MAN page from SuSE 8.X xscreensaver-4.02-1.ximian.4.i386.rpm
Section: User Commands (1)
blitspin - rotate a bitmap in an interesting way
] [-background color
] [-window] [-root][-mono] [-install] [-visual visual
] [-bitmap filename
] [-delay2 usecs
program repeatedly rotates a bitmap by 90 degrees byusing logical operations: the bitmap is divided into quadrants, and thequadrants are shifted clockwise. Then the same thing is done again withprogressively 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.
accepts the following options:
- Draw on a newly-created window. This is the default.
- Draw on the root window.
- If on a color display, pretend we're on a monochrome display.
- Install a private colormap for the window.
- -visual visual
- Specify which visual to use. Legal values are the name of a visual class,or the id number (decimal or hex) of a specific visual.
- -bitmap filename
- The file name of a bitmap to rotate. It need not be square: it will be padded with the background color. If unspecified or thestring (default), a builtin bitmap is used.
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 bitmapname is not a fully-qualified pathname.
- If this option is specified, then the image which is spun will be grabbedfrom the portion of the screen underlying the blitspin window, or fromthe system's video input, or from a random file on disk, as indicated bythe grabDesktopImages, grabVideoFrames, and chooseRandomImages options in the ~/.xscreensaver file;seexscreensaver-demo(1)for more details.
- -delay microseconds
- How long to delay between steps of the rotation process, in microseconds.Default is 500000, one-half second.
- -delay2 microseconds
- How long to delay between each 90-degree rotation, in microseconds.Default is 500000, one-half second.DISPLAYto get the default host and display number.
to get the name of a resource file that overrides the global resourcesstored in the RESOURCE_MANAGER property.
Copyright © 1992, 1993, 1997, 2001 by Jamie Zawinski.Permission to use, copy, modify, distribute, and sell this software and itsdocumentation for any purpose is hereby granted without fee, provided thatthe above copyright notice appear in all copies and that both that copyrightnotice and this permission notice appear in supporting documentation. Norepresentations are made about the suitability of this software for anypurpose. It is provided "as is" without express or implied warranty.
Jamie Zawinski <jwzAATTjwz.org>, 17-aug-92.
Based on SmallTalk code which appeared in the August 1981 issue of Bytemagazine.
- SEE ALSO
This document was created byman2html,using the manual pages.