1blitspin(6x) XScreenSaver manual blitspin(6x)
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6 blitspin - rotate a bitmap in an interesting way
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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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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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24 blitspin accepts the following options:
25 --window
27 Draw on a newly-created window. This is the default.
28 --root Draw on the root window.
30 --window-id number
32 Draw on the specified window.
33 --mono If on a color display, pretend we're on a monochrome display.
35 --install
37 Install a private colormap for the window.
38 --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.
43 --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.
48 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.
52 The *bitmapFilePath resource will be searched if the bitmap
54 name is not a fully-qualified pathname.
55 --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.
63 --delay microseconds
65 How long to delay between steps of the rotation process, in mi‐
66 croseconds. Default is 500000, one-half second.
67 --duration seconds
69 How long to run before loading a new image. Default 120 sec‐
70 onds.
71 --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.
76 --fps Display the current frame rate and CPU load.
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80 XENVIRONMENT to get the name of a resource file that overrides the
81 global resources stored in the RESOURCE_MANAGER property.
82 XSCREENSAVER_WINDOW
84 The window ID to use with --root.
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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.
99
101 Jamie Zawinski <jwz@jwz.org>, 17-aug-92.
102 Based on SmallTalk code which appeared in the August 1981 issue of Byte
104 magazine.
105X Version 11 6.08-1.fc39 (17-Oct-2023) blitspin(6x)