argv += get_video_args(argv, &w, &h, &bpp, &flags);
89 if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
91 "Couldn't initialize SDL: %s\n", SDL_GetError());
95 /* Initialize the display, always use hardware palette */
96 screen = SDL_SetVideoMode(w, h, bpp, flags | SDL_HWPALETTE);
97 if ( screen == NULL ) {
98 fprintf(stderr, "Couldn't set %dx%d video mode: %s\n",
99 w, h, SDL_GetError());
103 /* Set the window manager title bar */
104 SDL_WM_SetCaption("SDL gamma test", "testgamma");
106 /* Set the desired gamma, if any */
109 gamma = (float)atof(*argv);
111 if ( SDL_SetGamma(gamma, gamma, gamma) < 0 ) {
112 fprintf(stderr, "Unable to set gamma: %s\n", SDL_GetError());
116 #if 0 /* This isn't supported. Integrating the gamma ramps isn't exact */
117 /* See what gamma was actually set */
119 if ( SDL_GetGamma(&real[0], &real[1], &real[2]) < 0 ) {
120 printf("Couldn't get gamma: %s\n", SDL_GetError());
122 printf("Set gamma values: R=%2.2f, G=%2.2f, B=%2.2f\n",
123 real[0], real[1], real[2]);
127 /* Do all the drawing work */
128 image = SDL_LoadBMP("sample.bmp");
132 dst.x = (screen->w - image->w)/2;
133 dst.y = (screen->h - image->h)/2;
136 SDL_BlitSurface(image, NULL, screen, &dst);
137 SDL_UpdateRects(screen, 1, &dst);
140 /* Wait a bit, handling events */
141 then = SDL_GetTicks();
143 while ( (SDL_GetTicks()-then) < timeout ) {
146 while ( SDL_PollEvent(&event) ) {
147 switch (event.type) {
148 case SDL_QUIT: /* Quit now */
152 switch (event.key.keysym.sym) {
153 case SDLK_SPACE: /* Go longer.. */
158 SDL_SetGamma(gamma, gamma, gamma);
162 SDL_SetGamma(gamma, gamma, gamma);
175 /* Perform a gamma flash to red using color ramps */
176 while ( gamma < 10.0 ) {
177 /* Increase the red gamma and decrease everything else... */
179 CalculateGamma(gamma, red_ramp);
180 CalculateGamma(1.0/gamma, ramp);
181 SDL_SetGammaRamp(red_ramp, ramp, ramp);
183 /* Finish completely red */
184 memset(red_ramp, 255, sizeof(red_ramp));
185 memset(ramp, 0, sizeof(ramp));
186 SDL_SetGammaRamp(red_ramp, ramp, ramp);
188 /* Now fade out to black */
189 for ( i=(red_ramp[0] >> 8); i >= 0; --i ) {
190 memset(red_ramp, i, sizeof(red_ramp));
191 SDL_SetGammaRamp(red_ramp, NULL, NULL);