Files in This Directory
-----------------------
blanks.hex        Filler glyphs for all unassigned code points in the BMP
masks.hex         Masks to XOR out combining circles, etc., in final font
rc-base.hex       Glyphs common to all font builds
rc-cjk.hex        Roman Czyborra's original CJK glyphs (with some additions)
rc-hangul.hex     Hangul Syllables glyphs
rc-priv.hex       Private Use glyphs
substitutes.hex   Substitutes for glyphs in font .hex files, for final font
wqy-cjk.hex       Wen Quan Yi CJK glyphs (with some additions)

An output font is made by combining these files (which must
therefore not have duplicate code points among themselves):

     blanks.hex rc-base.hex rc-hangul.hex rc-priv.hex

Also, either rc-cjk.hex or wqy-cjk.hex is added to produce the
final font.  Therefore, the code points defined in rc-cjk.hex
and wqy-cjk.hex are the same (except that wqy-cjk.hex has full
coverage of the Unicode Basic Multilingual Plane CJK ideographs
and rc-cjk.hex does not).  The rc-cjk.hex file preserves the
original set of CJK ideographs used by Roman Czyborra.  The
Wen Quan Yi CJK ideographs are in many cases cleaner (far fewer
solid black boxes in the ideographs).  This makes them easier
to read.

The files rc-base.hex, rc-hangul.hex, rc-priv.hex, rc-cjk.hex,
and wqy-cjk.hex contain whole divisions of blocks of 256 code
points with one exception: the half-block U+2E00..U+2E7F is 
in rc-base.hex, while the half-block U+2E80..U+2EFF is in both
rc-cjk.hex and wqy-cjk.hex.  This division might change in the
future so that all glyph files contain entries in 256 code point
blocks.  The division currently exists because U+2E00..U+2E7F
contain Western glyphs, and U+2E80..U+2EFF contain CJK glyphs.

The masks.hex and substitutes.hex files are special files used
by uniunmask to convert a preliminary font to a final font
suitable for text.  This allows an original font to contain
special glyphs for illustration purposes (for example, combining
circles) that will be removed from the final font.

If a glyph in substitutes.hex has no hex bitmap after the colon,
that glyph is removed from the final font; this technique is
used to provide illustrations for noncharacters and different
types of spaces in the "reference" (full) font, with no visible
glyph in the final font.  The width of the replacement glyph
in substitutes.hex is the width that the final glyph will have.
For example, a space code point can have a 16x16 glyph in the
reference font, and be replaced with 32 zeroes in the final
font to become an 8 pixel wide space.

If a glyph exists in both substitutes.hex and masks.hex, the
entry in substitutes.hex overrides the entry in masks.hex.

The uniunmask program will expect masks.hex and substitutes.hex
to reside in the current working directory from which uniunmask
is invoked.

