Using the image cache.

[Brian McGee]

Hi,


I'm using FreeType for an engine that renders text on demand.  To make 
this as efficient as possible I'm using the cache API for all my 
rendering.  I'm calling FTC_ImageCache_LookupScaler to get my FT_Glyph, 
and using FT_Glyph.advance.x to move the cursor to the next start.


I'm having a problem, however, rendering certain text for SOME fonts.  
For instance, Anonymous Pro 
(https://fonts.google.com/specimen/Anonymous+Pro?query=Anonymous). The 
issue can be seen when rendering text like "MAIL."  I get a big gap 
between the M and the A.

Investigating this with FontForge, the issue appears to be that the A 
has a negative left-side bearing.  If I adjust the cursor position by 
this amount before I render the A, everything looks perfect.


My issue, however, is that the left side bearing isn't available in an 
FT_Glyph.  It's only available, it seems (as horiBearingX) in the 
FT_Face.glyph.metrics (FT_Glyph_Metrics) structure.  And that's not 
getting updated when I'm loading a glyph from the cache.


What's the best way to deal with this issue?


Thanks,


Brian