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

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  * ifs --- Modified iterated functions system.
   3  */
   4 #if !defined( lint ) && !defined( SABER )
   5 static const char sccsid[] = "@(#)ifs.c    4.02 97/04/01 xlockmore";
   6 #endif
   7
   8 /* Copyright (c) 1997 by Massimino Pascal (Pascal.Massimon@ens.fr)
   9  *
  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  * 10-May-97: jwz@netscape.com: turned into a standalone program.
  25  *                        Made it render into an offscreen bitmap and then copy
  26  *                        that onto the screen, to reduce flicker.
  27  */
  28
  29 #ifdef STANDALONE
  30 # define PROGCLASS                                      "IFS"
  31 # define HACK_INIT                                      init_ifs
  32 # define HACK_DRAW                                      draw_ifs
  33 # define ifs_opts                                       xlockmore_opts
  34 # define DEFAULTS       "*delay:                20000 \n"                       \
  35                                         "*ncolors:              100   \n"
  36 # define SMOOTH_COLORS
  37 # include "xlockmore.h"                         /* from the xscreensaver distribution */
  38 #else  /* !STANDALONE */
  39 # include "xlock.h"                                     /* from the xlockmore distribution */
  40 #endif /* !STANDALONE */
  41
  42 ModeSpecOpt ifs_opts = {
  43   0, NULL, 0, NULL, NULL };
  44
  45 /*****************************************************/
  46 /*****************************************************/
  47
  48 typedef float DBL;
  49 typedef short int F_PT;
  50
  51 /* typedef float               F_PT; */
  52
  53 /*****************************************************/
  54
  55 #define FIX 12
  56 #define UNIT   ( 1<<FIX )
  57 #define MAX_SIMI  6
  58
  59    /* settings for a PC 120Mhz... */
  60 #define MAX_DEPTH_2  10
  61 #define MAX_DEPTH_3  6
  62 #define MAX_DEPTH_4  4
  63 #define MAX_DEPTH_5  3
  64
  65 #define DBL_To_F_PT(x)  (F_PT)( (DBL)(UNIT)*(x) )
  66
  67 /*****************************************************/
  68
  69 static int  Max_Colors;
  70 static ModeInfo *The_MI;
  71 static F_PT Lx, Ly;
  72 static int  D;
  73 static Display *display;
  74 static GC   gc;
  75 static Window window;
  76
  77 /*****************************************************/
  78
  79 typedef struct Similitude_Struct SIMI;
  80 typedef struct Fractal_Struct FRACTAL;
  81
  82 struct Similitude_Struct {
  83
  84         DBL         c_x, c_y;
  85         DBL         r, r2, A, A2;
  86         F_PT        Ct, St, Ct2, St2;
  87         F_PT        Cx, Cy;
  88         F_PT        R, R2;
  89 };
  90
  91 struct Fractal_Struct {
  92
  93         int         Nb_Simi;
  94         SIMI        Components[5 * MAX_SIMI];
  95         int         Depth, Col;
  96         int         Count, Speed;
  97         int         Width, Height, Lx, Ly;
  98         DBL         r_mean, dr_mean, dr2_mean;
  99         int         Cur_Pt, Max_Pt;
 100         XPoint     *Buffer1, *Buffer2;
 101     Pixmap      dbuf;   /* jwz */
 102     GC          dbuf_gc;
 103 };
 104
 105 static FRACTAL *Root = NULL, *Cur_F;
 106 static XPoint *Buf;
 107 static int  Cur_Pt;
 108
 109
 110 /*****************************************************/
 111 /*****************************************************/
 112
 113 static      DBL
 114 Gauss_Rand(DBL c, DBL A, DBL S)
 115 {
 116         DBL         y;
 117
 118         y = (DBL) LRAND() / MAXRAND;
 119         y = A * (1.0 - exp(-y * y * S)) / (1.0 - exp(-S));
 120         if (NRAND(2))
 121                 return (c + y);
 122         return (c - y);
 123 }
 124
 125 static      DBL
 126 Half_Gauss_Rand(DBL c, DBL A, DBL S)
 127 {
 128         DBL         y;
 129
 130         y = (DBL) LRAND() / MAXRAND;
 131         y = A * (1.0 - exp(-y * y * S)) / (1.0 - exp(-S));
 132         return (c + y);
 133 }
 134
 135 static void
 136 Random_Simis(FRACTAL * F, SIMI * Cur, int i)
 137 {
 138         while (i--) {
 139                 Cur->c_x = Gauss_Rand(0.0, .8, 4.0);
 140                 Cur->c_y = Gauss_Rand(0.0, .8, 4.0);
 141                 Cur->r = Gauss_Rand(F->r_mean, F->dr_mean, 3.0);
 142                 Cur->r2 = Half_Gauss_Rand(0.0, F->dr2_mean, 2.0);
 143                 Cur->A = Gauss_Rand(0.0, 360.0, 4.0) * (M_PI / 180.0);
 144                 Cur->A2 = Gauss_Rand(0.0, 360.0, 4.0) * (M_PI / 180.0);
 145                 Cur++;
 146         }
 147 }
 148
 149 /***************************************************************/
 150
 151 void
 152 init_ifs(ModeInfo * mi)
 153 {
 154         int         i;
 155         FRACTAL    *Fractal;
 156
 157         if (Root == NULL) {
 158                 Root = (FRACTAL *) calloc(
 159                                        MI_NUM_SCREENS(mi), sizeof (FRACTAL));
 160                 if (Root == NULL)
 161                         return;
 162         }
 163         Fractal = &Root[MI_SCREEN(mi)];
 164
 165         if (Fractal->Max_Pt) {
 166                 free(Fractal->Buffer1);
 167                 free(Fractal->Buffer2);
 168         }
 169         i = (NRAND(4)) + 2;     /* Number of centers */
 170         switch (i) {
 171                 case 3:
 172                         Fractal->Depth = MAX_DEPTH_3;
 173                         Fractal->r_mean = .6;
 174                         Fractal->dr_mean = .4;
 175                         Fractal->dr2_mean = .3;
 176                         break;
 177
 178                 case 4:
 179                         Fractal->Depth = MAX_DEPTH_4;
 180                         Fractal->r_mean = .5;
 181                         Fractal->dr_mean = .4;
 182                         Fractal->dr2_mean = .3;
 183                         break;
 184
 185                 case 5:
 186                         Fractal->Depth = MAX_DEPTH_5;
 187                         Fractal->r_mean = .5;
 188                         Fractal->dr_mean = .4;
 189                         Fractal->dr2_mean = .3;
 190                         break;
 191
 192                 default:
 193                 case 2:
 194                         Fractal->Depth = MAX_DEPTH_2;
 195                         Fractal->r_mean = .7;
 196                         Fractal->dr_mean = .3;
 197                         Fractal->dr2_mean = .4;
 198                         break;
 199         }
 200         /* (void) fprintf( stderr, "N=%d\n", i ); */
 201         Fractal->Nb_Simi = i;
 202         Fractal->Max_Pt = Fractal->Nb_Simi - 1;
 203         for (i = 0; i <= Fractal->Depth + 2; ++i)
 204                 Fractal->Max_Pt *= Fractal->Nb_Simi;
 205
 206         Fractal->Buffer1 = (XPoint *) calloc(Fractal->Max_Pt, sizeof (XPoint));
 207         if (Fractal->Buffer1 == NULL)
 208                 goto Abort;
 209         Fractal->Buffer2 = (XPoint *) calloc(Fractal->Max_Pt, sizeof (XPoint));
 210         if (Fractal->Buffer2 == NULL)
 211                 goto Abort;
 212
 213         Fractal->Speed = 6;
 214         Fractal->Width = MI_WIN_WIDTH(mi);
 215         Fractal->Height = MI_WIN_HEIGHT(mi);
 216         Fractal->Cur_Pt = 0;
 217         Fractal->Count = 0;
 218         Fractal->Lx = (Fractal->Width - 1) / 2;
 219         Fractal->Ly = (Fractal->Height - 1) / 2;
 220         Fractal->Col = NRAND(MI_NPIXELS(mi) - 1) + 1;
 221
 222         Random_Simis(Fractal, Fractal->Components, 5 * MAX_SIMI);
 223
 224         Fractal->dbuf = XCreatePixmap(MI_DISPLAY(mi), MI_WINDOW(mi),
 225                                                                   Fractal->Width, Fractal->Height, 1);
 226         if (Fractal->dbuf)
 227           {
 228                 XGCValues gcv;
 229                 gcv.foreground = 0;
 230                 gcv.background = 0;
 231                 gcv.function = GXcopy;
 232                 Fractal->dbuf_gc = XCreateGC(MI_DISPLAY(mi), Fractal->dbuf,
 233                                                                          GCForeground|GCBackground|GCFunction,
 234                                                                          &gcv);
 235                 XFillRectangle(MI_DISPLAY(mi), Fractal->dbuf,
 236                                            Fractal->dbuf_gc, 0,0, Fractal->Width, Fractal->Height);
 237
 238                 XSetBackground(MI_DISPLAY(mi), MI_GC(mi), MI_WIN_BLACK_PIXEL(mi));
 239                 XSetFunction(MI_DISPLAY(mi), MI_GC(mi), GXcopy);
 240           }
 241
 242         XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
 243         return;
 244
 245       Abort:
 246         if (Fractal->Buffer1 != NULL)
 247                 free(Fractal->Buffer1);
 248         if (Fractal->Buffer2 != NULL)
 249                 free(Fractal->Buffer2);
 250         Fractal->Buffer1 = NULL;
 251         Fractal->Buffer2 = NULL;
 252         Fractal->Max_Pt = 0;
 253         return;
 254 }
 255
 256
 257 /***************************************************************/
 258
 259 #ifndef __GNUC__
 260 # define inline /* */
 261 #endif
 262
 263 static inline void
 264 Transform(SIMI * Simi, F_PT xo, F_PT yo, F_PT * x, F_PT * y)
 265 {
 266         F_PT        xx, yy;
 267
 268         xo = xo - Simi->Cx;
 269         xo = (xo * Simi->R) / UNIT;
 270         yo = yo - Simi->Cy;
 271         yo = (yo * Simi->R) / UNIT;
 272
 273         xx = xo - Simi->Cx;
 274         xx = (xx * Simi->R2) / UNIT;
 275         yy = -yo - Simi->Cy;
 276         yy = (yy * Simi->R2) / UNIT;
 277
 278         *x = ((xo * Simi->Ct - yo * Simi->St + xx * Simi->Ct2 - yy * Simi->St2) / UNIT) + Simi->Cx;
 279         *y = ((xo * Simi->St + yo * Simi->Ct + xx * Simi->St2 + yy * Simi->Ct2) / UNIT) + Simi->Cy;
 280 }
 281
 282 /***************************************************************/
 283
 284 static void
 285 Trace(F_PT xo, F_PT yo)
 286 {
 287         F_PT        x, y, i;
 288         SIMI       *Cur;
 289
 290         Cur = Cur_F->Components;
 291         for (i = Cur_F->Nb_Simi; i; --i, Cur++) {
 292                 Transform(Cur, xo, yo, &x, &y);
 293                 Buf->x = Lx + (x * Lx / (UNIT * 2));
 294                 Buf->y = Ly - (y * Ly / (UNIT * 2));
 295                 Buf++;
 296                 Cur_Pt++;
 297
 298                 if (D && ((x - xo) >> 4) && ((y - yo) >> 4)) {
 299                         D--;
 300                         Trace(x, y);
 301                         D++;
 302                 }
 303         }
 304 }
 305
 306 static void
 307 Draw_Fractal(FRACTAL * F)
 308 {
 309         int         i, j;
 310         F_PT        x, y, xo, yo;
 311         SIMI       *Cur, *Simi;
 312
 313         for (Cur = F->Components, i = F->Nb_Simi; i; --i, Cur++) {
 314                 Cur->Cx = DBL_To_F_PT(Cur->c_x);
 315                 Cur->Cy = DBL_To_F_PT(Cur->c_y);
 316
 317                 Cur->Ct = DBL_To_F_PT(cos(Cur->A));
 318                 Cur->St = DBL_To_F_PT(sin(Cur->A));
 319                 Cur->Ct2 = DBL_To_F_PT(cos(Cur->A2));
 320                 Cur->St2 = DBL_To_F_PT(sin(Cur->A2));
 321
 322                 Cur->R = DBL_To_F_PT(Cur->r);
 323                 Cur->R2 = DBL_To_F_PT(Cur->r2);
 324         }
 325
 326
 327         Cur_Pt = 0;
 328         Cur_F = F;
 329         Buf = F->Buffer2;
 330         Lx = F->Lx;
 331         Ly = F->Ly;
 332         D = F->Depth;
 333         for (Cur = F->Components, i = F->Nb_Simi; i; --i, Cur++) {
 334                 xo = Cur->Cx;
 335                 yo = Cur->Cy;
 336                 for (Simi = F->Components, j = F->Nb_Simi; j; --j, Simi++) {
 337                         if (Simi == Cur)
 338                                 continue;
 339                         Transform(Simi, xo, yo, &x, &y);
 340                         Trace(x, y);
 341                 }
 342         }
 343
 344         /* Erase previous */
 345
 346         if (F->Cur_Pt) {
 347                 XSetForeground(display, gc, MI_WIN_BLACK_PIXEL(The_MI));
 348                 if (F->dbuf)    /* jwz */
 349                   {
 350                         XSetForeground(display, F->dbuf_gc, 0);
 351 /*                  XDrawPoints(display, F->dbuf, F->dbuf_gc, F->Buffer1, F->Cur_Pt,
 352                                             CoordModeOrigin); */
 353                     XFillRectangle(display, F->dbuf, F->dbuf_gc, 0, 0,
 354                                                    F->Width, F->Height);
 355                   }
 356                 else
 357                   XDrawPoints(display, window, gc, F->Buffer1, F->Cur_Pt,
 358                                           CoordModeOrigin);
 359         }
 360         if (Max_Colors < 2)
 361                 XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(The_MI));
 362         else
 363                 XSetForeground(display, gc, MI_PIXEL(The_MI, F->Col % Max_Colors));
 364         if (Cur_Pt) {
 365           if (F->dbuf)
 366                 {
 367                   XSetForeground(display, F->dbuf_gc, 1);
 368                   XDrawPoints(display, F->dbuf, F->dbuf_gc, F->Buffer2, Cur_Pt,
 369                                           CoordModeOrigin);
 370                 }
 371           else
 372                 XDrawPoints(display, window, gc, F->Buffer2, Cur_Pt, CoordModeOrigin);
 373         }
 374
 375         if (F->dbuf)
 376           XCopyPlane(display, F->dbuf, window, gc, 0,0,F->Width,F->Height,0,0, 1);
 377
 378         F->Cur_Pt = Cur_Pt;
 379         Buf = F->Buffer1;
 380         F->Buffer1 = F->Buffer2;
 381         F->Buffer2 = Buf;
 382 }
 383
 384
 385 void
 386 draw_ifs(ModeInfo * mi)
 387 {
 388         int         i;
 389         FRACTAL    *F;
 390         DBL         u, uu, v, vv, u0, u1, u2, u3;
 391         SIMI       *S, *S1, *S2, *S3, *S4;
 392
 393         The_MI = mi;
 394         display = MI_DISPLAY(mi);
 395         window = MI_WINDOW(mi);
 396         gc = MI_GC(mi);
 397         Max_Colors = MI_NPIXELS(mi);
 398
 399         F = &Root[MI_SCREEN(mi)];
 400
 401         u = (DBL) (F->Count) * (DBL) (F->Speed) / 1000.0;
 402         uu = u * u;
 403         v = 1.0 - u;
 404         vv = v * v;
 405         u0 = vv * v;
 406         u1 = 3.0 * vv * u;
 407         u2 = 3.0 * v * uu;
 408         u3 = u * uu;
 409
 410         S = F->Components;
 411         S1 = S + F->Nb_Simi;
 412         S2 = S1 + F->Nb_Simi;
 413         S3 = S2 + F->Nb_Simi;
 414         S4 = S3 + F->Nb_Simi;
 415
 416         for (i = F->Nb_Simi; i; --i, S++, S1++, S2++, S3++, S4++) {
 417                 S->c_x = u0 * S1->c_x + u1 * S2->c_x + u2 * S3->c_x + u3 * S4->c_x;
 418                 S->c_y = u0 * S1->c_y + u1 * S2->c_y + u2 * S3->c_y + u3 * S4->c_y;
 419                 S->r = u0 * S1->r + u1 * S2->r + u2 * S3->r + u3 * S4->r;
 420                 S->r2 = u0 * S1->r2 + u1 * S2->r2 + u2 * S3->r2 + u3 * S4->r2;
 421                 S->A = u0 * S1->A + u1 * S2->A + u2 * S3->A + u3 * S4->A;
 422                 S->A2 = u0 * S1->A2 + u1 * S2->A2 + u2 * S3->A2 + u3 * S4->A2;
 423         }
 424
 425         Draw_Fractal(F);
 426
 427         if (F->Count >= 1000 / F->Speed) {
 428                 S = F->Components;
 429                 S1 = S + F->Nb_Simi;
 430                 S2 = S1 + F->Nb_Simi;
 431                 S3 = S2 + F->Nb_Simi;
 432                 S4 = S3 + F->Nb_Simi;
 433
 434                 for (i = F->Nb_Simi; i; --i, S++, S1++, S2++, S3++, S4++) {
 435                         S2->c_x = 2.0 * S4->c_x - S3->c_x;
 436                         S2->c_y = 2.0 * S4->c_y - S3->c_y;
 437                         S2->r = 2.0 * S4->r - S3->r;
 438                         S2->r2 = 2.0 * S4->r2 - S3->r2;
 439                         S2->A = 2.0 * S4->A - S3->A;
 440                         S2->A2 = 2.0 * S4->A2 - S3->A2;
 441
 442                         *S1 = *S4;
 443                 }
 444                 Random_Simis(F, F->Components + 3 * F->Nb_Simi, F->Nb_Simi);
 445
 446                 Random_Simis(F, F->Components + 4 * F->Nb_Simi, F->Nb_Simi);
 447
 448                 F->Count = 0;
 449         } else
 450                 F->Count++;
 451
 452         F->Col++;
 453 }
 454
 455
 456 /***************************************************************/
 457
 458 void
 459 release_ifs(ModeInfo * mi)
 460 {
 461         int         i;
 462
 463         if (Root == NULL)
 464                 return;
 465
 466         for (i = 0; i < MI_NUM_SCREENS(mi); ++i) {
 467                 if (Root[i].Buffer1 != NULL)
 468                         free(Root[i].Buffer1);
 469                 if (Root[i].Buffer2 != NULL)
 470                         free(Root[i].Buffer2);
 471                 if (Root[i].dbuf)
 472                         XFreePixmap(MI_DISPLAY(mi), Root[i].dbuf);
 473                 if (Root[i].dbuf_gc)
 474                         XFreeGC(MI_DISPLAY(mi), Root[i].dbuf_gc);
 475         }
 476         free(Root);
 477         Root = NULL;
 478 }