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

   1 /* -*- Mode: C; tab-width: 4 -*- */
   2 /* thornbird --- continuously varying Thornbird set */
   3
   4 #if 0
   5 static const char sccsid[] = "@(#)thornbird.c   5.00 2000/11/01 xlockmore";
   6 #endif
   7
   8 /*-
   9  * Copyright (c) 1996 by Tim Auckland <tda10.geo@yahoo.com>
  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  * "thornbird" shows a view of the "Bird in a Thornbush" fractal,
  24  * continuously varying the three free parameters.
  25  *
  26  * Revision History:
  27  * 01-Nov-2000: Allocation checks
  28  * 04-Jun-1999: 3D tumble added by Tim Auckland
  29  * 31-Jul-1997: Adapted from discrete.c Copyright (c) 1996 by Tim Auckland
  30  */
  31
  32 #ifdef STANDALONE
  33 # define MODE_thornbird
  34 #define DEFAULTS        "*delay:    10000 \n" \
  35                                         "*count:    100   \n" \
  36                                          "*cycles:  400   \n" \
  37                                          "*ncolors: 64    \n" \
  38                                          "*fpsSolid: true    \n" \
  39
  40 # define BRIGHT_COLORS
  41 # define thornbird_handle_event 0
  42 # include "xlockmore.h"         /* in xscreensaver distribution */
  43 #else /* STANDALONE */
  44 # include "xlock.h"             /* in xlockmore distribution */
  45 #endif /* STANDALONE */
  46
  47 #ifdef MODE_thornbird
  48
  49 ENTRYPOINT ModeSpecOpt thornbird_opts =
  50 {0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
  51
  52 #ifdef USE_MODULES
  53 ModStruct   thornbird_description =
  54 {"thornbird", "init_thornbird", "draw_thornbird", "release_thornbird",
  55  "refresh_thornbird", "init_thornbird", (char *) NULL, &thornbird_opts,
  56  1000, 800, 16, 1, 64, 1.0, "",
  57  "Shows an animated Bird in a Thorn Bush fractal map", 0, NULL};
  58
  59 #endif
  60
  61 #define balance_rand(v) ((LRAND()/MAXRAND*(v))-((v)/2)) /* random around 0 */
  62
  63 typedef struct {
  64         int         maxx;
  65         int         maxy;       /* max of the screen */
  66         double      a;
  67         double      b;
  68         double      c;
  69         double      d;
  70         double      e;
  71         double      i;
  72         double      j;          /* thornbird parameters */
  73     struct {
  74           double  f1;
  75           double  f2;
  76         }           liss;
  77     struct {
  78           double  theta;
  79           double  dtheta;
  80           double  phi;
  81           double  dphi;
  82         }           tumble;
  83     int         inc;
  84         int         pix;
  85         int         count;
  86         int         nbuffers;
  87         XPoint    **pointBuffer;        /* pointer for XDrawPoints */
  88 } thornbirdstruct;
  89
  90 static thornbirdstruct *thornbirds = (thornbirdstruct *) NULL;
  91
  92 static void
  93 free_thornbird(thornbirdstruct *hp)
  94 {
  95         if (hp->pointBuffer != NULL) {
  96                 int         buffer;
  97
  98                 for (buffer = 0; buffer < hp->nbuffers; buffer++)
  99                         if (hp->pointBuffer[buffer] != NULL)
 100                                 (void) free((void *) hp->pointBuffer[buffer]);
 101                 (void) free((void *) hp->pointBuffer);
 102                 hp->pointBuffer = (XPoint **) NULL;
 103         }
 104 }
 105
 106 ENTRYPOINT void
 107 init_thornbird (ModeInfo * mi)
 108 {
 109         thornbirdstruct *hp;
 110
 111         if (thornbirds == NULL) {
 112                 if ((thornbirds =
 113                      (thornbirdstruct *) calloc(MI_NUM_SCREENS(mi),
 114                                           sizeof (thornbirdstruct))) == NULL)
 115                         return;
 116         }
 117         hp = &thornbirds[MI_SCREEN(mi)];
 118
 119
 120         hp->maxx = MI_WIDTH(mi);
 121         hp->maxy = MI_HEIGHT(mi);
 122
 123         hp->b = 0.1;
 124         hp->i = hp->j = 0.1;
 125
 126         hp->pix = 0;
 127         hp->inc = 0;
 128
 129         hp->nbuffers = MI_CYCLES(mi);
 130
 131         if (hp->pointBuffer == NULL)
 132                 if ((hp->pointBuffer = (XPoint **) calloc(MI_CYCLES(mi),
 133                                 sizeof (XPoint *))) == NULL) {
 134                         free_thornbird(hp);
 135                         return;
 136                 }
 137
 138         if (hp->pointBuffer[0] == NULL)
 139                 if ((hp->pointBuffer[0] = (XPoint *) malloc(MI_COUNT(mi) *
 140                                 sizeof (XPoint))) == NULL) {
 141                         free_thornbird(hp);
 142                         return;
 143                 }
 144
 145         /* select frequencies for parameter variation */
 146         hp->liss.f1 = LRAND() % 5000;
 147         hp->liss.f2 = LRAND() % 2000;
 148
 149         /* choose random 3D tumbling */
 150         hp->tumble.theta = 0;
 151         hp->tumble.phi = 0;
 152         hp->tumble.dtheta = balance_rand(0.001);
 153         hp->tumble.dphi = balance_rand(0.005);
 154
 155         /* Clear the background. */
 156         MI_CLEARWINDOW(mi);
 157
 158         hp->count = 0;
 159 }
 160
 161
 162 ENTRYPOINT void
 163 draw_thornbird(ModeInfo * mi)
 164 {
 165         Display    *dsp = MI_DISPLAY(mi);
 166         Window      win = MI_WINDOW(mi);
 167         double      oldj, oldi;
 168         int         batchcount = MI_COUNT(mi);
 169         int         k;
 170         XPoint     *xp;
 171         GC          gc = MI_GC(mi);
 172         int         erase;
 173         int         current;
 174
 175         double      sint, cost, sinp, cosp;
 176         thornbirdstruct *hp;
 177
 178         if (thornbirds == NULL)
 179                 return;
 180         hp = &thornbirds[MI_SCREEN(mi)];
 181         if (hp->pointBuffer == NULL)
 182                 return;
 183
 184         erase = (hp->inc + 1) % MI_CYCLES(mi);
 185         current = hp->inc % MI_CYCLES(mi);
 186         k = batchcount;
 187
 188
 189         xp = hp->pointBuffer[current];
 190
 191         /* vary papameters */
 192         hp->a = 1.99 + (0.4 * sin(hp->inc / hp->liss.f1) +
 193                                         0.05 * cos(hp->inc / hp->liss.f2));
 194         hp->c = 0.80 + (0.15 * cos(hp->inc / hp->liss.f1) +
 195                                         0.05 * sin(hp->inc / hp->liss.f2));
 196
 197         /* vary view */
 198         hp->tumble.theta += hp->tumble.dtheta;
 199         hp->tumble.phi += hp->tumble.dphi;
 200         sint = sin(hp->tumble.theta);
 201         cost = cos(hp->tumble.theta);
 202         sinp = sin(hp->tumble.phi);
 203         cosp = cos(hp->tumble.phi);
 204
 205         while (k--) {
 206                 oldj = hp->j;
 207                 oldi = hp->i;
 208
 209                 hp->j = oldi;
 210                 hp->i = (1 - hp->c) * cos(M_PI * hp->a * oldj) + hp->c * hp->b;
 211                 hp->b = oldj;
 212
 213                 xp->x = (short)
 214                   (hp->maxx / 2 * (1
 215                                                    + sint*hp->j + cost*cosp*hp->i - cost*sinp*hp->b));
 216                 xp->y = (short)
 217                   (hp->maxy / 2 * (1
 218                                                    - cost*hp->j + sint*cosp*hp->i - sint*sinp*hp->b));
 219                 xp++;
 220         }
 221
 222         MI_IS_DRAWN(mi) = True;
 223
 224         if (hp->pointBuffer[erase] == NULL) {
 225                 if ((hp->pointBuffer[erase] = (XPoint *) malloc(MI_COUNT(mi) *
 226                                 sizeof (XPoint))) == NULL) {
 227                         free_thornbird(hp);
 228                         return;
 229                 }
 230         } else {
 231                 XSetForeground(dsp, gc, MI_BLACK_PIXEL(mi));
 232                 XDrawPoints(dsp, win, gc, hp->pointBuffer[erase],
 233                             batchcount, CoordModeOrigin);
 234         }
 235         if (MI_NPIXELS(mi) > 2) {
 236                 XSetForeground(dsp, gc, MI_PIXEL(mi, hp->pix));
 237 #if 0
 238                 if (erase == 0) /* change colours after "cycles" cycles */
 239 #else
 240         if (!((hp->inc + 1) % (1 + (MI_CYCLES(mi) / 3)))) /* jwz: sooner */
 241 #endif
 242                         if (++hp->pix >= MI_NPIXELS(mi))
 243                                 hp->pix = 0;
 244         } else
 245                 XSetForeground(dsp, gc, MI_WHITE_PIXEL(mi));
 246
 247         XDrawPoints(dsp, win, gc, hp->pointBuffer[current],
 248                     batchcount, CoordModeOrigin);
 249         hp->inc++;
 250 }
 251
 252 ENTRYPOINT void
 253 reshape_thornbird(ModeInfo * mi, int width, int height)
 254 {
 255   XClearWindow (MI_DISPLAY (mi), MI_WINDOW(mi));
 256   init_thornbird (mi);
 257 }
 258
 259 ENTRYPOINT void
 260 release_thornbird(ModeInfo * mi)
 261 {
 262         if (thornbirds != NULL) {
 263                 int         screen;
 264
 265                 for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
 266                         free_thornbird(&thornbirds[screen]);
 267                 (void) free((void *) thornbirds);
 268                 thornbirds = (thornbirdstruct *) NULL;
 269         }
 270 }
 271
 272 ENTRYPOINT void
 273 refresh_thornbird (ModeInfo * mi)
 274 {
 275         MI_CLEARWINDOW(mi);
 276 }
 277
 278
 279 XSCREENSAVER_MODULE ("Thornbird", thornbird)
 280
 281 #endif /* MODE_thornbird */