27.11 Defining fontsets
Emacs creates a standard fontset automatically according to the value
standard-fontset-spec. This fontset's name is
or just ‘fontset-standard’ for short.
Bold, italic, and bold-italic variants of the standard fontset are
created automatically. Their names have ‘bold’ instead of
‘medium’, or ‘i’ instead of ‘r’, or both.
If you specify a default ASCII font with the ‘Font’ resource or
the ‘-fn’ argument, Emacs generates a fontset from it
automatically. This is the startup fontset and its name is
fontset-startup. It does this by replacing the foundry,
family, add_style, and average_width fields of the
font name with ‘*’, replacing charset_registry field with
‘fontset’, and replacing charset_encoding field with
‘startup’, then using the resulting string to specify a fontset.
For instance, if you start Emacs this way,
emacs -fn "*courier-medium-r-normal--14-140-*-iso8859-1"
Emacs generates the following fontset and uses it for the initial X
With the X resource ‘Emacs.Font’, you can specify a fontset name
just like an actual font name. But be careful not to specify a fontset
name in a wildcard resource like ‘Emacs*Font’—that wildcard
specification matches various other resources, such as for menus, and
menus cannot handle fontsets.
You can specify additional fontsets using X resources named
‘Fontset-n’, where n is an integer starting from 0.
The resource value should have this form:
fontpattern should have the form of a standard X font name, except
for the last two fields. They should have the form
The fontset has two names, one long and one short. The long name is
fontpattern. The short name is ‘fontset-alias’. You
can refer to the fontset by either name.
The construct ‘charset:font’ specifies which font to
use (in this fontset) for one particular character set. Here,
charset is the name of a character set, and font is the
font to use for that character set. You can use this construct any
number of times in defining one fontset.
For the other character sets, Emacs chooses a font based on
fontpattern. It replaces ‘fontset-alias’ with values
that describe the character set. For the ASCII character font,
‘fontset-alias’ is replaced with ‘ISO8859-1’.
In addition, when several consecutive fields are wildcards, Emacs
collapses them into a single wildcard. This is to prevent use of
auto-scaled fonts. Fonts made by scaling larger fonts are not usable
for editing, and scaling a smaller font is not useful because it is
better to use the smaller font in its own size, which is what Emacs
Thus if fontpattern is this,
the font specification for ASCII characters would be this:
and the font specification for Chinese GB2312 characters would be this:
You may not have any Chinese font matching the above font
specification. Most X distributions include only Chinese fonts that
have ‘song ti’ or ‘fangsong ti’ in family field. In
such a case, ‘Fontset-n’ can be specified as below:
Then, the font specifications for all but Chinese GB2312 characters have
‘fixed’ in the family field, and the font specification for
Chinese GB2312 characters has a wild card ‘*’ in the family
The function that processes the fontset resource value to create the
fontset is called
create-fontset-from-fontset-spec. You can also
call this function explicitly to create a fontset.
See Font X, for more information about font naming in X.