e14743d1 |
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 | |