Re: [ft-devel] Porting Free Type on 8 Bit platform!

[Antoine Leca]

Sorry to answer this late.

On Friday, September 23, 2005 06:18Z Kiran Mahajan wrote:

> I want to know that, Is it possible to port freetype2 on 8
> bit platform like 8 Bit microcontrollers based on 8051 core
> or 8 Bit Rabbit processors?

In theory yes, but you should provide a fair amount of _standard_ ("ANSI") C
library support, an area where those compilers are not premium. In fact, you
should be very cautious with the ads, and double check everything.

Also, performances will be probably sluggish: Freetype usually handles
anything as 32-bit values (long), which operations on an 8-bit processor are
very expensive; for example, with Freetype1 (much more compact than the
current) on 16-bit targets, there were a 30%+ performance penalty with
respect to 32-bit, for this only reason.

And last but not least, the footprint of the target (code as well as data)
is very likely to exceed the addressing limits; again from my experience
with 16-bit (segmented) target, I was not successful at shrinking it into
the 64K code + 64K data limits, and I was forced to use the so-called
"large" model, which incurred another penalty.
It has been a while, so perhaps the more modular architecture of FT2 might
allow you to carefully select a reduced set, which in turn can be shoehorsed
into the 64K code limit; the 64K data limit depends heavily upon the fonts
you gave it, and of parameters such as maximum scale or cache size, so it is
probably achievable to go with it.


Antoine