| 1 | /* |
| 2 | * testpalette.c |
| 3 | * |
| 4 | * A simple test of runtime palette modification for animation |
| 5 | * (using the SDL_SetPalette() API). |
| 6 | */ |
| 7 | |
| 8 | #include <stdio.h> |
| 9 | #include <stdlib.h> |
| 10 | #include <string.h> |
| 11 | #include <math.h> |
| 12 | |
| 13 | /* This isn't in the Windows headers */ |
| 14 | #ifndef M_PI |
| 15 | #define M_PI 3.14159265358979323846 |
| 16 | #endif |
| 17 | |
| 18 | #include "SDL.h" |
| 19 | |
| 20 | /* screen size */ |
| 21 | #define SCRW 640 |
| 22 | #define SCRH 480 |
| 23 | |
| 24 | #define NBOATS 5 |
| 25 | #define SPEED 2 |
| 26 | |
| 27 | #ifndef MIN |
| 28 | #define MIN(a, b) ((a) < (b) ? (a) : (b)) |
| 29 | #endif |
| 30 | #ifndef MAX |
| 31 | #define MAX(a, b) ((a) > (b) ? (a) : (b)) |
| 32 | #endif |
| 33 | |
| 34 | /* |
| 35 | * wave colours: Made by taking a narrow cross-section of a wave picture |
| 36 | * in Gimp, saving in PPM ascii format and formatting with Emacs macros. |
| 37 | */ |
| 38 | static SDL_Color wavemap[] = { |
| 39 | {0,2,103}, {0,7,110}, {0,13,117}, {0,19,125}, |
| 40 | {0,25,133}, {0,31,141}, {0,37,150}, {0,43,158}, |
| 41 | {0,49,166}, {0,55,174}, {0,61,182}, {0,67,190}, |
| 42 | {0,73,198}, {0,79,206}, {0,86,214}, {0,96,220}, |
| 43 | {5,105,224}, {12,112,226}, {19,120,227}, {26,128,229}, |
| 44 | {33,135,230}, {40,143,232}, {47,150,234}, {54,158,236}, |
| 45 | {61,165,238}, {68,173,239}, {75,180,241}, {82,188,242}, |
| 46 | {89,195,244}, {96,203,246}, {103,210,248}, {112,218,250}, |
| 47 | {124,224,250}, {135,226,251}, {146,229,251}, {156,231,252}, |
| 48 | {167,233,252}, {178,236,252}, {189,238,252}, {200,240,252}, |
| 49 | {211,242,252}, {222,244,252}, {233,247,252}, {242,249,252}, |
| 50 | {237,250,252}, {209,251,252}, {174,251,252}, {138,252,252}, |
| 51 | {102,251,252}, {63,250,252}, {24,243,252}, {7,225,252}, |
| 52 | {4,203,252}, {3,181,252}, {2,158,252}, {1,136,251}, |
| 53 | {0,111,248}, {0,82,234}, {0,63,213}, {0,50,192}, |
| 54 | {0,39,172}, {0,28,152}, {0,17,132}, {0,7,114} |
| 55 | }; |
| 56 | |
| 57 | /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ |
| 58 | static void quit(int rc) |
| 59 | { |
| 60 | SDL_Quit(); |
| 61 | exit(rc); |
| 62 | } |
| 63 | |
| 64 | static void sdlerr(char *when) |
| 65 | { |
| 66 | fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError()); |
| 67 | quit(1); |
| 68 | } |
| 69 | |
| 70 | /* create a background surface */ |
| 71 | static SDL_Surface *make_bg(SDL_Surface *screen, int startcol) |
| 72 | { |
| 73 | int i; |
| 74 | SDL_Surface *bg = SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h, |
| 75 | 8, 0, 0, 0, 0); |
| 76 | if(!bg) |
| 77 | sdlerr("creating background surface"); |
| 78 | |
| 79 | /* set the palette to the logical screen palette so that blits |
| 80 | won't be translated */ |
| 81 | SDL_SetColors(bg, screen->format->palette->colors, 0, 256); |
| 82 | |
| 83 | /* Make a wavy background pattern using colours 0-63 */ |
| 84 | if(SDL_LockSurface(bg) < 0) |
| 85 | sdlerr("locking background"); |
| 86 | for(i = 0; i < SCRH; i++) { |
| 87 | Uint8 *p = (Uint8 *)bg->pixels + i * bg->pitch; |
| 88 | int j, d; |
| 89 | d = 0; |
| 90 | for(j = 0; j < SCRW; j++) { |
| 91 | int v = MAX(d, -2); |
| 92 | v = MIN(v, 2); |
| 93 | if(i > 0) |
| 94 | v += p[-bg->pitch] + 65 - startcol; |
| 95 | p[j] = startcol + (v & 63); |
| 96 | d += ((rand() >> 3) % 3) - 1; |
| 97 | } |
| 98 | } |
| 99 | SDL_UnlockSurface(bg); |
| 100 | return(bg); |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * Return a surface flipped horisontally. Only works for 8bpp; |
| 105 | * extension to arbitrary bitness is left as an exercise for the reader. |
| 106 | */ |
| 107 | static SDL_Surface *hflip(SDL_Surface *s) |
| 108 | { |
| 109 | int i; |
| 110 | SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8, |
| 111 | 0, 0, 0, 0); |
| 112 | /* copy palette */ |
| 113 | SDL_SetColors(z, s->format->palette->colors, |
| 114 | 0, s->format->palette->ncolors); |
| 115 | if(SDL_LockSurface(s) < 0 || SDL_LockSurface(z) < 0) |
| 116 | sdlerr("locking flip images"); |
| 117 | |
| 118 | for(i = 0; i < s->h; i++) { |
| 119 | int j; |
| 120 | Uint8 *from = (Uint8 *)s->pixels + i * s->pitch; |
| 121 | Uint8 *to = (Uint8 *)z->pixels + i * z->pitch + s->w - 1; |
| 122 | for(j = 0; j < s->w; j++) |
| 123 | to[-j] = from[j]; |
| 124 | } |
| 125 | |
| 126 | SDL_UnlockSurface(z); |
| 127 | SDL_UnlockSurface(s); |
| 128 | return z; |
| 129 | } |
| 130 | |
| 131 | int main(int argc, char **argv) |
| 132 | { |
| 133 | SDL_Color cmap[256]; |
| 134 | SDL_Surface *screen; |
| 135 | SDL_Surface *bg; |
| 136 | SDL_Surface *boat[2]; |
| 137 | unsigned vidflags = 0; |
| 138 | unsigned start; |
| 139 | int fade_max = 400; |
| 140 | int fade_level, fade_dir; |
| 141 | int boatcols, frames, i, red; |
| 142 | int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS]; |
| 143 | int gamma_fade = 0; |
| 144 | int gamma_ramp = 0; |
| 145 | |
| 146 | if(SDL_Init(SDL_INIT_VIDEO) < 0) |
| 147 | sdlerr("initialising SDL"); |
| 148 | |
| 149 | while(--argc) { |
| 150 | ++argv; |
| 151 | if(strcmp(*argv, "-hw") == 0) |
| 152 | vidflags |= SDL_HWSURFACE; |
| 153 | else if(strcmp(*argv, "-fullscreen") == 0) |
| 154 | vidflags |= SDL_FULLSCREEN; |
| 155 | else if(strcmp(*argv, "-nofade") == 0) |
| 156 | fade_max = 1; |
| 157 | else if(strcmp(*argv, "-gamma") == 0) |
| 158 | gamma_fade = 1; |
| 159 | else if(strcmp(*argv, "-gammaramp") == 0) |
| 160 | gamma_ramp = 1; |
| 161 | else { |
| 162 | fprintf(stderr, |
| 163 | "usage: testpalette " |
| 164 | " [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n"); |
| 165 | quit(1); |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | /* Ask explicitly for 8bpp and a hardware palette */ |
| 170 | if((screen = SDL_SetVideoMode(SCRW, SCRH, 8, vidflags | SDL_HWPALETTE)) == NULL) { |
| 171 | fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n", |
| 172 | SCRW, SCRH, SDL_GetError()); |
| 173 | quit(1); |
| 174 | } |
| 175 | |
| 176 | if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_FALSE); |
| 177 | |
| 178 | if((boat[0] = SDL_LoadBMP("sail.bmp")) == NULL) |
| 179 | sdlerr("loading sail.bmp"); |
| 180 | /* We've chosen magenta (#ff00ff) as colour key for the boat */ |
| 181 | SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY | SDL_RLEACCEL, |
| 182 | SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff)); |
| 183 | boatcols = boat[0]->format->palette->ncolors; |
| 184 | boat[1] = hflip(boat[0]); |
| 185 | SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY | SDL_RLEACCEL, |
| 186 | SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff)); |
| 187 | |
| 188 | /* |
| 189 | * First set the physical screen palette to black, so the user won't |
| 190 | * see our initial drawing on the screen. |
| 191 | */ |
| 192 | memset(cmap, 0, sizeof(cmap)); |
| 193 | SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256); |
| 194 | |
| 195 | /* |
| 196 | * Proper palette management is important when playing games with the |
| 197 | * colormap. We have divided the palette as follows: |
| 198 | * |
| 199 | * index 0..(boatcols-1): used for the boat |
| 200 | * index boatcols..(boatcols+63): used for the waves |
| 201 | */ |
| 202 | SDL_SetPalette(screen, SDL_LOGPAL, |
| 203 | boat[0]->format->palette->colors, 0, boatcols); |
| 204 | SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64); |
| 205 | |
| 206 | /* |
| 207 | * Now the logical screen palette is set, and will remain unchanged. |
| 208 | * The boats already have the same palette so fast blits can be used. |
| 209 | */ |
| 210 | memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color)); |
| 211 | |
| 212 | /* save the index of the red colour for later */ |
| 213 | red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00); |
| 214 | |
| 215 | bg = make_bg(screen, boatcols); /* make a nice wavy background surface */ |
| 216 | |
| 217 | /* initial screen contents */ |
| 218 | if(SDL_BlitSurface(bg, NULL, screen, NULL) < 0) |
| 219 | sdlerr("blitting background to screen"); |
| 220 | SDL_Flip(screen); /* actually put the background on screen */ |
| 221 | |
| 222 | /* determine initial boat placements */ |
| 223 | for(i = 0; i < NBOATS; i++) { |
| 224 | boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w; |
| 225 | boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1); |
| 226 | boatdir[i] = ((rand() >> 5) & 1) * 2 - 1; |
| 227 | } |
| 228 | |
| 229 | start = SDL_GetTicks(); |
| 230 | frames = 0; |
| 231 | fade_dir = 1; |
| 232 | fade_level = 0; |
| 233 | do { |
| 234 | SDL_Event e; |
| 235 | SDL_Rect updates[NBOATS]; |
| 236 | SDL_Rect r; |
| 237 | int redphase; |
| 238 | |
| 239 | /* A small event loop: just exit on any key or mouse button event */ |
| 240 | while(SDL_PollEvent(&e)) { |
| 241 | if(e.type == SDL_KEYDOWN || e.type == SDL_QUIT |
| 242 | || e.type == SDL_MOUSEBUTTONDOWN) { |
| 243 | if(fade_dir < 0) |
| 244 | fade_level = 0; |
| 245 | fade_dir = -1; |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | /* move boats */ |
| 250 | for(i = 0; i < NBOATS; i++) { |
| 251 | int old_x = boatx[i]; |
| 252 | /* update boat position */ |
| 253 | boatx[i] += boatdir[i] * SPEED; |
| 254 | if(boatx[i] <= -boat[0]->w || boatx[i] >= SCRW) |
| 255 | boatdir[i] = -boatdir[i]; |
| 256 | |
| 257 | /* paint over the old boat position */ |
| 258 | r.x = old_x; |
| 259 | r.y = boaty[i]; |
| 260 | r.w = boat[0]->w; |
| 261 | r.h = boat[0]->h; |
| 262 | if(SDL_BlitSurface(bg, &r, screen, &r) < 0) |
| 263 | sdlerr("blitting background"); |
| 264 | |
| 265 | /* construct update rectangle (bounding box of old and new pos) */ |
| 266 | updates[i].x = MIN(old_x, boatx[i]); |
| 267 | updates[i].y = boaty[i]; |
| 268 | updates[i].w = boat[0]->w + SPEED; |
| 269 | updates[i].h = boat[0]->h; |
| 270 | /* clip update rectangle to screen */ |
| 271 | if(updates[i].x < 0) { |
| 272 | updates[i].w += updates[i].x; |
| 273 | updates[i].x = 0; |
| 274 | } |
| 275 | if(updates[i].x + updates[i].w > SCRW) |
| 276 | updates[i].w = SCRW - updates[i].x; |
| 277 | } |
| 278 | |
| 279 | for(i = 0; i < NBOATS; i++) { |
| 280 | /* paint boat on new position */ |
| 281 | r.x = boatx[i]; |
| 282 | r.y = boaty[i]; |
| 283 | if(SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL, |
| 284 | screen, &r) < 0) |
| 285 | sdlerr("blitting boat"); |
| 286 | } |
| 287 | |
| 288 | /* cycle wave palette */ |
| 289 | for(i = 0; i < 64; i++) |
| 290 | cmap[boatcols + ((i + frames) & 63)] = wavemap[i]; |
| 291 | |
| 292 | if(fade_dir) { |
| 293 | /* Fade the entire palette in/out */ |
| 294 | fade_level += fade_dir; |
| 295 | |
| 296 | if(gamma_fade) { |
| 297 | /* Fade linearly in gamma level (lousy) */ |
| 298 | float level = (float)fade_level / fade_max; |
| 299 | if(SDL_SetGamma(level, level, level) < 0) |
| 300 | sdlerr("setting gamma"); |
| 301 | |
| 302 | } else if(gamma_ramp) { |
| 303 | /* Fade using gamma ramp (better) */ |
| 304 | Uint16 ramp[256]; |
| 305 | for(i = 0; i < 256; i++) |
| 306 | ramp[i] = (i * fade_level / fade_max) << 8; |
| 307 | if(SDL_SetGammaRamp(ramp, ramp, ramp) < 0) |
| 308 | sdlerr("setting gamma ramp"); |
| 309 | |
| 310 | } else { |
| 311 | /* Fade using direct palette manipulation (best) */ |
| 312 | memcpy(cmap, screen->format->palette->colors, |
| 313 | boatcols * sizeof(SDL_Color)); |
| 314 | for(i = 0; i < boatcols + 64; i++) { |
| 315 | cmap[i].r = cmap[i].r * fade_level / fade_max; |
| 316 | cmap[i].g = cmap[i].g * fade_level / fade_max; |
| 317 | cmap[i].b = cmap[i].b * fade_level / fade_max; |
| 318 | } |
| 319 | } |
| 320 | if(fade_level == fade_max) |
| 321 | fade_dir = 0; |
| 322 | } |
| 323 | |
| 324 | /* pulse the red colour (done after the fade, for a night effect) */ |
| 325 | redphase = frames % 64; |
| 326 | cmap[red].r = (int)(255 * sin(redphase * M_PI / 63)); |
| 327 | |
| 328 | SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64); |
| 329 | |
| 330 | /* update changed areas of the screen */ |
| 331 | SDL_UpdateRects(screen, NBOATS, updates); |
| 332 | frames++; |
| 333 | } while(fade_level > 0); |
| 334 | |
| 335 | printf("%d frames, %.2f fps\n", |
| 336 | frames, 1000.0 * frames / (SDL_GetTicks() - start)); |
| 337 | |
| 338 | if (vidflags & SDL_FULLSCREEN) SDL_ShowCursor (SDL_TRUE); |
| 339 | SDL_Quit(); |
| 340 | return 0; |
| 341 | } |
| 342 | |