Re: [ft-devel] BDF and FT_Set_Pixel_Sizes

[Werner LEMBERG]

> <quote>
> This means that setting the pixel size to, say, 8x8 doesn't
> guarantee in any way that you get glyph bitmaps that all fit within
> an 8x8 cell (sometimes even far from it).
> 
> ...
> 
> For BDF and PCF formats, this function uses the sum of the
> `FONT_ASCENT' and `FONT_DESCENT' properties of the bitmap font.
> </quote>
> 
> I find these two paragraphs conflicting.  If we use the sum of
> FONT_ASCENT and FONT_DESCENT to match against, then all glyphs are
> within the 8x8 cell, provided FT_Set_Pixel_Size( face, 8, 8 )
> returns success.

How do you come to this conclusion?  The original BDF specification
(found in the X11 distribution) says that both FONT_ASCENT and
FONT_DESCENT are *logical* values.  They don't guarantee that all
bitmap glyphs are within this range.

FT_Set_Pixel_Sizes by no means define the global bounding box of a
face.

> I also have a (maybe stupid) question.  Why don't we simply have
> 
> FT_Set_Pixel_Sizes( face, w, h )
> {
>       FT_Set_Char_Size( face, w, h, 72, 72 ):
> }

Sorry, I forgot the details.  It was quite complicated to define an
interface which is uniform across all different bitmap formats.


    Werner