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                                     "*lowrez: True \n" \
  41
  42 # define BRIGHT_COLORS
  43 # define release_thornbird 0
  44 # define reshape_thornbird 0
  45 # define thornbird_handle_event 0
  46 # include "xlockmore.h"         /* in xscreensaver distribution */
  47 #else /* STANDALONE */
  48 # include "xlock.h"             /* in xlockmore distribution */
  49 #endif /* STANDALONE */
  50
  51 #ifdef MODE_thornbird
  52
  53 ENTRYPOINT ModeSpecOpt thornbird_opts =
  54 {0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
  55
  56 #ifdef USE_MODULES
  57 ModStruct   thornbird_description =
  58 {"thornbird", "init_thornbird", "draw_thornbird", (char *) NULL,
  59  "refresh_thornbird", "init_thornbird", "free_thornbird", &thornbird_opts,
  60  1000, 800, 16, 1, 64, 1.0, "",
  61  "Shows an animated Bird in a Thorn Bush fractal map", 0, NULL};
  62
  63 #endif
  64
  65 #define balance_rand(v) ((LRAND()/MAXRAND*(v))-((v)/2)) /* random around 0 */
  66
  67 typedef struct {
  68         int         maxx;
  69         int         maxy;       /* max of the screen */
  70         double      a;
  71         double      b;
  72         double      c;
  73         double      d;
  74         double      e;
  75         double      i;
  76         double      j;          /* thornbird parameters */
  77     struct {
  78           double  f1;
  79           double  f2;
  80         }           liss;
  81     struct {
  82           double  theta;
  83           double  dtheta;
  84           double  phi;
  85           double  dphi;
  86         }           tumble;
  87     int         inc;
  88         int         pix;
  89         int         count;
  90         int         nbuffers;
  91         XPoint    **pointBuffer;        /* pointer for XDrawPoints */
  92 } thornbirdstruct;
  93
  94 static thornbirdstruct *thornbirds = (thornbirdstruct *) NULL;
  95
  96 ENTRYPOINT void
  97 free_thornbird(ModeInfo * mi)
  98 {
  99         thornbirdstruct *hp = &thornbirds[MI_SCREEN(mi)];
 100         if (hp->pointBuffer != NULL) {
 101                 int         buffer;
 102
 103                 for (buffer = 0; buffer < hp->nbuffers; buffer++)
 104                         if (hp->pointBuffer[buffer] != NULL)
 105                                 (void) free((void *) hp->pointBuffer[buffer]);
 106                 (void) free((void *) hp->pointBuffer);
 107                 hp->pointBuffer = (XPoint **) NULL;
 108         }
 109 }
 110
 111 ENTRYPOINT void
 112 init_thornbird (ModeInfo * mi)
 113 {
 114         thornbirdstruct *hp;
 115
 116         MI_INIT (mi, thornbirds);
 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(mi);
 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(mi);
 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 (MI_COUNT(mi) < 1) MI_COUNT(mi) = 1;
 225         if (hp->pointBuffer[erase] == NULL) {
 226                 if ((hp->pointBuffer[erase] = (XPoint *) malloc(MI_COUNT(mi) *
 227                                 sizeof (XPoint))) == NULL) {
 228                         free_thornbird(mi);
 229                         return;
 230                 }
 231         } else {
 232                 XSetForeground(dsp, gc, MI_BLACK_PIXEL(mi));
 233                 XDrawPoints(dsp, win, gc, hp->pointBuffer[erase],
 234                             batchcount, CoordModeOrigin);
 235         }
 236         if (MI_NPIXELS(mi) > 2) {
 237                 XSetForeground(dsp, gc, MI_PIXEL(mi, hp->pix));
 238 #if 0
 239                 if (erase == 0) /* change colours after "cycles" cycles */
 240 #else
 241         if (!((hp->inc + 1) % (1 + (MI_CYCLES(mi) / 3)))) /* jwz: sooner */
 242 #endif
 243                         if (++hp->pix >= MI_NPIXELS(mi))
 244                                 hp->pix = 0;
 245         } else
 246                 XSetForeground(dsp, gc, MI_WHITE_PIXEL(mi));
 247
 248         XDrawPoints(dsp, win, gc, hp->pointBuffer[current],
 249                     batchcount, CoordModeOrigin);
 250         hp->inc++;
 251 }
 252
 253 #ifndef STANDALONE
 254 ENTRYPOINT void
 255 refresh_thornbird (ModeInfo * mi)
 256 {
 257         MI_CLEARWINDOW(mi);
 258 }
 259 #endif
 260
 261
 262 XSCREENSAVER_MODULE ("Thornbird", thornbird)
 263
 264 #endif /* MODE_thornbird */