RE: [ft-devel] Structure Viewer for TTF files

[James Newtons Massmind]

Thank you! Based on your sample from ttx, I was able to figure out the
(several) things I had wrong, and it is now working correctly. I don't want
to show the actual points that the contour will follow, but rather the data
that makes up that contour, so my result isn't the same, but I can manually
get from mine to ttx's as a way of verifying my result.

Just to explain again: I think what ttx and other programs are giving you is
an interpretation of the raw data rather than allowing you to examine the
actual raw data. E.g. in the binary data for this example, there is no 1248
value in any of the coordinate data. That value is only seen if you
accumulate the prior values. In 010Editor, my template breaks out the raw
binary data and presents you with a specific address and length in the TTF
file that will be used to develop that item.

I've attached another screen shot to attempt to show what I mean. Ttx shows
what the TTF file decompiles to... 010Editor shows where that data came from
and so WHY the TTF decompiles as it does. The current version is at
http://www.massmind.org/techref/datafile/ttfs.htm

Thanks again: I wouldn't have gotten this far without your help. I've never
seen anything as complex and poorly documented as this... I'm going to go
stare at a wall for the rest of the weekend.

---
James.
 
 

> -----Original Message-----
> From: Werner LEMBERG [mailto:address@hidden 
> Sent: 2005 Apr 08, Fri 11:20
> To: address@hidden
> Cc: address@hidden
> Subject: Re: [ft-devel] Structure Viewer for TTF files
> 
> 
> > Would it be horrible of me to ask if someone could look at 
> this screen 
> > shot and tell me if the template results look reasonable?  I don't 
> > expect anyone to directly check it against the binary data, 
> but there 
> > are a few things about it that concern me.
> 
> The point coordinates are not correct.  See below what ttx 
> returns for the first glyph in the `glyf' glyph (I actually 
> checked the binary values so it should be the same).
> 
> You might have a look at the FreeType function `TT_Load_Simple_Glyph'
> in src/truetype/ttgload.c to see how the data in the `glyf' 
> table should be handled.  I'm not sure whether your editor's 
> template mechanism is powerful enough to extract the glyph 
> coordinates depending on both the compressedFlag values and 
> the coordinates of previous points.
> 
> 
>     Werner
> 
> 
> ======================================================================
> 
>   <TTGlyph name=".notdef" xMin="256" yMin="0" xMax="1280" yMax="1280">
>     <contour>
>       <pt x="256" y="0" on="1"/>
>       <pt x="256" y="1280" on="1"/>
>       <pt x="1280" y="1280" on="1"/>
>       <pt x="1280" y="0" on="1"/>   
>     </contour>
>     <contour> 
>       <pt x="288" y="32" on="1"/>
>       <pt x="1248" y="32" on="1"/>
>       <pt x="1248" y="1248" on="1"/>
>       <pt x="288" y="1248" on="1"/> 
>     </contour>
> 
>

010ttf-simpleglyf.PNG
Description: PNG image