NAME

       unihexrotate - rotate Unifont hex glyphs in quarter turn increments

SYNOPSIS

       unihexrotate [-n quarter-turns] [input-font.hex] > output-font.hex

DESCRIPTION

       unihexrotate reads a GNU Unifont .hex format file named on the command line, or from stdin
       if no filename is given.  If a number of quarter turns is specified, it rotates each glyph
       clockwise  by that number of quarter turns, or counterclockwise if the number is negative.
       The resulting modified .hex file is written to stdout.  The  format  of  a  .hex  file  is
       described in the unifont(5) man page.

       If  the number of quarter turns is not specified, unihexrotate will rotate each glyph by a
       default value of one quarter turn (i.e., 90 degrees) clockwise.

       unihexrotate only supports Unifont .hex files with  glyphs  that  are  8  columns  and  16
       columns  wide.   If  an 8-column glyph is rotated, it is first centered within a 16-column
       glyph so the rotation will be performed on a 16-by-16 pixel glyph.  One additional use  of
       this  program  is  that a glyph can be converted from 8 columns wide to 16 columns wide by
       specifying a rotation of 0 quarter turns.

OPTIONS

       -n    Specify an integer number of quarter turn clockwise rotations to perform,  typically
             as  "-n  0" through "-n 3" (alternatively as "-n=0" through "-n=3") for rotations of
             0,  90,  180,  or  270  degrees,  respectively.   Negative   values   will   perform
             counterclockwise rotations by the specified number of quarter turns.

EXAMPLES

       This  example extracts the Mongolian glyphs in the "unifont-base.hex" file (located in the
       "font/plane00" directory) and pipes them to unihexrotate to rotate by the  default  amount
       of  one  quarter  turn clockwise (i.e., by 90 degrees).  The basic Mongolian glyphs are in
       the Unicode range U+1800 through U+18AF.  The original glyphs  in  "unifont-base.hex"  are
       drawn  for  horizontal rendering (as per the Unicode Standard).  The output rotated glyphs
       are suitable for rendering  Mongolian  in  its  traditional  vertical  form.   Because  no
       filename is specified to unihexrotate in this example, its input is taken from stdin.

              grep "^18[0-A]" unifont-base.hex | unihexrotate > vertical.hex

       The   next   example   reverses   the  rotation  performed  above,  by  one  quarter  turn
       counterclockwise.  In this example, the input filename "vertical.hex" is specified.

              unihexrotate -n -1 vertical.hex > horizontal.hex

FILES

       Unifont .hex format input and output files.

SEE ALSO

       bdfimplode(1), hex2bdf(1), hex2otf(1), hex2sfd(1), hexbraille(1), hexdraw(1), hexkinya(1),
       hexmerge(1),  johab2ucs2(1),  unibdf2hex(1), unibmp2hex(1), unibmpbump(1), unicoverage(1),
       unidup(1),    unifont(5),    unifont-viewer(1),     unifont1per(1),     unifontchojung(1),
       unifontksx(1),    unifontpic(1),    unigencircles(1),    unigenwidth(1),    unihex2bmp(1),
       unihex2png(1), unihexfill(1), unihexgen(1), unipagecount(1), unipng2hex(1)

AUTHOR

       unihexrotate was written by David Corbett.

LICENSE

       unihexrotate is Copyright © 2019 David Corbett.

       This program is free software; you can redistribute it and/or modify it under the terms of
       the  GNU  General  Public  License  as  published  by the Free Software Foundation; either
       version 2 of the License, or (at your option) any later version.

BUGS

       No known bugs exist.

                                           2019 Feb 23                            UNIHEXROTATE(1)