Font attributes are properties of a font, which can be combined to uniquely specify a font on a given platform. There are some portable attributes which can be used on all platforms; other attributes are platform specific and will be ignored or signal errors when used on the wrong platform.
Font descriptions are externalizable objects which contain a set of font attributes. When using a font description in a font lookup operation, missing attributes are treated as wildcards (as are those with value
:wild
) and invalid attributes signal errors. The result of a font lookup contains all the attributes needed to uniquely specify a font on that platform.
The
:stock
font attribute is special: it can be used to reliably look up a system font on all platforms.
Font descriptions can be manipulated using the functions
merge-font-descriptions
and
augment-font-description
.
These are the current set of portable font attributes and their portable types:
