Re: Graphics: Title and label properties

[Maciek Gajewski]

Michael Goffioul wrote:
> I would have done the opposite and consider 2D as a special case,
> so you have a complete view of the problem from the beginning.
> But I guess it's a matter of taste.

Yes, yes, you're right. I've already avoided implementing 3D in Qt backend for 
too long. I should pospone work on in-octave features unitl my primary 
testbed (Qt-backend) is functional enough.

> Well, I think it's a little bit more complicated than that. For instance,
> TeX-like formatting (like subscripts or superscripts) will have an
> influence on the text extent. We had some discussions with Shai about how
> to tackle all of this and we end up with the following design ideas
> (this is largely inspired by what I did in JHandles):
> - separate font rendering, font metrics and text representation
> (with TeX formatting info...)
> - use a recursive container pattern to represent text content
> (Shai already came with a set of classes, maybe you could post
> it on the mailing list)
> - use a visitor pattern to process the text and perform various
> operations; among possible operations are: computing bounding
> box, rendering...
>
> Based on that, computing the text extent means parsing the text
> representation tree with a fontmetrics provider (here we thought
> naturally about using FreeType library).

Whoa!

I don't get it - why such a features _inside_ octave? Isn't it backend stuff?  
thought that octave only provides backend with text position (in plot 
coordinates) and string (be it plain or TeX). Why such a low-level features 
in core graphics code?

Maciek Gajewski