Re: [ft-devel] BDF and FT_Set_Pixel_Sizes

[Chia-I Wu]

On Sat, Dec 03, 2005 at 04:15:09PM +0800, Chia-I Wu wrote:
> 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.  Or put it in another way, it means when the face is scalable,
> we should set
>       x_scale = 8 / ( face->bbox.xMax - faec->bbox.xMin ),
>       y_scale = 8 / ( face->bbox.yMax - faec->bbox.yMin ),
> so that all glyphs are within the 8x8 cell.  And this is really not
> intuitive.
Any comment?

I found this mail

http://lists.gnu.org/archive/html/freetype-devel/2004-07/msg00011.html

and BDF_Set_Pixel_Sizes was changed because otherwise
FTC_Manager_LookupSize would return error if we set

  scaler.width  = face->available_sizes->width;
  scaler.height = face->available_sizes->height;
  scaler.pixel  = TRUE;

But shouldn't the scaler be set up like this:

  scaler.width  = face->available_sizes->x_ppem;
  scaler.height = face->available_sizes->y_ppem;
  scaler.pixel  = TRUE;

?

> 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 ):
> }
> 
> ?
(More looking forward to comments on this question actually)

-- 
Regards,
olv