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

   1 /* -*- Mode: C; tab-width: 4 -*- */
   2 /* strange --- strange attractors */
   3
   4 #if 0
   5 static const char sccsid[] = "@(#)strange.c     5.00 2000/11/01 xlockmore";
   6 #endif
   7
   8 /*-
   9 * Copyright (c) 1997 by Massimino Pascal <Pascal.Massimon@ens.fr>
  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: jwz@jwz.org: turned into a standalone program.
  26 *              Made it render into an offscreen bitmap and then copy
  27 *              that onto the screen, to reduce flicker.
  28 *
  29 * strange attractors are not so hard to find...
  30 */
  31
  32 /* TODO: Bring over tweaks from 3.x version.
  33 * For a good idea of what's missing, diff strange.c.20081107-good2 against strange.c-3.29
  34 * We forked from the 3.29 series at 20081107, so anything added since then may be missing.
  35 */
  36
  37 #ifdef STANDALONE
  38 # define MODE_strange
  39 # define DEFAULTS       "*delay: 10000 \n" \
  40                                         "*ncolors: 100 \n" \
  41                                         "*fpsSolid: True \n"
  42
  43 # define SMOOTH_COLORS
  44 # define refresh_strange 0
  45 # define reshape_strange 0
  46 # define strange_handle_event 0
  47 # include "xlockmore.h"         /* from the xscreensaver distribution */
  48 #else /* !STANDALONE */
  49 # include "xlock.h"             /* from the xlockmore distribution */
  50 #endif /* !STANDALONE */
  51
  52 #ifdef MODE_strange
  53 #define DEF_CURVE  "10"
  54 #define DEF_POINTS "5500"
  55
  56 /*static int curve;*/
  57 static int points;
  58
  59 static XrmOptionDescRec opts[] =
  60 {
  61 /*              {"-curve",  ".strange.curve",  XrmoptionSepArg, 0}, */
  62                 {"-points", ".strange.points", XrmoptionSepArg, 0},
  63 };
  64 static argtype vars[] =
  65 {
  66 /*              {&curve,  "curve",  "Curve",  DEF_CURVE,  t_Int},*/
  67                 {&points, "points", "Points", DEF_POINTS, t_Int},
  68 };
  69 static OptionStruct desc[] =
  70 {
  71 /*              {"-curve", "set the curve factor of the attractors"},*/
  72                 {"-points", "change the number of points/iterations each frame"},
  73 };
  74 ENTRYPOINT ModeSpecOpt strange_opts =
  75 {sizeof opts / sizeof opts[0], opts,
  76 sizeof vars / sizeof vars[0], vars, desc};
  77
  78 #ifdef USE_MODULES
  79 ModStruct   strange_description =
  80 {"strange", "init_strange", "draw_strange", "release_strange",
  81 "init_strange", "init_strange", (char *) NULL, &strange_opts,
  82 1000, 1, 1, 1, 64, 1.0, "",
  83 "Shows strange attractors", 0, NULL};
  84 #endif
  85
  86 #ifdef HAVE_COCOA
  87 # define NO_DBUF
  88 #endif
  89
  90 typedef float DBL;
  91 typedef int PRM;
  92
  93 #define UNIT (1<<12)
  94 #define UNIT2 (1<<14)
  95 /* #define UNIT2 (3140*UNIT/1000) */
  96
  97 #define SKIP_FIRST      100
  98 #define DBL_To_PRM(x)  (PRM)( (DBL)(UNIT)*(x) )
  99
 100
 101 #define DO_FOLD(a) (a)<0 ? -A->Fold[ (-(a))&(UNIT2-1) ] : A->Fold[ (a)&(UNIT2-1) ]
 102
 103 #if 0
 104 #define DO_FOLD(a) (a)<-UNIT2 ? -A->Fold[(-(a))%UNIT2] : (a)<0 ? -A->Fold[ -(a) ] :\
 105 (a)>UNIT2 ? A->Fold[ (a)%UNIT2 ] : A->Fold[ (a) ]
 106 #define DO_FOLD(a) DBL_To_PRM( sin( (DBL)(a)/UNIT ) )
 107 #define DO_FOLD(a) (a)<0 ? DBL_To_PRM( exp( 16.0*(a)/UNIT2 ) )-1.0 : \
 108 DBL_To_PRM( 1.0-exp( -16.0*(a)/UNIT2 ) )
 109 #endif
 110
 111 /* useAccumulator performs two functions:
 112 * If it is defined, then support for the accumulator will be compiled.
 113 * It is also the condition for which the accumulator renderer will engage.
 114 */
 115 #define useAccumulator (Root->Max_Pt > 6000)
 116 #define ACC_GAMMA 10.0
 117 #define NUM_COLS 150
 118 /* Extra options: */
 119 #define VARY_SPEED_TO_AVOID_BOREDOM
 120 #define POINTS_HISTORY
 121 #define MERGE_FRAMES 3
 122
 123 /******************************************************************/
 124
 125 #define MAX_PRM 3*5
 126
 127 typedef struct _ATTRACTOR {
 128         DBL         Prm1[MAX_PRM], Prm2[MAX_PRM];
 129         PRM         Prm[MAX_PRM], *Fold;
 130         void        (*Iterate) (struct _ATTRACTOR *, PRM, PRM, PRM *, PRM *);
 131         XPoint     *Buffer1, *Buffer2;
 132         int         Cur_Pt, Max_Pt;
 133         int         Col, Count, Speed;
 134         int         Width, Height;
 135         Pixmap      dbuf;       /* jwz */
 136         GC          dbuf_gc;
 137         #ifdef useAccumulator
 138                 int **accMap;
 139         #endif
 140 } ATTRACTOR;
 141
 142 static ATTRACTOR *Root = (ATTRACTOR *) NULL;
 143
 144 #ifdef useAccumulator
 145 XColor* cols;
 146 #endif
 147
 148 #ifdef POINTS_HISTORY
 149 static int numOldPoints;
 150 static int* oldPointsX;
 151 static int* oldPointsY;
 152 static int oldPointsIndex;
 153 static int startedClearing;
 154 #endif
 155
 156 static DBL  Amp_Prm[MAX_PRM] =
 157 {
 158         1.0, 3.5, 3.5, 2.5, 4.7,
 159         1.0, 3.5, 3.6, 2.5, 4.7,
 160         1.0, 1.5, 2.2, 2.1, 3.5
 161 };
 162 static DBL  Mid_Prm[MAX_PRM] =
 163 {
 164         0.0, 1.5, 0.0, .5, 1.5,
 165         0.0, 1.5, 0.0, .5, 1.5,
 166         0.0, 1.5, -1.0, -.5, 2.5,
 167 };
 168
 169 static      DBL
 170 Gauss_Rand(DBL c, DBL A, DBL S)
 171 {
 172         DBL         y;
 173
 174         y = (DBL) LRAND() / MAXRAND;
 175         y = A * (1.0 - exp(-y * y * S)) / (1.0 - exp(-S));
 176         if (NRAND(2))
 177                 return (c + y);
 178         else
 179                 return (c - y);
 180 }
 181
 182 static void
 183 Random_Prm(DBL * Prm)
 184 {
 185         int         i;
 186
 187         for (i = 0; i < MAX_PRM; ++i)
 188                 Prm[i] = Gauss_Rand(Mid_Prm[i], Amp_Prm[i], 4.0);
 189 }
 190
 191 /***************************************************************/
 192
 193   /* 2 examples of non-linear map */
 194
 195 static void
 196 Iterate_X2(ATTRACTOR * A, PRM x, PRM y, PRM * xo, PRM * yo)
 197 {
 198         PRM         xx, yy, xy, x2y, y2x, Tmp;
 199
 200         xx = (x * x) / UNIT;
 201         x2y = (xx * y) / UNIT;
 202         yy = (y * y) / UNIT;
 203         y2x = (yy * x) / UNIT;
 204         xy = (x * y) / UNIT;
 205
 206         Tmp = A->Prm[1] * xx + A->Prm[2] * xy + A->Prm[3] * yy + A->Prm[4] * x2y;
 207         Tmp = A->Prm[0] - y + (Tmp / UNIT);
 208         *xo = DO_FOLD(Tmp);
 209         Tmp = A->Prm[6] * xx + A->Prm[7] * xy + A->Prm[8] * yy + A->Prm[9] * y2x;
 210         Tmp = A->Prm[5] + x + (Tmp / UNIT);
 211         *yo = DO_FOLD(Tmp);
 212 }
 213
 214 static void
 215 Iterate_X3(ATTRACTOR * A, PRM x, PRM y, PRM * xo, PRM * yo)
 216 {
 217         PRM         xx, yy, xy, x2y, y2x, Tmp_x, Tmp_y, Tmp_z;
 218
 219         xx = (x * x) / UNIT;
 220         x2y = (xx * y) / UNIT;
 221         yy = (y * y) / UNIT;
 222         y2x = (yy * x) / UNIT;
 223         xy = (x * y) / UNIT;
 224
 225         Tmp_x = A->Prm[1] * xx + A->Prm[2] * xy + A->Prm[3] * yy + A->Prm[4] * x2y;
 226         Tmp_x = A->Prm[0] - y + (Tmp_x / UNIT);
 227         Tmp_x = DO_FOLD(Tmp_x);
 228
 229         Tmp_y = A->Prm[6] * xx + A->Prm[7] * xy + A->Prm[8] * yy + A->Prm[9] * y2x;
 230         Tmp_y = A->Prm[5] + x + (Tmp_y / UNIT);
 231
 232         Tmp_y = DO_FOLD(Tmp_y);
 233
 234         Tmp_z = A->Prm[11] * xx + A->Prm[12] * xy + A->Prm[13] * yy + A->Prm[14] * y2x;
 235         Tmp_z = A->Prm[10] + x + (Tmp_z / UNIT);
 236         Tmp_z = UNIT + Tmp_z * Tmp_z / UNIT;
 237
 238         *xo = (Tmp_x * UNIT) / Tmp_z;
 239         *yo = (Tmp_y * UNIT) / Tmp_z;
 240 }
 241
 242 static void (*Funcs[2]) (ATTRACTOR *, PRM, PRM, PRM *, PRM *) = {
 243         Iterate_X2, Iterate_X3
 244 };
 245
 246 /***************************************************************/
 247
 248 static void
 249 free_strange(Display *display, ATTRACTOR *A)
 250 {
 251         if (A->Buffer1 != NULL) {
 252                 (void) free((void *) A->Buffer1);
 253                 A->Buffer1 = (XPoint *) NULL;
 254         }
 255         if (A->Buffer2 != NULL) {
 256                 (void) free((void *) A->Buffer2);
 257                 A->Buffer2 = (XPoint *) NULL;
 258         }
 259         if (A->dbuf) {
 260                 XFreePixmap(display, A->dbuf);
 261                 A->dbuf = None;
 262         }
 263         if (A->dbuf_gc) {
 264                 XFreeGC(display, A->dbuf_gc);
 265                 A->dbuf_gc = None;
 266         }
 267         if (A->Fold != NULL) {
 268                 (void) free((void *) A->Fold);
 269                 A->Fold = (PRM *) NULL;
 270         }
 271 }
 272
 273 ENTRYPOINT void
 274 draw_strange(ModeInfo * mi)
 275 {
 276         int         i, j, n, Cur_Pt;
 277         PRM         x, y, xo, yo;
 278         DBL         u;
 279         XPoint     *Buf;
 280         Display    *display = MI_DISPLAY(mi);
 281         Window      window = MI_WINDOW(mi);
 282         GC          gc = MI_GC(mi);
 283         DBL         Lx, Ly;
 284         void        (*Iterate) (ATTRACTOR *, PRM, PRM, PRM *, PRM *);
 285         PRM         xmin, xmax, ymin, ymax;
 286         ATTRACTOR  *A;
 287
 288         if (Root == NULL)
 289                 return;
 290         A = &Root[MI_SCREEN(mi)];
 291         if (A->Fold == NULL)
 292                 return;
 293
 294         Cur_Pt = A->Cur_Pt;
 295         Iterate = A->Iterate;
 296
 297         u = (DBL) (A->Count) / 40000.0;
 298         for (j = MAX_PRM - 1; j >= 0; --j)
 299                 A->Prm[j] = DBL_To_PRM((1.0 - u) * A->Prm1[j] + u * A->Prm2[j]);
 300
 301         /* We collect the accumulation of the orbits in the 2d int array field. */
 302 #ifndef POINTS_HISTORY
 303         #ifdef useAccumulator
 304                 if (useAccumulator) {
 305                         for (i=0;i<A->Width;i++) {
 306                                 for (j=0;j<A->Height;j++) {
 307                                         A->accMap[i][j] = 0;
 308
 309                                 }
 310                         }
 311                 }
 312         #endif
 313 #endif
 314
 315         x = y = DBL_To_PRM(.0);
 316         for (n = SKIP_FIRST; n; --n) {
 317                 (*Iterate) (A, x, y, &xo, &yo);
 318                 x = xo + NRAND(8) - 4;
 319                 y = yo + NRAND(8) - 4;
 320         }
 321
 322         xmax = 0;
 323         xmin = UNIT * 4;
 324         ymax = 0;
 325         ymin = UNIT * 4;
 326         A->Cur_Pt = 0;
 327         Buf = A->Buffer2;
 328         Lx = (DBL) A->Width / UNIT / 2.2;
 329         Ly = (DBL) A->Height / UNIT / 2.2;
 330         for (n = A->Max_Pt; n; --n) {
 331                 (*Iterate) (A, x, y, &xo, &yo);
 332                 #ifdef useAccumulator
 333                 if (useAccumulator) {
 334                         int mx,my;
 335                         mx = (short) ( A->Width*0.1 + A->Width*0.8 * (xo - xmin) / (xmax - xmin) );
 336                         my = (short) ( A->Width*0.1 + (A->Height - A->Width*0.2) * (yo - ymin) / (ymax - ymin) );
 337                         if (mx>=0 && my>=0 && mx<A->Width && my<A->Height) {
 338                                 A->accMap[mx][my]++;
 339                         }
 340 #ifdef POINTS_HISTORY
 341                 /* #define clearOldPoint(i) { if (startedClearing) { field[oldPoints[i].x][oldPoints[i].y]--; } }
 342                 #define saveUnplot(X,Y) { clearOldPoint(oldPointsIndex) oldPoints[oldPointsIndex].x = X; oldPoints[oldPointsIndex].y = Y; oldPointsIndex = (oldPointsIndex + 1) % numOldPoints; if (oldPointsIndex==0) { startedClearing=1; } }
 343                 saveUnplot(mx,my) */
 344                 if (startedClearing) {
 345                         int oldX = oldPointsX[oldPointsIndex];
 346                         int oldY = oldPointsY[oldPointsIndex];
 347                         if (oldX>=0 && oldY>=0 && oldX<A->Width && oldY<A->Height) {
 348                                 A->accMap[oldX][oldY]--;
 349                         }
 350                 }
 351                 oldPointsX[oldPointsIndex] = mx;
 352                 oldPointsY[oldPointsIndex] = my;
 353                 oldPointsIndex = (oldPointsIndex + 1) % numOldPoints;
 354                 if (oldPointsIndex==0) { startedClearing=1; }
 355 #endif
 356                 } else {
 357                 #endif
 358                         Buf->x = (int) (Lx * (x + DBL_To_PRM(1.1)));
 359                         Buf->y = (int) (Ly * (DBL_To_PRM(1.1) - y));
 360                         Buf++;
 361                         A->Cur_Pt++;
 362                 #ifdef useAccumulator
 363                 }
 364                 #endif
 365                 /* (void) fprintf( stderr, "X,Y: %d %d    ", Buf->x, Buf->y ); */
 366                 if (xo > xmax)
 367                         xmax = xo;
 368                 else if (xo < xmin)
 369                         xmin = xo;
 370                 if (yo > ymax)
 371                         ymax = yo;
 372                 else if (yo < ymin)
 373                         ymin = yo;
 374                 x = xo + NRAND(8) - 4;
 375                 y = yo + NRAND(8) - 4;
 376         }
 377
 378         MI_IS_DRAWN(mi) = True;
 379
 380         XSetForeground(display, gc, MI_BLACK_PIXEL(mi));
 381
 382         #ifdef useAccumulator
 383         if (useAccumulator) {
 384                 float colorScale;
 385                 int col;
 386                 #ifdef VARY_SPEED_TO_AVOID_BOREDOM
 387                 int pixelCount = 0;
 388                 #endif
 389                 colorScale = (A->Width*A->Height/640.0/480.0*800000.0/(float)A->Max_Pt*(float)NUM_COLS/256);
 390                 if (A->dbuf != None) {
 391                         XSetForeground(display, A->dbuf_gc, 0);
 392                         XFillRectangle(display, A->dbuf, A->dbuf_gc, 0, 0, A->Width, A->Height);
 393                 } else {
 394                         XSetForeground(display, gc, MI_BLACK_PIXEL(mi));
 395                         XFillRectangle(display, window, gc, 0, 0, A->Width, A->Height);
 396                 }
 397                 for (i=0;i<A->Width;i++) {
 398                         for (j=0;j<A->Height;j++) {
 399                                 if (A->accMap[i][j]>0) {
 400                                         col = (float)A->accMap[i][j] * colorScale;
 401                                         if (col>NUM_COLS-1) {
 402                                                 col = NUM_COLS-1;
 403                                         }
 404                                         #ifdef VARY_SPEED_TO_AVOID_BOREDOM
 405                                         if (col>0) {
 406                                                 if (col<NUM_COLS-1)  /* we don't count maxxed out pixels */
 407                                                         pixelCount++;
 408                                         }
 409                                         #endif
 410                                         if (MI_NPIXELS(mi) < 2)
 411                                                 XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
 412                                         else
 413                                                 /*XSetForeground(display, gc, MI_PIXEL(mi, A->Col % MI_NPIXELS(mi)));*/
 414                                                 XSetForeground(display, gc, cols[col].pixel);
 415                                         if (A->dbuf != None) {
 416                                                 XSetForeground(display, A->dbuf_gc, cols[col].pixel);
 417                                                 XDrawPoint(display, A->dbuf, A->dbuf_gc, i, j);
 418                                         } else {
 419                                                 XSetForeground(display, gc, cols[col].pixel);
 420                                                 XDrawPoint(display, window, gc, i, j);
 421                                         }
 422                                 }
 423                         }
 424                 }
 425                 if (A->dbuf != None) {
 426                         XCopyArea(display, A->dbuf, window, gc, 0, 0, A->Width, A->Height, 0, 0);
 427                 }
 428                 #ifdef VARY_SPEED_TO_AVOID_BOREDOM
 429                         /* Increaase the rate of change of the parameters if the attractor has become visually boring. */
 430                         if ((xmax - xmin < DBL_To_PRM(.2)) && (ymax - ymin < DBL_To_PRM(.2))) {
 431                                 A->Speed *= 1.25;
 432                         } else if (pixelCount>0 && pixelCount<A->Width*A->Height/1000) {
 433                                 A->Speed *= 1.25;  /* A->Count = 1000; */
 434                         } else {
 435                                 A->Speed = 4; /* reset to normal/default */
 436                         }
 437                         if (A->Speed > 32)
 438                                 A->Speed = 32;
 439                         A->Count += A->Speed;
 440                         if (A->Count >= 1000) {
 441                                 for (i = MAX_PRM - 1; i >= 0; --i)
 442                                         A->Prm1[i] = A->Prm2[i];
 443                                 Random_Prm(A->Prm2);
 444                                 A->Count = 0;
 445                         }
 446                 #endif
 447         } else {
 448         #endif
 449
 450         if (A->dbuf != None) {          /* jwz */
 451                 XSetForeground(display, A->dbuf_gc, 0);
 452 /* XDrawPoints(display, A->dbuf, A->dbuf_gc, A->Buffer1,
 453   Cur_Pt,CoordModeOrigin); */
 454                 XFillRectangle(display, A->dbuf, A->dbuf_gc, 0, 0, A->Width, A->Height);
 455         } else
 456                 XDrawPoints(display, window, gc, A->Buffer1, Cur_Pt, CoordModeOrigin);
 457
 458         if (MI_NPIXELS(mi) < 2)
 459                 XSetForeground(display, gc, MI_WHITE_PIXEL(mi));
 460         else
 461                 XSetForeground(display, gc, MI_PIXEL(mi, A->Col % MI_NPIXELS(mi)));
 462
 463         if (A->dbuf != None) {
 464                 XSetForeground(display, A->dbuf_gc, 1);
 465                 XDrawPoints(display, A->dbuf, A->dbuf_gc, A->Buffer2, A->Cur_Pt,
 466                             CoordModeOrigin);
 467                 XCopyPlane(display, A->dbuf, window, gc, 0, 0, A->Width, A->Height, 0, 0, 1);
 468         } else
 469                 XDrawPoints(display, window, gc, A->Buffer2, A->Cur_Pt, CoordModeOrigin);
 470
 471         #ifdef useAccumulator
 472         }
 473         #endif
 474
 475         Buf = A->Buffer1;
 476         A->Buffer1 = A->Buffer2;
 477         A->Buffer2 = Buf;
 478
 479         if ((xmax - xmin < DBL_To_PRM(.2)) && (ymax - ymin < DBL_To_PRM(.2)))
 480                 A->Count += 4 * A->Speed;
 481         else
 482                 A->Count += A->Speed;
 483         if (A->Count >= 1000) {
 484                 for (i = MAX_PRM - 1; i >= 0; --i)
 485                         A->Prm1[i] = A->Prm2[i];
 486                 Random_Prm(A->Prm2);
 487                 A->Count = 0;
 488         }
 489         A->Col++;
 490 }
 491
 492
 493 /***************************************************************/
 494
 495 ENTRYPOINT void
 496 init_strange(ModeInfo * mi)
 497 {
 498         Display    *display = MI_DISPLAY(mi);
 499         Window      window = MI_WINDOW(mi);
 500 #ifndef NO_DBUF
 501         GC          gc = MI_GC(mi);
 502 #endif
 503         ATTRACTOR  *Attractor;
 504
 505 #ifdef POINTS_HISTORY
 506         startedClearing=0;
 507         oldPointsIndex=0;
 508 #endif
 509
 510         if (Root == NULL) {
 511                 if ((Root = (ATTRACTOR *) calloc(MI_NUM_SCREENS(mi),
 512                                 sizeof (ATTRACTOR))) == NULL)
 513                         return;
 514         }
 515         Attractor = &Root[MI_SCREEN(mi)];
 516
 517         if (Attractor->Fold == NULL) {
 518                 int         i;
 519
 520                 if ((Attractor->Fold = (PRM *) calloc(UNIT2 + 1,
 521                                 sizeof (PRM))) == NULL) {
 522                         free_strange(display, Attractor);
 523                         return;
 524                 }
 525                 for (i = 0; i <= UNIT2; ++i) {
 526                         DBL         x;
 527
 528                         /* x = ( DBL )(i)/UNIT2; */
 529                         /* x = sin( M_PI/2.0*x ); */
 530                         /* x = sqrt( x ); */
 531                         /* x = x*x; */
 532                         /* x = x*(1.0-x)*4.0; */
 533                         x = (DBL) (i) / UNIT;
 534                         x = sin(x);
 535                         Attractor->Fold[i] = DBL_To_PRM(x);
 536                 }
 537         }
 538
 539         Attractor->Max_Pt = points;
 540
 541         if (Attractor->Buffer1 == NULL)
 542                 if ((Attractor->Buffer1 = (XPoint *) calloc(Attractor->Max_Pt,
 543                                 sizeof (XPoint))) == NULL) {
 544                         free_strange(display, Attractor);
 545                         return;
 546                 }
 547         if (Attractor->Buffer2 == NULL)
 548                 if ((Attractor->Buffer2 = (XPoint *) calloc(Attractor->Max_Pt,
 549                                 sizeof (XPoint))) == NULL) {
 550                         free_strange(display, Attractor);
 551                         return;
 552                 }
 553
 554         Attractor->Width = MI_WIDTH(mi);
 555         Attractor->Height = MI_HEIGHT(mi);
 556         Attractor->Cur_Pt = 0;
 557         Attractor->Count = 0;
 558         Attractor->Col = NRAND(MI_NPIXELS(mi));
 559         Attractor->Speed = 4;
 560
 561         Attractor->Iterate = Funcs[NRAND(2)];
 562         Random_Prm(Attractor->Prm1);
 563         Random_Prm(Attractor->Prm2);
 564 #ifndef NO_DBUF
 565         if (Attractor->dbuf != None)
 566                 XFreePixmap(display, Attractor->dbuf);
 567 #ifdef useAccumulator
 568 #define colorDepth ( useAccumulator ? MI_DEPTH(mi) : 1 )
 569 #else
 570 #define colorDepth 1
 571 #endif
 572         Attractor->dbuf = XCreatePixmap(display, window,
 573              Attractor->Width, Attractor->Height, colorDepth);
 574         /* Allocation checked */
 575         if (Attractor->dbuf != None) {
 576                 XGCValues   gcv;
 577
 578                 gcv.foreground = 0;
 579                 gcv.background = 0;
 580 #ifndef HAVE_COCOA
 581                 gcv.graphics_exposures = False;
 582 #endif /* HAVE_COCOA */
 583                 gcv.function = GXcopy;
 584
 585                 if (Attractor->dbuf_gc != None)
 586                         XFreeGC(display, Attractor->dbuf_gc);
 587
 588                 if ((Attractor->dbuf_gc = XCreateGC(display, Attractor->dbuf,
 589 #ifndef HAVE_COCOA
 590                                 GCGraphicsExposures |
 591 #endif /* HAVE_COCOA */
 592                                GCFunction | GCForeground | GCBackground,
 593                                 &gcv)) == None) {
 594                         XFreePixmap(display, Attractor->dbuf);
 595                         Attractor->dbuf = None;
 596                 } else {
 597                         XFillRectangle(display, Attractor->dbuf, Attractor->dbuf_gc,
 598                                 0, 0, Attractor->Width, Attractor->Height);
 599                         XSetBackground(display, gc, MI_BLACK_PIXEL(mi));
 600                         XSetFunction(display, gc, GXcopy);
 601                 }
 602         }
 603 #endif
 604
 605
 606 #ifdef useAccumulator
 607         #define A Attractor
 608         if (useAccumulator) {
 609                 XWindowAttributes xgwa;
 610                 int i,j;
 611                 XGetWindowAttributes (display, window, &xgwa);
 612                 /* cmap = xgwa.colormap; */
 613                 /* cmap = XCreateColormap(display, window, MI_VISUAL(mi), AllocAll); */
 614                 Attractor->accMap = (int**)calloc(Attractor->Width,sizeof(int*));
 615                 for (i=0;i<Attractor->Width;i++) {
 616                         Attractor->accMap[i] = (int*)calloc(Attractor->Height,sizeof(int));
 617                         for (j=0;j<Attractor->Height;j++) {
 618                                 Attractor->accMap[i][j] = 0;
 619                         }
 620                 }
 621 #ifdef POINTS_HISTORY
 622                 numOldPoints = A->Max_Pt * MERGE_FRAMES;
 623                 oldPointsX = (int*)calloc(numOldPoints,sizeof(int));
 624                 oldPointsY = (int*)calloc(numOldPoints,sizeof(int));
 625 #endif
 626                 cols = (XColor*)calloc(NUM_COLS,sizeof(XColor));
 627                 for (i=0;i<NUM_COLS;i++) {
 628                         float li;
 629                         #define MINBLUE 1
 630                         #define FULLBLUE 128
 631                         li = MINBLUE + (255.0-MINBLUE) * log(1.0 + ACC_GAMMA*(float)i/NUM_COLS) / log(1.0 + ACC_GAMMA);
 632                         if (li<FULLBLUE) {
 633                                 cols[i].red = 0;
 634                                 cols[i].green = 0;
 635                                 cols[i].blue = 65536*li/FULLBLUE;
 636                         } else {
 637                                 cols[i].red = 65536*(li-FULLBLUE)/(256-FULLBLUE);
 638                                 cols[i].green = 65536*(li-FULLBLUE)/(256-FULLBLUE);
 639                                 cols[i].blue = 65535;
 640                         }
 641                         XAllocColor (display, xgwa.colormap, &cols[i]);
 642                         /*
 643                         if (!XAllocColor(MI_DISPLAY(mi), cmap, &cols[i])) {
 644                         if (!XAllocColor(display, cmap, &cols[i])) {
 645                                 cols[i].pixel = WhitePixel (display, DefaultScreen (display));
 646                                 cols[i].red = cols[i].green = cols[i].blue = 0xFFFF;
 647                         }
 648                         */
 649                 }
 650                 /*
 651                 XSetWindowColormap(display, window, cmap);
 652                 (void) XSetWMColormapWindows(display, window, &window, 1);
 653                 XInstallColormap(display, cmap);
 654                 XStoreColors(display, cmap, cols, 256);
 655                 */
 656         }
 657         #undef A
 658 #endif
 659         MI_CLEARWINDOW(mi);
 660
 661         /* Do not want any exposure events from XCopyPlane */
 662         XSetGraphicsExposures(display, MI_GC(mi), False);
 663 }
 664
 665 /***************************************************************/
 666
 667 ENTRYPOINT void
 668 release_strange(ModeInfo * mi)
 669 {
 670         if (Root != NULL) {
 671                 int         screen;
 672
 673 #ifdef useAccumulator
 674                 int i;
 675                 (void) free((void *) cols);
 676                 for (i=0;i<Root->Width;i++) {
 677                         (void) free((void *) Root->accMap[i]);
 678                 }
 679                 (void) free((void *) Root->accMap);
 680 #endif
 681 #ifdef POINTS_HISTORY
 682                 free(oldPointsX);
 683                 free(oldPointsY);
 684 #endif
 685                 for (screen = 0; screen < MI_NUM_SCREENS(mi); ++screen)
 686                         free_strange(MI_DISPLAY(mi), &Root[screen]);
 687                 (void) free((void *) Root);
 688                 Root = (ATTRACTOR *) NULL;
 689         }
 690 }
 691
 692 XSCREENSAVER_MODULE ("Strange", strange)
 693
 694 #endif /* MODE_strange */