1blitspin(6x)                  XScreenSaver manual                 blitspin(6x)
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NAME

6       blitspin - rotate a bitmap in an interesting way
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SYNOPSIS

9       blitspin  [--display host:display.screen] [--foreground color] [--back‐
10       ground color] [--window] [--root] [--window-id number] [--mono]  [--in‐
11       stall]  [--visual visual] [--bitmap filename] [--delay usecs] [--delay2
12       usecs] [--duration secs]
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DESCRIPTION

15       The blitspin program repeatedly rotates a bitmap by 90 degrees by using
16       logical operations: the bitmap is divided into quadrants, and the quad‐
17       rants are shifted clockwise.  Then the same thing is  done  again  with
18       progressively  smaller  quadrants,  except  that all sub-quadrants of a
19       given size are rotated in parallel.  So this takes O(16*log2(N))  blits
20       of size NxN, with the limitation that the image must be square, and the
21       size must be a power of 2.
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OPTIONS

24       blitspin accepts the following options:
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26       --window
27               Draw on a newly-created window.  This is the default.
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29       --root  Draw on the root window.
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31       --window-id number
32               Draw on the specified window.
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34       --mono  If on a color display, pretend we're on a monochrome display.
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36       --install
37               Install a private colormap for the window.
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39       --visual visual
40               Specify which visual to use.  Legal values are the  name  of  a
41               visual  class,  or the id number (decimal or hex) of a specific
42               visual.
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44       --bitmap filename
45               The file name of a bitmap to rotate.  It need not be square: it
46               will  be  padded  with the background color.  If unspecified or
47               the string (default), a builtin bitmap is used.
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49               If support for the XPM library was enabled at compile-time, the
50               specified  file  may  be in XPM format as well as XBM, and thus
51               may be a color image.
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53               The *bitmapFilePath resource will be  searched  if  the  bitmap
54               name is not a fully-qualified pathname.
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56       --grab-screen
57               If  this option is specified, then the image which is spun will
58               be grabbed from the portion of the screen underlying the  blit‐
59               spin window, or from the system's video input, or from a random
60               file on disk, as indicated by the grabDesktopImages,  grabVide‐
61               oFrames,  and chooseRandomImages options in the ~/.xscreensaver
62               file; see xscreensaver-settings(1) for more details.
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64       --delay microseconds
65               How long to delay between steps of the rotation process, in mi‐
66               croseconds.  Default is 500000, one-half second.
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68       --duration seconds
69               How  long  to run before loading a new image.  Default 120 sec‐
70               onds.
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72       --delay2 microseconds
73               How long to delay between each 90-degree rotation, in microsec‐
74               onds.   Default is 500000, one-half second.  DISPLAY to get the
75               default host and display number.
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77       --fps   Display the current frame rate and CPU load.
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ENVIRONMENT

80       XENVIRONMENT to get the name of a  resource  file  that  overrides  the
81       global resources stored in the RESOURCE_MANAGER property.
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83       XSCREENSAVER_WINDOW
84               The window ID to use with --root.
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SEE ALSO

87       X(1),  xscreensaver(1),  xscreensaver-settings(1),  xscreensaver-getim‐
88       age(6x)
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91       Copyright © 1992, 1993, 1997, 2001 by Jamie  Zawinski.   Permission  to
92       use,  copy, modify, distribute, and sell this software and its documen‐
93       tation for any purpose is hereby granted without fee, provided that the
94       above  copyright  notice  appear in all copies and that both that copy‐
95       right notice and this permission notice appear in supporting documenta‐
96       tion.   No representations are made about the suitability of this soft‐
97       ware for any purpose.  It is provided "as is" without  express  or  im‐
98       plied warranty.
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AUTHOR

101       Jamie Zawinski <jwz@jwz.org>, 17-aug-92.
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103       Based on SmallTalk code which appeared in the August 1981 issue of Byte
104       magazine.
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108X Version 11               6.08-1.fc39 (17-Oct-2023)              blitspin(6x)
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