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 file name of a bitmap to rotate. It need not be square: it
30 will be padded with the background color. If unspecified or the
31 string \fI(default)\fP, a builtin bitmap is used.
33 If support for the \fBXPM\fP library was enabled at compile-time,
34 the specified file may be in XPM format as well as XBM, and thus
37 The \fB*bitmapFilePath\fP resource will be searched if the bitmap
38 name is not a fully-qualified pathname.
42 .B \-delay microseconds
43 How long to delay between steps of the rotation process, in microseconds.
44 Default is 500000, one-half second.
47 .B \-delay2 microseconds
48 How long to delay between each 90-degree rotation, in microseconds.
49 Default is 500000, one-half second.
51 to get the default host and display number.
54 to get the name of a resource file that overrides the global resources
55 stored in the RESOURCE_MANAGER property.
60 Copyright \(co 1992, 1993 by Jamie Zawinski. Permission to use, copy, modify,
61 distribute, and sell this software and its documentation for any purpose is
62 hereby granted without fee, provided that the above copyright notice appear
63 in all copies and that both that copyright notice and this permission notice
64 appear in supporting documentation. No representations are made about the
65 suitability of this software for any purpose. It is provided "as is" without
66 express or implied warranty.
68 Jamie Zawinski <jwz@mcom.com>, 17-aug-92.
70 Based on SmallTalk code which appeared in the August 1981 issue of Byte