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

[Turner, David]

Hi all,

> > 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?
> 
> You mean that all registers and operators are based on 8bit entities?
> This won't work with FreeType unless you have a library which emulates
> 16bit support.  Note that compilation on 16bit systems isn't tested
> very well, and recent additions might have broken a clean build.
> Nevertheless, the fixes should be trivial since we try hard to avoid
> dependencies on a certain register depth to make FreeType work on 16,
> 32, and 64bit architectures.
> 

the problem isn't register size per se. It's possible to emulate
a 16-bit machine even on 8-bit CPUs with sufficient compiler tricks
(and I even remember that my 8-bit Apple II came with a _built-in_ 
emulator for a virtual 16-bit machine called 'sweet16' :-)

what's hard are things like the memory model. I don't think that
8-bit machines are allowed to address more than 64 Kb of memory
without using bank switches, or some sort of segmentation.

Segmentation can be handled transparently by the compiler, but it
has a terrible performance impact. And when you consider that the
FreeType code deals with an awful lot of 32-bit values, I can't
believe performance would be acceptable.

The original poster seemed to only want to use bitmapped font
formats. I'd avise him to define its own format, and use something
like FreeType on a "modern" platform to generate the corresponding
files...

Hope this helps,

- David Turner
- The FreeType Project  (www.freetype.org)