| /* |
| * testpalette.c |
| * |
| * A simple test of runtime palette modification for animation |
| * (using the SDL_SetPalette() API). |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <math.h> |
| |
| #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_SetSurfacePalette(bg, screen->format->palette); |
| |
| /* 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; |
| if (boatcols >= 256) |
| sdlerr("too many colors in sail.bmp"); |
| 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; |
| } |
