--- /dev/null
+/* -*- Mode: C; tab-width: 4 -*- */
+/* thornbird --- continuously varying Thornbird set */
+
+#if !defined( lint ) && !defined( SABER )
+static const char sccsid[] = "@(#)thornbird.c 5.00 2000/11/01 xlockmore";
+
+#endif
+
+/*-
+ * Copyright (c) 1996 by Tim Auckland <Tim.Auckland@Procket.com>
+ *
+ * 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.
+ *
+ * "thornbird" shows a view of the "Bird in a Thornbush" fractal,
+ * continuously varying the three free parameters.
+ *
+ * Revision History:
+ * 01-Nov-2000: Allocation checks
+ * 04-Jun-1999: 3D tumble added by Tim Auckland
+ * 31-Jul-1997: Adapted from discrete.c Copyright (c) 1996 by Tim Auckland
+ */
+
+#ifdef STANDALONE
+#define MODE_thornbird
+#define PROGCLASS "Thornbird"
+#define HACK_INIT init_thornbird
+#define HACK_DRAW draw_thornbird
+#define thornbird_opts xlockmore_opts
+#define DEFAULTS "*delay: 10000 \n" \
+ "*count: 800 \n" \
+ "*cycles: 16 \n" \
+ "*ncolors: 64 \n"
+#define SMOOTH_COLORS
+#include "xlockmore.h" /* in xscreensaver distribution */
+#else /* STANDALONE */
+#include "xlock.h" /* in xlockmore distribution */
+#endif /* STANDALONE */
+
+#ifdef MODE_thornbird
+
+ModeSpecOpt thornbird_opts =
+{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
+
+#ifdef USE_MODULES
+ModStruct thornbird_description =
+{"thornbird", "init_thornbird", "draw_thornbird", "release_thornbird",
+ "refresh_thornbird", "init_thornbird", (char *) NULL, þbird_opts,
+ 1000, 800, 16, 1, 64, 1.0, "",
+ "Shows an animated Bird in a Thorn Bush fractal map", 0, NULL};
+
+#endif
+
+#define balance_rand(v) ((LRAND()/MAXRAND*(v))-((v)/2)) /* random around 0 */
+
+typedef struct {
+ int maxx;
+ int maxy; /* max of the screen */
+ double a;
+ double b;
+ double c;
+ double d;
+ double e;
+ double i;
+ double j; /* thornbird parameters */
+ struct {
+ double f1;
+ double f2;
+ } liss;
+ struct {
+ double theta;
+ double dtheta;
+ double phi;
+ double dphi;
+ } tumble;
+ int inc;
+ int pix;
+ int count;
+ int nbuffers;
+ XPoint **pointBuffer; /* pointer for XDrawPoints */
+} thornbirdstruct;
+
+static thornbirdstruct *thornbirds = (thornbirdstruct *) NULL;
+
+static void
+free_thornbird(thornbirdstruct *hp)
+{
+ if (hp->pointBuffer != NULL) {
+ int buffer;
+
+ for (buffer = 0; buffer < hp->nbuffers; buffer++)
+ if (hp->pointBuffer[buffer] != NULL)
+ (void) free((void *) hp->pointBuffer[buffer]);
+ (void) free((void *) hp->pointBuffer);
+ hp->pointBuffer = (XPoint **) NULL;
+ }
+}
+
+void
+init_thornbird(ModeInfo * mi)
+{
+ thornbirdstruct *hp;
+
+ if (thornbirds == NULL) {
+ if ((thornbirds =
+ (thornbirdstruct *) calloc(MI_NUM_SCREENS(mi),
+ sizeof (thornbirdstruct))) == NULL)
+ return;
+ }
+ hp = þbirds[MI_SCREEN(mi)];
+
+
+ hp->maxx = MI_WIDTH(mi);
+ hp->maxy = MI_HEIGHT(mi);
+
+ hp->b = 0.1;
+ hp->i = hp->j = 0.1;
+
+ hp->pix = 0;
+ hp->inc = 0;
+
+ hp->nbuffers = MI_CYCLES(mi);
+
+ if (hp->pointBuffer == NULL)
+ if ((hp->pointBuffer = (XPoint **) calloc(MI_CYCLES(mi),
+ sizeof (XPoint *))) == NULL) {
+ free_thornbird(hp);
+ return;
+ }
+
+ if (hp->pointBuffer[0] == NULL)
+ if ((hp->pointBuffer[0] = (XPoint *) malloc(MI_COUNT(mi) *
+ sizeof (XPoint))) == NULL) {
+ free_thornbird(hp);
+ return;
+ }
+
+ /* select frequencies for parameter variation */
+ hp->liss.f1 = LRAND() % 5000;
+ hp->liss.f2 = LRAND() % 2000;
+
+ /* choose random 3D tumbling */
+ hp->tumble.theta = 0;
+ hp->tumble.phi = 0;
+ hp->tumble.dtheta = balance_rand(0.001);
+ hp->tumble.dphi = balance_rand(0.005);
+
+ /* Clear the background. */
+ MI_CLEARWINDOW(mi);
+
+ hp->count = 0;
+}
+
+
+void
+draw_thornbird(ModeInfo * mi)
+{
+ Display *dsp = MI_DISPLAY(mi);
+ Window win = MI_WINDOW(mi);
+ double oldj, oldi;
+ int batchcount = MI_COUNT(mi);
+ int k;
+ XPoint *xp;
+ GC gc = MI_GC(mi);
+ int erase;
+ int current;
+
+ double sint, cost, sinp, cosp;
+ thornbirdstruct *hp;
+
+ if (thornbirds == NULL)
+ return;
+ hp = þbirds[MI_SCREEN(mi)];
+ if (hp->pointBuffer == NULL)
+ return;
+
+ erase = (hp->inc + 1) % MI_CYCLES(mi);
+ current = hp->inc % MI_CYCLES(mi);
+ k = batchcount;
+
+
+ xp = hp->pointBuffer[current];
+
+ /* vary papameters */
+ hp->a = 1.99 + (0.4 * sin(hp->inc / hp->liss.f1) +
+ 0.05 * cos(hp->inc / hp->liss.f2));
+ hp->c = 0.80 + (0.15 * cos(hp->inc / hp->liss.f1) +
+ 0.05 * sin(hp->inc / hp->liss.f2));
+
+ /* vary view */
+ hp->tumble.theta += hp->tumble.dtheta;
+ hp->tumble.phi += hp->tumble.dphi;
+ sint = sin(hp->tumble.theta);
+ cost = cos(hp->tumble.theta);
+ sinp = sin(hp->tumble.phi);
+ cosp = cos(hp->tumble.phi);
+
+ while (k--) {
+ oldj = hp->j;
+ oldi = hp->i;
+
+ hp->j = oldi;
+ hp->i = (1 - hp->c) * cos(M_PI * hp->a * oldj) + hp->c * hp->b;
+ hp->b = oldj;
+
+ xp->x = (short)
+ (hp->maxx / 2 * (1
+ + sint*hp->j + cost*cosp*hp->i - cost*sinp*hp->b));
+ xp->y = (short)
+ (hp->maxy / 2 * (1
+ - cost*hp->j + sint*cosp*hp->i - sint*sinp*hp->b));
+ xp++;
+ }
+
+ MI_IS_DRAWN(mi) = True;
+
+ if (hp->pointBuffer[erase] == NULL) {
+ if ((hp->pointBuffer[erase] = (XPoint *) malloc(MI_COUNT(mi) *
+ sizeof (XPoint))) == NULL) {
+ free_thornbird(hp);
+ return;
+ }
+ } else {
+ XSetForeground(dsp, gc, MI_BLACK_PIXEL(mi));
+ XDrawPoints(dsp, win, gc, hp->pointBuffer[erase],
+ batchcount, CoordModeOrigin);
+ }
+ if (MI_NPIXELS(mi) > 2) {
+ XSetForeground(dsp, gc, MI_PIXEL(mi, hp->pix));
+ if (erase == 0) /* change colours after "cycles" cycles */
+ if (++hp->pix >= MI_NPIXELS(mi))
+ hp->pix = 0;
+ } else
+ XSetForeground(dsp, gc, MI_WHITE_PIXEL(mi));
+
+ XDrawPoints(dsp, win, gc, hp->pointBuffer[current],
+ batchcount, CoordModeOrigin);
+ hp->inc++;
+
+}
+
+void
+release_thornbird(ModeInfo * mi)
+{
+ if (thornbirds != NULL) {
+ int screen;
+
+ for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++)
+ free_thornbird(þbirds[screen]);
+ (void) free((void *) thornbirds);
+ thornbirds = (thornbirdstruct *) NULL;
+ }
+}
+
+void
+refresh_thornbird(ModeInfo * mi)
+{
+ MI_CLEARWINDOW(mi);
+}
+
+#endif /* MODE_thornbird */
projects / xscreensaver / blobdiff