Re: Handle graphics plotting functions

I think there's some sort of misunderstanding somewhere.

> You need a C++ function to draw the following objects:
> > axes, image, light, line, patch, rectangle, surface, text?
> > I propose to narrow it down:
> > axes, image, light, line, patch, text.
>
> Octplot already supports line,patch,text,surface (2D),axes,figure
>
> > rectangle and surface can be implemented on top of patch, no?
>
> yes, although doing surface in c++ is more optimised which is why I
>
> 1. I lost you on the back-end vs. middle-end terminology
> 2. Almost all properties are needed for "correctly" drawing an object,
>

Basically, there's a back-end. In a simple world-view, the back-end is
OpenGL. However, as you know you can't call OpenGL from .m files. So you can
either write OpenGL bindings for Octave, or you can write the minimum you
need to write to do HGO. What I want to write is a "minimal OpenGL" so you
can do the actual HGO in octave.

Because octave is so slow, it's not a good idea to have this back-end at
exactly the same level as OpenGL. Instead, the back-end should be slightly
better than OpenGL. However, since this octave-OpenGL adapter is written in
C++, I just want to make sure it's as simple as heck.

The "middle-end" is the thing that takes gold-standard HGO-like structs like
Matlab produces, and when "drawnow" is called, calls the back-end and draws
everything. The middle end is written all in .m files, and its input is
standard Matlab stuff, but its output is black magic that feeds into the
back-end. For an example, look at the myplot.m function I have. The input to
myplot isn't gold-standard like plot(), but it looks a lot like plot(). It
takes a n by 2 matrix, interprets it as [x1 y1; ...; xn yn] and then
basically does the equivalent of plot(X,Y). However, to do so it calls my
black-magic C++ back-end, and it converts this n by 2 matrix into what the
back-end needs.

Basically, I was hoping to do the entire HGO like the myplot.m file I gave,
only the input would be identical to Matlab.

I guess the front-end is how you use plot(), line() and so on.

Anyway, I guess I'll just muck around and see where it takes me.

Cheers,

Sebastien Loisel