1 .TH XScreenSaver 1 "22-mar-93" "X Version 11"
3 attraction - interactions of opposing forces
6 [\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP] [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-points \fIint\fP] [\-threshold \fIint\fP] [\-mode balls | lines | polygons | splines | filled-splines | tails ] [\-color-mode cycle | random] [\-size \fIint\fP] [\-segments \fIint\fP] [\-delay \fIusecs\fP] [\-color-shift \fIdegrees\fP] [\-radius \fIint\fP] [\-vx \fIint\fP] [\-vy \fIint\fP] [\-glow] [\-noglow] [\-orbit]
8 The \fIattraction\fP program has several visually different modes of
9 operation, all of which are based on the interactions of a set of control
10 points which attract each other up to a certain distance, and then begin
11 to repel each other. The attraction/repulsion is proportional to the
12 distance between any two particles.
15 accepts the following options:
18 Draw on a newly-created window. This is the default.
21 Draw on the root window.
24 If on a color display, pretend we're on a monochrome display.
27 How many control points should be used, or 0 to select the number randomly.
28 Default 0. Between 3 and 15 works best.
30 .B \-threshold integer
31 The distance (in pixels) from each particle at which the attractive force
32 becomes repulsive. Default 100.
34 .B \-mode "balls | lines | polygons | tails | splines | filled-splines"
35 In \fIballs\fP mode (the default) the control points are drawn as filled
36 circles. The larger the circle, the more massive the particle.
38 In \fIlines\fP mode, the control points are connected by straight lines;
39 the effect is something like \fIqix\fP.
41 In \fIpolygons\fP mode, the control points are connected by straight
42 lines, and filled in. This is most interesting in color.
44 In \fIsplines\fP mode, a closed spline is interpolated from the control
47 In \fIfilled-splines\fP mode, the splines are filled in instead of being
48 outlines. This is most interesting in color.
50 In \fItails\fP mode, the path which each particle follows is indicated
51 by a worm-like trail, whose length is controlled by the \fIsegments\fP
54 .B \-color-mode cycle | random
55 Whether colors should cycle through the spectrum, or be picked randomly.
58 The size of the balls in pixels, or 0, meaning to select the sizes
59 randomly (the default.) If this is specified, then all balls will be
60 the same size. This option has an effect in all modes, since the ``size''
61 of the balls controls their mass.
64 If in \fIlines\fP or \fIpolygons\fP mode, how many sets of line segments
65 or polygons should be drawn. Default 100. This has no effect in \fIballs\fP
66 mode. If \fIsegments\fP is 0, then no segments will ever be erased (this
67 is only useful in color.)
69 .B \-delay microseconds
70 How much of a delay should be introduced between steps of the animation.
71 Default 10000, or about 0.01 seconds.
73 .B \-color-shift degrees
74 If on a color display, the color of the line segments or polygons will
75 cycle through the spectrum. This specifies how far the hue of each segment
76 should be from the next, in degrees on the HSV wheel. Default 3.
77 This has no effect in \fIballs\fP mode.
80 The size in pixels of the circle on which the points are initially positioned.
81 The default is slightly smaller than the size of the window.
84 This is consulted only in \fIballs\fP mode. If this is specified, then
85 the saturation of the colors of the points will vary according to their
86 current acceleration. This has the effect that the balls flare brighter
87 when they are reacting to each other most strongly.
89 In \fIglow\fP mode, all of the balls will be drawn the same (random)
90 color, modulo the saturation shifts. In non-glow mode, the balls will
91 each be drawn in a random color that doesn't change.
94 Don't do ``glowing.'' This is the default.
99 Initial velocity of the balls. This has no effect in \fB\-orbit\fP mode.
102 Make the initial force on each ball be tangential to the circle on which
103 they are initially placed, with the right velocity to hold them in orbit
104 about each other. After a while, roundoff errors will cause the orbit
108 In orbit mode, the initial velocity of the balls is multiplied by this;
109 a number less than 1 will make the balls pull closer together, and a larger
110 number will make them move apart. The default is 1, meaning stability.
115 to get the default host and display number.
118 to get the name of a resource file that overrides the global resources
119 stored in the RESOURCE_MANAGER property.
124 Copyright \(co 1992, 1993 by Jamie Zawinski. Permission to use, copy, modify,
125 distribute, and sell this software and its documentation for any purpose is
126 hereby granted without fee, provided that the above copyright notice appear
127 in all copies and that both that copyright notice and this permission notice
128 appear in supporting documentation. No representations are made about the
129 suitability of this software for any purpose. It is provided "as is" without
130 express or implied warranty.
132 Jamie Zawinski <jwz@mcom.com>, 13-aug-92.