Re: [Freetype] Using a pre loaded Face object

[David Turner]

Hello Nir,

Nir Rostoker a écrit :
> 
> Hi !
> In order to save some RAM memory, I thought of loading a Face object to the
> ROM ( I have noticed that on some font files) the Face object (with out the
> LIb object and the Font file) might take 5k of RAM.
>
Yes, and I believe that most of these are taken by the bytecode stack
and the CVT table for the TrueType font. These are internal _mutable_
tables required to properly hint TrueType glyphs, and there is no
way to put them in ROM.. or to reduce their size..
 
> As far as I understand the only object that is being changed in the face
> object while using the same font file, is the size metrics, which are being
> re-sized when I set a new char size.
>
Plus some internal data that are driver-specific and whose size and use
cannot be easily predicted.. You'll probably need a different font format
if you want to use less memory.

And note that Type1 is _not_ a good candidate either, for different
reasons.. It might be worth trying OpenType/CFF though..

> Do you know if there are other part in the Face object that might be changed
> during run time ?
> Do you know of a good way of saving memory by saving most of the Face object
> in the ROM ?
>
Saving the face object in ROM is not generally possible and a pain to
implement. There's no way we're going to modify the engine to support
such an exotic feature, so try to chose a different font, or different
font formats..

Regards,
- David