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