Sun 20 Apr 2008 11:28:07 AM UTC, original submission:
How (or whether) to implement combining marks in a monospace font?
A couple of people have complained lately, so I'm opening this bug report to track it.
Many applications insist that the widths of the bounding boxes of all characters in a monospace font should be the same. There are exceptions, but it is safest for them really all to be the same.
On the other hand, a primitive way to implement combining marks is an "overstrike", a character of zero width whose glyph is placed to one side, so it is drawn over a neighboring character.
It would seem to be a conflict.
So far I know:
1) Many Linux apps tolerate zero-width characters in a monospace font (but not other widths!)
2) In Windows, fonts loaded as TrueType are recognized as monospace only if all characters are of the same width.
3) In Windows, fonts loaded as OpenType may be recognized as monospace if they have some zero-width characters.
4) On my system (Ubuntu gutsy), xterms (and derivatives) clip these overstrike characters, rendering the point moot.
Joe Wells has reported that older xterms worked with older versions of FreeMono to effect an overstrike. He wants this behaviour to continue.
At this point, I'm not sure what to do about this. I'm not even sure it is to be regarded as a font problem.
|