1 .TH XScreenSaver 1 "17-aug-92" "X Version 11"
3 blitspin - rotate a bitmap in an interesting way
6 [\-display \fIhost:display.screen\fP] [\-foreground \fIcolor\fP] [\-background \fIcolor\fP] [\-window] [\-root] [\-mono] [\-bitmap \fIfilename\fP] [\-delay \fIusecs\fP] [\-delay2 \fIusecs\fP]
8 The \fIblitspin\fP program repeatedly rotates a bitmap by 90 degrees by
9 using logical operations: the bitmap is divided into quadrants, and the
10 quadrants are shifted clockwise. Then the same thing is done again with
11 progressively smaller quadrants, except that all sub-quadrants of a
12 given size are rotated in parallel. So this takes \fBO(16*log2(N))\fP
13 blits of size NxN, with the limitation that the image must be square,
14 and the size must be a power of 2.
17 accepts the following options:
20 Draw on a newly-created window. This is the default.
23 Draw on the root window.
26 If on a color display, pretend we're on a monochrome display.
28 .B \-bitmap bitmap-name
29 The bitmap to rotate. It need not be square: it will be padded with
30 the background color. Default is \fIxlogo64\fP, but \fIescherknot\fP
31 is also nice. You really need to run this on a bigger bitmap than
32 those shipped with the X distribution to do it justice.
34 The \fB*bitmapFilePath\fP resource will be searched if the bitmap name
35 is not a fully-qualified pathname.
39 .B \-delay microseconds
40 How long to delay between steps of the rotation process, in microseconds.
41 Default is 500000, one-half second.
44 .B \-delay2 microseconds
45 How long to delay between each 90-degree rotation, in microseconds.
46 Default is 500000, one-half second.
48 to get the default host and display number.
51 to get the name of a resource file that overrides the global resources
52 stored in the RESOURCE_MANAGER property.
57 Copyright \(co 1992 by Jamie Zawinski. Permission to use, copy, modify,
58 distribute, and sell this software and its documentation for any purpose is
59 hereby granted without fee, provided that the above copyright notice appear
60 in all copies and that both that copyright notice and this permission notice
61 appear in supporting documentation. No representations are made about the
62 suitability of this software for any purpose. It is provided "as is" without
63 express or implied warranty.
65 Jamie Zawinski <jwz@lucid.com>, 17-aug-92.
67 Based on SmallTalk code which appeared in the August 1981 issue of Byte