about contibuting to octave

[Ben Abbott]

On Mar 3, 2009, at 12:44 AM, Shai Ayal wrote:

> On Tue, Mar 3, 2009 at 7:17 AM, xianghang liu  
> <xianghangliu at gmail.com> wrote:
>> Yes, I think I am interested in this. Would you please tell me how  
>> to start
>> and give me more details about this?
>> Thanks.
>>
>> Xianghang
>> On Tue, Mar 3, 2009 at 12:33 PM, Shai Ayal <shaiay at gmail.com> wrote:
>>>
>>> On Tue, Mar 3, 2009 at 4:36 AM, xianghang liu <xianghangliu at gmail.com 
>>> >
>>> wrote:
>>>> Hi,
>>>> I am a C++ developer very interested in Octave and would like to
>>>> contribute.
>>>> I have had a look at projects listed at
>>>> http://www.gnu.org/software/octave/projects.html. I would like to
>>>> contribute
>>>> numerical  and IO related projects in the list. Would you please  
>>>> show me
>>>> a
>>>> more current copy of this?
>>> Hi,
>>>
>>> I'm not sure it's what you meant by IO related, but the graphics
>>> system is really in need of a c++ developer. We need someone to
>>> implement text objects.
>>> If this interests you, I'm sure Michael and I could help you start  
>>> out
>>>
>>> Shai
>>
>
> Great!
> I'll give you a very brief overview with which you can start, and just
> ask question as you go. It's also better if you ask on the maintainers
> list (or at least cc the list) instead of me directly for 3 reasons:
> 1. someone else might be able to answer better/before me
> 2. someone else will be able to correct me!
> 3. we will have a record of the discussion and changes that everyone  
> can see.
>
> Also, please use bottom posting as it is much easier to read later
>
> The graphics system in octave is made of two parts -
> 1. core graphics, which includes all the parts that are independent of
> the actual graphics implementation and underlaying OS (i.e. the object
> hierarchy,  setting/getting properties and more). Core graphics is
> implemented in the (very large) files:
> graphics.h.in, graphics.cc. graphics.h.in is converted to graphics.h
> by the script genprops.awk. all of these files are in the src
> directory
> 2. backends - these are in charge of the actual rendering and deal
> with the underlaying graphics system. Currently we have 2 backends,
> the gnuplot backend and the fltk backend which uses the
> opengl-renderer.
>
> The text object is very complex (probably why it is left undone) in
> that it is a core graphics object, but also has dependencies on the
> backend: As Ben noted, the text object has an "extent" property which
> should hold the text bounding box. This is dependent on the text and
> font properties. Only the backend knows the font properties, so this
> has to communicated from the backend to the core-graphics system. We
> need to decide how to do this and implement.
> Also there is the whole issue of simple TeX rendering for text.
>
> Shai

Shai,

Regarding the comment "Only the backend knows the font properties",  
are font properties independent of the backend?

Ben