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@netscape.com: 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 */
61 #else /* !STANDALONE */
62 # include "xlock.h" /* from the xlockmore distribution */
63 #endif /* !STANDALONE */
68 #define DEF_JONG "False"
69 #define DEF_SINE "False"
71 static XrmOptionDescRec opts[] =
73 {"-jong", ".hop.jong", XrmoptionNoArg, (caddr_t) "on"},
74 {"+jong", ".hop.jong", XrmoptionNoArg, (caddr_t) "off"},
75 {"-sine", ".hop.sine", XrmoptionNoArg, (caddr_t) "on"},
76 {"+sine", ".hop.sine", XrmoptionNoArg, (caddr_t) "off"}
78 static argtype vars[] =
80 {(caddr_t *) & jong, "jong", "Jong", DEF_JONG, t_Bool},
81 {(caddr_t *) & sine, "sine", "Sine", DEF_SINE, t_Bool}
83 static OptionStruct desc[] =
85 {"-/+jong", "turn on/off jong format"},
86 {"-/+sine", "turn on/off sine format"}
89 ModeSpecOpt hop_opts = { 4, opts, 2, vars, desc };
96 #define OPS 2 /* Sine might be too close to a Swastika for some... */
103 int centery; /* center of the screen */
109 double j; /* hopalong parameters */
117 static hopstruct *hops = NULL;
118 static XPoint *pointBuffer = 0; /* pointer for XDrawPoints */
121 init_hop(ModeInfo * mi)
123 Display *display = MI_DISPLAY(mi);
129 if ((hops = (hopstruct *) calloc(MI_NUM_SCREENS(mi),
130 sizeof (hopstruct))) == NULL)
133 hp = &hops[MI_SCREEN(mi)];
135 hp->centerx = MI_WIN_WIDTH(mi) / 2;
136 hp->centery = MI_WIN_HEIGHT(mi) / 2;
137 /* Make the other operations less common since they are less interesting */
138 if (MI_WIN_IS_FULLRANDOM(mi)) {
139 hp->op = NRAND(OPS+2); /* jwz: make the others a bit more likely. */
151 range = sqrt((double) hp->centerx * hp->centerx +
152 (double) hp->centery * hp->centery) / (10.0 + NRAND(10));
154 hp->a = (LRAND() / MAXRAND) * range - range / 2.0;
155 hp->b = (LRAND() / MAXRAND) * range - range / 2.0;
156 hp->c = (LRAND() / MAXRAND) * range - range / 2.0;
161 hp->a = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
162 hp->b = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
163 hp->c = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
164 hp->d = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
167 hp->a = M_PI + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.7;
170 if (MI_NPIXELS(mi) > 2)
171 hp->pix = NRAND(MI_NPIXELS(mi));
173 hp->inc = (int) ((LRAND() / MAXRAND) * 200) - 100;
174 hp->bufsize = MI_BATCHCOUNT(mi);
177 pointBuffer = (XPoint *) malloc(hp->bufsize * sizeof (XPoint));
179 XClearWindow(display, MI_WINDOW(mi));
181 XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
187 draw_hop(ModeInfo * mi)
189 hopstruct *hp = &hops[MI_SCREEN(mi)];
191 XPoint *xp = pointBuffer;
195 if (MI_NPIXELS(mi) > 2) {
196 XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_PIXEL(mi, hp->pix));
197 if (++hp->pix >= MI_NPIXELS(mi))
204 oldi = hp->i + hp->inc;
205 hp->j = hp->a - hp->i;
206 hp->i = oldj + ((hp->i < 0)
207 ? sqrt(fabs(hp->b * oldi - hp->c))
208 : -sqrt(fabs(hp->b * oldi - hp->c)));
209 xp->x = hp->centerx + (int) (hp->i + hp->j);
210 xp->y = hp->centery - (int) (hp->i - hp->j);
214 oldi = hp->i + 4 * hp->inc / hp->centerx;
217 hp->j = sin(hp->c * hp->i) - cos(hp->d * hp->j);
218 hp->i = sin(hp->a * oldj) - cos(hp->b * oldi);
219 xp->x = hp->centerx + (int) (hp->centerx * (hp->i + hp->j) / 4.0);
220 xp->y = hp->centery - (int) (hp->centery * (hp->i - hp->j) / 4.0);
223 oldi = hp->i + hp->inc;
224 hp->j = hp->a - hp->i;
225 hp->i = oldj - sin(oldi);
226 xp->x = hp->centerx + (int) (hp->i + hp->j);
227 xp->y = hp->centery - (int) (hp->i - hp->j);
232 XDrawPoints(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi),
233 pointBuffer, hp->bufsize, CoordModeOrigin);
234 if (++hp->count > MI_CYCLES(mi))
239 release_hop(ModeInfo * mi)
242 (void) free((void *) hops);
246 (void) free((void *) pointBuffer);
252 refresh_hop(ModeInfo * mi)
254 XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));