git.hungrycats.org Git - xscreensaver/blob - hacks/demon.c

   1 /* -*- Mode: C; tab-width: 4 -*- */
   2 /* demon --- David Griffeath's cellular automata */
   3
   4 #if 0
   5 static const char sccsid[] = "@(#)demon.c       5.00 2000/11/01 xlockmore";
   6 #endif
   7
   8 /*-
   9  * Copyright (c) 1995 by David Bagley.
  10  *
  11  * Permission to use, copy, modify, and distribute this software and its
  12  * documentation for any purpose and without fee is hereby granted,
  13  * provided that the above copyright notice appear in all copies and that
  14  * both that copyright notice and this permission notice appear in
  15  * supporting documentation.
  16  *
  17  * This file is provided AS IS with no warranties of any kind.  The author
  18  * shall have no liability with respect to the infringement of copyrights,
  19  * trade secrets or any patents by this file or any part thereof.  In no
  20  * event will the author be liable for any lost revenue or profits or
  21  * other special, indirect and consequential damages.
  22  *
  23  * Revision History:
  24  * 01-Nov-2000: Allocation checks
  25  * 10-May-1997: Compatible with xscreensaver
  26  * 16-Apr-1997: -neighbors 3, 9 (not sound mathematically), 12, and 8 added
  27  * 30-May-1996: Ron Hitchens <ron@idiom.com>
  28  *            Fixed memory management that caused leaks
  29  * 14-Apr-1996: -neighbors 6 runtime-time option added
  30  * 21-Aug-1995: Coded from A.K. Dewdney's "Computer Recreations", Scientific
  31  *              American Magazine" Aug 1989 pp 102-105.  Also very similar
  32  *              to hodgepodge machine described in A.K. Dewdney's "Computer
  33  *              Recreations", Scientific American Magazine" Aug 1988
  34  *              pp 104-107.  Also used life.c as a guide.
  35  */
  36
  37 /*-
  38  * A cellular universe of 4 phases debris, droplets, defects, and demons.
  39  */
  40
  41 /*-
  42   Grid     Number of Neighbors
  43   ----     ------------------
  44   Square   4 or 8
  45   Hexagon  6
  46   Triangle 3, 9, or 12
  47 */
  48
  49 #ifndef HAVE_COCOA
  50 # define DO_STIPPLE
  51 #endif
  52
  53 #ifdef STANDALONE
  54 # define MODE_demon
  55 # define DEFAULTS       "*delay:   50000 \n" \
  56                                         "*count:   0     \n" \
  57                                         "*cycles:  1000  \n" \
  58                                         "*size:    -7    \n" \
  59                                         "*ncolors: 64    \n" \
  60                                         "*fpsSolid: true    \n" \
  61
  62 # define reshape_demon 0
  63 # define demon_handle_event 0
  64 # define UNIFORM_COLORS
  65 # include "xlockmore.h"         /* in xscreensaver distribution */
  66 #else /* STANDALONE */
  67 # include "xlock.h"             /* in xlockmore distribution */
  68 #endif /* STANDALONE */
  69 #include "automata.h"
  70
  71 #ifdef MODE_demon
  72
  73 /*-
  74  * neighbors of 0 randomizes it between 3, 4, 6, 8, 9, and 12.
  75  */
  76 #define DEF_NEIGHBORS  "0"      /* choose random value */
  77
  78 static int  neighbors;
  79
  80 static XrmOptionDescRec opts[] =
  81 {
  82         {"-neighbors", ".demon.neighbors", XrmoptionSepArg, 0}
  83 };
  84
  85 static argtype vars[] =
  86 {
  87         {&neighbors, "neighbors", "Neighbors", DEF_NEIGHBORS, t_Int}
  88 };
  89 static OptionStruct desc[] =
  90 {
  91         {"-neighbors num", "squares 4 or 8, hexagons 6, triangles 3, 9 or 12"}
  92 };
  93
  94 ENTRYPOINT ModeSpecOpt demon_opts =
  95 {sizeof opts / sizeof opts[0], opts, sizeof vars / sizeof vars[0], vars, desc};
  96
  97 #ifdef USE_MODULES
  98 ModStruct   demon_description =
  99 {"demon", "init_demon", "draw_demon", "release_demon",
 100  "refresh_demon", "init_demon", (char *) NULL, &demon_opts,
 101  50000, 0, 1000, -7, 64, 1.0, "",
 102  "Shows Griffeath's cellular automata", 0, NULL};
 103
 104 #endif
 105
 106 #define DEMONBITS(n,w,h)\
 107   if ((dp->pixmaps[dp->init_bits]=\
 108   XCreatePixmapFromBitmapData(display,window,(char *)n,w,h,1,0,1))==None){\
 109   free_demon(display,dp); return;} else {dp->init_bits++;}
 110
 111 #define REDRAWSTEP 2000         /* How many cells to draw per cycle */
 112 #define MINSTATES 2
 113 #define MINGRIDSIZE 24
 114 #define MINSIZE 4
 115 #define NEIGHBORKINDS 6
 116
 117 /* Singly linked list */
 118 typedef struct _CellList {
 119         XPoint      pt;
 120         struct _CellList *next;
 121 } CellList;
 122
 123 typedef struct {
 124         int         generation;
 125         int         xs, ys;
 126         int         xb, yb;
 127         int         nrows, ncols;
 128         int         width, height;
 129         int         states;
 130         int         state;
 131         int         redrawing, redrawpos;
 132         int        *ncells;
 133         CellList  **cellList;
 134         unsigned char *oldcell, *newcell;
 135         int         neighbors;
 136         int         init_bits;
 137         GC          stippledGC;
 138         Pixmap      pixmaps[NUMSTIPPLES - 1];
 139         union {
 140                 XPoint      hexagon[6];
 141                 XPoint      triangle[2][3];
 142         } shape;
 143 } demonstruct;
 144
 145 static char plots[2][NEIGHBORKINDS] =
 146 {
 147         {3, 4, 6, 8, 9, 12},    /* Neighborhoods */
 148         {12, 16, 18, 20, 22, 24}        /* Number of states */
 149 };
 150
 151 static demonstruct *demons = (demonstruct *) NULL;
 152
 153 static void
 154 drawcell(ModeInfo * mi, int col, int row, unsigned char state)
 155 {
 156         demonstruct *dp = &demons[MI_SCREEN(mi)];
 157         GC          gc;
 158
 159         if (!state) {
 160                 XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_BLACK_PIXEL(mi));
 161                 gc = MI_GC(mi);
 162         } else if (MI_NPIXELS(mi) >= NUMSTIPPLES) {
 163                 XSetForeground(MI_DISPLAY(mi), MI_GC(mi),
 164                            MI_PIXEL(mi, (((int) state - 1) * MI_NPIXELS(mi) /
 165                                          (dp->states - 1)) % MI_NPIXELS(mi)));
 166                 gc = MI_GC(mi);
 167         } else {
 168                 XGCValues   gcv;
 169
 170 #ifdef DO_STIPPLE
 171                 gcv.stipple = dp->pixmaps[(state - 1) % (NUMSTIPPLES - 1)];
 172 #endif /* DO_STIPPLE */
 173                 gcv.foreground = MI_WHITE_PIXEL(mi);
 174                 gcv.background = MI_BLACK_PIXEL(mi);
 175                 XChangeGC(MI_DISPLAY(mi), dp->stippledGC,
 176                           GCStipple | GCForeground | GCBackground, &gcv);
 177                 gc = dp->stippledGC;
 178         }
 179         if (dp->neighbors == 6) {
 180                 int         ccol = 2 * col + !(row & 1), crow = 2 * row;
 181
 182                 dp->shape.hexagon[0].x = dp->xb + ccol * dp->xs;
 183                 dp->shape.hexagon[0].y = dp->yb + crow * dp->ys;
 184                 if (dp->xs == 1 && dp->ys == 1)
 185                         XDrawPoint(MI_DISPLAY(mi), MI_WINDOW(mi),
 186                                        gc, dp->shape.hexagon[0].x, dp->shape.hexagon[0].y);
 187                 else
 188                         XFillPolygon(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 189                             dp->shape.hexagon, 6, Convex, CoordModePrevious);
 190         } else if (dp->neighbors == 4 || dp->neighbors == 8) {
 191                 XFillRectangle(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 192                 dp->xb + dp->xs * col, dp->yb + dp->ys * row,
 193                 dp->xs - (dp->xs > 3), dp->ys - (dp->ys > 3));
 194         } else {                /* TRI */
 195                 int         orient = (col + row) % 2;   /* O left 1 right */
 196
 197                 dp->shape.triangle[orient][0].x = dp->xb + col * dp->xs;
 198                 dp->shape.triangle[orient][0].y = dp->yb + row * dp->ys;
 199                 if (dp->xs <= 3 || dp->ys <= 3)
 200                         XDrawPoint(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 201                         ((orient) ? -1 : 1) + dp->shape.triangle[orient][0].x,
 202                                        dp->shape.triangle[orient][0].y);
 203                 else {
 204                         if (orient)
 205                                 dp->shape.triangle[orient][0].x += (dp->xs / 2 - 1);
 206                         else
 207                                 dp->shape.triangle[orient][0].x -= (dp->xs / 2 - 1);
 208                         XFillPolygon(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 209                                      dp->shape.triangle[orient], 3, Convex, CoordModePrevious);
 210
 211                 }
 212         }
 213 }
 214
 215 static Bool
 216 addtolist(ModeInfo * mi, int col, int row, unsigned char state)
 217 {
 218         demonstruct *dp = &demons[MI_SCREEN(mi)];
 219         CellList   *current;
 220
 221         current = dp->cellList[state];
 222         if ((dp->cellList[state] = (CellList *)
 223                 malloc(sizeof (CellList))) == NULL) {
 224                 return False;
 225         }
 226         dp->cellList[state]->pt.x = col;
 227         dp->cellList[state]->pt.y = row;
 228         dp->cellList[state]->next = current;
 229         dp->ncells[state]++;
 230         return True;
 231 }
 232
 233 #ifdef DEBUG
 234 static void
 235 print_state(ModeInfo * mi, int state)
 236 {
 237         demonstruct *dp = &demons[MI_SCREEN(mi)];
 238         CellList   *locallist;
 239         int         i = 0;
 240
 241         locallist = dp->cellList[state];
 242         (void) printf("state %d\n", state);
 243         while (locallist) {
 244                 (void) printf("%d       x %d, y %d\n", i,
 245                               locallist->pt.x, locallist->pt.y);
 246                 locallist = locallist->next;
 247                 i++;
 248         }
 249 }
 250
 251 #endif
 252
 253 static void
 254 free_state(demonstruct * dp, int state)
 255 {
 256         CellList   *current;
 257
 258         while (dp->cellList[state]) {
 259                 current = dp->cellList[state];
 260                 dp->cellList[state] = dp->cellList[state]->next;
 261                 (void) free((void *) current);
 262         }
 263         dp->cellList[state] = (CellList *) NULL;
 264         if (dp->ncells != NULL)
 265                 dp->ncells[state] = 0;
 266 }
 267
 268
 269 static void
 270 free_list(demonstruct * dp)
 271 {
 272         int         state;
 273
 274         for (state = 0; state < dp->states; state++)
 275                 free_state(dp, state);
 276         (void) free((void *) dp->cellList);
 277         dp->cellList = (CellList **) NULL;
 278 }
 279
 280 static void
 281 free_struct(demonstruct * dp)
 282 {
 283         if (dp->cellList != NULL) {
 284                 free_list(dp);
 285         }
 286         if (dp->ncells != NULL) {
 287                 (void) free((void *) dp->ncells);
 288                 dp->ncells = (int *) NULL;
 289         }
 290         if (dp->oldcell != NULL) {
 291                 (void) free((void *) dp->oldcell);
 292                 dp->oldcell = (unsigned char *) NULL;
 293         }
 294         if (dp->newcell != NULL) {
 295                 (void) free((void *) dp->newcell);
 296                 dp->newcell = (unsigned char *) NULL;
 297         }
 298 }
 299
 300 static void
 301 free_demon(Display *display, demonstruct *dp)
 302 {
 303         int         shade;
 304
 305         if (dp->stippledGC != None) {
 306                 XFreeGC(display, dp->stippledGC);
 307                 dp->stippledGC = None;
 308         }
 309         for (shade = 0; shade < dp->init_bits; shade++) {
 310                 XFreePixmap(display, dp->pixmaps[shade]);
 311         }
 312         dp->init_bits = 0;
 313         free_struct(dp);
 314 }
 315
 316 static Bool
 317 draw_state(ModeInfo * mi, int state)
 318 {
 319         demonstruct *dp = &demons[MI_SCREEN(mi)];
 320         GC          gc;
 321         XRectangle *rects;
 322         CellList   *current;
 323
 324         if (!state) {
 325                 XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_BLACK_PIXEL(mi));
 326                 gc = MI_GC(mi);
 327         } else if (MI_NPIXELS(mi) >= NUMSTIPPLES) {
 328                 XSetForeground(MI_DISPLAY(mi), MI_GC(mi),
 329                            MI_PIXEL(mi, (((int) state - 1) * MI_NPIXELS(mi) /
 330                                          (dp->states - 1)) % MI_NPIXELS(mi)));
 331                 gc = MI_GC(mi);
 332         } else {
 333                 XGCValues   gcv;
 334
 335 #ifdef DO_STIPPLE
 336                 gcv.stipple = dp->pixmaps[(state - 1) % (NUMSTIPPLES - 1)];
 337 #endif /* DO_STIPPLE */
 338                 gcv.foreground = MI_WHITE_PIXEL(mi);
 339                 gcv.background = MI_BLACK_PIXEL(mi);
 340                 XChangeGC(MI_DISPLAY(mi), dp->stippledGC,
 341                           GCStipple | GCForeground | GCBackground, &gcv);
 342                 gc = dp->stippledGC;
 343         }
 344         if (dp->neighbors == 6) {       /* Draw right away, slow */
 345                 current = dp->cellList[state];
 346                 while (current) {
 347                         int         col, row, ccol, crow;
 348
 349                         col = current->pt.x;
 350                         row = current->pt.y;
 351                         ccol = 2 * col + !(row & 1), crow = 2 * row;
 352                         dp->shape.hexagon[0].x = dp->xb + ccol * dp->xs;
 353                         dp->shape.hexagon[0].y = dp->yb + crow * dp->ys;
 354                         if (dp->xs == 1 && dp->ys == 1)
 355                                 XDrawPoint(MI_DISPLAY(mi), MI_WINDOW(mi),
 356                                                gc, dp->shape.hexagon[0].x, dp->shape.hexagon[0].y);
 357                         else
 358                                 XFillPolygon(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 359                                              dp->shape.hexagon, 6, Convex, CoordModePrevious);
 360                         current = current->next;
 361                 }
 362         } else if (dp->neighbors == 4 || dp->neighbors == 8) {
 363                 /* Take advantage of XDrawRectangles */
 364                 int         ncells = 0;
 365
 366                 /* Create Rectangle list from part of the cellList */
 367                 if ((rects = (XRectangle *) malloc(dp->ncells[state] *
 368                          sizeof (XRectangle))) == NULL) {
 369                         return False;
 370                 }
 371                 current = dp->cellList[state];
 372                 while (current) {
 373                         rects[ncells].x = dp->xb + current->pt.x * dp->xs;
 374                         rects[ncells].y = dp->yb + current->pt.y * dp->ys;
 375                         rects[ncells].width = dp->xs - (dp->xs > 3);
 376                         rects[ncells].height = dp->ys - (dp->ys > 3);
 377                         current = current->next;
 378                         ncells++;
 379                 }
 380                 /* Finally get to draw */
 381                 XFillRectangles(MI_DISPLAY(mi), MI_WINDOW(mi), gc, rects, ncells);
 382                 /* Free up rects list and the appropriate part of the cellList */
 383                 (void) free((void *) rects);
 384         } else {                /* TRI */
 385                 current = dp->cellList[state];
 386                 while (current) {
 387                         int         col, row, orient;
 388
 389                         col = current->pt.x;
 390                         row = current->pt.y;
 391                         orient = (col + row) % 2;       /* O left 1 right */
 392                         dp->shape.triangle[orient][0].x = dp->xb + col * dp->xs;
 393                         dp->shape.triangle[orient][0].y = dp->yb + row * dp->ys;
 394                         if (dp->xs <= 3 || dp->ys <= 3)
 395                                 XDrawPoint(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 396                                                ((orient) ? -1 : 1) + dp->shape.triangle[orient][0].x,
 397                                       dp->shape.triangle[orient][0].y);
 398                         else {
 399                                 if (orient)
 400                                         dp->shape.triangle[orient][0].x += (dp->xs / 2 - 1);
 401                                 else
 402                                         dp->shape.triangle[orient][0].x -= (dp->xs / 2 - 1);
 403                                 XFillPolygon(MI_DISPLAY(mi), MI_WINDOW(mi), gc,
 404                                              dp->shape.triangle[orient], 3, Convex, CoordModePrevious);
 405                         }
 406                         current = current->next;
 407                 }
 408         }
 409         free_state(dp, state);
 410         return True;
 411 }
 412
 413 static void
 414 RandomSoup(ModeInfo * mi)
 415 {
 416         demonstruct *dp = &demons[MI_SCREEN(mi)];
 417         int         row, col, mrow = 0;
 418
 419         for (row = 0; row < dp->nrows; ++row) {
 420                 for (col = 0; col < dp->ncols; ++col) {
 421                         dp->oldcell[col + mrow] =
 422                                 (unsigned char) LRAND() % ((unsigned char) dp->states);
 423                         if (!addtolist(mi, col, row, dp->oldcell[col + mrow]))
 424                                 return; /* sparse soup */
 425                 }
 426                 mrow += dp->ncols;
 427         }
 428 }
 429
 430 ENTRYPOINT void
 431 init_demon (ModeInfo * mi)
 432 {
 433         Display    *display = MI_DISPLAY(mi);
 434         int         size = MI_SIZE(mi), nk;
 435         demonstruct *dp;
 436
 437         if (demons == NULL) {
 438                 if ((demons = (demonstruct *) calloc(MI_NUM_SCREENS(mi),
 439                                               sizeof (demonstruct))) == NULL)
 440                         return;
 441         }
 442         dp = &demons[MI_SCREEN(mi)];
 443
 444         dp->generation = 0;
 445         dp->redrawing = 0;
 446 #ifdef DO_STIPPLE
 447         if (MI_NPIXELS(mi) < NUMSTIPPLES) {
 448           Window window = MI_WINDOW(mi);
 449           if (dp->stippledGC == None) {
 450                         XGCValues   gcv;
 451
 452                         gcv.fill_style = FillOpaqueStippled;
 453                         if ((dp->stippledGC = XCreateGC(display, window,
 454                                  GCFillStyle, &gcv)) == None) {
 455                                 free_demon(display, dp);
 456                                 return;
 457                         }
 458                 }
 459                 if (dp->init_bits == 0) {
 460                         int         i;
 461
 462                         for (i = 1; i < NUMSTIPPLES; i++) {
 463                                 DEMONBITS(stipples[i], STIPPLESIZE, STIPPLESIZE);
 464                         }
 465                 }
 466         }
 467 #endif /* DO_STIPPLE */
 468         free_struct(dp);
 469
 470         for (nk = 0; nk < NEIGHBORKINDS; nk++) {
 471                 if (neighbors == plots[0][nk]) {
 472                         dp->neighbors = plots[0][nk];
 473                         break;
 474                 }
 475                 if (nk == NEIGHBORKINDS - 1) {
 476                         nk = NRAND(NEIGHBORKINDS);
 477                         dp->neighbors = plots[0][nk];
 478                         break;
 479                 }
 480         }
 481
 482         dp->states = MI_COUNT(mi);
 483         if (dp->states < -MINSTATES)
 484                 dp->states = NRAND(-dp->states - MINSTATES + 1) + MINSTATES;
 485         else if (dp->states < MINSTATES)
 486                 dp->states = plots[1][nk];
 487         if ((dp->cellList = (CellList **) calloc(dp->states,
 488                 sizeof (CellList *))) == NULL) {
 489                 free_demon(display, dp);
 490                 return;
 491         }
 492         if ((dp->ncells = (int *) calloc(dp->states, sizeof (int))) == NULL) {
 493                 free_demon(display, dp);
 494                 return;
 495         }
 496
 497         dp->state = 0;
 498
 499         dp->width = MI_WIDTH(mi);
 500         dp->height = MI_HEIGHT(mi);
 501
 502         if (dp->neighbors == 6) {
 503                 int         nccols, ncrows, i;
 504
 505                 if (dp->width < 8)
 506                         dp->width = 8;
 507                 if (dp->height < 8)
 508                         dp->height = 8;
 509                 if (size < -MINSIZE)
 510                         dp->ys = NRAND(MIN(-size, MAX(MINSIZE, MIN(dp->width, dp->height) /
 511                                       MINGRIDSIZE)) - MINSIZE + 1) + MINSIZE;
 512                 else if (size < MINSIZE) {
 513                         if (!size)
 514                                 dp->ys = MAX(MINSIZE, MIN(dp->width, dp->height) / MINGRIDSIZE);
 515                         else
 516                                 dp->ys = MINSIZE;
 517                 } else
 518                         dp->ys = MIN(size, MAX(MINSIZE, MIN(dp->width, dp->height) /
 519                                                MINGRIDSIZE));
 520                 dp->xs = dp->ys;
 521                 nccols = MAX(dp->width / dp->xs - 2, 2);
 522                 ncrows = MAX(dp->height / dp->ys - 1, 4);
 523                 dp->ncols = nccols / 2;
 524                 dp->nrows = 2 * (ncrows / 4);
 525                 dp->xb = (dp->width - dp->xs * nccols) / 2 + dp->xs / 2;
 526                 dp->yb = (dp->height - dp->ys * (ncrows / 2) * 2) / 2 + dp->ys - 2;
 527                 for (i = 0; i < 6; i++) {
 528                         dp->shape.hexagon[i].x = (dp->xs - 1) * hexagonUnit[i].x;
 529                         dp->shape.hexagon[i].y = ((dp->ys - 1) * hexagonUnit[i].y / 2) * 4 / 3;
 530                 }
 531         } else if (dp->neighbors == 4 || dp->neighbors == 8) {
 532                 if (size < -MINSIZE)
 533                         dp->ys = NRAND(MIN(-size, MAX(MINSIZE, MIN(dp->width, dp->height) /
 534                                       MINGRIDSIZE)) - MINSIZE + 1) + MINSIZE;
 535                 else if (size < MINSIZE) {
 536                         if (!size)
 537                                 dp->ys = MAX(MINSIZE, MIN(dp->width, dp->height) / MINGRIDSIZE);
 538                         else
 539                                 dp->ys = MINSIZE;
 540                 } else
 541                         dp->ys = MIN(size, MAX(MINSIZE, MIN(dp->width, dp->height) /
 542                                                MINGRIDSIZE));
 543                 dp->xs = dp->ys;
 544                 dp->ncols = MAX(dp->width / dp->xs, 2);
 545                 dp->nrows = MAX(dp->height / dp->ys, 2);
 546                 dp->xb = (dp->width - dp->xs * dp->ncols) / 2;
 547                 dp->yb = (dp->height - dp->ys * dp->nrows) / 2;
 548         } else {                /* TRI */
 549                 int         orient, i;
 550
 551                 if (dp->width < 2)
 552                         dp->width = 2;
 553                 if (dp->height < 2)
 554                         dp->height = 2;
 555                 if (size < -MINSIZE)
 556                         dp->ys = NRAND(MIN(-size, MAX(MINSIZE, MIN(dp->width, dp->height) /
 557                                       MINGRIDSIZE)) - MINSIZE + 1) + MINSIZE;
 558                 else if (size < MINSIZE) {
 559                         if (!size)
 560                                 dp->ys = MAX(MINSIZE, MIN(dp->width, dp->height) / MINGRIDSIZE);
 561                         else
 562                                 dp->ys = MINSIZE;
 563                 } else
 564                         dp->ys = MIN(size, MAX(MINSIZE, MIN(dp->width, dp->height) /
 565                                                MINGRIDSIZE));
 566                 dp->xs = (int) (1.52 * dp->ys);
 567                 dp->ncols = (MAX(dp->width / dp->xs - 1, 2) / 2) * 2;
 568                 dp->nrows = (MAX(dp->height / dp->ys - 1, 2) / 2) * 2;
 569                 dp->xb = (dp->width - dp->xs * dp->ncols) / 2 + dp->xs / 2;
 570                 dp->yb = (dp->height - dp->ys * dp->nrows) / 2 + dp->ys / 2;
 571                 for (orient = 0; orient < 2; orient++) {
 572                         for (i = 0; i < 3; i++) {
 573                                 dp->shape.triangle[orient][i].x =
 574                                         (dp->xs - 2) * triangleUnit[orient][i].x;
 575                                 dp->shape.triangle[orient][i].y =
 576                                         (dp->ys - 2) * triangleUnit[orient][i].y;
 577                         }
 578                 }
 579         }
 580
 581         MI_CLEARWINDOW(mi);
 582
 583         if ((dp->oldcell = (unsigned char *)
 584                 malloc(dp->ncols * dp->nrows * sizeof (unsigned char))) == NULL) {
 585                 free_demon(display, dp);
 586                 return;
 587         }
 588
 589         if ((dp->newcell = (unsigned char *)
 590                 malloc(dp->ncols * dp->nrows * sizeof (unsigned char))) == NULL) {
 591                 free_demon(display, dp);
 592                 return;
 593         }
 594
 595         RandomSoup(mi);
 596 }
 597
 598 ENTRYPOINT void
 599 draw_demon (ModeInfo * mi)
 600 {
 601         int         i, j, k, l, mj = 0, ml;
 602         demonstruct *dp;
 603
 604         if (demons == NULL)
 605                 return;
 606         dp = &demons[MI_SCREEN(mi)];
 607         if (dp->cellList == NULL)
 608                 return;
 609
 610         MI_IS_DRAWN(mi) = True;
 611         if (dp->state >= dp->states) {
 612                 (void) memcpy((char *) dp->newcell, (char *) dp->oldcell,
 613                               dp->ncols * dp->nrows * sizeof (unsigned char));
 614
 615                 if (dp->neighbors == 6) {
 616                         for (j = 0; j < dp->nrows; j++) {
 617                                 for (i = 0; i < dp->ncols; i++) {
 618                                         /* NE */
 619                                         if (!(j & 1))
 620                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 621                                         else
 622                                                 k = i;
 623                                         l = (!j) ? dp->nrows - 1 : j - 1;
 624                                         ml = l * dp->ncols;
 625                                         if (dp->oldcell[k + ml] ==
 626                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 627                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 628                                         /* E */
 629                                         k = (i + 1 == dp->ncols) ? 0 : i + 1;
 630                                         ml = mj;
 631                                         if (dp->oldcell[k + ml] ==
 632                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 633                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 634                                         /* SE */
 635                                         if (!(j & 1))
 636                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 637                                         else
 638                                                 k = i;
 639                                         l = (j + 1 == dp->nrows) ? 0 : j + 1;
 640                                         ml = l * dp->ncols;
 641                                         if (dp->oldcell[k + ml] ==
 642                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 643                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 644                                         /* SW */
 645                                         if (j & 1)
 646                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 647                                         else
 648                                                 k = i;
 649                                         l = (j + 1 == dp->nrows) ? 0 : j + 1;
 650                                         ml = l * dp->ncols;
 651                                         if (dp->oldcell[k + ml] ==
 652                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 653                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 654                                         /* W */
 655                                         k = (!i) ? dp->ncols - 1 : i - 1;
 656                                         ml = mj;
 657                                         if (dp->oldcell[k + ml] ==
 658                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 659                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 660                                         /* NW */
 661                                         if (j & 1)
 662                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 663                                         else
 664                                                 k = i;
 665                                         l = (!j) ? dp->nrows - 1 : j - 1;
 666                                         ml = l * dp->ncols;
 667                                         if (dp->oldcell[k + ml] ==
 668                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 669                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 670                                 }
 671                                 mj += dp->ncols;
 672                         }
 673                 } else if (dp->neighbors == 4 || dp->neighbors == 8) {
 674                         for (j = 0; j < dp->nrows; j++) {
 675                                 for (i = 0; i < dp->ncols; i++) {
 676                                         /* N */
 677                                         k = i;
 678                                         l = (!j) ? dp->nrows - 1 : j - 1;
 679                                         ml = l * dp->ncols;
 680                                         if (dp->oldcell[k + ml] ==
 681                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 682                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 683                                         /* E */
 684                                         k = (i + 1 == dp->ncols) ? 0 : i + 1;
 685                                         ml = mj;
 686                                         if (dp->oldcell[k + ml] ==
 687                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 688                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 689                                         /* S */
 690                                         k = i;
 691                                         l = (j + 1 == dp->nrows) ? 0 : j + 1;
 692                                         ml = l * dp->ncols;
 693                                         if (dp->oldcell[k + ml] ==
 694                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 695                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 696                                         /* W */
 697                                         k = (!i) ? dp->ncols - 1 : i - 1;
 698                                         l = j;
 699                                         ml = mj;
 700                                         if (dp->oldcell[k + ml] ==
 701                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 702                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 703                                 }
 704                                 mj += dp->ncols;
 705                         }
 706                         if (dp->neighbors == 8) {
 707                                 mj = 0;
 708                                 for (j = 0; j < dp->nrows; j++) {
 709                                         for (i = 0; i < dp->ncols; i++) {
 710                                                 /* NE */
 711                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 712                                                 l = (!j) ? dp->nrows - 1 : j - 1;
 713                                                 ml = l * dp->ncols;
 714                                                 if (dp->oldcell[k + ml] ==
 715                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 716                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 717                                                 /* SE */
 718                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 719                                                 l = (j + 1 == dp->nrows) ? 0 : j + 1;
 720                                                 ml = l * dp->ncols;
 721                                                 if (dp->oldcell[k + ml] ==
 722                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 723                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 724                                                 /* SW */
 725                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 726                                                 l = (j + 1 == dp->nrows) ? 0 : j + 1;
 727                                                 ml = l * dp->ncols;
 728                                                 if (dp->oldcell[k + ml] ==
 729                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 730                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 731                                                 /* NW */
 732                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 733                                                 l = (!j) ? dp->nrows - 1 : j - 1;
 734                                                 ml = l * dp->ncols;
 735                                                 if (dp->oldcell[k + ml] ==
 736                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 737                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 738                                         }
 739                                         mj += dp->ncols;
 740                                 }
 741                         }
 742                 } else if (dp->neighbors == 3 || dp->neighbors == 9 ||
 743                            dp->neighbors == 12) {
 744                         for (j = 0; j < dp->nrows; j++) {
 745                                 for (i = 0; i < dp->ncols; i++) {
 746                                         if ((i + j) % 2) {      /* right */
 747                                                 /* W */
 748                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 749                                                 ml = mj;
 750                                                 if (dp->oldcell[k + ml] ==
 751                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 752                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 753                                         } else {        /* left */
 754                                                 /* E */
 755                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 756                                                 ml = mj;
 757                                                 if (dp->oldcell[k + ml] ==
 758                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 759                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 760                                         }
 761                                         /* N */
 762                                         k = i;
 763                                         l = (!j) ? dp->nrows - 1 : j - 1;
 764                                         ml = l * dp->ncols;
 765                                         if (dp->oldcell[k + ml] ==
 766                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 767                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 768                                         /* S */
 769                                         k = i;
 770                                         l = (j + 1 == dp->nrows) ? 0 : j + 1;
 771                                         ml = l * dp->ncols;
 772                                         if (dp->oldcell[k + ml] ==
 773                                             (int) (dp->oldcell[i + mj] + 1) % dp->states)
 774                                                 dp->newcell[i + mj] = dp->oldcell[k + ml];
 775                                 }
 776                                 mj += dp->ncols;
 777                         }
 778                         if (dp->neighbors == 9 || dp->neighbors == 12) {
 779                                 mj = 0;
 780                                 for (j = 0; j < dp->nrows; j++) {
 781                                         for (i = 0; i < dp->ncols; i++) {
 782                                                 /* NN */
 783                                                 k = i;
 784                                                 if (!j)
 785                                                         l = dp->nrows - 2;
 786                                                 else if (!(j - 1))
 787                                                         l = dp->nrows - 1;
 788                                                 else
 789                                                         l = j - 2;
 790                                                 ml = l * dp->ncols;
 791                                                 if (dp->oldcell[k + ml] ==
 792                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 793                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 794                                                 /* SS */
 795                                                 k = i;
 796                                                 if (j + 1 == dp->nrows)
 797                                                         l = 1;
 798                                                 else if (j + 2 == dp->nrows)
 799                                                         l = 0;
 800                                                 else
 801                                                         l = j + 2;
 802                                                 ml = l * dp->ncols;
 803                                                 if (dp->oldcell[k + ml] ==
 804                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 805                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 806                                                 /* NW */
 807                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 808                                                 l = (!j) ? dp->nrows - 1 : j - 1;
 809                                                 ml = l * dp->ncols;
 810                                                 if (dp->oldcell[k + ml] ==
 811                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 812                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 813                                                 /* NE */
 814                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 815                                                 l = (!j) ? dp->nrows - 1 : j - 1;
 816                                                 ml = l * dp->ncols;
 817                                                 if (dp->oldcell[k + ml] ==
 818                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 819                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 820                                                 /* SW */
 821                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 822                                                 l = (j + 1 == dp->nrows) ? 0 : j + 1;
 823                                                 ml = l * dp->ncols;
 824                                                 if (dp->oldcell[k + ml] ==
 825                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 826                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 827                                                 /* SE */
 828                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 829                                                 l = (j + 1 == dp->nrows) ? 0 : j + 1;
 830                                                 ml = l * dp->ncols;
 831                                                 if (dp->oldcell[k + ml] ==
 832                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 833                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 834                                         }
 835                                         mj += dp->ncols;
 836                                 }
 837                                 if (dp->neighbors == 12) {
 838                                         mj = 0;
 839                                         for (j = 0; j < dp->nrows; j++) {
 840                                                 for (i = 0; i < dp->ncols; i++) {
 841                                                         if ((i + j) % 2) {      /* right */
 842                                                                 /* NNW */
 843                                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 844                                                                 if (!j)
 845                                                                         l = dp->nrows - 2;
 846                                                                 else if (!(j - 1))
 847                                                                         l = dp->nrows - 1;
 848                                                                 else
 849                                                                         l = j - 2;
 850                                                                 ml = l * dp->ncols;
 851                                                                 if (dp->oldcell[k + ml] ==
 852                                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 853                                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 854                                                                 /* SSW */
 855                                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 856                                                                 if (j + 1 == dp->nrows)
 857                                                                         l = 1;
 858                                                                 else if (j + 2 == dp->nrows)
 859                                                                         l = 0;
 860                                                                 else
 861                                                                         l = j + 2;
 862                                                                 ml = l * dp->ncols;
 863                                                                 if (dp->oldcell[k + ml] ==
 864                                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 865                                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 866                                                                 /* EE */
 867                                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 868                                                                 l = j;
 869                                                                 ml = mj;
 870                                                                 if (dp->oldcell[k + ml] ==
 871                                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 872                                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 873                                                         } else {        /* left */
 874                                                                 /* NNE */
 875                                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 876                                                                 if (!j)
 877                                                                         l = dp->nrows - 2;
 878                                                                 else if (!(j - 1))
 879                                                                         l = dp->nrows - 1;
 880                                                                 else
 881                                                                         l = j - 2;
 882                                                                 ml = l * dp->ncols;
 883                                                                 if (dp->oldcell[k + ml] ==
 884                                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 885                                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 886                                                                 /* SSE */
 887                                                                 k = (i + 1 == dp->ncols) ? 0 : i + 1;
 888                                                                 if (j + 1 == dp->nrows)
 889                                                                         l = 1;
 890                                                                 else if (j + 2 == dp->nrows)
 891                                                                         l = 0;
 892                                                                 else
 893                                                                         l = j + 2;
 894                                                                 ml = l * dp->ncols;
 895                                                                 if (dp->oldcell[k + ml] ==
 896                                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 897                                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 898                                                                 /* WW */
 899                                                                 k = (!i) ? dp->ncols - 1 : i - 1;
 900                                                                 l = j;
 901                                                                 ml = mj;
 902                                                                 if (dp->oldcell[k + ml] ==
 903                                                                     (int) (dp->oldcell[i + mj] + 1) % dp->states)
 904                                                                         dp->newcell[i + mj] = dp->oldcell[k + ml];
 905                                                         }
 906                                                 }
 907                                                 mj += dp->ncols;
 908                                         }
 909                                 }
 910                         }
 911                 }
 912                 mj = 0;
 913                 for (j = 0; j < dp->nrows; j++) {
 914                         for (i = 0; i < dp->ncols; i++)
 915                                 if (dp->oldcell[i + mj] != dp->newcell[i + mj]) {
 916                                         dp->oldcell[i + mj] = dp->newcell[i + mj];
 917                                         if (!addtolist(mi, i, j, dp->oldcell[i + mj])) {
 918                                                 free_demon(MI_DISPLAY(mi), dp);
 919                                                 return;
 920                                         }
 921                                 }
 922                         mj += dp->ncols;
 923                 }
 924                 if (++dp->generation > MI_CYCLES(mi))
 925                         init_demon(mi);
 926                 dp->state = 0;
 927         } else {
 928                 if (dp->ncells[dp->state])
 929                         if (!draw_state(mi, dp->state)) {
 930                                 free_demon(MI_DISPLAY(mi), dp);
 931                                 return;
 932                         }
 933                 dp->state++;
 934         }
 935         if (dp->redrawing) {
 936                 for (i = 0; i < REDRAWSTEP; i++) {
 937                         if (dp->oldcell[dp->redrawpos]) {
 938                                 drawcell(mi, dp->redrawpos % dp->ncols, dp->redrawpos / dp->ncols,
 939                                          dp->oldcell[dp->redrawpos]);
 940                         }
 941                         if (++(dp->redrawpos) >= dp->ncols * dp->nrows) {
 942                                 dp->redrawing = 0;
 943                                 break;
 944                         }
 945                 }
 946         }
 947 }
 948
 949
 950 ENTRYPOINT void
 951 release_demon (ModeInfo * mi)
 952 {
 953         if (demons != NULL) {
 954                 int         screen;
 955
 956                 for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
 957                         free_demon(MI_DISPLAY(mi), &demons[screen]);
 958                 (void) free((void *) demons);
 959                 demons = (demonstruct *) NULL;
 960         }
 961 }
 962
 963 ENTRYPOINT void
 964 refresh_demon (ModeInfo * mi)
 965 {
 966         demonstruct *dp;
 967
 968         if (demons == NULL)
 969                 return;
 970         dp = &demons[MI_SCREEN(mi)];
 971
 972         dp->redrawing = 1;
 973         dp->redrawpos = 0;
 974 }
 975
 976 XSCREENSAVER_MODULE ("Demon", demon)
 977
 978 #endif /* MODE_demon */