DragonFly On-Line Manual Pages

blitspin(6)                   XScreenSaver manual                  blitspin(6)

NAME
       blitspin - rotate a bitmap in an interesting way

SYNOPSIS
       blitspin [-display host:display.screen] [-foreground color]
       [-background color] [-window] [-root] [-mono] [-install] [-visual
       visual] [-bitmap filename] [-delay usecs] [-delay2 usecs] [-duration
       secs]

DESCRIPTION
       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.

OPTIONS
       blitspin accepts the following options:

       -window Draw on a newly-created window.  This is the default.

       -root   Draw on the root window.

       -mono   If on a color display, pretend we're on a monochrome display.

       -install
               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
               the string (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 bitmap
               name is not a fully-qualified pathname.

       -grab-screen
               If this option is specified, then the image which is spun will
               be grabbed from the portion of the screen underlying the
               blitspin window, or from the system's video input, or from a
               random file on disk, as indicated by the grabDesktopImages,
               grabVideoFrames, and chooseRandomImages options in the
               ~/.xscreensaver file; see xscreensaver-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.

       -duration seconds
               How long to run before loading a new image.  Default 120
               seconds.

       -delay2 microseconds
               How long to delay between each 90-degree rotation, in
               microseconds.  Default is 500000, one-half second.  DISPLAY to
               get the default host and display number.

       -fps    Display the current frame rate and CPU load.

ENVIRONMENT
       XENVIRONMENT to get the name of a resource file that overrides the
       global resources stored in the RESOURCE_MANAGER property.

SEE ALSO
       X(1), xscreensaver(1), xscreensaver-demo(1), xscreensaver-getimage(1)

COPYRIGHT
       Copyright (C) 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.

AUTHOR
       Jamie Zawinski <jwz@jwz.org>, 17-aug-92.

       Based on SmallTalk code which appeared in the August 1981 issue of Byte
       magazine.

X Version 11                  5.34 (24-Oct-2015)                   blitspin(6)