--- /dev/null
+/* -*- Mode: C; tab-width: 4 -*-
+ * hop --- real plane fractals.
+ */
+#if !defined( lint ) && !defined( SABER )
+static const char sccsid[] = "@(#)hop.c 4.02 97/04/01 xlockmore";
+#endif
+
+/* Copyright (c) 1988-91 by Patrick J. Naughton.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose and without fee is hereby granted,
+ * provided that the above copyright notice appear in all copies and that
+ * both that copyright notice and this permission notice appear in
+ * supporting documentation.
+ *
+ * This file is provided AS IS with no warranties of any kind. The author
+ * shall have no liability with respect to the infringement of copyrights,
+ * trade secrets or any patents by this file or any part thereof. In no
+ * event will the author be liable for any lost revenue or profits or
+ * other special, indirect and consequential damages.
+ *
+ * Revision History:
+ * Changes of David Bagley <bagleyd@bigfoot.com>
+ * 10-May-97: jwz@netscape.com: ported from xlockmore 4.03a10 to be a
+ * standalone program and thus usable with xscreensaver
+ * (I threw away my 1992 port and started over.)
+ * 27-Jul-95: added Peter de Jong's hop from Scientific American
+ * July 87 p. 111. Sometimes they are amazing but there are a
+ * few duds (I did not see a pattern in the parameters).
+ * 29-Mar-95: changed name from hopalong to hop
+ * 09-Dec-94: added sine hop
+ *
+ * (12-Aug-92: jwz@lucid.com: made xlock version run standalone.)
+ *
+ * Changes of Patrick J. Naughton
+ * 29-Oct-90: fix bad (int) cast.
+ * 29-Jul-90: support for multiple screens.
+ * 08-Jul-90: new timing and colors and new algorithm for fractals.
+ * 15-Dec-89: Fix for proper skipping of {White,Black}Pixel() in colors.
+ * 08-Oct-89: Fixed long standing typo bug in RandomInitHop();
+ * Fixed bug in memory allocation in init_hop();
+ * Moved seconds() to an extern.
+ * Got rid of the % mod since .mod is slow on a sparc.
+ * 20-Sep-89: Lint.
+ * 31-Aug-88: Forked from xlock.c for modularity.
+ * 23-Mar-88: Coded HOPALONG routines from Scientific American Sept. 86 p. 14.
+ */
+
+#ifdef STANDALONE
+# define PROGCLASS "Hopalong"
+# define HACK_INIT init_hop
+# define HACK_DRAW draw_hop
+# define HACK_FREE release_hop
+# define hop_opts xlockmore_opts
+# define DEFAULTS "*count: 1000 \n" \
+ "*cycles: 2500 \n" \
+ "*delay: 10000 \n" \
+ "*ncolors: 200 \n"
+# define SMOOTH_COLORS
+# include "xlockmore.h" /* from the xscreensaver distribution */
+#else /* !STANDALONE */
+# include "xlock.h" /* from the xlockmore distribution */
+#endif /* !STANDALONE */
+
+static Bool jong;
+static Bool sine;
+
+#define DEF_JONG "False"
+#define DEF_SINE "False"
+
+static XrmOptionDescRec opts[] =
+{
+ {"-jong", ".hop.jong", XrmoptionNoArg, (caddr_t) "on"},
+ {"+jong", ".hop.jong", XrmoptionNoArg, (caddr_t) "off"},
+ {"-sine", ".hop.sine", XrmoptionNoArg, (caddr_t) "on"},
+ {"+sine", ".hop.sine", XrmoptionNoArg, (caddr_t) "off"}
+};
+static argtype vars[] =
+{
+ {(caddr_t *) & jong, "jong", "Jong", DEF_JONG, t_Bool},
+ {(caddr_t *) & sine, "sine", "Sine", DEF_SINE, t_Bool}
+};
+static OptionStruct desc[] =
+{
+ {"-/+jong", "turn on/off jong format"},
+ {"-/+sine", "turn on/off sine format"}
+};
+
+ModeSpecOpt hop_opts = { 4, opts, 2, vars, desc };
+
+
+#define SQRT 0
+#define JONG 1
+#define SINE 2
+#ifdef OFFENDING
+#define OPS 2 /* Sine might be too close to a Swastika for some... */
+#else
+#define OPS 3
+#endif
+
+typedef struct {
+ int centerx;
+ int centery; /* center of the screen */
+ double a;
+ double b;
+ double c;
+ double d;
+ double i;
+ double j; /* hopalong parameters */
+ int inc;
+ int pix;
+ int op;
+ int count;
+ int bufsize;
+} hopstruct;
+
+static hopstruct *hops = NULL;
+static XPoint *pointBuffer = 0; /* pointer for XDrawPoints */
+
+void
+init_hop(ModeInfo * mi)
+{
+ Display *display = MI_DISPLAY(mi);
+ GC gc = MI_GC(mi);
+ hopstruct *hp;
+ double range;
+
+ if (hops == NULL) {
+ if ((hops = (hopstruct *) calloc(MI_NUM_SCREENS(mi),
+ sizeof (hopstruct))) == NULL)
+ return;
+ }
+ hp = &hops[MI_SCREEN(mi)];
+
+ hp->centerx = MI_WIN_WIDTH(mi) / 2;
+ hp->centery = MI_WIN_HEIGHT(mi) / 2;
+ /* Make the other operations less common since they are less interesting */
+ if (MI_WIN_IS_FULLRANDOM(mi)) {
+ hp->op = NRAND(OPS+2); /* jwz: make the others a bit more likely. */
+ if (hp->op >= OPS)
+ hp->op = SQRT;
+ } else {
+ hp->op = SQRT;
+ if (jong)
+ hp->op = JONG;
+ else if (sine)
+ hp->op = SINE;
+ }
+ switch (hp->op) {
+ case SQRT:
+ range = sqrt((double) hp->centerx * hp->centerx +
+ (double) hp->centery * hp->centery) / (10.0 + NRAND(10));
+
+ hp->a = (LRAND() / MAXRAND) * range - range / 2.0;
+ hp->b = (LRAND() / MAXRAND) * range - range / 2.0;
+ hp->c = (LRAND() / MAXRAND) * range - range / 2.0;
+ if (LRAND() & 1)
+ hp->c = 0.0;
+ break;
+ case JONG:
+ hp->a = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
+ hp->b = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
+ hp->c = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
+ hp->d = (LRAND() / MAXRAND) * 2.0 * M_PI - M_PI;
+ break;
+ case SINE:
+ hp->a = M_PI + ((LRAND() / MAXRAND) * 2.0 - 1.0) * 0.7;
+ break;
+ }
+ if (MI_NPIXELS(mi) > 2)
+ hp->pix = NRAND(MI_NPIXELS(mi));
+ hp->i = hp->j = 0.0;
+ hp->inc = (int) ((LRAND() / MAXRAND) * 200) - 100;
+ hp->bufsize = MI_BATCHCOUNT(mi);
+
+ if (!pointBuffer)
+ pointBuffer = (XPoint *) malloc(hp->bufsize * sizeof (XPoint));
+
+ XClearWindow(display, MI_WINDOW(mi));
+
+ XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
+ hp->count = 0;
+}
+
+
+void
+draw_hop(ModeInfo * mi)
+{
+ hopstruct *hp = &hops[MI_SCREEN(mi)];
+ double oldj, oldi;
+ XPoint *xp = pointBuffer;
+ int k = hp->bufsize;
+
+ hp->inc++;
+ if (MI_NPIXELS(mi) > 2) {
+ XSetForeground(MI_DISPLAY(mi), MI_GC(mi), MI_PIXEL(mi, hp->pix));
+ if (++hp->pix >= MI_NPIXELS(mi))
+ hp->pix = 0;
+ }
+ while (k--) {
+ oldj = hp->j;
+ switch (hp->op) {
+ case SQRT:
+ oldi = hp->i + hp->inc;
+ hp->j = hp->a - hp->i;
+ hp->i = oldj + ((hp->i < 0)
+ ? sqrt(fabs(hp->b * oldi - hp->c))
+ : -sqrt(fabs(hp->b * oldi - hp->c)));
+ xp->x = hp->centerx + (int) (hp->i + hp->j);
+ xp->y = hp->centery - (int) (hp->i - hp->j);
+ break;
+ case JONG:
+ if (hp->centerx > 0)
+ oldi = hp->i + 4 * hp->inc / hp->centerx;
+ else
+ oldi = hp->i;
+ hp->j = sin(hp->c * hp->i) - cos(hp->d * hp->j);
+ hp->i = sin(hp->a * oldj) - cos(hp->b * oldi);
+ xp->x = hp->centerx + (int) (hp->centerx * (hp->i + hp->j) / 4.0);
+ xp->y = hp->centery - (int) (hp->centery * (hp->i - hp->j) / 4.0);
+ break;
+ case SINE:
+ oldi = hp->i + hp->inc;
+ hp->j = hp->a - hp->i;
+ hp->i = oldj - sin(oldi);
+ xp->x = hp->centerx + (int) (hp->i + hp->j);
+ xp->y = hp->centery - (int) (hp->i - hp->j);
+ break;
+ }
+ xp++;
+ }
+ XDrawPoints(MI_DISPLAY(mi), MI_WINDOW(mi), MI_GC(mi),
+ pointBuffer, hp->bufsize, CoordModeOrigin);
+ if (++hp->count > MI_CYCLES(mi))
+ init_hop(mi);
+}
+
+void
+release_hop(ModeInfo * mi)
+{
+ if (hops != NULL) {
+ (void) free((void *) hops);
+ hops = NULL;
+ }
+ if (pointBuffer) {
+ (void) free((void *) pointBuffer);
+ pointBuffer = NULL;
+ }
+}
+
+void
+refresh_hop(ModeInfo * mi)
+{
+ XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
+}
projects / xscreensaver / blobdiff