Counts the number of unknown glyphs in @layout.
This function can be used to determine if there are any fonts available to render all characters in a certain string, or when used in combination with %PANGO_ATTR_FALLBACK, to check if a certain font supports all the characters in the string.
The number of unknown glyphs in @layout.
1.16
See Implementation
Counts the number of unknown glyphs in @layout.
This function can be used to determine if there are any fonts available to render all characters in a certain string, or when used in combination with %PANGO_ATTR_FALLBACK, to check if a certain font supports all the characters in the string.