Mercurial > sdl-ios-xcode
view test/testgamma.c @ 5172:ededa1ccf91c
Switched the SDL 1.2 compatibility to use the window surface, so it's fast even when there's no hardware acceleration available.
This means that the YUV overlay now uses software, but that's okay since fast YUV code should be using the textures now anyway.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Thu, 03 Feb 2011 21:13:55 -0800 |
parents | c121d94672cb |
children |
line wrap: on
line source
/* 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); }