ftp://ftp.uni-heidelberg.de/pub/X11/contrib/applications/xscreensaver-2.07.tar.gz

[xscreensaver] / hacks / sierpinski.c

diff --git a/hacks/sierpinski.c b/hacks/sierpinski.c
new file mode 100644 (file)
index 0000000..a75c3eb
--- /dev/null
+++ b/hacks/sierpinski.c
@@ -0,0 +1,162 @@
+/* -*- Mode: C; tab-width: 4 -*-
+ * tri --- Sierpinski triangle fractal.
+ */
+#if !defined( lint ) && !defined( SABER )
+static const char sccsid[] = "@(#)tri.c        4.00 97/01/01 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:
+ * 10-May-97: jwz@netscape.com: turned into a standalone program.
+ * 05-Sep-96: Desmond Daignault Datatimes Incorporated
+ *            <tekdd@dtol.datatimes.com> .
+ */
+
+#ifdef STANDALONE
+# define PROGCLASS                                     "Sierpinski"
+# define HACK_INIT                                     init_tri
+# define HACK_DRAW                                     draw_tri
+# define tri_opts                                      xlockmore_opts
+# define DEFAULTS      "*count:                2000    \n"                     \
+                                       "*cycles:               100     \n"                     \
+                                       "*delay:                400000  \n"                     \
+                                       "*ncolors:              64   \n"
+# include "xlockmore.h"                                /* from the xscreensaver distribution */
+#else  /* !STANDALONE */
+# include "xlock.h"                                    /* from the xlockmore distribution */
+#endif /* !STANDALONE */
+
+ModeSpecOpt tri_opts = {
+  0, NULL, 0, NULL, NULL };
+
+typedef struct {
+       int         width, height;
+       int         time;
+       int         px, py;
+       int         total_npoints;
+       int         npoints[3];
+       unsigned long colors[3];
+       XPoint     *pointBuffer[3];
+       XPoint      vertex[3];
+} tristruct;
+
+static tristruct *tris = NULL;
+
+static void
+startover(ModeInfo * mi)
+{
+       int         j;
+       tristruct  *tp = &tris[MI_SCREEN(mi)];
+
+       if (MI_NPIXELS(mi) > 2) {
+               tp->colors[0] = (NRAND(MI_NPIXELS(mi)));
+               tp->colors[1] = (tp->colors[0] + MI_NPIXELS(mi) / 7 +
+                            NRAND(2 * MI_NPIXELS(mi) / 7)) % MI_NPIXELS(mi);
+               tp->colors[2] = (tp->colors[0] + 4 * MI_NPIXELS(mi) / 7 +
+                            NRAND(2 * MI_NPIXELS(mi) / 7)) % MI_NPIXELS(mi);
+       }
+       for (j = 0; j < 3; j++) {
+               tp->vertex[j].x = NRAND(tp->width);
+               tp->vertex[j].y = NRAND(tp->height);
+       }
+       tp->px = NRAND(tp->width);
+       tp->py = NRAND(tp->height);
+       tp->time = 0;
+       XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
+}
+
+void
+init_tri(ModeInfo * mi)
+{
+       tristruct  *tp;
+       int         i;
+
+       if (tris == NULL) {
+               if ((tris = (tristruct *) calloc(MI_NUM_SCREENS(mi),
+                                                sizeof (tristruct))) == NULL)
+                       return;
+       }
+       tp = &tris[MI_SCREEN(mi)];
+
+       tp->width = MI_WIN_WIDTH(mi);
+       tp->height = MI_WIN_HEIGHT(mi);
+
+       tp->total_npoints = MI_BATCHCOUNT(mi);
+       if (tp->total_npoints < 1)
+               tp->total_npoints = 1;
+       for (i = 0; i < 3; i++) {
+               if (!tp->pointBuffer[i])
+                       tp->pointBuffer[i] = (XPoint *) malloc(tp->total_npoints *
+                                                           sizeof (XPoint));
+       }
+       startover(mi);
+}
+
+void
+draw_tri(ModeInfo * mi)
+{
+       Display    *display = MI_DISPLAY(mi);
+       GC          gc = MI_GC(mi);
+       tristruct  *tp = &tris[MI_SCREEN(mi)];
+       XPoint     *xp[3];
+       int         i = 0, v;
+
+       if (MI_NPIXELS(mi) <= 2)
+               XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
+       for (i = 0; i < 3; i++)
+               xp[i] = tp->pointBuffer[i];
+       for (i = 0; i < tp->total_npoints; i++) {
+               v = NRAND(3);
+               tp->px = (tp->px + tp->vertex[v].x) / 2;
+               tp->py = (tp->py + tp->vertex[v].y) / 2;
+               xp[v]->x = tp->px;
+               xp[v]->y = tp->py;
+               xp[v]++;
+               tp->npoints[v]++;
+       }
+       for (i = 0; i < 3; i++) {
+               if (MI_NPIXELS(mi) > 2)
+                       XSetForeground(display, gc, MI_PIXEL(mi, tp->colors[i]));
+               XDrawPoints(display, MI_WINDOW(mi), gc, tp->pointBuffer[i], tp->npoints[i],
+                           CoordModeOrigin);
+               tp->npoints[i] = 0;
+       }
+       if (++tp->time >= MI_CYCLES(mi))
+               startover(mi);
+}
+
+void
+release_tri(ModeInfo * mi)
+{
+       if (tris != NULL) {
+               int         screen, i;
+
+               for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
+                       for (i = 0; i < 3; i++)
+                               if (tris[screen].pointBuffer[i] != NULL) {
+                                       (void) free((void *) tris[screen].pointBuffer[i]);
+                               }
+               }
+               (void) free((void *) tris);
+               tris = NULL;
+       }
+}
+
+void
+refresh_tri(ModeInfo * mi)
+{
+       /* Do nothing, it will refresh by itself */
+}