| 1 | .TH XScreenSaver 1 "10-May-97" "X Version 11" |
|---|
| 2 | .SH NAME |
|---|
| 3 | penrose - draws quasiperiodic tilings |
|---|
| 4 | .SH SYNOPSIS |
|---|
| 5 | .B penrose |
|---|
| 6 | [\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP] [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-install] [\-visual \fIvisual\fP] [\-ncolors \fIinteger\fP] [\-delay \fImicroseconds\fP] [\-redoDelay \fIseconds\fP] [\-size \fIinteger\fP] [\-ammann] [\-no\-ammann] |
|---|
| 7 | |
|---|
| 8 | .SH DESCRIPTION |
|---|
| 9 | The \fIpenrose\fP program draws quasiperiodic tilings. |
|---|
| 10 | |
|---|
| 11 | See Onoda, Steinhardt, DiVincenzo and Socolar in |
|---|
| 12 | Phys. Rev. Lett. 60, #25, 1988 or |
|---|
| 13 | Strandburg in Computers in Physics, Sep/Oct 1991. |
|---|
| 14 | |
|---|
| 15 | This implementation uses the simpler version of the growth |
|---|
| 16 | algorithm, i.e., if there are no forced vertices, a randomly chosen |
|---|
| 17 | tile is added to a randomly chosen vertex (no preference for those |
|---|
| 18 | 108 degree angles). |
|---|
| 19 | |
|---|
| 20 | There are two essential differences to the algorithm presented in |
|---|
| 21 | the literature: First, we do not allow the tiling to enclose an |
|---|
| 22 | untiled area. Whenever this is in danger of happening, we just |
|---|
| 23 | do not add the tile, hoping for a better random choice the next |
|---|
| 24 | time. Second, when choosing a vertex randomly, we will take |
|---|
| 25 | one that lies withing the viewport if available. If this seems to |
|---|
| 26 | cause enclosures in the forced rule case, we will allow invisible |
|---|
| 27 | vertices to be chosen. |
|---|
| 28 | |
|---|
| 29 | Tiling is restarted whenever one of the following happens: there |
|---|
| 30 | are no incomplete vertices within the viewport or the tiling has |
|---|
| 31 | extended a window's length beyond the edge of the window |
|---|
| 32 | horizontally or vertically or forced rule choice has failed 100 |
|---|
| 33 | times due to areas about to become enclosed. |
|---|
| 34 | |
|---|
| 35 | Although quasiperiodic tilings are produced, the tiles themselves are |
|---|
| 36 | not penrose tiles (darts and kites). In contrast to penrose tiles, |
|---|
| 37 | these tiles can be arranged to form a periodic tiling. |
|---|
| 38 | |
|---|
| 39 | .SH OPTIONS |
|---|
| 40 | .I penrose |
|---|
| 41 | accepts the following options: |
|---|
| 42 | .TP 8 |
|---|
| 43 | .B \-window |
|---|
| 44 | Draw on a newly-created window. This is the default. |
|---|
| 45 | .TP 8 |
|---|
| 46 | .B \-root |
|---|
| 47 | Draw on the root window. |
|---|
| 48 | .TP 8 |
|---|
| 49 | .B \-mono |
|---|
| 50 | If on a color display, pretend we're on a monochrome display. |
|---|
| 51 | .TP 8 |
|---|
| 52 | .B \-install |
|---|
| 53 | Install a private colormap for the window. |
|---|
| 54 | .TP 8 |
|---|
| 55 | .B \-visual \fIvisual\fP |
|---|
| 56 | Specify which visual to use. Legal values are the name of a visual class, |
|---|
| 57 | or the id number (decimal or hex) of a specific visual. |
|---|
| 58 | .TP 8 |
|---|
| 59 | .B \-ncolors \fIinteger\fP |
|---|
| 60 | How many colors should be used (if possible). Default 64. |
|---|
| 61 | The colors are chosen randomly. |
|---|
| 62 | .TP 8 |
|---|
| 63 | .B \-size \fIinteger\fP |
|---|
| 64 | How big the tiles should be. Default 40 pixels. |
|---|
| 65 | |
|---|
| 66 | .TP 8 |
|---|
| 67 | .B \-delay \fImilliseconds\fP |
|---|
| 68 | How long (in 1/1,000,000'ths of a second) to wait between drawing each |
|---|
| 69 | tile. Default 10,000 or .01 seconds. |
|---|
| 70 | |
|---|
| 71 | .TP 8 |
|---|
| 72 | .B \-redoDelay \fIseconds\fP |
|---|
| 73 | How long to wait between starting a completely new tiling. Default 3 seconds. |
|---|
| 74 | |
|---|
| 75 | .TP 8 |
|---|
| 76 | .B \-ammann |
|---|
| 77 | .TP 8 |
|---|
| 78 | .B \-no\-ammann |
|---|
| 79 | Whether Ammann lines should be added. |
|---|
| 80 | |
|---|
| 81 | .SH ENVIRONMENT |
|---|
| 82 | .PP |
|---|
| 83 | .TP 8 |
|---|
| 84 | .B DISPLAY |
|---|
| 85 | to get the default host and display number. |
|---|
| 86 | .TP 8 |
|---|
| 87 | .B XENVIRONMENT |
|---|
| 88 | to get the name of a resource file that overrides the global resources |
|---|
| 89 | stored in the RESOURCE_MANAGER property. |
|---|
| 90 | .SH SEE ALSO |
|---|
| 91 | .BR X (1), |
|---|
| 92 | .BR xscreensaver (1), |
|---|
| 93 | .BR xlock (1) |
|---|
| 94 | .SH COPYRIGHT |
|---|
| 95 | Copyright \(co 1996 by Timo Korvola. |
|---|
| 96 | |
|---|
| 97 | Permission to use, copy, modify, and distribute this software and its |
|---|
| 98 | documentation for any purpose and without fee is hereby granted, |
|---|
| 99 | provided that the above copyright notice appear in all copies and that |
|---|
| 100 | both that copyright notice and this permission notice appear in |
|---|
| 101 | supporting documentation. |
|---|
| 102 | .SH AUTHOR |
|---|
| 103 | Timo Korvola <tkorvola@dopey.hut.fi>, 1996. |
|---|
| 104 | |
|---|
| 105 | Ability to run standalone or with \fIxscreensaver\fP added by |
|---|
| 106 | Jamie Zawinski <jwz@jwz.org>, 10-May-97. |
|---|
