1penrose(6x) XScreenSaver manual penrose(6x)
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6 penrose - draws quasiperiodic tilings
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9 penrose [--display host:display.screen] [--foreground color] [--back‐
10 ground color] [--window] [--root] [--window-id number][--mono] [--in‐
11 stall] [--visual visual] [--ncolors integer] [--delay microseconds]
12 [--size integer] [--ammann] [--no-ammann]
13 [--fps]
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17 The penrose program draws quasiperiodic tilings.
18 See Onoda, Steinhardt, DiVincenzo and Socolar in Phys. Rev. Lett. 60,
20 #25, 1988 or Strandburg in Computers in Physics, Sep/Oct 1991.
21 This implementation uses the simpler version of the growth algorithm,
23 i.e., if there are no forced vertices, a randomly chosen tile is added
24 to a randomly chosen vertex (no preference for those 108 degree an‐
25 gles).
26 There are two essential differences to the algorithm presented in the
28 literature: First, we do not allow the tiling to enclose an untiled
29 area. Whenever this is in danger of happening, we just do not add the
30 tile, hoping for a better random choice the next time. Second, when
31 choosing a vertex randomly, we will take one that lies within the view‐
32 port if available. If this seems to cause enclosures in the forced
33 rule case, we will allow invisible vertices to be chosen.
34 Tiling is restarted whenever one of the following happens: there are no
36 incomplete vertices within the viewport or the tiling has extended a
37 window's length beyond the edge of the window horizontally or verti‐
38 cally or forced rule choice has failed 100 times due to areas about to
39 become enclosed.
40 Although quasiperiodic tilings are produced, the tiles themselves are
42 not penrose tiles (darts and kites). In contrast to penrose tiles,
43 these tiles can be arranged to form a periodic tiling.
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47 penrose accepts the following options:
48 --window
50 Draw on a newly-created window. This is the default.
51 --root Draw on the root window.
53 --window-id number
55 Draw on the specified window.
56 --mono If on a color display, pretend we're on a monochrome display.
58 --install
60 Install a private colormap for the window.
61 --visual visual
63 Specify which visual to use. Legal values are the name of a
64 visual class, or the id number (decimal or hex) of a specific
65 visual.
66 --ncolors integer
68 How many colors should be used (if possible). Default 64. The
69 colors are chosen randomly.
70 --size integer
72 How big the tiles should be. Default 40 pixels.
73 --delay milliseconds
76 How long (in 1/1,000,000'ths of a second) to wait between draw‐
77 ing each tile. Default 10,000 or .01 seconds.
78 --ammann
81 --no-ammann
83 Whether Ammann lines should be added.
84 --fps Display the current frame rate and CPU load.
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89 DISPLAY to get the default host and display number.
90 XENVIRONMENT
92 to get the name of a resource file that overrides the global
93 resources stored in the RESOURCE_MANAGER property.
94 XSCREENSAVER_WINDOW
96 The window ID to use with --root.
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99 X(1), xscreensaver(1), xlock(1)
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102 Copyright © 1996 by Timo Korvola.
103 Permission to use, copy, modify, and distribute this software and its
105 documentation for any purpose and without fee is hereby granted, pro‐
106 vided that the above copyright notice appear in all copies and that
107 both that copyright notice and this permission notice appear in sup‐
108 porting documentation.
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111 Timo Korvola <tkorvola@dopey.hut.fi>, 1996.
112 Ability to run standalone or with xscreensaver added by Jamie Zawinski
114 <jwz@jwz.org>, 10-May-97.
115X Version 11 6.06-1.fc37 (12-Dec-2022) penrose(6x)