-/* xscreensaver, Copyright (c) 1992, 1995 Jamie Zawinski <jwz@netscape.com>
+/* xscreensaver, Copyright (c) 1992, 1995, 1996, 1997
+ * 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
* implied warranty.
*/
+/* Algorithm from a Mac program by Chris Tate, written in 1988 or so. */
+
+/* 18-Sep-97: Johannes Keukelaar (johannes@nada.kth.se): Improved screen
+ * eraser.
+ * 10-May-97: merged ellipse code by Dan Stromberg <strombrg@nis.acs.uci.edu>
+ * as found in xlockmore 4.03a10.
+ * 1992: jwz created.
+ */
+
+/* 25 April 2002: Matthew Strait <straitm@mathcs.carleton.edu> added
+-subdelay option so the drawing process can be watched */
+
#include <math.h>
#include "screenhack.h"
+#include "erase.h"
static double sins [360];
static double coss [360];
-static GC draw_gc, erase_gc;
+static GC draw_gc;
static unsigned int default_fg_pixel;
+static int sleep_time;
+static int subdelay;
static void
-init_helix (dpy, window)
- Display *dpy;
- Window window;
+init_helix (Display *dpy, Window window)
{
int i;
XGCValues gcv;
get_pixel_resource ("foreground", "Foreground", dpy, cmap);
draw_gc = XCreateGC (dpy, window, GCForeground, &gcv);
gcv.foreground = get_pixel_resource ("background", "Background", dpy, cmap);
- erase_gc = XCreateGC (dpy, window, GCForeground, &gcv);
for (i = 0; i < 360; i++)
{
}
static int
-gcd (a, b)
- int a, b;
+gcd (int a, int b)
{
while (b > 0)
{
}
static void
-helix (dpy, window,
- radius1, radius2, d_angle,
- factor1, factor2, factor3, factor4)
- Display *dpy;
- Window window;
- int radius1, radius2, d_angle;
- int factor1, factor2, factor3, factor4;
+helix (Display *dpy, Window window,
+ int radius1, int radius2, int d_angle,
+ int factor1, int factor2, int factor3, int factor4)
{
XWindowAttributes xgwa;
int width, height;
for (i = 0; i < limit; i++)
{
int tmp;
-#define pmod(x,y) (tmp = (x % y), (tmp >= 0 ? tmp : tmp + y))
+#define pmod(x,y) (tmp=((x) % (y)), (tmp >= 0 ? tmp : (tmp + (y))))
+
x1 = xmid + (((double) radius1) * sins [pmod ((angle * factor1), 360)]);
y1 = ymid + (((double) radius2) * coss [pmod ((angle * factor2), 360)]);
XDrawLine (dpy, window, draw_gc, x1, y1, x2, y2);
y2 = ymid + (((double) radius1) * coss [pmod ((angle * factor4), 360)]);
XDrawLine (dpy, window, draw_gc, x1, y1, x2, y2);
angle += d_angle;
+
+ /* if we sleep every time, it's too slow */
+ if(subdelay && i%16 == 0) usleep(subdelay);
+
+ XFlush (dpy);
+ }
+}
+
+static void
+trig (Display *dpy, Window window,
+ int d_angle, int factor1, int factor2,
+ int offset, int d_angle_offset, int dir, int density)
+{
+ XWindowAttributes xgwa;
+ int width, height;
+ int xmid, ymid;
+ int x1, y1, x2, y2;
+ int tmp, angle;
+ Colormap cmap;
+
+ XClearWindow (dpy, window);
+ XGetWindowAttributes (dpy, window, &xgwa);
+ cmap = xgwa.colormap;
+ width = xgwa.width;
+ height = xgwa.height;
+
+ xmid = width / 2;
+ ymid = height / 2;
+
+ while (d_angle >= -360 && d_angle <= 360)
+ {
+ angle = d_angle + d_angle_offset;
+ x1 = (sins [pmod(angle * factor1, 360)] * xmid) + xmid;
+ y1 = (coss [pmod(angle * factor1, 360)] * ymid) + ymid;
+ x2 = (sins [pmod(angle * factor2 + offset, 360)] * xmid) + xmid;
+ y2 = (coss [pmod(angle * factor2 + offset, 360)] * ymid) + ymid;
+ XDrawLine(dpy, window, draw_gc, x1, y1, x2, y2);
+ tmp = (int) 360 / (2 * density * factor1 * factor2);
+ if (tmp == 0) /* Do not want it getting stuck... */
+ tmp = 1; /* Would not need if floating point */
+ d_angle += dir * tmp;
+
+ /* this draws faster, so we sleep somewhat more often */
+ if(subdelay && d_angle%4 == 0) usleep(subdelay);
+
+ /* without this, the subdelay effect is lost */
XFlush (dpy);
}
}
#define min(a,b) ((a)<(b)?(a):(b))
static void
-random_helix (dpy, window)
- Display *dpy;
- Window window;
+random_helix (Display *dpy, Window window, XColor *color, Bool *got_color)
{
Colormap cmap;
int width, height;
int radius, radius1, radius2, d_angle, factor1, factor2, factor3, factor4;
double divisor;
- XColor color;
- int i, got_color = 0;
XWindowAttributes xgwa;
XGetWindowAttributes (dpy, window, &xgwa);
width = xgwa.width;
else
{
hsv_to_rgb (random () % 360, frand (1.0), frand (0.5) + 0.5,
- &color.red, &color.green, &color.blue);
- if ((got_color = XAllocColor (dpy, cmap, &color)))
- XSetForeground (dpy, draw_gc, color.pixel);
+ &color->red, &color->green, &color->blue);
+ if ((*got_color = XAllocColor (dpy, cmap, color)))
+ XSetForeground (dpy, draw_gc, color->pixel);
else
XSetForeground (dpy, draw_gc, default_fg_pixel);
}
helix (dpy, window, radius1, radius2, d_angle,
factor1, factor2, factor3, factor4);
+}
+
+static void
+random_trig (Display *dpy, Window window, XColor *color, Bool *got_color)
+{
+ Colormap cmap;
+ int width, height;
+ int radius, d_angle, factor1, factor2;
+ int offset, d_angle_offset, dir, density;
- XSync (dpy, True);
- sleep (5);
+ XWindowAttributes xgwa;
+ XGetWindowAttributes (dpy, window, &xgwa);
+ width = xgwa.width;
+ height = xgwa.height;
+ cmap = xgwa.colormap;
+
+ radius = min (width, height) / 2;
+
+ d_angle = 0;
+ factor1 = (random() % 8) + 1;
+ do {
+ factor2 = (random() % 8) + 1;
+ } while (factor1 == factor2);
- for (i = 0; i < height; i++)
+ dir = (random() & 1) ? 1 : -1;
+ d_angle_offset = random() % 360;
+ offset = ((random() % ((360 / 4) - 1)) + 1) / 4;
+ density = 1 << ((random() % 4) + 4); /* Higher density, higher angles */
+
+ if (mono_p)
+ XSetForeground (dpy, draw_gc, default_fg_pixel);
+ else
{
- int y = (random () % height);
- XDrawLine (dpy, window, erase_gc, 0, y, width, y);
- XFlush (dpy);
- if ((i % 50) == 0)
- usleep (10000);
+ hsv_to_rgb (random () % 360, frand (1.0), frand (0.5) + 0.5,
+ &color->red, &color->green, &color->blue);
+ if ((*got_color = XAllocColor (dpy, cmap, color)))
+ XSetForeground (dpy, draw_gc, color->pixel);
+ else
+ XSetForeground (dpy, draw_gc, default_fg_pixel);
}
- XClearWindow (dpy, window);
- if (got_color) XFreeColors (dpy, cmap, &color.pixel, 1, 0);
- XSync (dpy, True);
+ trig (dpy, window, d_angle, factor1, factor2,
+ offset, d_angle_offset, dir, density);
+}
+
+static void
+random_helix_or_trig (Display *dpy, Window window)
+{
+ Bool free_color = False;
+ XColor color;
+ int width, height;
+ XWindowAttributes xgwa;
+ Colormap cmap;
+ XGetWindowAttributes (dpy, window, &xgwa);
+ width = xgwa.width;
+ height = xgwa.height;
+ cmap = xgwa.colormap;
+
+ if (random() & 1)
+ random_helix(dpy, window, &color, &free_color);
+ else
+ random_trig(dpy, window, &color, &free_color);
+
+ XSync (dpy, False);
+ screenhack_handle_events (dpy);
+ sleep ( sleep_time );
+
+ screenhack_handle_events (dpy);
+ erase_full_window(dpy, window);
+
+ if (free_color) XFreeColors (dpy, cmap, &color.pixel, 1, 0);
+ XSync (dpy, False);
+ screenhack_handle_events (dpy);
sleep (1);
}
char *progclass = "Helix";
char *defaults [] = {
- "Helix.background: black", /* to placate SGI */
+ ".background: black",
+ "*delay: 5",
+ "*subdelay: 0",
0
};
-XrmOptionDescRec options [] = { { 0, } };
-int options_size = 0;
+XrmOptionDescRec options [] = {
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { "-subdelay", ".subdelay", XrmoptionSepArg, 0 },
+ { 0, 0, 0, 0 },
+};
+int options_size = (sizeof (options) / sizeof (options[0]));
void
-screenhack (dpy, window)
- Display *dpy;
- Window window;
+screenhack (Display *dpy, Window window)
{
+ sleep_time = get_integer_resource("delay", "Integer");
+ subdelay = get_integer_resource("subdelay", "Integer");
init_helix (dpy, window);
while (1)
- random_helix (dpy, window);
+ random_helix_or_trig (dpy, window);
}
projects / xscreensaver / blobdiff