--- /dev/null
+/* -*- Mode: C; tab-width: 4 -*- */
+/* sierpinski --- Sierpinski's triangle fractal */
+
+#if !defined( lint ) && !defined( SABER )
+static const char sccsid[] = "@(#)sierpinski.c 4.05 97/09/19 xlockmore";
+#endif
+
+/* Copyright (c) 1996 by Desmond Daignault
+ *
+ * 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:
+ * 18-Sep-97: 3D version Antti Kuntsi <kuntsi@iki.fi>.
+ * 20-May-97: Changed the name tri to sierpinski for more compatiblity
+ * 10-May-97: jwz@jwz.org: 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_sierpinski
+# define HACK_DRAW draw_sierpinski
+# define sierpinski_opts xlockmore_opts
+# define DEFAULTS "*delay: 400000 \n" \
+ "*count: 2000 \n" \
+ "*cycles: 100 \n" \
+ "*ncolors: 64 \n"
+# define BRIGHT_COLORS
+# include "xlockmore.h" /* from the xscreensaver distribution */
+#else /* !STANDALONE */
+# include "xlock.h" /* from the xlockmore distribution */
+#endif /* !STANDALONE */
+
+ModeSpecOpt sierpinski_opts =
+{0, NULL, 0, NULL, NULL};
+
+#define MAXCORNERS 4
+
+typedef struct {
+ int width, height;
+ int time;
+ int px, py;
+ int total_npoints;
+ int corners;
+ int npoints[MAXCORNERS];
+ unsigned long colors[MAXCORNERS];
+ XPoint *pointBuffer[MAXCORNERS];
+ XPoint vertex[MAXCORNERS];
+} sierpinskistruct;
+
+static sierpinskistruct *tris = NULL;
+
+static void
+startover(ModeInfo * mi)
+{
+ int j;
+ sierpinskistruct *sp = &tris[MI_SCREEN(mi)];
+
+ if (MI_NPIXELS(mi) > 2) {
+ if (sp->corners == 3) {
+ sp->colors[0] = (NRAND(MI_NPIXELS(mi)));
+ sp->colors[1] = (sp->colors[0] + MI_NPIXELS(mi) / 7 +
+ NRAND(2 * MI_NPIXELS(mi) / 7 + 1)) % MI_NPIXELS(mi);
+ sp->colors[2] = (sp->colors[0] + 4 * MI_NPIXELS(mi) / 7 +
+ NRAND(2 * MI_NPIXELS(mi) / 7 + 1)) % MI_NPIXELS(mi);
+ } else if (sp->corners == 4) {
+ sp->colors[0] = (NRAND(MI_NPIXELS(mi)));
+ sp->colors[1] = (sp->colors[0] + MI_NPIXELS(mi) / 7 +
+ NRAND(MI_NPIXELS(mi) / 7 + 1)) % MI_NPIXELS(mi);
+ sp->colors[2] = (sp->colors[0] + 3 * MI_NPIXELS(mi) / 7 +
+ NRAND(MI_NPIXELS(mi) / 7 + 1)) % MI_NPIXELS(mi);
+ sp->colors[3] = (sp->colors[0] + 5 * MI_NPIXELS(mi) / 7 +
+ NRAND(MI_NPIXELS(mi) / 7 + 1)) % MI_NPIXELS(mi);
+ } else {
+ (void) fprintf(stderr, "colors not set for %d corners\n", sp->corners);
+ }
+ }
+ for (j = 0; j < sp->corners; j++) {
+ sp->vertex[j].x = NRAND(sp->width);
+ sp->vertex[j].y = NRAND(sp->height);
+ }
+ sp->px = NRAND(sp->width);
+ sp->py = NRAND(sp->height);
+ sp->time = 0;
+ XClearWindow(MI_DISPLAY(mi), MI_WINDOW(mi));
+}
+
+void
+init_sierpinski(ModeInfo * mi)
+{
+ sierpinskistruct *sp;
+ int i;
+
+ if (tris == NULL) {
+ if ((tris = (sierpinskistruct *) calloc(MI_NUM_SCREENS(mi),
+ sizeof (sierpinskistruct))) == NULL)
+ return;
+ }
+ sp = &tris[MI_SCREEN(mi)];
+
+ sp->width = MI_WIN_WIDTH(mi);
+ sp->height = MI_WIN_HEIGHT(mi);
+
+ sp->total_npoints = MI_BATCHCOUNT(mi);
+ if (sp->total_npoints < 1)
+ sp->total_npoints = 1;
+ sp->corners = MI_SIZE(mi);
+ if (sp->corners < 3 || sp->corners > 4) {
+ sp->corners = (LRAND() & 1) + 3;
+ }
+ for (i = 0; i < sp->corners; i++) {
+ if (!sp->pointBuffer[i])
+ sp->pointBuffer[i] = (XPoint *) malloc(sp->total_npoints *
+ sizeof (XPoint));
+ }
+ startover(mi);
+}
+
+void
+draw_sierpinski(ModeInfo * mi)
+{
+ Display *display = MI_DISPLAY(mi);
+ GC gc = MI_GC(mi);
+ sierpinskistruct *sp = &tris[MI_SCREEN(mi)];
+ XPoint *xp[MAXCORNERS];
+ int i = 0, v;
+
+ if (MI_NPIXELS(mi) <= 2)
+ XSetForeground(display, gc, MI_WIN_WHITE_PIXEL(mi));
+ for (i = 0; i < sp->corners; i++)
+ xp[i] = sp->pointBuffer[i];
+ for (i = 0; i < sp->total_npoints; i++) {
+ v = NRAND(sp->corners);
+ sp->px = (sp->px + sp->vertex[v].x) / 2;
+ sp->py = (sp->py + sp->vertex[v].y) / 2;
+ xp[v]->x = sp->px;
+ xp[v]->y = sp->py;
+ xp[v]++;
+ sp->npoints[v]++;
+ }
+ for (i = 0; i < sp->corners; i++) {
+ if (MI_NPIXELS(mi) > 2)
+ XSetForeground(display, gc, MI_PIXEL(mi, sp->colors[i]));
+ XDrawPoints(display, MI_WINDOW(mi), gc, sp->pointBuffer[i], sp->npoints[i],
+ CoordModeOrigin);
+ sp->npoints[i] = 0;
+ }
+ if (++sp->time >= MI_CYCLES(mi))
+ startover(mi);
+}
+
+void
+release_sierpinski(ModeInfo * mi)
+{
+ if (tris != NULL) {
+ int screen, i;
+
+ for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
+ for (i = 0; i < MAXCORNERS; i++)
+ if (tris[screen].pointBuffer[i] != NULL) {
+ (void) free((void *) tris[screen].pointBuffer[i]);
+ }
+ }
+ (void) free((void *) tris);
+ tris = NULL;
+ }
+}
+
+void
+refresh_sierpinski(ModeInfo * mi)
+{
+ /* Do nothing, it will refresh by itself */
+}
projects / xscreensaver / blobdiff