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Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1
From: |
Stefan Seefeld |
Subject: |
Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 |
Date: |
Sat, 14 Oct 2000 21:28:38 -0400 |
Werner LEMBERG wrote:
> > the idea is to avoid dynamic typing (which is what you suggest if
> > you want to query a given font instance for the presence of a
> > specific feature) but rather use static typing, i.e. to make a
> > TTFont a *type*, which can be checked for at compile time. Only this
> > type and its associated API provides the means to access TT specific
> > features.
>
> I fully agree. But (to continue your example) which values should be
> queried with get_general_feature? And in which format shall the
> values be returned?
it wasn't meant to be used exactly that way. It was merely an illustration
of how to extend types. What I would propose is similar to the 'dynamic_cast'
template in C++ (and often referred to as 'narrowing', or 'downcasting':
Given the current (general) API, you may add a method which 'tries' to cast
the font type to a special font type. As with dynamic_cast, this call will
simply return 0 if the font isn't of the required type, the sub type if it is.
FT_Face face;
// create the face here
TT_Face ttface;
if (narrow_to_TT(face, ttface) == -1) { // error...};
// now you can operate on TT_Face, which provides a richer API than FT_Face
Hope this helps,
Stefan
_______________________________________________________
Stefan Seefeld
Departement de Physique
Universite de Montreal
email: address@hidden
_______________________________________________________
...ich hab' noch einen Koffer in Berlin...
- Re: FT_Get_Char_Index() returns 0 for char(0x020), (continued)
- Re: FT_Get_Char_Index() returns 0 for char(0x020), Just van Rossum, 2000/10/15
- Re: FT_Get_Char_Index() returns 0 for char(0x020), Tom Kacvinsky, 2000/10/15
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 - anewsnapshot, Sergey Babkin, 2000/10/13
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 - anewsnapshot, Werner LEMBERG, 2000/10/13
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1, Sergey Babkin, 2000/10/14
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1, Stefan Seefeld, 2000/10/14
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1, Werner LEMBERG, 2000/10/15
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1,
Stefan Seefeld <=
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1, Werner LEMBERG, 2000/10/15
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 -anewsnapshot, Sergey Babkin, 2000/10/15
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 -anewsnapshot, Werner LEMBERG, 2000/10/15
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 -anewsnapshot, Sergey Babkin, 2000/10/15
- Re: [ttf2pt1-devel] Re: FreeType front-end in ttf2pt1 -anewsnapshot, Werner LEMBERG, 2000/10/15