[ft] Font Metrics

[Martin Olbrich]

Hi,

I am a bit confused about the number and scaling of different font metrics.

For my program I am searching for the maximum distance above/under the 
baseline of a given font in the scaling of the pixels after rendering. I 
have tried it with "Face.bbox.yMin / yMax", but I dont know about the 
right scaling to get it to pixel units.
Do I need the "Face.units_per_EM" for that?

The other metric I need is the width of the string. I calculated it as 
the sum over "Face.glyph.advance.x/64" of all glyphs. ( with 
"FT_Set_Char_Size(face, fontSize*64., fontSize*64., 100, 100);" )
Is that the correct value?

Thank you for any help.
martin.