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comparison test/testpalette.c @ 0:74212992fb08

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Initial revision
author Sam Lantinga <slouken@lokigames.com>
date Thu, 26 Apr 2001 16:45:43 +0000
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children be9c9c8f6d53
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-1:000000000000 0:74212992fb08
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 static void sdlerr(char *when)
58 {
59 fprintf(stderr, "SDL error: %s: %s\n", when, SDL_GetError());
60 exit(1);
61 }
62
63 /* create a background surface */
64 static SDL_Surface *make_bg(SDL_Surface *screen, int startcol)
65 {
66 int i;
67 SDL_Surface *bg = SDL_CreateRGBSurface(SDL_SWSURFACE, screen->w, screen->h,
68 8, 0, 0, 0, 0);
69 if(!bg)
70 sdlerr("creating background surface");
71
72 /* set the palette to the logical screen palette so that blits
73 won't be translated */
74 SDL_SetColors(bg, screen->format->palette->colors, 0, 256);
75
76 /* Make a wavy background pattern using colours 0-63 */
77 if(SDL_LockSurface(bg) < 0)
78 sdlerr("locking background");
79 for(i = 0; i < SCRH; i++) {
80 Uint8 *p = (Uint8 *)bg->pixels + i * bg->pitch;
81 int j, d;
82 d = 0;
83 for(j = 0; j < SCRW; j++) {
84 int v = MAX(d, -2);
85 v = MIN(v, 2);
86 if(i > 0)
87 v += p[-bg->pitch] + 65 - startcol;
88 p[j] = startcol + (v & 63);
89 d += ((rand() >> 3) % 3) - 1;
90 }
91 }
92 SDL_UnlockSurface(bg);
93 return(bg);
94 }
95
96 /*
97 * Return a surface flipped horisontally. Only works for 8bpp;
98 * extension to arbitrary bitness is left as an exercise for the reader.
99 */
100 static SDL_Surface *hflip(SDL_Surface *s)
101 {
102 int i;
103 SDL_Surface *z = SDL_CreateRGBSurface(SDL_SWSURFACE, s->w, s->h, 8,
104 0, 0, 0, 0);
105 /* copy palette */
106 SDL_SetColors(z, s->format->palette->colors,
107 0, s->format->palette->ncolors);
108 if(SDL_LockSurface(s) < 0 || SDL_LockSurface(z) < 0)
109 sdlerr("locking flip images");
110
111 for(i = 0; i < s->h; i++) {
112 int j;
113 Uint8 *from = (Uint8 *)s->pixels + i * s->pitch;
114 Uint8 *to = (Uint8 *)z->pixels + i * z->pitch + s->w - 1;
115 for(j = 0; j < s->w; j++)
116 to[-j] = from[j];
117 }
118
119 SDL_UnlockSurface(z);
120 SDL_UnlockSurface(s);
121 return z;
122 }
123
124 int main(int argc, char **argv)
125 {
126 SDL_Color cmap[256];
127 SDL_Surface *screen;
128 SDL_Surface *bg;
129 SDL_Surface *boat[2];
130 unsigned vidflags = 0;
131 unsigned start;
132 int fade_max = 400;
133 int fade_level, fade_dir;
134 int boatcols, frames, i, red;
135 int boatx[NBOATS], boaty[NBOATS], boatdir[NBOATS];
136 int gamma_fade = 0;
137 int gamma_ramp = 0;
138
139 if(SDL_Init(SDL_INIT_VIDEO) < 0)
140 sdlerr("initialising SDL");
141
142 atexit(SDL_Quit);
143
144 while(--argc) {
145 ++argv;
146 if(strcmp(*argv, "-hw") == 0)
147 vidflags |= SDL_HWSURFACE;
148 else if(strcmp(*argv, "-fullscreen") == 0)
149 vidflags |= SDL_FULLSCREEN;
150 else if(strcmp(*argv, "-nofade") == 0)
151 fade_max = 1;
152 else if(strcmp(*argv, "-gamma") == 0)
153 gamma_fade = 1;
154 else if(strcmp(*argv, "-gammaramp") == 0)
155 gamma_ramp = 1;
156 else {
157 fprintf(stderr,
158 "usage: testpalette "
159 " [-hw] [-fullscreen] [-nofade] [-gamma] [-gammaramp]\n");
160 return 1;
161 }
162 }
163
164 /* Ask explicitly for 8bpp and a hardware palette */
165 if(!(screen = SDL_SetVideoMode(SCRW, SCRH, 8, vidflags | SDL_HWPALETTE))) {
166 fprintf(stderr, "error setting %dx%d 8bpp indexed mode: %s\n",
167 SCRW, SCRH, SDL_GetError());
168 return 1;
169 }
170
171 if(!(boat[0] = SDL_LoadBMP("sail.bmp")))
172 sdlerr("loading sail.bmp");
173 /* We've chosen magenta (#ff00ff) as colour key for the boat */
174 SDL_SetColorKey(boat[0], SDL_SRCCOLORKEY | SDL_RLEACCEL,
175 SDL_MapRGB(boat[0]->format, 0xff, 0x00, 0xff));
176 boatcols = boat[0]->format->palette->ncolors;
177 boat[1] = hflip(boat[0]);
178 SDL_SetColorKey(boat[1], SDL_SRCCOLORKEY | SDL_RLEACCEL,
179 SDL_MapRGB(boat[1]->format, 0xff, 0x00, 0xff));
180
181 /*
182 * First set the physical screen palette to black, so the user won't
183 * see our initial drawing on the screen.
184 */
185 memset(cmap, 0, sizeof(cmap));
186 SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, 256);
187
188 /*
189 * Proper palette management is important when playing games with the
190 * colormap. We have divided the palette as follows:
191 *
192 * index 0..(boatcols-1): used for the boat
193 * index boatcols..(boatcols+63): used for the waves
194 */
195 SDL_SetPalette(screen, SDL_LOGPAL,
196 boat[0]->format->palette->colors, 0, boatcols);
197 SDL_SetPalette(screen, SDL_LOGPAL, wavemap, boatcols, 64);
198
199 /*
200 * Now the logical screen palette is set, and will remain unchanged.
201 * The boats already have the same palette so fast blits can be used.
202 */
203 memcpy(cmap, screen->format->palette->colors, 256 * sizeof(SDL_Color));
204
205 /* save the index of the red colour for later */
206 red = SDL_MapRGB(screen->format, 0xff, 0x00, 0x00);
207
208 bg = make_bg(screen, boatcols); /* make a nice wavy background surface */
209
210 /* initial screen contents */
211 if(SDL_BlitSurface(bg, NULL, screen, NULL) < 0)
212 sdlerr("blitting background to screen");
213 SDL_Flip(screen); /* actually put the background on screen */
214
215 /* determine initial boat placements */
216 for(i = 0; i < NBOATS; i++) {
217 boatx[i] = (rand() % (SCRW + boat[0]->w)) - boat[0]->w;
218 boaty[i] = i * (SCRH - boat[0]->h) / (NBOATS - 1);
219 boatdir[i] = ((rand() >> 5) & 1) * 2 - 1;
220 }
221
222 start = SDL_GetTicks();
223 frames = 0;
224 fade_dir = 1;
225 fade_level = 0;
226 do {
227 SDL_Event e;
228 SDL_Rect updates[NBOATS];
229 SDL_Rect r;
230 int redphase;
231
232 /* A small event loop: just exit on any key or mouse button event */
233 while(SDL_PollEvent(&e)) {
234 if(e.type == SDL_KEYDOWN || e.type == SDL_QUIT
235 || e.type == SDL_MOUSEBUTTONDOWN) {
236 if(fade_dir < 0)
237 fade_level = 0;
238 fade_dir = -1;
239 }
240 }
241
242 /* move boats */
243 for(i = 0; i < NBOATS; i++) {
244 int old_x = boatx[i];
245 /* update boat position */
246 boatx[i] += boatdir[i] * SPEED;
247 if(boatx[i] <= -boat[0]->w || boatx[i] >= SCRW)
248 boatdir[i] = -boatdir[i];
249
250 /* paint over the old boat position */
251 r.x = old_x;
252 r.y = boaty[i];
253 r.w = boat[0]->w;
254 r.h = boat[0]->h;
255 if(SDL_BlitSurface(bg, &r, screen, &r) < 0)
256 sdlerr("blitting background");
257
258 /* construct update rectangle (bounding box of old and new pos) */
259 updates[i].x = MIN(old_x, boatx[i]);
260 updates[i].y = boaty[i];
261 updates[i].w = boat[0]->w + SPEED;
262 updates[i].h = boat[0]->h;
263 /* clip update rectangle to screen */
264 if(updates[i].x < 0) {
265 updates[i].w += updates[i].x;
266 updates[i].x = 0;
267 }
268 if(updates[i].x + updates[i].w > SCRW)
269 updates[i].w = SCRW - updates[i].x;
270 }
271
272 for(i = 0; i < NBOATS; i++) {
273 /* paint boat on new position */
274 r.x = boatx[i];
275 r.y = boaty[i];
276 if(SDL_BlitSurface(boat[(boatdir[i] + 1) / 2], NULL,
277 screen, &r) < 0)
278 sdlerr("blitting boat");
279 }
280
281 /* cycle wave palette */
282 for(i = 0; i < 64; i++)
283 cmap[boatcols + ((i + frames) & 63)] = wavemap[i];
284
285 if(fade_dir) {
286 /* Fade the entire palette in/out */
287 fade_level += fade_dir;
288
289 if(gamma_fade) {
290 /* Fade linearly in gamma level (lousy) */
291 float level = (float)fade_level / fade_max;
292 if(SDL_SetGamma(level, level, level) < 0)
293 sdlerr("setting gamma");
294
295 } else if(gamma_ramp) {
296 /* Fade using gamma ramp (better) */
297 Uint16 ramp[256];
298 for(i = 0; i < 256; i++)
299 ramp[i] = (i * fade_level / fade_max) << 8;
300 if(SDL_SetGammaRamp(ramp, ramp, ramp) < 0)
301 sdlerr("setting gamma ramp");
302
303 } else {
304 /* Fade using direct palette manipulation (best) */
305 memcpy(cmap, screen->format->palette->colors,
306 boatcols * sizeof(SDL_Color));
307 for(i = 0; i < boatcols + 64; i++) {
308 cmap[i].r = cmap[i].r * fade_level / fade_max;
309 cmap[i].g = cmap[i].g * fade_level / fade_max;
310 cmap[i].b = cmap[i].b * fade_level / fade_max;
311 }
312 }
313 if(fade_level == fade_max)
314 fade_dir = 0;
315 }
316
317 /* pulse the red colour (done after the fade, for a night effect) */
318 redphase = frames % 64;
319 cmap[red].r = (int)(255 * sin(redphase * M_PI / 63));
320
321 SDL_SetPalette(screen, SDL_PHYSPAL, cmap, 0, boatcols + 64);
322
323 /* update changed areas of the screen */
324 SDL_UpdateRects(screen, NBOATS, updates);
325 frames++;
326 } while(fade_level > 0);
327
328 printf("%d frames, %.2f fps\n",
329 frames, 1000.0 * frames / (SDL_GetTicks() - start));
330 return 0;
331 }
332