--- /dev/null
+/* Whirlygig -- an experiment in X programming
+ *
+ * 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.
+ *
+ * When I was in trigonometry class as a kid, I remember being fascinated
+ * by the beauty of the shapes one receives when playing with sine waves
+ * Here is a little experiment to show that beauty is simple
+ */
+#include <math.h>
+#include "screenhack.h"
+#include <stdio.h>
+
+static XColor colors[1000];
+static int ncolors = 1000;
+static int current_color = 0;
+
+int
+draw_dot(Display *dpy,
+ Window window,
+ Colormap cmap,
+ GC fgc, GC bgc,
+ int current_time,
+ int origin_x, int origin_y,
+ int screen_num, double xspeed, double yspeed,
+ int whirlies, int nlines)
+{
+ int size, last_size; /* The size of my dot */
+ int start_arc = 0; /* Start my circle at 0 degrees */
+ int end_arc = 23040; /* The number of degrees in a X circle (360 * 64) */
+ int horiz, vert; /* These will contain the new x,y coordinates to put my dot */
+ int last_horiz ,last_vert; /* These contain the positions to black out */
+ int last_time;
+ int count, line_count;
+ int line_offset, last_line_offset;
+ int color_offset;
+ XWindowAttributes xgwa;
+ XGetWindowAttributes (dpy, window, &xgwa);
+ if (++current_color >= ncolors)
+ current_color = 0;
+ for (count = 0; count < whirlies; count++) {
+ color_offset = (current_color + (10 * count )) % ncolors;
+ if (current_time == count) {
+ last_time = current_time;
+ }
+ else {
+ current_time = current_time + count;
+ last_time = current_time - 1;
+ }
+ last_horiz = compute_x(last_time, origin_x, xspeed);
+ last_vert = compute_y(last_time, origin_y, yspeed);
+ horiz = compute_x(current_time, origin_x, xspeed);
+ vert = compute_y(current_time, origin_y, yspeed);
+ for (line_count = 0; line_count < nlines; line_count++) {
+ last_line_offset = (int)(80.0 * line_count * sin((double)last_time / 90));
+ line_offset = (int)(80.0 * line_count * sin((double)current_time / 90));
+ last_size = (int)(15.0 + 5.0 * sin((double)last_time / 180.0));
+ size = (int)(15.0 + 5.0 * sin((double)current_time / 180.0));
+ /* Get rid of the old circle */
+ XSetForeground(dpy, bgc, BlackPixel(dpy, screen_num));
+ XFillArc(dpy, window, bgc, last_horiz, last_line_offset+last_vert, last_size, last_size, start_arc, end_arc);
+ /* Draw in the new circle */
+ XSetForeground(dpy, bgc, colors[color_offset].pixel);
+ XFillArc(dpy, window, bgc, horiz, line_offset+vert, size, size, start_arc, end_arc);
+ }
+ }
+ XSync (dpy, False);
+ if (current_time == 23040)
+ {
+ return(1);
+ }
+ else
+ {
+ return(0);
+ }
+}
+
+int compute_x(int the_time, int origin, double xspeed)
+{
+ double funky = (((the_time % 360) * 1.0) / 180.0) * M_PI;
+ double the_cosine = cos((double)the_time / (180.0 * xspeed));
+ double dist_mod_x = cos((double)funky) * (origin - 50);
+ int horiz_pos = origin + (the_cosine * dist_mod_x);
+ return(horiz_pos);
+}
+
+int compute_y(int the_time, int origin, double yspeed)
+{
+ double funky = (((the_time % 360) * 1.0) / 180.0) * M_PI;
+ double the_sine = sin((double)the_time / (180.0 * yspeed));
+ double dist_mod_y = sin((double)funky) * (origin - 50);
+ int vert_pos = origin + (the_sine * dist_mod_y);
+ return(vert_pos);
+}
+
+char *progclass = "Whirlygig";
+
+char *defaults [] = {
+ ".background: black",
+ ".foreground: white",
+ "*xspeed: 1.0",
+ "*yspeed: 1.0",
+ "*whirlies: 10",
+ "*nlines: 1",
+ 0
+};
+
+XrmOptionDescRec options [] = {
+ { "-xspeed", ".xspeed", XrmoptionSepArg, 0 },
+ { "-yspeed", ".yspeed", XrmoptionSepArg, 0 },
+ { "-whirlies", ".whirlies",XrmoptionSepArg, 0 },
+ { "-nlines", ".nlines",XrmoptionSepArg, 0 },
+ { 0, 0, 0, 0 }
+};
+
+void screenhack (Display *dpy, Window window)
+{
+ GC fgc, bgc; /* the foreground and background graphics contexts */
+ XGCValues gcv; /* The structure to hold the GC data */
+ XWindowAttributes xgwa; /* A structure to hold window data */
+ Bool writable = get_boolean_resource ("cycle", "Boolean");
+ double xspeed = get_float_resource( "xspeed", "Float");
+ double yspeed = get_float_resource( "yspeed", "Float");
+ int whirlies = get_integer_resource( "whirlies", "Integer");
+ int nlines = get_integer_resource( "nlines", "Integer");
+ int time_counter = 0; /* This will be incremented in my while loop so that I can move my circle */
+ int screen_num = DefaultScreen(dpy);
+ int half_width, half_height;
+ XGetWindowAttributes (dpy, window, &xgwa);
+
+ half_width = xgwa.width / 2;
+ half_height = xgwa.height / 2;
+
+ gcv.foreground = get_pixel_resource("foreground", "Foreground", dpy, xgwa.colormap);
+ fgc = XCreateGC (dpy, window, GCForeground, &gcv);
+ gcv.foreground = get_pixel_resource("background", "Background", dpy, xgwa.colormap);
+ bgc = XCreateGC (dpy, window, GCForeground, &gcv);
+ make_uniform_colormap (dpy, xgwa.visual, xgwa.colormap,
+ colors, &ncolors,
+ True, &writable, True);
+ mono_p = True;
+ if (!mono_p)
+ {
+ GC tmp = fgc;
+ fgc = bgc;
+ bgc = tmp;
+ }
+
+ while (1)
+ {
+ /* draw_dot will return an interger. If this interger is 0, then continue incrementing
+ time_counter, if it is 1, then reset it to zero... It should only become 1 with the sine
+ is 0 and the cosine is 1 */
+ if (draw_dot(dpy, window, xgwa.colormap, fgc, bgc, time_counter, half_width, half_height, screen_num, xspeed , yspeed, whirlies, nlines) == 1) {
+ time_counter = 1;
+ }
+ else {
+ time_counter++;
+ }
+ screenhack_handle_events (dpy);
+
+ if (!writable)
+ usleep(10);
+ }
+}
+
projects / xscreensaver / blobdiff