| |
| /* Bring up a window and manipulate the gamma on it */ |
| |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <math.h> |
| |
| #include "SDL.h" |
| |
| /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ |
| static void |
| quit(int rc) |
| { |
| SDL_Quit(); |
| exit(rc); |
| } |
| |
| /* Turn a normal gamma value into an appropriate gamma ramp */ |
| void |
| CalculateGamma(double gamma, Uint16 * ramp) |
| { |
| int i, value; |
| |
| gamma = 1.0 / gamma; |
| for (i = 0; i < 256; ++i) { |
| value = (int) (pow((double) i / 256.0, gamma) * 65535.0 + 0.5); |
| if (value > 65535) { |
| value = 65535; |
| } |
| ramp[i] = (Uint16) value; |
| } |
| } |
| |
| /* This can be used as a general routine for all of the test programs */ |
| int |
| get_video_args(char *argv[], int *w, int *h, int *bpp, Uint32 * flags) |
| { |
| int i; |
| |
| *w = 640; |
| *h = 480; |
| *bpp = 0; |
| *flags = SDL_SWSURFACE; |
| |
| for (i = 1; argv[i]; ++i) { |
| if (strcmp(argv[i], "-width") == 0) { |
| if (argv[i + 1]) { |
| *w = atoi(argv[++i]); |
| } |
| } else if (strcmp(argv[i], "-height") == 0) { |
| if (argv[i + 1]) { |
| *h = atoi(argv[++i]); |
| } |
| } else if (strcmp(argv[i], "-bpp") == 0) { |
| if (argv[i + 1]) { |
| *bpp = atoi(argv[++i]); |
| } |
| } else if (strcmp(argv[i], "-fullscreen") == 0) { |
| *flags |= SDL_FULLSCREEN; |
| } else if (strcmp(argv[i], "-hw") == 0) { |
| *flags |= SDL_HWSURFACE; |
| } else if (strcmp(argv[i], "-hwpalette") == 0) { |
| *flags |= SDL_HWPALETTE; |
| } else |
| break; |
| } |
| return i; |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| SDL_Surface *screen; |
| SDL_Surface *image; |
| float gamma; |
| int i; |
| int w, h, bpp; |
| Uint32 flags; |
| Uint16 ramp[256]; |
| Uint16 red_ramp[256]; |
| Uint32 then, timeout; |
| |
| /* Check command line arguments */ |
| argv += get_video_args(argv, &w, &h, &bpp, &flags); |
| |
| /* Initialize SDL */ |
| if (SDL_Init(SDL_INIT_VIDEO) < 0) { |
| fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); |
| return (1); |
| } |
| |
| /* Initialize the display, always use hardware palette */ |
| screen = SDL_SetVideoMode(w, h, bpp, flags | SDL_HWPALETTE); |
| if (screen == NULL) { |
| fprintf(stderr, "Couldn't set %dx%d video mode: %s\n", |
| w, h, SDL_GetError()); |
| quit(1); |
| } |
| |
| /* Set the window manager title bar */ |
| SDL_WM_SetCaption("SDL gamma test", "testgamma"); |
| |
| /* Set the desired gamma, if any */ |
| gamma = 1.0f; |
| if (*argv) { |
| gamma = (float) atof(*argv); |
| } |
| if (SDL_SetGamma(gamma, gamma, gamma) < 0) { |
| fprintf(stderr, "Unable to set gamma: %s\n", SDL_GetError()); |
| quit(1); |
| } |
| #if 0 /* This isn't supported. Integrating the gamma ramps isn't exact */ |
| /* See what gamma was actually set */ |
| float real[3]; |
| if (SDL_GetGamma(&real[0], &real[1], &real[2]) < 0) { |
| printf("Couldn't get gamma: %s\n", SDL_GetError()); |
| } else { |
| printf("Set gamma values: R=%2.2f, G=%2.2f, B=%2.2f\n", |
| real[0], real[1], real[2]); |
| } |
| #endif |
| |
| /* Do all the drawing work */ |
| image = SDL_LoadBMP("sample.bmp"); |
| if (image) { |
| SDL_Rect dst; |
| |
| dst.x = (screen->w - image->w) / 2; |
| dst.y = (screen->h - image->h) / 2; |
| dst.w = image->w; |
| dst.h = image->h; |
| SDL_BlitSurface(image, NULL, screen, &dst); |
| SDL_UpdateRects(screen, 1, &dst); |
| } |
| |
| /* Wait a bit, handling events */ |
| then = SDL_GetTicks(); |
| timeout = (5 * 1000); |
| while ((SDL_GetTicks() - then) < timeout) { |
| SDL_Event event; |
| |
| while (SDL_PollEvent(&event)) { |
| switch (event.type) { |
| case SDL_QUIT: /* Quit now */ |
| timeout = 0; |
| break; |
| case SDL_KEYDOWN: |
| switch (event.key.keysym.sym) { |
| case SDLK_SPACE: /* Go longer.. */ |
| timeout += (5 * 1000); |
| break; |
| case SDLK_UP: |
| gamma += 0.2f; |
| SDL_SetGamma(gamma, gamma, gamma); |
| break; |
| case SDLK_DOWN: |
| gamma -= 0.2f; |
| SDL_SetGamma(gamma, gamma, gamma); |
| break; |
| case SDLK_ESCAPE: |
| timeout = 0; |
| break; |
| default: |
| break; |
| } |
| break; |
| } |
| } |
| } |
| |
| /* Perform a gamma flash to red using color ramps */ |
| while (gamma < 10.0) { |
| /* Increase the red gamma and decrease everything else... */ |
| gamma += 0.1f; |
| CalculateGamma(gamma, red_ramp); |
| CalculateGamma(1.0 / gamma, ramp); |
| SDL_SetGammaRamp(red_ramp, ramp, ramp); |
| } |
| /* Finish completely red */ |
| memset(red_ramp, 255, sizeof(red_ramp)); |
| memset(ramp, 0, sizeof(ramp)); |
| SDL_SetGammaRamp(red_ramp, ramp, ramp); |
| |
| /* Now fade out to black */ |
| for (i = (red_ramp[0] >> 8); i >= 0; --i) { |
| memset(red_ramp, i, sizeof(red_ramp)); |
| SDL_SetGammaRamp(red_ramp, NULL, NULL); |
| } |
| SDL_Delay(1 * 1000); |
| |
| SDL_Quit(); |
| return (0); |
| } |