git.maemo.org Git - xscreensaver/blob - xscreensaver/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 # define BRIGHT_COLORS
  39 # define reshape_thornbird 0
  40 # define thornbird_handle_event 0
  41 # include "xlockmore.h"         /* in xscreensaver distribution */
  42 #else /* STANDALONE */
  43 # include "xlock.h"             /* in xlockmore distribution */
  44 #endif /* STANDALONE */
  45
  46 #ifdef MODE_thornbird
  47
  48 ENTRYPOINT ModeSpecOpt thornbird_opts =
  49 {0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
  50
  51 #ifdef USE_MODULES
  52 ModStruct   thornbird_description =
  53 {"thornbird", "init_thornbird", "draw_thornbird", "release_thornbird",
  54  "refresh_thornbird", "init_thornbird", (char *) NULL, &thornbird_opts,
  55  1000, 800, 16, 1, 64, 1.0, "",
  56  "Shows an animated Bird in a Thorn Bush fractal map", 0, NULL};
  57
  58 #endif
  59
  60 #define balance_rand(v) ((LRAND()/MAXRAND*(v))-((v)/2)) /* random around 0 */
  61
  62 typedef struct {
  63         int         maxx;
  64         int         maxy;       /* max of the screen */
  65         double      a;
  66         double      b;
  67         double      c;
  68         double      d;
  69         double      e;
  70         double      i;
  71         double      j;          /* thornbird parameters */
  72     struct {
  73           double  f1;
  74           double  f2;
  75         }           liss;
  76     struct {
  77           double  theta;
  78           double  dtheta;
  79           double  phi;
  80           double  dphi;
  81         }           tumble;
  82     int         inc;
  83         int         pix;
  84         int         count;
  85         int         nbuffers;
  86         XPoint    **pointBuffer;        /* pointer for XDrawPoints */
  87 } thornbirdstruct;
  88
  89 static thornbirdstruct *thornbirds = (thornbirdstruct *) NULL;
  90
  91 static void
  92 free_thornbird(thornbirdstruct *hp)
  93 {
  94         if (hp->pointBuffer != NULL) {
  95                 int         buffer;
  96
  97                 for (buffer = 0; buffer < hp->nbuffers; buffer++)
  98                         if (hp->pointBuffer[buffer] != NULL)
  99                                 (void) free((void *) hp->pointBuffer[buffer]);
 100                 (void) free((void *) hp->pointBuffer);
 101                 hp->pointBuffer = (XPoint **) NULL;
 102         }
 103 }
 104
 105 ENTRYPOINT void
 106 init_thornbird (ModeInfo * mi)
 107 {
 108         thornbirdstruct *hp;
 109
 110         if (thornbirds == NULL) {
 111                 if ((thornbirds =
 112                      (thornbirdstruct *) calloc(MI_NUM_SCREENS(mi),
 113                                           sizeof (thornbirdstruct))) == NULL)
 114                         return;
 115         }
 116         hp = &thornbirds[MI_SCREEN(mi)];
 117
 118
 119         hp->maxx = MI_WIDTH(mi);
 120         hp->maxy = MI_HEIGHT(mi);
 121
 122         hp->b = 0.1;
 123         hp->i = hp->j = 0.1;
 124
 125         hp->pix = 0;
 126         hp->inc = 0;
 127
 128         hp->nbuffers = MI_CYCLES(mi);
 129
 130         if (hp->pointBuffer == NULL)
 131                 if ((hp->pointBuffer = (XPoint **) calloc(MI_CYCLES(mi),
 132                                 sizeof (XPoint *))) == NULL) {
 133                         free_thornbird(hp);
 134                         return;
 135                 }
 136
 137         if (hp->pointBuffer[0] == NULL)
 138                 if ((hp->pointBuffer[0] = (XPoint *) malloc(MI_COUNT(mi) *
 139                                 sizeof (XPoint))) == NULL) {
 140                         free_thornbird(hp);
 141                         return;
 142                 }
 143
 144         /* select frequencies for parameter variation */
 145         hp->liss.f1 = LRAND() % 5000;
 146         hp->liss.f2 = LRAND() % 2000;
 147
 148         /* choose random 3D tumbling */
 149         hp->tumble.theta = 0;
 150         hp->tumble.phi = 0;
 151         hp->tumble.dtheta = balance_rand(0.001);
 152         hp->tumble.dphi = balance_rand(0.005);
 153
 154         /* Clear the background. */
 155         MI_CLEARWINDOW(mi);
 156
 157         hp->count = 0;
 158 }
 159
 160
 161 ENTRYPOINT void
 162 draw_thornbird(ModeInfo * mi)
 163 {
 164         Display    *dsp = MI_DISPLAY(mi);
 165         Window      win = MI_WINDOW(mi);
 166         double      oldj, oldi;
 167         int         batchcount = MI_COUNT(mi);
 168         int         k;
 169         XPoint     *xp;
 170         GC          gc = MI_GC(mi);
 171         int         erase;
 172         int         current;
 173
 174         double      sint, cost, sinp, cosp;
 175         thornbirdstruct *hp;
 176
 177         if (thornbirds == NULL)
 178                 return;
 179         hp = &thornbirds[MI_SCREEN(mi)];
 180         if (hp->pointBuffer == NULL)
 181                 return;
 182
 183         erase = (hp->inc + 1) % MI_CYCLES(mi);
 184         current = hp->inc % MI_CYCLES(mi);
 185         k = batchcount;
 186
 187
 188         xp = hp->pointBuffer[current];
 189
 190         /* vary papameters */
 191         hp->a = 1.99 + (0.4 * sin(hp->inc / hp->liss.f1) +
 192                                         0.05 * cos(hp->inc / hp->liss.f2));
 193         hp->c = 0.80 + (0.15 * cos(hp->inc / hp->liss.f1) +
 194                                         0.05 * sin(hp->inc / hp->liss.f2));
 195
 196         /* vary view */
 197         hp->tumble.theta += hp->tumble.dtheta;
 198         hp->tumble.phi += hp->tumble.dphi;
 199         sint = sin(hp->tumble.theta);
 200         cost = cos(hp->tumble.theta);
 201         sinp = sin(hp->tumble.phi);
 202         cosp = cos(hp->tumble.phi);
 203
 204         while (k--) {
 205                 oldj = hp->j;
 206                 oldi = hp->i;
 207
 208                 hp->j = oldi;
 209                 hp->i = (1 - hp->c) * cos(M_PI * hp->a * oldj) + hp->c * hp->b;
 210                 hp->b = oldj;
 211
 212                 xp->x = (short)
 213                   (hp->maxx / 2 * (1
 214                                                    + sint*hp->j + cost*cosp*hp->i - cost*sinp*hp->b));
 215                 xp->y = (short)
 216                   (hp->maxy / 2 * (1
 217                                                    - cost*hp->j + sint*cosp*hp->i - sint*sinp*hp->b));
 218                 xp++;
 219         }
 220
 221         MI_IS_DRAWN(mi) = True;
 222
 223         if (hp->pointBuffer[erase] == NULL) {
 224                 if ((hp->pointBuffer[erase] = (XPoint *) malloc(MI_COUNT(mi) *
 225                                 sizeof (XPoint))) == NULL) {
 226                         free_thornbird(hp);
 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
 252 ENTRYPOINT void
 253 release_thornbird(ModeInfo * mi)
 254 {
 255         if (thornbirds != NULL) {
 256                 int         screen;
 257
 258                 for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
 259                         free_thornbird(&thornbirds[screen]);
 260                 (void) free((void *) thornbirds);
 261                 thornbirds = (thornbirdstruct *) NULL;
 262         }
 263 }
 264
 265 ENTRYPOINT void
 266 refresh_thornbird (ModeInfo * mi)
 267 {
 268         MI_CLEARWINDOW(mi);
 269 }
 270
 271
 272 XSCREENSAVER_MODULE ("Thornbird", thornbird)
 273
 274 #endif /* MODE_thornbird */