-/* xscreensaver, Copyright (c) 1992 Jamie Zawinski <jwz@mcom.com>
+/* xscreensaver, Copyright (c) 1992, 1995, 1996, 1997, 1998, 2001
+ * 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
/* Simulation of a pair of quasi-gravitational fields, maybe sorta kinda
a little like the strong and weak electromagnetic forces. Derived from
- a Lispm screensaver by John Pezaris <pz@mit.edu>.
+ a Lispm screensaver by John Pezaris <pz@mit.edu>. Mouse control and
+ viscosity added by "Philip Edward Cutone, III" <pc2d+@andrew.cmu.edu>.
John sez:
- The simulation started out as a purely accurate gravitational simulation,
- but, with constant simulation step size, I quickly realized the field being
- simulated while grossly gravitational was, in fact, non-conservative. It
- also had the rather annoying behavior of dealing very badly with colliding
- orbs. Therefore, I implemented a negative-gravity region (with two
- thresholds; as I read your code, you only implemented one) to prevent orbs
- from every coming too close together, and added a viscosity factor if the
- speed of any orb got too fast. This provides a nice stable system with
- interesting behavior.
-
- I had experimented with a number of fields including the van der Waals
- force (very interesting orbiting behavior) and 1/r^3 gravity (not as
- interesting as 1/r^2). An even normal viscosity (rather than the
- thresholded version to bleed excess energy) is also not interesting.
- The 1/r^2, -1/r^2, -10/r^2 thresholds proved not only robust but also
- interesting -- the orbs never collided and the threshold viscosity fixed
- the non-conservational problem.
- */
+ The simulation started out as a purely accurate gravitational
+ simulation, but, with constant simulation step size, I quickly
+ realized the field being simulated while grossly gravitational
+ was, in fact, non-conservative. It also had the rather annoying
+ behavior of dealing very badly with colliding orbs. Therefore,
+ I implemented a negative-gravity region (with two thresholds; as
+ I read your code, you only implemented one) to prevent orbs from
+ every coming too close together, and added a viscosity factor if
+ the speed of any orb got too fast. This provides a nice stable
+ system with interesting behavior.
+
+ I had experimented with a number of fields including the van der
+ Waals force (very interesting orbiting behavior) and 1/r^3
+ gravity (not as interesting as 1/r^2). An even normal viscosity
+ (rather than the thresholded version to bleed excess energy) is
+ also not interesting. The 1/r^2, -1/r^2, -10/r^2 thresholds
+ proved not only robust but also interesting -- the orbs never
+ collided and the threshold viscosity fixed the
+ non-conservational problem.
+
+ Philip sez:
+ > An even normal viscosity (rather than the thresholded version to
+ > bleed excess energy) is also not interesting.
+
+ unless you make about 200 points.... set the viscosity to about .8
+ and drag the mouse through it. it makes a nice wave which travels
+ through the field.
+
+ And (always the troublemaker) Joe Keane <jgk@jgk.org> sez:
+
+ Despite what John sez, the field being simulated is always
+ conservative. The real problem is that it uses a simple hack,
+ computing acceleration *based only on the starting position*,
+ instead of a real differential equation solver. Thus you'll
+ always have energy coming out of nowhere, although it's most
+ blatant when balls get close together. If it were done right,
+ you wouldn't need viscosity or artificial limits on how close
+ the balls can get.
+
+ Matt <straitm@carleton.edu> sez:
+
+ Added a switch to remove the walls.
+
+ Added a switch to make the threshold viscosity optional. If
+ nomaxspeed is specified, then balls going really fast do not
+ recieve special treatment.
+
+ I've made tail mode prettier by eliminating the first erase line
+ that drew from the upper left corner to the starting position of
+ each point.
+
+ Made the balls in modes other than "balls" bounce exactly at the
+ walls. (Because the graphics for different modes are drawn
+ differently with respect to the "actual" position of the point,
+ they used to be able to run somewhat past the walls, or bounce
+ before hitting them.)
+
+ Added an option to output each ball's speed in the form of a bar
+ graph drawn on the same window as the balls. If only x or y is
+ selected, they will be represented on the appropriate axis down
+ the center of the window. If both are selected, they will both
+ be displayed along the diagonal such that the x and y bars for
+ each point start at the same place. If speed is selected, the
+ speed will be displayed down the left side. */
-#include "screenhack.h"
-#include "spline.h"
#include <stdio.h>
#include <math.h>
-#ifdef VMS
-#define M_PI 3.14159265358979323846
-#endif
-#if __STDC__
-#include <math.h> /* for M_PI */
-#endif
+#include "screenhack.h"
+#include "spline.h"
struct ball {
- float x, y;
- float vx, vy;
- float dx, dy;
- float mass;
+ double x, y;
+ double vx, vy;
+ double dx, dy;
+ double mass;
int size;
- XColor color;
+ int pixel_index;
int hue;
};
-static unsigned int default_fg_pixel;
static struct ball *balls;
+static double *x_vels;
+static double *y_vels;
+static double *speeds;
static int npoints;
static int threshold;
static int delay;
static int segments;
static Bool glow_p;
static Bool orbit_p;
+static Bool walls_p;
+static Bool maxspeed_p;
+static Bool cbounce_p;
static XPoint *point_stack;
-static int point_stack_size, point_stack_fp, pixel_stack_fp, pixel_stack_size;
-static unsigned long *pixel_stack;
-static unsigned int color_shift;
+static int point_stack_size, point_stack_fp;
+static XColor *colors;
+static int ncolors;
+static int fg_index;
+static int color_shift;
+Bool no_erase_yet; /* for tail mode fix */
+
+/*flip mods for mouse interaction*/
+static Bool mouse_p;
+int mouse_x, mouse_y, mouse_mass, root_x, root_y;
+static double viscosity;
static enum object_mode {
ball_mode, line_mode, polygon_mode, spline_mode, spline_filled_mode,
tail_mode
} mode;
-static enum color_mode {
- cycle_mode, random_mode
-} cmode;
+static enum graph_mode {
+ graph_none, graph_x, graph_y, graph_both, graph_speed
+} graph_mode;
static GC draw_gc, erase_gc;
+/* The normal (and max) width for a graph bar */
+#define BAR_SIZE 11
#define MAX_SIZE 16
-
#define min(a,b) ((a)<(b)?(a):(b))
#define max(a,b) ((a)>(b)?(a):(b))
static void
-init_balls (dpy, window)
- Display *dpy;
- Window window;
+init_balls (Display *dpy, Window window)
{
int i;
XWindowAttributes xgwa;
int xlim, ylim, midx, midy, r, vx, vy;
double th;
Colormap cmap;
- char *mode_str;
+ char *mode_str, *graph_mode_str;
+
XGetWindowAttributes (dpy, window, &xgwa);
xlim = xgwa.width;
ylim = xgwa.height;
cmap = xgwa.colormap;
midx = xlim/2;
midy = ylim/2;
+ walls_p = get_boolean_resource ("walls", "Boolean");
+
+ /* if there aren't walls, don't set a limit on the radius */
r = get_integer_resource ("radius", "Integer");
- if (r <= 0 || r > min (xlim/2, ylim/2))
+ if (r <= 0 || (r > min (xlim/2, ylim/2) && walls_p) )
r = min (xlim/2, ylim/2) - 50;
+
vx = get_integer_resource ("vx", "Integer");
vy = get_integer_resource ("vy", "Integer");
+
npoints = get_integer_resource ("points", "Integer");
if (npoints < 1)
npoints = 3 + (random () % 5);
balls = (struct ball *) malloc (npoints * sizeof (struct ball));
+
+ no_erase_yet = 1; /* for tail mode fix */
+
segments = get_integer_resource ("segments", "Integer");
if (segments < 0) segments = 1;
+
threshold = get_integer_resource ("threshold", "Integer");
if (threshold < 0) threshold = 0;
+
delay = get_integer_resource ("delay", "Integer");
- if (delay < 0) delay = 0;
+ if (delay < 0) delay = 0;
+
global_size = get_integer_resource ("size", "Integer");
if (global_size < 0) global_size = 0;
+
glow_p = get_boolean_resource ("glow", "Boolean");
+
orbit_p = get_boolean_resource ("orbit", "Boolean");
+
+ maxspeed_p = get_boolean_resource ("maxspeed", "Boolean");
+
+ cbounce_p = get_boolean_resource ("cbounce", "Boolean");
+
color_shift = get_integer_resource ("colorShift", "Integer");
- if (color_shift >= 360) color_shift = 5;
+ if (color_shift <= 0) color_shift = 5;
+
+ /*flip mods for mouse interaction*/
+ mouse_p = get_boolean_resource ("mouse", "Boolean");
+ mouse_mass = get_integer_resource ("mouseSize", "Integer");
+ mouse_mass = mouse_mass * mouse_mass *10;
+
+ viscosity = get_float_resource ("viscosity", "Float");
mode_str = get_string_resource ("mode", "Mode");
if (! mode_str) mode = ball_mode;
- else if (!strcmp (mode_str, "balls")) mode = ball_mode;
- else if (!strcmp (mode_str, "lines")) mode = line_mode;
- else if (!strcmp (mode_str, "polygons")) mode = polygon_mode;
- else if (!strcmp (mode_str, "tails")) mode = tail_mode;
- else if (!strcmp (mode_str, "splines")) mode = spline_mode;
- else if (!strcmp (mode_str, "filled-splines")) mode = spline_filled_mode;
+ else if (!strcmp (mode_str, "balls")) mode = ball_mode;
+ else if (!strcmp (mode_str, "lines")) mode = line_mode;
+ else if (!strcmp (mode_str, "polygons")) mode = polygon_mode;
+ else if (!strcmp (mode_str, "tails")) mode = tail_mode;
+ else if (!strcmp (mode_str, "splines")) mode = spline_mode;
+ else if (!strcmp (mode_str, "filled-splines"))mode = spline_filled_mode;
else {
fprintf (stderr,
"%s: mode must be balls, lines, tails, polygons, splines, or\n\
exit (1);
}
- mode_str = get_string_resource ("colorMode", "ColorMode");
- if (! mode_str) cmode = cycle_mode;
- else if (!strcmp (mode_str, "cycle")) cmode = cycle_mode;
- else if (!strcmp (mode_str, "random")) cmode = random_mode;
+ graph_mode_str = get_string_resource ("graphmode", "Mode");
+ if (! graph_mode_str) graph_mode = graph_none;
+ else if (!strcmp (graph_mode_str, "x")) graph_mode = graph_x;
+ else if (!strcmp (graph_mode_str, "y")) graph_mode = graph_y;
+ else if (!strcmp (graph_mode_str, "both")) graph_mode = graph_both;
+ else if (!strcmp (graph_mode_str, "speed")) graph_mode = graph_speed;
+ else if (!strcmp (graph_mode_str, "none")) graph_mode = graph_none;
else {
- fprintf (stderr, "%s: colorMode must be cycle or random, not \"%s\"\n",
- progname, mode_str);
+ fprintf (stderr,
+ "%s: graphmode must be speed, x, y, both, or none, not \"%s\"\n",
+ progname, graph_mode_str);
exit (1);
}
+ /* only allocate memory if it is needed */
+ if(graph_mode != graph_none)
+ {
+ if(graph_mode == graph_x || graph_mode == graph_both)
+ x_vels = (double *) malloc (npoints * sizeof (double));
+ if(graph_mode == graph_y || graph_mode == graph_both)
+ y_vels = (double *) malloc (npoints * sizeof (double));
+ if(graph_mode == graph_speed)
+ speeds = (double *) malloc (npoints * sizeof (double));
+ }
+
if (mode != ball_mode && mode != tail_mode) glow_p = False;
if (mode == polygon_mode && npoints < 3)
mode = line_mode;
+ ncolors = get_integer_resource ("colors", "Colors");
+ if (ncolors < 2) ncolors = 2;
+ if (ncolors <= 2) mono_p = True;
+ colors = 0;
+
+ if (!mono_p)
+ {
+ fg_index = 0;
+ switch (mode)
+ {
+ case ball_mode:
+ if (glow_p)
+ {
+ int H = random() % 360;
+ double S1 = 0.25;
+ double S2 = 1.00;
+ double V = frand(0.25) + 0.75;
+ colors = (XColor *) malloc(sizeof(*colors) * (ncolors+1));
+ make_color_ramp (dpy, cmap, H, S1, V, H, S2, V, colors, &ncolors,
+ False, True, False);
+ }
+ else
+ {
+ ncolors = npoints;
+ colors = (XColor *) malloc(sizeof(*colors) * (ncolors+1));
+ make_random_colormap (dpy, xgwa.visual, cmap, colors, &ncolors,
+ True, True, False, True);
+ }
+ break;
+ case line_mode:
+ case polygon_mode:
+ case spline_mode:
+ case spline_filled_mode:
+ case tail_mode:
+ colors = (XColor *) malloc(sizeof(*colors) * (ncolors+1));
+ make_smooth_colormap (dpy, xgwa.visual, cmap, colors, &ncolors,
+ True, False, True);
+ break;
+ default:
+ abort ();
+ }
+ }
+
+ if (!mono_p && ncolors <= 2)
+ {
+ if (colors) free (colors);
+ colors = 0;
+ mono_p = True;
+ }
+
if (mode != ball_mode)
{
int size = (segments ? segments : 1);
point_stack_size = size * (npoints + 1);
point_stack = (XPoint *) calloc (point_stack_size, sizeof (XPoint));
point_stack_fp = 0;
- if (segments > 0)
- pixel_stack_size = segments;
- else
- pixel_stack_size = (360 / color_shift);
- pixel_stack = (unsigned long *)
- calloc (pixel_stack_size, sizeof (unsigned int));
- pixel_stack_fp = 0;
}
gcv.line_width = (mode == tail_mode
: 1);
gcv.cap_style = (mode == tail_mode ? CapRound : CapButt);
- gcv.foreground = default_fg_pixel =
- get_pixel_resource ("foreground", "Foreground", dpy, cmap);
+ if (mono_p)
+ gcv.foreground = get_pixel_resource("foreground", "Foreground", dpy, cmap);
+ else
+ gcv.foreground = colors[fg_index].pixel;
draw_gc = XCreateGC (dpy, window, GCForeground|GCLineWidth|GCCapStyle, &gcv);
- gcv.foreground = get_pixel_resource ("background", "Background", dpy, cmap);
+
+ gcv.foreground = get_pixel_resource("background", "Background", dpy, cmap);
erase_gc = XCreateGC (dpy, window, GCForeground|GCLineWidth|GCCapStyle,&gcv);
- if (!mono_p && mode != ball_mode)
- for (i = 0; i < pixel_stack_size; i++)
- {
- XColor color;
- color.pixel = default_fg_pixel;
- XQueryColor (dpy, cmap, &color);
- if (!XAllocColor (dpy, cmap, &color)) abort ();
- pixel_stack [i] = color.pixel;
- }
#define rand_size() min (MAX_SIZE, 8 + (random () % (MAX_SIZE - 9)))
balls [i].vx = vx ? vx : ((6.0 - (random () % 11)) / 8.0);
balls [i].vy = vy ? vy : ((6.0 - (random () % 11)) / 8.0);
}
- balls [i].color.pixel = default_fg_pixel;
- balls [i].color.flags = DoRed | DoGreen | DoBlue;
- if (!mono_p)
- {
- if (i != 0 && (glow_p || mode != ball_mode))
- balls [i].hue = balls [0].hue;
- else
- balls [i].hue = random () % 360;
- hsv_to_rgb (balls [i].hue, 1.0, 1.0,
- &balls [i].color.red, &balls [i].color.green,
- &balls [i].color.blue);
- if (!XAllocColor (dpy, cmap, &balls [i].color))
- mono_p = True; /* just give up */
- }
+ if (mono_p || mode != ball_mode)
+ balls [i].pixel_index = -1;
+ else if (glow_p)
+ balls [i].pixel_index = 0;
+ else
+ balls [i].pixel_index = random() % ncolors;
}
+ /* This lets modes where the points don't really have any size use the whole
+ window. Otherwise, since the points still have a positive size
+ assigned to them, they will be bounced somewhat early. Mass and size are
+ seperate, so this shouldn't cause problems. It's a bit kludgy, tho.
+ */
+ if(mode == line_mode || mode == spline_mode ||
+ mode == spline_filled_mode || mode == polygon_mode)
+ {
+ for(i = 1; i < npoints; i++)
+ {
+ balls[i].size = 0;
+ }
+ }
+
if (orbit_p)
{
double a = 0;
}
if (mono_p) glow_p = False;
+
XClearWindow (dpy, window);
}
static void
-compute_force (i, dx_ret, dy_ret)
- int i;
- float *dx_ret, *dy_ret;
+compute_force (int i, double *dx_ret, double *dy_ret)
{
int j;
+ double x_dist, y_dist, dist, dist2;
*dx_ret = 0;
*dy_ret = 0;
for (j = 0; j < npoints; j++)
{
- float x_dist, y_dist, dist, dist2;
-
if (i == j) continue;
x_dist = balls [j].x - balls [i].x;
y_dist = balls [j].y - balls [i].y;
if (dist > 0.1) /* the balls are not overlapping */
{
- float new_acc = ((balls[j].mass / dist2) *
- ((dist < threshold) ? -1.0 : 1.0));
- float new_acc_dist = new_acc / dist;
+ double new_acc = ((balls[j].mass / dist2) *
+ ((dist < threshold) ? -1.0 : 1.0));
+ double new_acc_dist = new_acc / dist;
+ *dx_ret += new_acc_dist * x_dist;
+ *dy_ret += new_acc_dist * y_dist;
+ }
+ else
+ { /* the balls are overlapping; move randomly */
+ *dx_ret += (frand (10.0) - 5.0);
+ *dy_ret += (frand (10.0) - 5.0);
+ }
+ }
+
+ if (mouse_p)
+ {
+ x_dist = mouse_x - balls [i].x;
+ y_dist = mouse_y - balls [i].y;
+ dist2 = (x_dist * x_dist) + (y_dist * y_dist);
+ dist = sqrt (dist2);
+
+ if (dist > 0.1) /* the balls are not overlapping */
+ {
+ double new_acc = ((mouse_mass / dist2) *
+ ((dist < threshold) ? -1.0 : 1.0));
+ double new_acc_dist = new_acc / dist;
*dx_ret += new_acc_dist * x_dist;
*dy_ret += new_acc_dist * y_dist;
}
}
}
+
+/* Draws meters along the diagonal for the x velocity */
+static void
+draw_meter_x(Display *dpy, Window window, GC draw_gc,
+ struct ball *balls, int i, int alone)
+{
+ XWindowAttributes xgwa;
+ int x1,x2,y,w1,w2,h;
+ XGetWindowAttributes (dpy, window, &xgwa);
+
+ /* set the width of the bars to use */
+ if(xgwa.height < BAR_SIZE*npoints)
+ {
+ y = i*(xgwa.height/npoints);
+ h = (xgwa.height/npoints) - 2;
+ }
+ else
+ {
+ y = BAR_SIZE*i;
+ h = BAR_SIZE - 2;
+ }
+
+ if(alone)
+ {
+ x1 = xgwa.width/2;
+ x2 = x1;
+ }
+ else
+ {
+ x1 = i*(h+2);
+ if(x1 < i)
+ x1 = i;
+ x2 = x1;
+ }
+
+ if(y<1) y=i;
+ if(h<1) h=1;
+
+ w1 = (int)(20*x_vels[i]);
+ w2 = (int)(20*balls[i].vx);
+ x_vels[i] = balls[i].vx;
+
+ if (w1<0) {
+ w1=-w1;
+ x1=x1-w1;
+ }
+ if (w2<0) {
+ w2=-w2;
+ x2=x2-w2;
+ }
+ XDrawRectangle(dpy,window,erase_gc,x1+(h+2)/2,y,w1,h);
+ XDrawRectangle(dpy,window,draw_gc,x2+(h+2)/2,y,w2,h);
+}
+
+/* Draws meters along the diagonal for the y velocity.
+ Is there some way to make draw_meter_x and draw_meter_y
+ one function instead of two without making them completely unreadable?
+*/
+static void
+draw_meter_y (Display *dpy, Window window, GC draw_gc,
+ struct ball *balls, int i, int alone)
+{
+ XWindowAttributes xgwa;
+ int y1,y2,x,h1,h2,w;
+ XGetWindowAttributes (dpy, window, &xgwa);
+
+ if(xgwa.height < BAR_SIZE*npoints){ /*needs to be height still */
+ x = i*(xgwa.height/npoints);
+ w = (xgwa.height/npoints) - 2;
+ }
+ else{
+ x = BAR_SIZE*i;
+ w = BAR_SIZE - 2;
+ }
+
+ if(alone)
+ {
+ y1 = xgwa.height/2;
+ y2 = y1;
+ }
+ else
+ {
+ y1 = i*(w+2);
+ if(y1 < i)
+ y1 = i;
+ y2 = y1;
+ }
+
+ if(x < 1) x = i;
+ if(w < 1) w = 1;
+
+ h1 = (int)(20*y_vels[i]);
+ h2 = (int)(20*balls[i].vy);
+ y_vels[i] = balls[i].vy;
+
+ if (h1<0) {
+ h1=-h1;
+ y1=y1-h1;
+ }
+ if (h2<0) {
+ h2=-h2;
+ y2=y2-h2;
+ }
+ XDrawRectangle(dpy,window,erase_gc,x,y1+(w+2)/2,w,h1);
+ XDrawRectangle(dpy,window,draw_gc,x,y2+(w+2)/2,w,h2);
+}
+
+
+/* Draws meters of the total speed of the balls */
static void
-run_balls (dpy, window)
- Display *dpy;
- Window window;
+draw_meter_speed (Display *dpy, Window window, GC draw_gc,
+ struct ball *balls, int i)
+{
+ XWindowAttributes xgwa;
+ int y,x1,x2,h,w1,w2;
+ XGetWindowAttributes (dpy, window, &xgwa);
+
+ if(xgwa.height < BAR_SIZE*npoints)
+ {
+ y = i*(xgwa.height/npoints);
+ h = (xgwa.height/npoints) - 2;
+ }
+ else{
+ y = BAR_SIZE*i;
+ h = BAR_SIZE - 2;
+ }
+
+ x1 = 0;
+ x2 = x1;
+
+ if(y < 1) y = i;
+ if(h < 1) h = 1;
+
+ w1 = (int)(5*speeds[i]);
+ w2 = (int)(5*(balls[i].vy*balls[i].vy+balls[i].vx*balls[i].vx));
+ speeds[i] = balls[i].vy*balls[i].vy+balls[i].vx*balls[i].vx;
+
+ XDrawRectangle(dpy,window,erase_gc,x1,y,w1,h);
+ XDrawRectangle(dpy,window,draw_gc, x2,y,w2,h);
+}
+
+static void
+run_balls (Display *dpy, Window window, int total_ticks)
{
int last_point_stack_fp = point_stack_fp;
static int tick = 500, xlim, ylim;
static Colormap cmap;
- int i;
+
+ Window root1, child1; /*flip mods for mouse interaction*/
+ unsigned int mask;
+
+ int i, radius = global_size/2;
+ if(global_size == 0)
+ radius = (MAX_SIZE / 3);
+
+ if(graph_mode != graph_none)
+ {
+ if(graph_mode == graph_both)
+ {
+ for(i = 0; i < npoints; i++)
+ {
+ draw_meter_x(dpy,window,draw_gc, balls, i, 0);
+ draw_meter_y(dpy,window,draw_gc, balls, i, 0);
+ }
+ }
+ else if(graph_mode == graph_x)
+ {
+ for(i = 0; i < npoints; i++)
+ {
+ draw_meter_x(dpy,window,draw_gc, balls, i, 1);
+ }
+ }
+ else if(graph_mode == graph_y)
+ {
+ for(i = 0; i < npoints; i++)
+ {
+ draw_meter_y(dpy,window,draw_gc, balls, i, 1);
+ }
+ }
+ else if(graph_mode == graph_speed)
+ {
+ for(i = 0; i < npoints; i++)
+ {
+ draw_meter_speed(dpy,window,draw_gc, balls, i);
+ }
+ }
+
+ }
+
+ if (mouse_p)
+ {
+ XQueryPointer(dpy, window, &root1, &child1,
+ &root_x, &root_y, &mouse_x, &mouse_y, &mask);
+ }
if (tick++ == 500)
{
/* move the balls according to the forces now in effect */
for (i = 0; i < npoints; i++)
{
- float old_x = balls[i].x;
- float old_y = balls[i].y;
- float new_x, new_y;
+ double old_x = balls[i].x;
+ double old_y = balls[i].y;
+ double new_x, new_y;
int size = balls[i].size;
balls[i].vx += balls[i].dx;
balls[i].vy += balls[i].dy;
- /* don't let them get too fast: impose a terminal velocity
- (actually, make the medium have friction) */
- if (balls[i].vx > 10)
+ /* "don't let them get too fast: impose a terminal velocity
+ (actually, make the medium have friction)"
+ Well, what this first step really does is give the medium a
+ viscosity of .9 for balls going over the speed limit. Anyway,
+ this is now optional
+ */
+ if (balls[i].vx > 10 && maxspeed_p)
{
balls[i].vx *= 0.9;
balls[i].dx = 0;
}
- if (balls[i].vy > 10)
+ else if (viscosity != 1)
+ {
+ balls[i].vx *= viscosity;
+ }
+
+ if (balls[i].vy > 10 && maxspeed_p)
{
balls[i].vy *= 0.9;
balls[i].dy = 0;
}
+ else if (viscosity != 1)
+ {
+ balls[i].vy *= viscosity;
+ }
balls[i].x += balls[i].vx;
balls[i].y += balls[i].vy;
- /* bounce off the walls */
- if (balls[i].x >= (xlim - balls[i].size))
- {
- balls[i].x = (xlim - balls[i].size - 1);
- if (balls[i].vx > 0)
- balls[i].vx = -balls[i].vx;
- }
- if (balls[i].y >= (ylim - balls[i].size))
- {
- balls[i].y = (ylim - balls[i].size - 1);
- if (balls[i].vy > 0)
- balls[i].vy = -balls[i].vy;
- }
- if (balls[i].x <= 0)
- {
- balls[i].x = 0;
- if (balls[i].vx < 0)
- balls[i].vx = -balls[i].vx;
- }
- if (balls[i].y <= 0)
- {
- balls[i].y = 0;
- if (balls[i].vy < 0)
- balls[i].vy = -balls[i].vy;
- }
+ /* bounce off the walls if desired
+ note: a ball is actually its upper left corner */
+ if(walls_p)
+ {
+ if(cbounce_p) /* with correct bouncing */
+ {
+ /* so long as it's out of range, keep bouncing */
+
+ while( (balls[i].x >= (xlim - balls[i].size)) ||
+ (balls[i].y >= (ylim - balls[i].size)) ||
+ (balls[i].x <= 0) ||
+ (balls[i].y <= 0) )
+ {
+ if (balls[i].x >= (xlim - balls[i].size))
+ {
+ balls[i].x = (2*(xlim - balls[i].size) - balls[i].x);
+ balls[i].vx = -balls[i].vx;
+ }
+ if (balls[i].y >= (ylim - balls[i].size))
+ {
+ balls[i].y = (2*(ylim - balls[i].size) - balls[i].y);
+ balls[i].vy = -balls[i].vy;
+ }
+ if (balls[i].x <= 0)
+ {
+ balls[i].x = -balls[i].x;
+ balls[i].vx = -balls[i].vx;
+ }
+ if (balls[i].y <= 0)
+ {
+ balls[i].y = -balls[i].y;
+ balls[i].vy = -balls[i].vy;
+ }
+ }
+ }
+ else /* with old bouncing */
+ {
+ if (balls[i].x >= (xlim - balls[i].size))
+ {
+ balls[i].x = (xlim - balls[i].size - 1);
+ if (balls[i].vx > 0) /* why is this check here? */
+ balls[i].vx = -balls[i].vx;
+ }
+ if (balls[i].y >= (ylim - balls[i].size))
+ {
+ balls[i].y = (ylim - balls[i].size - 1);
+ if (balls[i].vy > 0)
+ balls[i].vy = -balls[i].vy;
+ }
+ if (balls[i].x <= 0)
+ {
+ balls[i].x = 0;
+ if (balls[i].vx < 0)
+ balls[i].vx = -balls[i].vx;
+ }
+ if (balls[i].y <= 0)
+ {
+ balls[i].y = 0;
+ if (balls[i].vy < 0)
+ balls[i].vy = -balls[i].vy;
+ }
+ }
+ }
new_x = balls[i].x;
new_y = balls[i].y;
- /* make color saturation be related to particle acceleration. */
- if (glow_p)
+ if (!mono_p)
{
- float limit = 0.5;
- double s, v, fraction;
- float vx = balls [i].dx;
- float vy = balls [i].dy;
- XColor new_color;
- if (vx < 0) vx = -vx;
- if (vy < 0) vy = -vy;
- fraction = vx + vy;
- if (fraction > limit) fraction = limit;
-
- s = 1 - (fraction / limit);
- v = 1.0;
-
- s = (s * 0.75) + 0.25;
-
- hsv_to_rgb (balls [i].hue, s, v,
- &new_color.red, &new_color.green, &new_color.blue);
- if (XAllocColor (dpy, cmap, &new_color))
+ if (mode == ball_mode)
{
- XFreeColors (dpy, cmap, &balls [i].color.pixel, 1, 0);
- balls [i].color = new_color;
+ if (glow_p)
+ {
+ /* make color saturation be related to particle
+ acceleration. */
+ double limit = 0.5;
+ double s, fraction;
+ double vx = balls [i].dx;
+ double vy = balls [i].dy;
+ if (vx < 0) vx = -vx;
+ if (vy < 0) vy = -vy;
+ fraction = vx + vy;
+ if (fraction > limit) fraction = limit;
+
+ s = 1 - (fraction / limit);
+ balls[i].pixel_index = (ncolors * s);
+ }
+ XSetForeground (dpy, draw_gc,
+ colors[balls[i].pixel_index].pixel);
}
}
if (mode == ball_mode)
{
- if (!mono_p)
- XSetForeground (dpy, draw_gc, balls [i].color.pixel);
XFillArc (dpy, window, erase_gc, (int) old_x, (int) old_y,
size, size, 0, 360*64);
XFillArc (dpy, window, draw_gc, (int) new_x, (int) new_y,
size, size, 0, 360*64);
}
- if (mode != ball_mode)
+ else
{
point_stack [point_stack_fp].x = new_x;
point_stack [point_stack_fp].y = new_y;
abort ();
if (!mono_p)
{
- XColor color2;
- color2 = balls [0].color;
- switch (cmode)
+ static int tick = 0;
+ if (tick++ == color_shift)
{
- case cycle_mode:
- cycle_hue (&color2, color_shift);
- break;
- case random_mode:
- color2.red = random () % 65535;
- color2.green = random () % 65535;
- color2.blue = random () % 65535;
- break;
- default:
- abort ();
+ tick = 0;
+ fg_index = (fg_index + 1) % ncolors;
+ XSetForeground (dpy, draw_gc, colors[fg_index].pixel);
}
-
- if (!XAllocColor (dpy, cmap, &color2))
- {
- color2 = balls [0].color;
- if (!XAllocColor (dpy, cmap, &balls [0].color))
- abort ();
- }
- pixel_stack [pixel_stack_fp++] = balls [0].color.pixel;
- if (pixel_stack_fp >= pixel_stack_size)
- pixel_stack_fp = 0;
- XFreeColors (dpy, cmap, pixel_stack + pixel_stack_fp, 1, 0);
- balls [0].color = color2;
- XSetForeground (dpy, draw_gc, balls [0].color.pixel);
}
}
break;
case tail_mode:
{
- int i;
for (i = 0; i < npoints; i++)
{
int index = point_stack_fp + i;
int next_index = (index + (npoints + 1)) % point_stack_size;
- XDrawLine (dpy, window, erase_gc,
- point_stack [index].x,
- point_stack [index].y,
- point_stack [next_index].x,
- point_stack [next_index].y);
-
+ if(no_erase_yet == 1)
+ {
+ if(total_ticks >= segments)
+ {
+ no_erase_yet = 0;
+ XDrawLine (dpy, window, erase_gc,
+ point_stack [index].x + radius,
+ point_stack [index].y + radius,
+ point_stack [next_index].x + radius,
+ point_stack [next_index].y + radius);
+ }
+ }
+ else
+ {
+ XDrawLine (dpy, window, erase_gc,
+ point_stack [index].x + radius,
+ point_stack [index].y + radius,
+ point_stack [next_index].x + radius,
+ point_stack [next_index].y + radius);
+ }
index = last_point_stack_fp + i;
next_index = (index - (npoints + 1)) % point_stack_size;
if (next_index < 0) next_index += point_stack_size;
point_stack [next_index].y == 0)
continue;
XDrawLine (dpy, window, draw_gc,
- point_stack [index].x,
- point_stack [index].y,
- point_stack [next_index].x,
- point_stack [next_index].y);
+ point_stack [index].x + radius,
+ point_stack [index].y + radius,
+ point_stack [next_index].x + radius,
+ point_stack [next_index].y + radius);
}
}
break;
case spline_mode:
case spline_filled_mode:
{
- int i;
static spline *s = 0;
if (! s) s = make_spline (npoints);
if (segments > 0)
abort ();
}
- XSync (dpy, True);
+ XSync (dpy, False);
}
\f
char *progclass = "Attraction";
char *defaults [] = {
- "Attraction.background: black", /* to placate SGI */
- "Attraction.foreground: white",
+ ".background: black",
+ ".foreground: white",
"*mode: balls",
+ "*graphmode: none",
"*points: 0",
"*size: 0",
+ "*colors: 200",
"*threshold: 100",
"*delay: 10000",
"*glow: false",
+ "*mouseSize: 10",
+ "*walls: true",
+ "*maxspeed: true",
+ "*cbounce: true",
+ "*mouse: false",
+ "*viscosity: 1",
"*orbit: false",
"*colorShift: 3",
- "*segments: 100",
+ "*segments: 500",
+ "*vMult: 0.9",
0
};
XrmOptionDescRec options [] = {
{ "-mode", ".mode", XrmoptionSepArg, 0 },
+ { "-graphmode", ".graphmode", XrmoptionSepArg, 0 },
+ { "-colors", ".colors", XrmoptionSepArg, 0 },
{ "-points", ".points", XrmoptionSepArg, 0 },
+ { "-color-shift", ".colorShift", XrmoptionSepArg, 0 },
{ "-threshold", ".threshold", XrmoptionSepArg, 0 },
{ "-segments", ".segments", XrmoptionSepArg, 0 },
{ "-delay", ".delay", XrmoptionSepArg, 0 },
{ "-size", ".size", XrmoptionSepArg, 0 },
- { "-color-mode", ".colorMode", XrmoptionSepArg, 0 },
- { "-color-shift", ".colorShift", XrmoptionSepArg, 0 },
{ "-radius", ".radius", XrmoptionSepArg, 0 },
{ "-vx", ".vx", XrmoptionSepArg, 0 },
{ "-vy", ".vy", XrmoptionSepArg, 0 },
{ "-vmult", ".vMult", XrmoptionSepArg, 0 },
+ { "-mouse-size", ".mouseSize", XrmoptionSepArg, 0 },
+ { "-viscosity", ".viscosity", XrmoptionSepArg, 0 },
+ { "-mouse", ".mouse", XrmoptionNoArg, "true" },
+ { "-nomouse", ".mouse", XrmoptionNoArg, "false" },
{ "-glow", ".glow", XrmoptionNoArg, "true" },
{ "-noglow", ".glow", XrmoptionNoArg, "false" },
- { "-orbit", ".orbit", XrmoptionNoArg, "true" }
+ { "-orbit", ".orbit", XrmoptionNoArg, "true" },
+ { "-nowalls", ".walls", XrmoptionNoArg, "false" },
+ { "-walls", ".walls", XrmoptionNoArg, "true" },
+ { "-nomaxspeed", ".maxspeed", XrmoptionNoArg, "false" },
+ { "-maxspeed", ".maxspeed", XrmoptionNoArg, "true" },
+ { "-correct-bounce", ".cbounce", XrmoptionNoArg, "false" },
+ { "-fast-bounce", ".cbounce", XrmoptionNoArg, "true" },
+ { 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)
{
+ /* for tail mode fix */
+ int total_ticks = 0;
+
init_balls (dpy, window);
while (1)
{
- run_balls (dpy, window);
- if (delay) usleep (delay);
+ total_ticks++;
+ run_balls (dpy, window, total_ticks);
+ screenhack_handle_events (dpy);
+ if (delay)
+ usleep (delay);
}
}
projects / xscreensaver / blobdiff