/* * testpalette.c * * A simple test of runtime palette modification for animation * (using the SDL_SetPalette() API). */ #include #include #include #include /* This isn't in the Windows headers */ #ifndef M_PI #define M_PI 3.14159265358979323846 #endif #include "SDL.h" /* screen size */ #define SCRW 640 #define SCRH 480 #define NBOATS 5 #define SPEED 2 #ifndef MIN #define MIN(a, b) ((a) < (b) ? (a) : (b)) #endif #ifndef MAX #define MAX(a, b) ((a) > (b) ? (a) : (b)) #endif /* * wave colours: Made by taking a narrow cross-section of a wave picture * in Gimp, saving in PPM ascii format and formatting with Emacs macros. */ static SDL_Color wavemap[] = { {0, 2, 103}, {0, 7, 110}, {0, 13, 117}, {0, 19, 125}, {0, 25, 133}, {0, 31, 141}, {0, 37, 150}, {0, 43, 158}, {0, 49, 166}, {0, 55, 174}, {0, 61, 182}, {0, 67, 190}, {0, 73, 198}, {0, 79, 206}, {0, 86, 214}, {0, 96, 220}, {5, 105, 224}, {12, 112, 226}, {19, 120, 227}, {26, 128, 229}, {33, 135, 230}, {40, 143, 232}, {47, 150, 234}, {54, 158, 236}, {61, 165, 238}, {68, 173, 239}, {75, 180, 241}, {82, 188, 242}, {89, 195, 244}, {96, 203, 246}, {103, 210, 248}, {112, 218, 250}, {124, 224, 250}, {135, 226, 251}, {146, 229, 251}, {156, 231, 252}, {167, 233, 252}, {178, 236, 252}, {189, 238, 252}, {200, 240, 252}, {211, 242, 252}, {222, 244, 252}, {233, 247, 252}, {242, 249, 252}, {237, 250, 252}, {209, 251, 252}, {174, 251, 252}, {138, 252, 252}, {102, 251, 252}, {63, 250, 252}, {24, 243, 252}, {7, 225, 252}, {4, 203, 252}, {3, 181, 252}, {2, 158, 252}, {1, 136, 251}, {0, 111, 248}, {0, 82, 234}, {0, 63, 213}, {0, 50, 192}, {0, 39, 172}, {0, 28, 152}, {0, 17, 132}, {0, 7, 114} }; /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ static void quit(int rc) { SDL_Quit(); exit(rc); } static void sdlerr(char *when) { fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError()); quit(1); } /* create a background surface */ static SDL_Surface * make_bg(SDL_Surface * screen, int startcol) { int i; SDL_Surface *bg = SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h, 8, 0, 0, 0, 0); if (!bg) sdlerr("creating background surface"); /* set the palette to the logical screen palette so that blits won't be translated */ SDL_SetColors(bg, screen->format->palette->colors, 0, 256); /* Make a wavy background pattern using colours 0-63 */ if (SDL_LockSurface(bg) < 0) sdlerr("locking background"); for (i = 0; i < SCRH; i++) { Uint8 *p = (Uint8 *) bg->pixels + i * bg->pitch; int j, d; d = 0; for (j = 0; j < SCRW; j++) { int v = MAX(d, -2); v = MIN(v, 2); if (i > 0) v += p[-bg->pitch] + 65 - startcol; p[j] = startcol + (v & 63); d += ((rand() >> 3) % 3) - 1; } } SDL_UnlockSurface(bg); return (bg); } /* * Return a surface flipped horisontally. Only works for 8bpp; * extension to arbitrary bitness is left as an exercise for the reader. */ static SDL_Surface * hflip(SDL_Surface * s) { int i; SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8, 0, 0, 0, 0); /* copy palette */ SDL_SetColors(z, s->format->palette->colors, 0, s->format->palette->ncolors); if (SDL_LockSurface(s) < 0 || SDL_LockSurface(z) < 0) sdlerr("locking flip images"); for (i = 0; i < s->h; i++) { int j; Uint8 *from = (Uint8 *) s->pixels + i * s->pitch; Uint8 *to = (Uint8 *) z->pixels + i * z->pitch + s->w - 1; for (j = 0; j < s->w; j++) to[-j] = from[j]; } SDL_UnlockSurface(z); SDL_UnlockSurface(s); return z; } int main(int argc, char **argv) { SDL_Color cmap[256]; SDL_Surface *screen; SDL_Surface *bg; SDL_Surface *boat[2]; unsigned vidflags = 0; unsigned start; int fade_max = 400; int fade_level, fade_dir; int boatcols, frames, i, red; int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS]; int gamma_fade = 0; int gamma_ramp = 0; if (SDL_Init(SDL_INIT_VIDEO) < 0) sdlerr("initialising SDL"); while (--argc) { ++argv; if (strcmp(*argv, "-hw") == 0) vidflags |= SDL_HWSURFACE; else if (strcmp(*argv, "-fullscreen") == 0) vidflags |= SDL_FULLSCREEN; else if (strcmp(*argv, "-nofade") == 0) fade_max = 1; else if (strcmp(*argv, "-gamma") == 0) gamma_fade = 1; else if (strcmp(*argv, "-gammaramp") == 0) gamma_ramp = 1; else { fprintf(stderr, "usage: testpalette " " [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n"); quit(1); } } /* Ask explicitly for 8bpp and a hardware palette */ if ((screen = SDL_SetVideoMode(SCRW, SCRH, 8, vidflags | SDL_HWPALETTE)) == NULL) { fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n", SCRW, SCRH, SDL_GetError()); quit(1); } if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor(SDL_FALSE); if ((boat[0] = SDL_LoadBMP("sail.bmp")) == NULL) sdlerr("loading sail.bmp"); /* We've chosen magenta (#ff00ff) as colour key for the boat */ SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY | SDL_RLEACCEL, SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff)); boatcols = boat[0]->format->palette->ncolors; boat[1] = hflip(boat[0]); SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY | SDL_RLEACCEL, SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff)); /* * First set the physical screen palette to black, so the user won't * see our initial drawing on the screen. */ memset(cmap, 0, sizeof(cmap)); SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256); /* * Proper palette management is important when playing games with the * colormap. We have divided the palette as follows: * * index 0..(boatcols-1): used for the boat * index boatcols..(boatcols+63): used for the waves */ SDL_SetPalette(screen, SDL_LOGPAL, boat[0]->format->palette->colors, 0, boatcols); SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64); /* * Now the logical screen palette is set, and will remain unchanged. * The boats already have the same palette so fast blits can be used. */ memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color)); /* save the index of the red colour for later */ red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00); bg = make_bg(screen, boatcols); /* make a nice wavy background surface */ /* initial screen contents */ if (SDL_BlitSurface(bg, NULL, screen, NULL) < 0) sdlerr("blitting background to screen"); SDL_Flip(screen); /* actually put the background on screen */ /* determine initial boat placements */ for (i = 0; i < NBOATS; i++) { boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w; boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1); boatdir[i] = ((rand() >> 5) & 1) * 2 - 1; } start = SDL_GetTicks(); frames = 0; fade_dir = 1; fade_level = 0; do { SDL_Event e; SDL_Rect updates[NBOATS]; SDL_Rect r; int redphase; /* A small event loop: just exit on any key or mouse button event */ while (SDL_PollEvent(&e)) { if (e.type == SDL_KEYDOWN || e.type == SDL_QUIT || e.type == SDL_MOUSEBUTTONDOWN) { if (fade_dir < 0) fade_level = 0; fade_dir = -1; } } /* move boats */ for (i = 0; i < NBOATS; i++) { int old_x = boatx[i]; /* update boat position */ boatx[i] += boatdir[i] * SPEED; if (boatx[i] <= -boat[0]->w || boatx[i] >= SCRW) boatdir[i] = -boatdir[i]; /* paint over the old boat position */ r.x = old_x; r.y = boaty[i]; r.w = boat[0]->w; r.h = boat[0]->h; if (SDL_BlitSurface(bg, &r, screen, &r) < 0) sdlerr("blitting background"); /* construct update rectangle (bounding box of old and new pos) */ updates[i].x = MIN(old_x, boatx[i]); updates[i].y = boaty[i]; updates[i].w = boat[0]->w + SPEED; updates[i].h = boat[0]->h; /* clip update rectangle to screen */ if (updates[i].x < 0) { updates[i].w += updates[i].x; updates[i].x = 0; } if (updates[i].x + updates[i].w > SCRW) updates[i].w = SCRW - updates[i].x; } for (i = 0; i < NBOATS; i++) { /* paint boat on new position */ r.x = boatx[i]; r.y = boaty[i]; if (SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL, screen, &r) < 0) sdlerr("blitting boat"); } /* cycle wave palette */ for (i = 0; i < 64; i++) cmap[boatcols + ((i + frames) & 63)] = wavemap[i]; if (fade_dir) { /* Fade the entire palette in/out */ fade_level += fade_dir; if (gamma_fade) { /* Fade linearly in gamma level (lousy) */ float level = (float) fade_level / fade_max; if (SDL_SetGamma(level, level, level) < 0) sdlerr("setting gamma"); } else if (gamma_ramp) { /* Fade using gamma ramp (better) */ Uint16 ramp[256]; for (i = 0; i < 256; i++) ramp[i] = (i * fade_level / fade_max) << 8; if (SDL_SetGammaRamp(ramp, ramp, ramp) < 0) sdlerr("setting gamma ramp"); } else { /* Fade using direct palette manipulation (best) */ memcpy(cmap, screen->format->palette->colors, boatcols * sizeof(SDL_Color)); for (i = 0; i < boatcols + 64; i++) { cmap[i].r = cmap[i].r * fade_level / fade_max; cmap[i].g = cmap[i].g * fade_level / fade_max; cmap[i].b = cmap[i].b * fade_level / fade_max; } } if (fade_level == fade_max) fade_dir = 0; } /* pulse the red colour (done after the fade, for a night effect) */ redphase = frames % 64; cmap[red].r = (int) (255 * sin(redphase * M_PI / 63)); SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64); /* update changed areas of the screen */ SDL_UpdateRects(screen, NBOATS, updates); frames++; } while (fade_level > 0); printf("%d frames, %.2f fps\n", frames, 1000.0 * frames / (SDL_GetTicks() - start)); if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor(SDL_TRUE); SDL_Quit(); return 0; }