1 /* -*- Mode: C; tab-width: 4 -*-
2 * hop --- real plane fractals.
4 #if !defined( lint ) && !defined( SABER )
5 static const char sccsid[] = "@(#)hop.c 4.02 97/04/01 xlockmore";
8 /* Copyright (c) 1988-91 by Patrick J. Naughton.
10 * Permission to use, copy, modify, and distribute this software and its
11 * documentation for any purpose and without fee is hereby granted,
12 * provided that the above copyright notice appear in all copies and that
13 * both that copyright notice and this permission notice appear in
14 * supporting documentation.
16 * This file is provided AS IS with no warranties of any kind. The author
17 * shall have no liability with respect to the infringement of copyrights,
18 * trade secrets or any patents by this file or any part thereof. In no
19 * event will the author be liable for any lost revenue or profits or
20 * other special, indirect and consequential damages.
23 * Changes of David Bagley <bagleyd@bigfoot.com>
24 * 10-May-97: jwz@jwz.org: ported from xlockmore 4.03a10 to be a
25 * standalone program and thus usable with xscreensaver
26 * (I threw away my 1992 port and started over.)
27 * 27-Jul-95: added Peter de Jong's hop from Scientific American
28 * July 87 p. 111. Sometimes they are amazing but there are a
29 * few duds (I did not see a pattern in the parameters).
30 * 29-Mar-95: changed name from hopalong to hop
31 * 09-Dec-94: added sine hop
33 * (12-Aug-92: jwz@lucid.com: made xlock version run standalone.)
35 * Changes of Patrick J. Naughton
36 * 29-Oct-90: fix bad (int) cast.
37 * 29-Jul-90: support for multiple screens.
38 * 08-Jul-90: new timing and colors and new algorithm for fractals.
39 * 15-Dec-89: Fix for proper skipping of {White,Black}Pixel() in colors.
40 * 08-Oct-89: Fixed long standing typo bug in RandomInitHop();
41 * Fixed bug in memory allocation in init_hop();
42 * Moved seconds() to an extern.
43 * Got rid of the % mod since .mod is slow on a sparc.
45 * 31-Aug-88: Forked from xlock.c for modularity.
46 * 23-Mar-88: Coded HOPALONG routines from Scientific American Sept. 86 p. 14.
50 # define PROGCLASS "Hopalong"
51 # define HACK_INIT init_hop
52 # define HACK_DRAW draw_hop
53 # define HACK_FREE release_hop
54 # define hop_opts xlockmore_opts
55 # define DEFAULTS "*count: 1000 \n" \
59 # define SMOOTH_COLORS
60 # include "xlockmore.h" /* from the xscreensaver distribution */
62 #else /* !STANDALONE */
63 # include "xlock.h" /* from the xlockmore distribution */
64 #endif /* !STANDALONE */
69 #define DEF_JONG "False"
70 #define DEF_SINE "False"
72 static XrmOptionDescRec opts[] =
74 {"-jong", ".hop.jong", XrmoptionNoArg, (caddr_t) "on"},
75 {"+jong", ".hop.jong", XrmoptionNoArg, (caddr_t) "off"},
76 {"-sine", ".hop.sine", XrmoptionNoArg, (caddr_t) "on"},
77 {"+sine", ".hop.sine", XrmoptionNoArg, (caddr_t) "off"}
79 static argtype vars[] =
81 {(caddr_t *) & jong, "jong", "Jong", DEF_JONG, t_Bool},
82 {(caddr_t *) & sine, "sine", "Sine", DEF_SINE, t_Bool}
84 static OptionStruct desc[] =
86 {"-/+jong", "turn on/off jong format"},
87 {"-/+sine", "turn on/off sine format"}
90 ModeSpecOpt hop_opts = { 4, opts, 2, vars, desc };
97 #define OPS 2 /* Sine might be too close to a Swastika for some... */
104 int centery; /* center of the screen */
110 double j; /* hopalong parameters */
118 static hopstruct *hops = NULL;
119 static XPoint *pointBuffer = 0; /* pointer for XDrawPoints */
122 init_hop(ModeInfo * mi)
124 Display *display = MI_DISPLAY(mi);
130 if ((hops = (hopstruct *) calloc(MI_NUM_SCREENS(mi),
131 sizeof (hopstruct))) == NULL)
134 hp = &hops[MI_SCREEN(mi)];
136 hp->centerx = MI_WIN_WIDTH(mi) / 2;
137 hp->centery = MI_WIN_HEIGHT(mi) / 2;
138 /* Make the other operations less common since they are less interesting */
139 if (MI_WIN_IS_FULLRANDOM(mi)) {
140 hp->op = NRAND(OPS+2); /* jwz: make the others a bit more likely. */
152 range = sqrt((double) hp->centerx * hp->centerx +
153 (double) hp->centery * hp->centery) / (10.0 + NRAND(10));
155 hp->a = (LRAND() / MAXRAND) * range - range / 2.0;
156 hp->b = (LRAND() / MAXRAND) * range - range / 2.0;
157 hp->c = (LRAND() / MAXRAND) * range - range / 2.0;
162 hp->a = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
163 hp->b = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
164 hp->c = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
165 hp->d = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
168 hp->a = M_PI + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.7;
171 if (MI_NPIXELS(mi) > 2)
172 hp->pix = NRAND(MI_NPIXELS(mi));
174 hp->inc = (int) ((LRAND() / MAXRAND) * 200) - 100;
175 hp->bufsize = MI_BATCHCOUNT(mi);
178 pointBuffer = (XPoint *) malloc(hp->bufsize * sizeof (XPoint));
180 XClearWindow(display, MI_WINDOW(mi));
182 XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
188 draw_hop(ModeInfo * mi)
190 hopstruct *hp = &hops[MI_SCREEN(mi)];
192 XPoint *xp = pointBuffer;
196 if (MI_NPIXELS(mi) > 2) {
197 XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_PIXEL(mi, hp->pix));
198 if (++hp->pix >= MI_NPIXELS(mi))
205 oldi = hp->i + hp->inc;
206 hp->j = hp->a - hp->i;
207 hp->i = oldj + ((hp->i < 0)
208 ? sqrt(fabs(hp->b * oldi - hp->c))
209 : -sqrt(fabs(hp->b * oldi - hp->c)));
210 xp->x = hp->centerx + (int) (hp->i + hp->j);
211 xp->y = hp->centery - (int) (hp->i - hp->j);
215 oldi = hp->i + 4 * hp->inc / hp->centerx;
218 hp->j = sin(hp->c * hp->i) - cos(hp->d * hp->j);
219 hp->i = sin(hp->a * oldj) - cos(hp->b * oldi);
220 xp->x = hp->centerx + (int) (hp->centerx * (hp->i + hp->j) / 4.0);
221 xp->y = hp->centery - (int) (hp->centery * (hp->i - hp->j) / 4.0);
224 oldi = hp->i + hp->inc;
225 hp->j = hp->a - hp->i;
226 hp->i = oldj - sin(oldi);
227 xp->x = hp->centerx + (int) (hp->i + hp->j);
228 xp->y = hp->centery - (int) (hp->i - hp->j);
233 XDrawPoints(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi),
234 pointBuffer, hp->bufsize, CoordModeOrigin);
235 if (++hp->count > MI_CYCLES(mi)) {
237 erase_full_window(MI_DISPLAY(mi), MI_WINDOW(mi));
238 #endif /* STANDALONE */
244 release_hop(ModeInfo * mi)
247 (void) free((void *) hops);
251 (void) free((void *) pointBuffer);
257 refresh_hop(ModeInfo * mi)
259 XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));