CJKV Information Processing, 2nd Edition

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Chapter 6: Font Formats, Glyph Sets, and Font Tools

is that glyphs are not isolated objects, but rather interact with one another. For example,

glyph substitution is now common, and kerning denes a context that aects more than

one glyph. In terms of suitable language for establishing such a cross-platform composite

font mechanism, XML seems like a clear and somewhat logical choice. XML’s human-

readable property is an obvious benet.

Should the Composite Font be instantiated as a separate le, perhaps as XML, or encap-

sulated in a new or existing OpenType table? As an XML le, its contents become more

visible to users. As an OpenType table, the Composite Font specication can become part

of the base, primary, or parent font. Also, should the component fonts be allowed to func-

tion as standalone fonts? ese are all very important questions and considerations. What

must be made clear is that a major motivation for such a Composite Font format is the

ability to address more than 64K glyphs through a single selectable font instance, and any

solution needs to bear this in mind.

Bitmapped Font Formats

Let us take a step back to a time when outline fonts were not common. e rst CJKV

fonts for use on computer systems were bitmapped. is meant that each glyph was con-

structed from a matrix of dots or pixels, each of which could be turned on or o—this

is referred to as a dot-ma ...