blitspin(6x) | XScreenSaver manual | blitspin(6x) |
blitspin - rotate a bitmap in an interesting way
blitspin [-display host:display.screen] [-foreground color] [-background color] [-window] [-root] [-mono] [-install] [-visual visual] [-bitmap filename] [-delay usecs] [-delay2 usecs] [-duration secs]
The blitspin program repeatedly rotates a bitmap by 90 degrees by using logical operations: the bitmap is divided into quadrants, and the quadrants are shifted clockwise. Then the same thing is done again with progressively smaller quadrants, except that all sub-quadrants of a given size are rotated in parallel. So this takes O(16*log2(N)) blits of size NxN, with the limitation that the image must be square, and the size must be a power of 2.
blitspin accepts the following options:
If support for the XPM library was enabled at compile-time, the specified file may be in XPM format as well as XBM, and thus may be a color image.
The *bitmapFilePath resource will be searched if the bitmap name is not a fully-qualified pathname.
XENVIRONMENT to get the name of a resource file that overrides the global resources stored in the RESOURCE_MANAGER property.
X(1), xscreensaver(1), xscreensaver-demo(1), xscreensaver-getimage(1)
Copyright © 1992, 1993, 1997, 2001 by Jamie Zawinski. Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. No representations are made about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.
Jamie Zawinski <jwz@jwz.org>, 17-aug-92.
Based on SmallTalk code which appeared in the August 1981 issue of Byte magazine.
5.42 (28-Dec-2018) | X Version 11 |