Ticket #10914 (closed defect: fixed)
eDGe not correctly displaying some MathML, consider embedding fonts
|Reported by:||maxwell||Owned by:||schatz|
|Priority:||critical||Milestone:||BugFix - 2010|
|Cc:||schatz||System Area:||Content Display|
|Primary Skill:||Several Equally|
|Suppress email to reporter:||no|
From an e-mail from Entourage:
"Some math symbols are being displayed as question marks. The math causing the problem is correctly encoded, but without the correct fonts, it will not display. You can see the problem in this EPUB: http://cnx.org/content/col10232/1.1/epub. If you look at the second chapter [Max: actually "Chapter 1"], you can see three question marks in a row (?,?,?). There are others inside equations."
"This file uses very specialized characters (ℚ, ℝ, ℂ) and yet it does not embed a font for them. Our fonts do not have these symbols. Font must be embedded in this case. I did not find an easy method to subset and embed the glyphs that they need, so they either have to embed the complete font or subset it by hand. The font still must be embedded, though. Math characters are not going to be available on all platforms."
Here is a page about how to embed fonts in EPUBs:
Since it presumably would make all the EPUBs larger, we might want to consider 1) only doing this for EPUBs with MathML, or 2) figuring out what class of characters are not displaying correctly and using images for these instead of the simple math method.