Re: about contibuting to octave

[Ben Abbott]

On Mar 4, 2009, at 5:09 AM, Michael Goffioul wrote:

> On Wed, Mar 4, 2009 at 9:22 AM, xianghang liu  
> <address@hidden> wrote:
> > In freetype, I found two functions
> >
> > FT_Outline_Get_BBox Compute the exact bounding box of an outline.
> > FT_Outline_Get_CBox Return an outline's ‘control box’.
> >
> > After a rough glance at ftgl's bounding box computation, I think it  
> > use
> > FT_Outline_Get_CBox to compute the box of each glyph and add them  
> > together
> > to get the extent of the string. Shall we just follow the same  
> > method?
>
> AFAIK, depending on the font, the width of a string is not the same as
> the sum of the width of all its characters. OTOH, I think you can  
> assume
> that the width of a string will always be <= than the sum of the  
> width of
> its characters. So adding the box of each glyph should give you a  
> maximum
> width anyway.
>
> Note that I'm not a font expert, so I might be wrong.
>
> Michael.

I'm uncertain about this as well. Does anyone following along know?

I was under the impression that the spacing between characters depends  
upon the neighboring characters (however, I might be thinking of  
LaTeX, which I'd expect to have a more complicated scheme). If a  
string's extent is not the sum of is character's extents, then we will  
require something to calculate the extents of a string directly. Which  
is something that gdlib and ftgl provide for.

In any event, I'm thrilled that xianghang has taken on this effort.  
From my perspective this represents the largest obstacle to improving  
the compatibility of the gnuplot backend.

Ben