--- /dev/null
+/* xscreensaver, Copyright (c) 1999 Jamie Zawinski <jwz@jwz.org>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation. No representations are made about the suitability of this
+ * software for any purpose. It is provided "as is" without express or
+ * implied warranty.
+ */
+
+#include <math.h>
+#include "screenhack.h"
+
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+# include "xdbe.h"
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+
+#define countof(x) (sizeof(x)/sizeof(*(x)))
+#define ABS(x) ((x)<0?-(x):(x))
+#define MAX(x,y) ((x)<(y)?(y):(x))
+#define MIN(x,y) ((x)>(y)?(y):(x))
+#define RAND(n) ((long) ((random() & 0x7fffffff) % ((long) (n))))
+#define RANDSIGN() ((random() & 1) ? 1 : -1)
+
+struct disc {
+ int theta; /* 0 - 360*64 */
+ int velocity;
+ int acceleration;
+ int limit;
+ GC gc;
+ void (*draw) (Display *, Drawable, struct disc *,
+ int x, int y, int radius);
+};
+
+
+static void
+draw_letters (Display *dpy, Drawable d, struct disc *disc,
+ int x, int y, int radius)
+{
+ XPoint points[50];
+ double th2 = 2 * M_PI * (disc->theta / ((double) 360*64));
+ double th;
+
+ /* W */
+
+ th = th2;
+
+ points[0].x = x + radius * 0.8 * cos(th - 0.07);
+ points[0].y = y + radius * 0.8 * sin(th - 0.07);
+
+ points[1].x = x + radius * 0.7 * cos(th - 0.05);
+ points[1].y = y + radius * 0.7 * sin(th - 0.05);
+
+ points[2].x = x + radius * 0.78 * cos(th);
+ points[2].y = y + radius * 0.78 * sin(th);
+
+ points[3].x = x + radius * 0.7 * cos(th + 0.05);
+ points[3].y = y + radius * 0.7 * sin(th + 0.05);
+
+ points[4].x = x + radius * 0.8 * cos(th + 0.07);
+ points[4].y = y + radius * 0.8 * sin(th + 0.07);
+
+ XDrawLines (dpy, d, disc->gc, points, 5, CoordModeOrigin);
+
+ /* 30 (1) */
+
+ th = th2 + (2 * M_PI * 0.08333);
+
+ points[0].x = x + radius * 0.78 * cos(th - 0.13);
+ points[0].y = y + radius * 0.78 * sin(th - 0.13);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.08);
+ points[1].y = y + radius * 0.8 * sin(th - 0.08);
+
+ points[2].x = x + radius * 0.78 * cos(th - 0.03);
+ points[2].y = y + radius * 0.78 * sin(th - 0.03);
+
+ points[3].x = x + radius * 0.76 * cos(th - 0.03);
+ points[3].y = y + radius * 0.76 * sin(th - 0.03);
+
+ points[4].x = x + radius * 0.75 * cos(th - 0.08);
+ points[4].y = y + radius * 0.75 * sin(th - 0.08);
+
+ points[5].x = x + radius * 0.74 * cos(th - 0.03);
+ points[5].y = y + radius * 0.74 * sin(th - 0.03);
+
+ points[6].x = x + radius * 0.72 * cos(th - 0.03);
+ points[6].y = y + radius * 0.72 * sin(th - 0.03);
+
+ points[7].x = x + radius * 0.7 * cos(th - 0.08);
+ points[7].y = y + radius * 0.7 * sin(th - 0.08);
+
+ points[8].x = x + radius * 0.72 * cos(th - 0.13);
+ points[8].y = y + radius * 0.72 * sin(th - 0.13);
+
+ XDrawLines (dpy, d, disc->gc, points, 9, CoordModeOrigin);
+
+ /* 30 (2) */
+
+ points[0].x = x + radius * 0.78 * cos(th + 0.03);
+ points[0].y = y + radius * 0.78 * sin(th + 0.03);
+
+ points[1].x = x + radius * 0.8 * cos(th + 0.08);
+ points[1].y = y + radius * 0.8 * sin(th + 0.08);
+
+ points[2].x = x + radius * 0.78 * cos(th + 0.13);
+ points[2].y = y + radius * 0.78 * sin(th + 0.13);
+
+ points[3].x = x + radius * 0.72 * cos(th + 0.13);
+ points[3].y = y + radius * 0.72 * sin(th + 0.13);
+
+ points[4].x = x + radius * 0.7 * cos(th + 0.08);
+ points[4].y = y + radius * 0.7 * sin(th + 0.08);
+
+ points[5].x = x + radius * 0.72 * cos(th + 0.03);
+ points[5].y = y + radius * 0.72 * sin(th + 0.03);
+
+ points[6] = points[0];
+
+ XDrawLines (dpy, d, disc->gc, points, 7, CoordModeOrigin);
+
+ /* 33 (1) */
+
+ th = th2 + (2 * M_PI * 0.16666);
+
+ points[0].x = x + radius * 0.78 * cos(th - 0.13);
+ points[0].y = y + radius * 0.78 * sin(th - 0.13);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.08);
+ points[1].y = y + radius * 0.8 * sin(th - 0.08);
+
+ points[2].x = x + radius * 0.78 * cos(th - 0.03);
+ points[2].y = y + radius * 0.78 * sin(th - 0.03);
+
+ points[3].x = x + radius * 0.76 * cos(th - 0.03);
+ points[3].y = y + radius * 0.76 * sin(th - 0.03);
+
+ points[4].x = x + radius * 0.75 * cos(th - 0.08);
+ points[4].y = y + radius * 0.75 * sin(th - 0.08);
+
+ points[5].x = x + radius * 0.74 * cos(th - 0.03);
+ points[5].y = y + radius * 0.74 * sin(th - 0.03);
+
+ points[6].x = x + radius * 0.72 * cos(th - 0.03);
+ points[6].y = y + radius * 0.72 * sin(th - 0.03);
+
+ points[7].x = x + radius * 0.7 * cos(th - 0.08);
+ points[7].y = y + radius * 0.7 * sin(th - 0.08);
+
+ points[8].x = x + radius * 0.72 * cos(th - 0.13);
+ points[8].y = y + radius * 0.72 * sin(th - 0.13);
+
+ XDrawLines (dpy, d, disc->gc, points, 9, CoordModeOrigin);
+
+ /* 33 (2) */
+
+ points[0].x = x + radius * 0.78 * cos(th + 0.03);
+ points[0].y = y + radius * 0.78 * sin(th + 0.03);
+
+ points[1].x = x + radius * 0.8 * cos(th + 0.08);
+ points[1].y = y + radius * 0.8 * sin(th + 0.08);
+
+ points[2].x = x + radius * 0.78 * cos(th + 0.13);
+ points[2].y = y + radius * 0.78 * sin(th + 0.13);
+
+ points[3].x = x + radius * 0.76 * cos(th + 0.13);
+ points[3].y = y + radius * 0.76 * sin(th + 0.13);
+
+ points[4].x = x + radius * 0.75 * cos(th + 0.08);
+ points[4].y = y + radius * 0.75 * sin(th + 0.08);
+
+ points[5].x = x + radius * 0.74 * cos(th + 0.13);
+ points[5].y = y + radius * 0.74 * sin(th + 0.13);
+
+ points[6].x = x + radius * 0.72 * cos(th + 0.13);
+ points[6].y = y + radius * 0.72 * sin(th + 0.13);
+
+ points[7].x = x + radius * 0.7 * cos(th + 0.08);
+ points[7].y = y + radius * 0.7 * sin(th + 0.08);
+
+ points[8].x = x + radius * 0.72 * cos(th + 0.03);
+ points[8].y = y + radius * 0.72 * sin(th + 0.03);
+
+ XDrawLines (dpy, d, disc->gc, points, 9, CoordModeOrigin);
+
+ /* N */
+
+ th = th2 + (2 * M_PI * 0.25);
+
+ points[0].x = x + radius * 0.7 * cos(th - 0.05);
+ points[0].y = y + radius * 0.7 * sin(th - 0.05);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.05);
+ points[1].y = y + radius * 0.8 * sin(th - 0.05);
+
+ points[2].x = x + radius * 0.7 * cos(th + 0.05);
+ points[2].y = y + radius * 0.7 * sin(th + 0.05);
+
+ points[3].x = x + radius * 0.8 * cos(th + 0.05);
+ points[3].y = y + radius * 0.8 * sin(th + 0.05);
+
+ XDrawLines (dpy, d, disc->gc, points, 4, CoordModeOrigin);
+
+ /* 3 */
+
+ th = th2 + (2 * M_PI * 0.33333);
+
+ points[0].x = x + radius * 0.78 * cos(th - 0.05);
+ points[0].y = y + radius * 0.78 * sin(th - 0.05);
+
+ points[1].x = x + radius * 0.8 * cos(th);
+ points[1].y = y + radius * 0.8 * sin(th);
+
+ points[2].x = x + radius * 0.78 * cos(th + 0.05);
+ points[2].y = y + radius * 0.78 * sin(th + 0.05);
+
+ points[3].x = x + radius * 0.76 * cos(th + 0.05);
+ points[3].y = y + radius * 0.76 * sin(th + 0.05);
+
+ points[4].x = x + radius * 0.75 * cos(th);
+ points[4].y = y + radius * 0.75 * sin(th);
+
+ points[5].x = x + radius * 0.74 * cos(th + 0.05);
+ points[5].y = y + radius * 0.74 * sin(th + 0.05);
+
+ points[6].x = x + radius * 0.72 * cos(th + 0.05);
+ points[6].y = y + radius * 0.72 * sin(th + 0.05);
+
+ points[7].x = x + radius * 0.7 * cos(th);
+ points[7].y = y + radius * 0.7 * sin(th);
+
+ points[8].x = x + radius * 0.72 * cos(th - 0.05);
+ points[8].y = y + radius * 0.72 * sin(th - 0.05);
+
+ XDrawLines (dpy, d, disc->gc, points, 9, CoordModeOrigin);
+
+ /* 6 */
+
+ th = th2 + (2 * M_PI * 0.41666);
+
+ points[0].x = x + radius * 0.78 * cos(th + 0.05);
+ points[0].y = y + radius * 0.78 * sin(th + 0.05);
+
+ points[1].x = x + radius * 0.8 * cos(th);
+ points[1].y = y + radius * 0.8 * sin(th);
+
+ points[2].x = x + radius * 0.78 * cos(th - 0.05);
+ points[2].y = y + radius * 0.78 * sin(th - 0.05);
+
+ points[3].x = x + radius * 0.72 * cos(th - 0.05);
+ points[3].y = y + radius * 0.72 * sin(th - 0.05);
+
+ points[4].x = x + radius * 0.7 * cos(th);
+ points[4].y = y + radius * 0.7 * sin(th);
+
+ points[5].x = x + radius * 0.72 * cos(th + 0.05);
+ points[5].y = y + radius * 0.72 * sin(th + 0.05);
+
+ points[6].x = x + radius * 0.74 * cos(th + 0.05);
+ points[6].y = y + radius * 0.74 * sin(th + 0.05);
+
+ points[7].x = x + radius * 0.76 * cos(th);
+ points[7].y = y + radius * 0.76 * sin(th);
+
+ points[8].x = x + radius * 0.74 * cos(th - 0.05);
+ points[8].y = y + radius * 0.74 * sin(th - 0.05);
+
+ XDrawLines (dpy, d, disc->gc, points, 9, CoordModeOrigin);
+
+
+ /* E */
+
+ th = th2 + (2 * M_PI * 0.5);
+
+ points[0].x = x + radius * 0.8 * cos(th + 0.05);
+ points[0].y = y + radius * 0.8 * sin(th + 0.05);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.05);
+ points[1].y = y + radius * 0.8 * sin(th - 0.05);
+
+ points[2].x = x + radius * 0.75 * cos(th - 0.05);
+ points[2].y = y + radius * 0.75 * sin(th - 0.05);
+
+ points[3].x = x + radius * 0.75 * cos(th + 0.025);
+ points[3].y = y + radius * 0.75 * sin(th + 0.025);
+
+ points[4].x = x + radius * 0.75 * cos(th - 0.05);
+ points[4].y = y + radius * 0.75 * sin(th - 0.05);
+
+ points[5].x = x + radius * 0.7 * cos(th - 0.05);
+ points[5].y = y + radius * 0.7 * sin(th - 0.05);
+
+ points[6].x = x + radius * 0.7 * cos(th + 0.05);
+ points[6].y = y + radius * 0.7 * sin(th + 0.05);
+
+ XDrawLines (dpy, d, disc->gc, points, 7, CoordModeOrigin);
+
+ /* 12 (1) */
+
+ th = th2 + (2 * M_PI * 0.58333);
+
+ points[0].x = x + radius * 0.77 * cos(th - 0.06);
+ points[0].y = y + radius * 0.77 * sin(th - 0.06);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.03);
+ points[1].y = y + radius * 0.8 * sin(th - 0.03);
+
+ points[2].x = x + radius * 0.7 * cos(th - 0.03);
+ points[2].y = y + radius * 0.7 * sin(th - 0.03);
+
+ XDrawLines (dpy, d, disc->gc, points, 3, CoordModeOrigin);
+
+ /* 12 (2) */
+
+ points[0].x = x + radius * 0.78 * cos(th + 0.02);
+ points[0].y = y + radius * 0.78 * sin(th + 0.02);
+
+ points[1].x = x + radius * 0.8 * cos(th + 0.07);
+ points[1].y = y + radius * 0.8 * sin(th + 0.07);
+
+ points[2].x = x + radius * 0.78 * cos(th + 0.11);
+ points[2].y = y + radius * 0.78 * sin(th + 0.11);
+
+ points[3].x = x + radius * 0.76 * cos(th + 0.11);
+ points[3].y = y + radius * 0.76 * sin(th + 0.11);
+
+ points[4].x = x + radius * 0.74 * cos(th + 0.02);
+ points[4].y = y + radius * 0.74 * sin(th + 0.02);
+
+ points[5].x = x + radius * 0.71 * cos(th + 0.03);
+ points[5].y = y + radius * 0.71 * sin(th + 0.03);
+
+ points[6].x = x + radius * 0.7 * cos(th + 0.03);
+ points[6].y = y + radius * 0.7 * sin(th + 0.03);
+
+ points[7].x = x + radius * 0.7 * cos(th + 0.13);
+ points[7].y = y + radius * 0.7 * sin(th + 0.13);
+
+ XDrawLines (dpy, d, disc->gc, points, 8, CoordModeOrigin);
+
+ /* 15 (1) */
+
+ th = th2 + (2 * M_PI * 0.66666);
+
+ points[0].x = x + radius * 0.77 * cos(th - 0.06);
+ points[0].y = y + radius * 0.77 * sin(th - 0.06);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.03);
+ points[1].y = y + radius * 0.8 * sin(th - 0.03);
+
+ points[2].x = x + radius * 0.7 * cos(th - 0.03);
+ points[2].y = y + radius * 0.7 * sin(th - 0.03);
+
+ XDrawLines (dpy, d, disc->gc, points, 3, CoordModeOrigin);
+
+ /* 15 (2) */
+
+ points[0].x = x + radius * 0.8 * cos(th + 0.11);
+ points[0].y = y + radius * 0.8 * sin(th + 0.11);
+
+ points[1].x = x + radius * 0.8 * cos(th + 0.02);
+ points[1].y = y + radius * 0.8 * sin(th + 0.02);
+
+ points[2].x = x + radius * 0.76 * cos(th + 0.02);
+ points[2].y = y + radius * 0.76 * sin(th + 0.02);
+
+ points[3].x = x + radius * 0.77 * cos(th + 0.06);
+ points[3].y = y + radius * 0.77 * sin(th + 0.06);
+
+ points[4].x = x + radius * 0.76 * cos(th + 0.10);
+ points[4].y = y + radius * 0.76 * sin(th + 0.10);
+
+ points[5].x = x + radius * 0.73 * cos(th + 0.11);
+ points[5].y = y + radius * 0.73 * sin(th + 0.11);
+
+ points[6].x = x + radius * 0.72 * cos(th + 0.10);
+ points[6].y = y + radius * 0.72 * sin(th + 0.10);
+
+ points[7].x = x + radius * 0.7 * cos(th + 0.06);
+ points[7].y = y + radius * 0.7 * sin(th + 0.06);
+
+ points[8].x = x + radius * 0.72 * cos(th + 0.02);
+ points[8].y = y + radius * 0.72 * sin(th + 0.02);
+
+ XDrawLines (dpy, d, disc->gc, points, 9, CoordModeOrigin);
+
+ /* S */
+
+ th = th2 + (2 * M_PI * 0.75);
+
+ points[0].x = x + radius * 0.78 * cos(th + 0.05);
+ points[0].y = y + radius * 0.78 * sin(th + 0.05);
+
+ points[1].x = x + radius * 0.8 * cos(th);
+ points[1].y = y + radius * 0.8 * sin(th);
+
+ points[2].x = x + radius * 0.78 * cos(th - 0.05);
+ points[2].y = y + radius * 0.78 * sin(th - 0.05);
+
+ points[3].x = x + radius * 0.76 * cos(th - 0.05);
+ points[3].y = y + radius * 0.76 * sin(th - 0.05);
+
+ points[4].x = x + radius * 0.74 * cos(th + 0.05);
+ points[4].y = y + radius * 0.74 * sin(th + 0.05);
+
+ points[5].x = x + radius * 0.72 * cos(th + 0.05);
+ points[5].y = y + radius * 0.72 * sin(th + 0.05);
+
+ points[6].x = x + radius * 0.7 * cos(th);
+ points[6].y = y + radius * 0.7 * sin(th);
+
+ points[7].x = x + radius * 0.72 * cos(th - 0.05);
+ points[7].y = y + radius * 0.72 * sin(th - 0.05);
+
+ XDrawLines (dpy, d, disc->gc, points, 8, CoordModeOrigin);
+
+ /* 21 (1) */
+
+ th = th2 + (2 * M_PI * 0.83333);
+
+ points[0].x = x + radius * 0.78 * cos(th - 0.13);
+ points[0].y = y + radius * 0.78 * sin(th - 0.13);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.08);
+ points[1].y = y + radius * 0.8 * sin(th - 0.08);
+
+ points[2].x = x + radius * 0.78 * cos(th - 0.03);
+ points[2].y = y + radius * 0.78 * sin(th - 0.03);
+
+ points[3].x = x + radius * 0.76 * cos(th - 0.03);
+ points[3].y = y + radius * 0.76 * sin(th - 0.03);
+
+ points[4].x = x + radius * 0.74 * cos(th - 0.12);
+ points[4].y = y + radius * 0.74 * sin(th - 0.12);
+
+ points[5].x = x + radius * 0.71 * cos(th - 0.13);
+ points[5].y = y + radius * 0.71 * sin(th - 0.13);
+
+ points[6].x = x + radius * 0.7 * cos(th - 0.13);
+ points[6].y = y + radius * 0.7 * sin(th - 0.13);
+
+ points[7].x = x + radius * 0.7 * cos(th - 0.02);
+ points[7].y = y + radius * 0.7 * sin(th - 0.02);
+
+ XDrawLines (dpy, d, disc->gc, points, 8, CoordModeOrigin);
+
+ /* 21 (2) */
+
+ points[0].x = x + radius * 0.77 * cos(th + 0.03);
+ points[0].y = y + radius * 0.77 * sin(th + 0.03);
+
+ points[1].x = x + radius * 0.8 * cos(th + 0.06);
+ points[1].y = y + radius * 0.8 * sin(th + 0.06);
+
+ points[2].x = x + radius * 0.7 * cos(th + 0.06);
+ points[2].y = y + radius * 0.7 * sin(th + 0.06);
+
+ XDrawLines (dpy, d, disc->gc, points, 3, CoordModeOrigin);
+
+ /* 24 (1) */
+
+ th = th2 + (2 * M_PI * 0.91666);
+
+ points[0].x = x + radius * 0.78 * cos(th - 0.13);
+ points[0].y = y + radius * 0.78 * sin(th - 0.13);
+
+ points[1].x = x + radius * 0.8 * cos(th - 0.08);
+ points[1].y = y + radius * 0.8 * sin(th - 0.08);
+
+ points[2].x = x + radius * 0.78 * cos(th - 0.03);
+ points[2].y = y + radius * 0.78 * sin(th - 0.03);
+
+ points[3].x = x + radius * 0.76 * cos(th - 0.03);
+ points[3].y = y + radius * 0.76 * sin(th - 0.03);
+
+ points[4].x = x + radius * 0.74 * cos(th - 0.12);
+ points[4].y = y + radius * 0.74 * sin(th - 0.12);
+
+ points[5].x = x + radius * 0.71 * cos(th - 0.13);
+ points[5].y = y + radius * 0.71 * sin(th - 0.13);
+
+ points[6].x = x + radius * 0.7 * cos(th - 0.13);
+ points[6].y = y + radius * 0.7 * sin(th - 0.13);
+
+ points[7].x = x + radius * 0.7 * cos(th - 0.02);
+ points[7].y = y + radius * 0.7 * sin(th - 0.02);
+
+ XDrawLines (dpy, d, disc->gc, points, 8, CoordModeOrigin);
+
+ /* 24 (2) */
+
+ points[0].x = x + radius * 0.69 * cos(th + 0.09);
+ points[0].y = y + radius * 0.69 * sin(th + 0.09);
+
+ points[1].x = x + radius * 0.8 * cos(th + 0.09);
+ points[1].y = y + radius * 0.8 * sin(th + 0.09);
+
+ points[2].x = x + radius * 0.72 * cos(th + 0.01);
+ points[2].y = y + radius * 0.72 * sin(th + 0.01);
+
+ points[3].x = x + radius * 0.72 * cos(th + 0.13);
+ points[3].y = y + radius * 0.72 * sin(th + 0.13);
+
+ XDrawLines (dpy, d, disc->gc, points, 4, CoordModeOrigin);
+}
+
+
+static void
+draw_ticks (Display *dpy, Drawable d, struct disc *disc,
+ int x, int y, int radius)
+{
+ XSegment segs[72];
+ int i;
+ double tick = (M_PI * 2) / 72;
+
+ for (i = 0; i < 72; i++)
+ {
+ int radius2 = radius;
+ double th = (i * tick) + (2 * M_PI * (disc->theta / ((double) 360*64)));
+
+ if (i % 6)
+ radius2 -= radius / 16;
+ else
+ radius2 -= radius / 8;
+
+ segs[i].x1 = x + radius * cos(th);
+ segs[i].y1 = y + radius * sin(th);
+ segs[i].x2 = x + radius2 * cos(th);
+ segs[i].y2 = y + radius2 * sin(th);
+ }
+ XDrawSegments (dpy, d, disc->gc, segs, countof(segs));
+
+ draw_letters (dpy, d, disc, x, y, radius);
+}
+
+
+static void
+draw_thin_arrow (Display *dpy, Drawable d, struct disc *disc,
+ int x, int y, int radius)
+{
+ XPoint points[3];
+ double th;
+ int radius2;
+ double tick = ((M_PI * 2) / 72) * 2;
+
+ radius *= 0.9;
+ radius2 = radius - (radius / 8) * 3;
+
+ th = 2 * M_PI * (disc->theta / ((double) 360*64));
+
+ points[0].x = x + radius * cos(th); /* tip */
+ points[0].y = y + radius * sin(th);
+
+ points[1].x = x + radius2 * cos(th - tick); /* tip left */
+ points[1].y = y + radius2 * sin(th - tick);
+
+ points[2].x = x + radius2 * cos(th + tick); /* tip right */
+ points[2].y = y + radius2 * sin(th + tick);
+
+ XDrawLine (dpy, d, disc->gc,
+ (int) (x + radius2 * cos(th)),
+ (int) (y + radius2 * sin(th)),
+ (int) (x + -radius * cos(th)),
+ (int) (y + -radius * sin(th)));
+
+ XFillPolygon (dpy, d, disc->gc, points, 3, Convex, CoordModeOrigin);
+}
+
+
+static void
+draw_thick_arrow (Display *dpy, Drawable d, struct disc *disc,
+ int x, int y, int radius)
+{
+ XPoint points[10];
+ double th;
+ int radius2, radius3;
+ double tick = ((M_PI * 2) / 72) * 2;
+
+ radius *= 0.9;
+ radius2 = radius - (radius / 8) * 3;
+ radius3 = radius - (radius / 8) * 2;
+ th = 2 * M_PI * (disc->theta / ((double) 360*64));
+
+ points[0].x = x + radius * cos(th); /* tip */
+ points[0].y = y + radius * sin(th);
+
+ points[1].x = x + radius2 * cos(th - tick); /* tip left */
+ points[1].y = y + radius2 * sin(th - tick);
+
+ points[2].x = x + radius2 * cos(th + tick); /* tip right */
+ points[2].y = y + radius2 * sin(th + tick);
+
+ points[3] = points[0];
+
+ XDrawLines (dpy, d, disc->gc, points, 4, CoordModeOrigin);
+
+ points[0].x = x + radius2 * cos(th - tick/2); /* top left */
+ points[0].y = y + radius2 * sin(th - tick/2);
+
+ points[1].x = x + -radius2 * cos(th + tick/2); /* bottom left */
+ points[1].y = y + -radius2 * sin(th + tick/2);
+
+ points[2].x = x + -radius3 * cos(th); /* bottom */
+ points[2].y = y + -radius3 * sin(th);
+
+ points[3].x = x + -radius * cos(th); /* bottom spike */
+ points[3].y = y + -radius * sin(th);
+
+ points[4] = points[2]; /* return */
+
+ points[5].x = x + -radius2 * cos(th - tick/2); /* bottom right */
+ points[5].y = y + -radius2 * sin(th - tick/2);
+
+ points[6].x = x + radius2 * cos(th + tick/2); /* top right */
+ points[6].y = y + radius2 * sin(th + tick/2);
+
+ XDrawLines (dpy, d, disc->gc, points, 7, CoordModeOrigin);
+}
+
+
+
+static void
+roll_disc (struct disc *disc)
+{
+ double th = disc->theta;
+ if (th < 0)
+ th = -(th + disc->velocity);
+ else
+ th = (th + disc->velocity);
+
+ if (th > (360*64))
+ th -= (360*64);
+ else if (th < 0)
+ th += (360*64);
+
+ disc->theta = (disc->theta > 0 ? th : -th);
+
+ disc->velocity += disc->acceleration;
+
+ if (disc->velocity > disc->limit ||
+ disc->velocity < -disc->limit)
+ disc->acceleration = -disc->acceleration;
+
+ /* Alter direction of rotational acceleration randomly. */
+ if (! (random() % 120))
+ disc->acceleration = -disc->acceleration;
+
+ /* Change acceleration very occasionally. */
+ if (! (random() % 200))
+ {
+ if (random() & 1)
+ disc->acceleration *= 1.2;
+ else
+ disc->acceleration *= 0.8;
+ }
+}
+
+
+static void
+init_spin (struct disc *disc)
+{
+ disc->limit = 5*64;
+ disc->theta = RAND(360*64);
+ disc->velocity = RAND(16) * RANDSIGN();
+ disc->acceleration = RAND(16) * RANDSIGN();
+}
+
+
+static void
+draw_compass (Display *dpy, Drawable d, struct disc **discs,
+ int x, int y, int radius)
+{
+ int i = 0;
+ while (discs[i])
+ {
+ discs[i]->draw (dpy, d, discs[i], x, y, radius);
+ roll_disc (discs[i]);
+ i++;
+ }
+}
+
+static void
+draw_pointer (Display *dpy, Drawable d, GC ptr_gc, GC dot_gc,
+ int x, int y, int radius)
+{
+ XPoint points[3];
+ int size = radius * 0.1;
+
+ /* top */
+
+ points[0].x = x - size;
+ points[0].y = y - radius - size;
+
+ points[1].x = x + size;
+ points[1].y = y - radius - size;
+
+ points[2].x = x;
+ points[2].y = y - radius;
+
+ XFillPolygon (dpy, d, ptr_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* top right */
+
+ points[0].x = x - (radius * 0.85);
+ points[0].y = y - (radius * 0.8);
+
+ points[1].x = x - (radius * 1.1);
+ points[1].y = y - (radius * 0.55);
+
+ points[2].x = x - (radius * 0.6);
+ points[2].y = y - (radius * 0.65);
+
+ XFillPolygon (dpy, d, ptr_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* left */
+
+ points[0].x = x - (radius * 1.05);
+ points[0].y = y;
+
+ points[1].x = x - (radius * 1.1);
+ points[1].y = y - (radius * 0.025);
+
+ points[2].x = x - (radius * 1.1);
+ points[2].y = y + (radius * 0.025);
+
+ XFillPolygon (dpy, d, dot_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* right */
+
+ points[0].x = x + (radius * 1.05);
+ points[0].y = y;
+
+ points[1].x = x + (radius * 1.1);
+ points[1].y = y - (radius * 0.025);
+
+ points[2].x = x + (radius * 1.1);
+ points[2].y = y + (radius * 0.025);
+
+ XFillPolygon (dpy, d, dot_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* bottom */
+
+ points[0].x = x;
+ points[0].y = y + (radius * 1.05);
+
+ points[1].x = x - (radius * 0.025);
+ points[1].y = y + (radius * 1.1);
+
+ points[2].x = x + (radius * 0.025);
+ points[2].y = y + (radius * 1.1);
+
+ XFillPolygon (dpy, d, dot_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* bottom left */
+
+ points[0].x = x + (radius * 0.74);
+ points[0].y = y + (radius * 0.74);
+
+ points[1].x = x + (radius * 0.78);
+ points[1].y = y + (radius * 0.75);
+
+ points[2].x = x + (radius * 0.75);
+ points[2].y = y + (radius * 0.78);
+
+ XFillPolygon (dpy, d, dot_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* top left */
+
+ points[0].x = x + (radius * 0.74);
+ points[0].y = y - (radius * 0.74);
+
+ points[1].x = x + (radius * 0.78);
+ points[1].y = y - (radius * 0.75);
+
+ points[2].x = x + (radius * 0.75);
+ points[2].y = y - (radius * 0.78);
+
+ XFillPolygon (dpy, d, dot_gc, points, 3, Convex, CoordModeOrigin);
+
+ /* bottom right */
+
+ points[0].x = x - (radius * 0.74);
+ points[0].y = y + (radius * 0.74);
+
+ points[1].x = x - (radius * 0.78);
+ points[1].y = y + (radius * 0.75);
+
+ points[2].x = x - (radius * 0.75);
+ points[2].y = y + (radius * 0.78);
+
+ XFillPolygon (dpy, d, dot_gc, points, 3, Convex, CoordModeOrigin);
+}
+
+\f
+char *progclass = "Compass";
+
+char *defaults [] = {
+ ".background: #000000",
+ ".foreground: #DDFFFF",
+ "*arrow1Foreground: #FFF66A",
+ "*arrow2Foreground: #F7D64A",
+ "*pointerForeground: #FF0000",
+ "*delay: 10000",
+ "*doubleBuffer: True",
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ "*useDBE: True",
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+ 0
+};
+
+XrmOptionDescRec options [] = {
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { "-db", ".doubleBuffer", XrmoptionNoArg, "True" },
+ { "-no-db", ".doubleBuffer", XrmoptionNoArg, "False" },
+ { 0, 0, 0, 0 }
+};
+
+void
+screenhack (Display *dpy, Window window)
+{
+ XGCValues gcv;
+ int delay = get_integer_resource ("delay", "Integer");
+ Bool dbuf = get_boolean_resource ("doubleBuffer", "Boolean");
+ struct disc *discs[4];
+ int x, y, size, size2;
+ GC ptr_gc;
+ GC erase_gc = 0;
+ XWindowAttributes xgwa;
+ Pixmap b=0, ba=0, bb=0; /* double-buffer to reduce flicker */
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ XdbeBackBuffer backb = 0;
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+
+ XGetWindowAttributes (dpy, window, &xgwa);
+ size2 = MIN(xgwa.width, xgwa.height);
+
+ if (size2 > 600) size2 = 600;
+
+ size = (size2 / 2) * 0.8;
+
+ x = xgwa.width/2;
+ y = xgwa.height/2;
+
+ if (dbuf)
+ {
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ b = backb = xdbe_get_backbuffer (dpy, window, XdbeUndefined);
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+
+ if (!b)
+ {
+ x = size2/2;
+ y = size2/2;
+ ba = XCreatePixmap (dpy, window, size2, size2, xgwa.depth);
+ bb = XCreatePixmap (dpy, window, size2, size2, xgwa.depth);
+ b = ba;
+ }
+ }
+ else
+ {
+ b = window;
+ }
+
+ discs[0] = (struct disc *) calloc (1, sizeof (struct disc));
+ discs[1] = (struct disc *) calloc (1, sizeof (struct disc));
+ discs[2] = (struct disc *) calloc (1, sizeof (struct disc));
+ discs[3] = 0;
+
+ gcv.foreground = get_pixel_resource ("foreground", "Foreground",
+ dpy, xgwa.colormap);
+ gcv.line_width = MAX(2, (size/60));
+ gcv.join_style = JoinBevel;
+ discs[0]->draw = draw_ticks;
+ discs[0]->gc = XCreateGC (dpy, b, GCForeground|GCLineWidth|GCJoinStyle,
+ &gcv);
+ init_spin (discs[0]);
+
+ gcv.foreground = get_pixel_resource ("arrow2Foreground", "Foreground",
+ dpy, xgwa.colormap);
+ gcv.line_width = MAX(4, (size / 30));
+ discs[1]->draw = draw_thick_arrow;
+ discs[1]->gc = XCreateGC (dpy, b, GCForeground|GCLineWidth, &gcv);
+ init_spin (discs[1]);
+
+ gcv.foreground = get_pixel_resource ("arrow1Foreground", "Foreground",
+ dpy, xgwa.colormap);
+ gcv.line_width = MAX(4, (size / 30));
+ discs[2]->draw = draw_thin_arrow;
+ discs[2]->gc = XCreateGC (dpy, b, GCForeground|GCLineWidth, &gcv);
+ init_spin (discs[2]);
+
+ gcv.foreground = get_pixel_resource ("pointerForeground", "Foreground",
+ dpy, xgwa.colormap);
+ ptr_gc = XCreateGC (dpy, b, GCForeground|GCLineWidth, &gcv);
+
+ gcv.foreground = get_pixel_resource ("background", "Background",
+ dpy, xgwa.colormap);
+ erase_gc = XCreateGC (dpy, b, GCForeground, &gcv);
+
+ if (ba) XFillRectangle (dpy, ba, erase_gc, 0, 0, size2, size2);
+ if (bb) XFillRectangle (dpy, bb, erase_gc, 0, 0, size2, size2);
+
+ while (1)
+ {
+ XFillRectangle (dpy, b, erase_gc, 0, 0, xgwa.width, xgwa.height);
+
+ draw_compass (dpy, b, discs, x, y, size);
+ draw_pointer (dpy, b, ptr_gc, discs[0]->gc, x, y, size);
+
+#ifdef HAVE_DOUBLE_BUFFER_EXTENSION
+ if (backb)
+ {
+ XdbeSwapInfo info[1];
+ info[0].swap_window = window;
+ info[0].swap_action = XdbeUndefined;
+ XdbeSwapBuffers (dpy, info, 1);
+ }
+ else
+#endif /* HAVE_DOUBLE_BUFFER_EXTENSION */
+ if (dbuf)
+ {
+ XCopyArea (dpy, b, window, erase_gc, 0, 0,
+ size2, size2,
+ xgwa.width/2 - x,
+ xgwa.height/2 - y);
+ b = (b == ba ? bb : ba);
+ }
+
+ XSync (dpy, False);
+ screenhack_handle_events (dpy);
+ if (delay)
+ usleep (delay);
+ }
+}