Re: [ft] Windows font driver Parser

[Werner LEMBERG]

[talking about the current git version of FreeType]

> 1) How windows font driver recognizes a window font file so that it can
>    parse it.

I suggest that you use a debugger.

  . Set a breakpoint at line 2255 in file `ftobjs.c' (in function
    `ft_open_face_internal').  Here the central loop starts that walks
    over all FreeType driver modules to find the right one.

  . Single-step over the following code until you get acquainted a
    bit.

  . Later on, set a breakpoint at line 1202 in file `ftobjs.c' (in
    function `open_face') and do single-stepping.  Here you enter the
    font module's `init_face' routines that check whether a given font
    file can be handled by the module.  If you are in the wrong module
    you can simply continue to the next call of the breakpoint.

> Like in Type 1 driver module case there is a file t1parse.c which
> actually checks the header of a file that, if it starts with some
> specific text than this driver is selected for further parsing and
> so on.

Since the windows font driver is much simpler, everything is in one
file.  The function to recognize a bitmap FNT file is `FNT_Face_Init'
(which is this module's `init_face' routine).

> 2) Is there any guide for the developer so that they can understand
>    the flow of Freetype how code flows from start to end?

No.  Such a guide doesn't make much sense IMHO since you are operating
at the lowest level of FreeType, and without knowing the intricate
details of the *whole* library you are rather lost.

You are invited, however, to contribute something :-) For example, you
might provide patches that add comments which you believe are missing
so that it is easier to understand what FreeType is doing.

A global overview is

  https://www.freetype.org/freetype2/docs/design/index.html

> In my case i just want to read type1 font file or winfnt font file
> and check the number of faces, font family name, style name etc.

What you *really* want is to find out how FreeType is doing that so
that you can write your own stuff, right?


    Werner