test/testpalette.c
author Holmes Futrell <hfutrell@umail.ucsb.edu>
Fri, 18 Jul 2008 19:23:13 +0000
branchgsoc2008_iphone
changeset 2377 e9a0bad0ea07
parent 1895 c121d94672cb
child 2669 e27bdcc80744
permissions -rw-r--r--
Just renamed it...
     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
    59 quit(int rc)
    60 {
    61     SDL_Quit();
    62     exit(rc);
    63 }
    64 
    65 static void
    66 sdlerr(char *when)
    67 {
    68     fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError());
    69     quit(1);
    70 }
    71 
    72 /* create a background surface */
    73 static SDL_Surface *
    74 make_bg(SDL_Surface * screen, int startcol)
    75 {
    76     int i;
    77     SDL_Surface *bg =
    78         SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h,
    79                              8, 0, 0, 0, 0);
    80     if (!bg)
    81         sdlerr("creating background surface");
    82 
    83     /* set the palette to the logical screen palette so that blits
    84        won't be translated */
    85     SDL_SetColors(bg, screen->format->palette->colors, 0, 256);
    86 
    87     /* Make a wavy background pattern using colours 0-63 */
    88     if (SDL_LockSurface(bg) < 0)
    89         sdlerr("locking background");
    90     for (i = 0; i < SCRH; i++) {
    91         Uint8 *p = (Uint8 *) bg->pixels + i * bg->pitch;
    92         int j, d;
    93         d = 0;
    94         for (j = 0; j < SCRW; j++) {
    95             int v = MAX(d, -2);
    96             v = MIN(v, 2);
    97             if (i > 0)
    98                 v += p[-bg->pitch] + 65 - startcol;
    99             p[j] = startcol + (v & 63);
   100             d += ((rand() >> 3) % 3) - 1;
   101         }
   102     }
   103     SDL_UnlockSurface(bg);
   104     return (bg);
   105 }
   106 
   107 /*
   108  * Return a surface flipped horisontally. Only works for 8bpp;
   109  * extension to arbitrary bitness is left as an exercise for the reader.
   110  */
   111 static SDL_Surface *
   112 hflip(SDL_Surface * s)
   113 {
   114     int i;
   115     SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8,
   116                                           0, 0, 0, 0);
   117     /* copy palette */
   118     SDL_SetColors(z, s->format->palette->colors,
   119                   0, s->format->palette->ncolors);
   120     if (SDL_LockSurface(s) < 0 || SDL_LockSurface(z) < 0)
   121         sdlerr("locking flip images");
   122 
   123     for (i = 0; i < s->h; i++) {
   124         int j;
   125         Uint8 *from = (Uint8 *) s->pixels + i * s->pitch;
   126         Uint8 *to = (Uint8 *) z->pixels + i * z->pitch + s->w - 1;
   127         for (j = 0; j < s->w; j++)
   128             to[-j] = from[j];
   129     }
   130 
   131     SDL_UnlockSurface(z);
   132     SDL_UnlockSurface(s);
   133     return z;
   134 }
   135 
   136 int
   137 main(int argc, char **argv)
   138 {
   139     SDL_Color cmap[256];
   140     SDL_Surface *screen;
   141     SDL_Surface *bg;
   142     SDL_Surface *boat[2];
   143     unsigned vidflags = 0;
   144     unsigned start;
   145     int fade_max = 400;
   146     int fade_level, fade_dir;
   147     int boatcols, frames, i, red;
   148     int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS];
   149     int gamma_fade = 0;
   150     int gamma_ramp = 0;
   151 
   152     if (SDL_Init(SDL_INIT_VIDEO) < 0)
   153         sdlerr("initialising SDL");
   154 
   155     while (--argc) {
   156         ++argv;
   157         if (strcmp(*argv, "-hw") == 0)
   158             vidflags |= SDL_HWSURFACE;
   159         else if (strcmp(*argv, "-fullscreen") == 0)
   160             vidflags |= SDL_FULLSCREEN;
   161         else if (strcmp(*argv, "-nofade") == 0)
   162             fade_max = 1;
   163         else if (strcmp(*argv, "-gamma") == 0)
   164             gamma_fade = 1;
   165         else if (strcmp(*argv, "-gammaramp") == 0)
   166             gamma_ramp = 1;
   167         else {
   168             fprintf(stderr,
   169                     "usage: testpalette "
   170                     " [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n");
   171             quit(1);
   172         }
   173     }
   174 
   175     /* Ask explicitly for 8bpp and a hardware palette */
   176     if ((screen =
   177          SDL_SetVideoMode(SCRW, SCRH, 8, vidflags | SDL_HWPALETTE)) == NULL) {
   178         fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n",
   179                 SCRW, SCRH, SDL_GetError());
   180         quit(1);
   181     }
   182 
   183     if (vidflags & SDL_FULLSCREEN)
   184         SDL_ShowCursor(SDL_FALSE);
   185 
   186     if ((boat[0] = SDL_LoadBMP("sail.bmp")) == NULL)
   187         sdlerr("loading sail.bmp");
   188     /* We've chosen magenta (#ff00ff) as colour key for the boat */
   189     SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY | SDL_RLEACCEL,
   190                     SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff));
   191     boatcols = boat[0]->format->palette->ncolors;
   192     boat[1] = hflip(boat[0]);
   193     SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY | SDL_RLEACCEL,
   194                     SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff));
   195 
   196     /*
   197      * First set the physical screen palette to black, so the user won't
   198      * see our initial drawing on the screen.
   199      */
   200     memset(cmap, 0, sizeof(cmap));
   201     SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256);
   202 
   203     /*
   204      * Proper palette management is important when playing games with the
   205      * colormap. We have divided the palette as follows:
   206      *
   207      * index 0..(boatcols-1):           used for the boat
   208      * index boatcols..(boatcols+63):   used for the waves
   209      */
   210     SDL_SetPalette(screen, SDL_LOGPAL,
   211                    boat[0]->format->palette->colors, 0, boatcols);
   212     SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64);
   213 
   214     /*
   215      * Now the logical screen palette is set, and will remain unchanged.
   216      * The boats already have the same palette so fast blits can be used.
   217      */
   218     memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color));
   219 
   220     /* save the index of the red colour for later */
   221     red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00);
   222 
   223     bg = make_bg(screen, boatcols);     /* make a nice wavy background surface */
   224 
   225     /* initial screen contents */
   226     if (SDL_BlitSurface(bg, NULL, screen, NULL) < 0)
   227         sdlerr("blitting background to screen");
   228     SDL_Flip(screen);           /* actually put the background on screen */
   229 
   230     /* determine initial boat placements */
   231     for (i = 0; i < NBOATS; i++) {
   232         boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w;
   233         boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1);
   234         boatdir[i] = ((rand() >> 5) & 1) * 2 - 1;
   235     }
   236 
   237     start = SDL_GetTicks();
   238     frames = 0;
   239     fade_dir = 1;
   240     fade_level = 0;
   241     do {
   242         SDL_Event e;
   243         SDL_Rect updates[NBOATS];
   244         SDL_Rect r;
   245         int redphase;
   246 
   247         /* A small event loop: just exit on any key or mouse button event */
   248         while (SDL_PollEvent(&e)) {
   249             if (e.type == SDL_KEYDOWN || e.type == SDL_QUIT
   250                 || e.type == SDL_MOUSEBUTTONDOWN) {
   251                 if (fade_dir < 0)
   252                     fade_level = 0;
   253                 fade_dir = -1;
   254             }
   255         }
   256 
   257         /* move boats */
   258         for (i = 0; i < NBOATS; i++) {
   259             int old_x = boatx[i];
   260             /* update boat position */
   261             boatx[i] += boatdir[i] * SPEED;
   262             if (boatx[i] <= -boat[0]->w || boatx[i] >= SCRW)
   263                 boatdir[i] = -boatdir[i];
   264 
   265             /* paint over the old boat position */
   266             r.x = old_x;
   267             r.y = boaty[i];
   268             r.w = boat[0]->w;
   269             r.h = boat[0]->h;
   270             if (SDL_BlitSurface(bg, &r, screen, &r) < 0)
   271                 sdlerr("blitting background");
   272 
   273             /* construct update rectangle (bounding box of old and new pos) */
   274             updates[i].x = MIN(old_x, boatx[i]);
   275             updates[i].y = boaty[i];
   276             updates[i].w = boat[0]->w + SPEED;
   277             updates[i].h = boat[0]->h;
   278             /* clip update rectangle to screen */
   279             if (updates[i].x < 0) {
   280                 updates[i].w += updates[i].x;
   281                 updates[i].x = 0;
   282             }
   283             if (updates[i].x + updates[i].w > SCRW)
   284                 updates[i].w = SCRW - updates[i].x;
   285         }
   286 
   287         for (i = 0; i < NBOATS; i++) {
   288             /* paint boat on new position */
   289             r.x = boatx[i];
   290             r.y = boaty[i];
   291             if (SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL,
   292                                 screen, &r) < 0)
   293                 sdlerr("blitting boat");
   294         }
   295 
   296         /* cycle wave palette */
   297         for (i = 0; i < 64; i++)
   298             cmap[boatcols + ((i + frames) & 63)] = wavemap[i];
   299 
   300         if (fade_dir) {
   301             /* Fade the entire palette in/out */
   302             fade_level += fade_dir;
   303 
   304             if (gamma_fade) {
   305                 /* Fade linearly in gamma level (lousy) */
   306                 float level = (float) fade_level / fade_max;
   307                 if (SDL_SetGamma(level, level, level) < 0)
   308                     sdlerr("setting gamma");
   309 
   310             } else if (gamma_ramp) {
   311                 /* Fade using gamma ramp (better) */
   312                 Uint16 ramp[256];
   313                 for (i = 0; i < 256; i++)
   314                     ramp[i] = (i * fade_level / fade_max) << 8;
   315                 if (SDL_SetGammaRamp(ramp, ramp, ramp) < 0)
   316                     sdlerr("setting gamma ramp");
   317 
   318             } else {
   319                 /* Fade using direct palette manipulation (best) */
   320                 memcpy(cmap, screen->format->palette->colors,
   321                        boatcols * sizeof(SDL_Color));
   322                 for (i = 0; i < boatcols + 64; i++) {
   323                     cmap[i].r = cmap[i].r * fade_level / fade_max;
   324                     cmap[i].g = cmap[i].g * fade_level / fade_max;
   325                     cmap[i].b = cmap[i].b * fade_level / fade_max;
   326                 }
   327             }
   328             if (fade_level == fade_max)
   329                 fade_dir = 0;
   330         }
   331 
   332         /* pulse the red colour (done after the fade, for a night effect) */
   333         redphase = frames % 64;
   334         cmap[red].r = (int) (255 * sin(redphase * M_PI / 63));
   335 
   336         SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64);
   337 
   338         /* update changed areas of the screen */
   339         SDL_UpdateRects(screen, NBOATS, updates);
   340         frames++;
   341     }
   342     while (fade_level > 0);
   343 
   344     printf("%d frames, %.2f fps\n",
   345            frames, 1000.0 * frames / (SDL_GetTicks() - start));
   346 
   347     if (vidflags & SDL_FULLSCREEN)
   348         SDL_ShowCursor(SDL_TRUE);
   349     SDL_Quit();
   350     return 0;
   351 }