Re: [Gzz] Coordinates, shape

[Tuomas Lukka]

> >>That doesn't answer the question. Where (code-wise) and what do we 
> >>clip?
> >
> >Code-wise, we'll have an encapsulated routine that takes the vob(s)
> >to draw the stencil, the routine to put the vobs inside.
> >
> >Or am I also understanding the question wrong here? I think we may
> >be using different concepts too often right now, with you thinking 
> >about the cell view and me about the buoy view.
> >
> 
> Yes, could be. What I mean is, if we don't change any semantics, the 
> cells will work if we clip by the coordsys hierarchy: i.e., if vob V is 
> in coordsys C1, C1 is in C2 and C2 in C3, then V is clipped to the 
> smallest area that is inside C1 AND inside C2 AND inside C3 (forgot the 
> mathematical term right now).

Intersection

> So,
> a) is that system ok for what you need in the demos? Or do you need the 
> more flexible approach already, where you can define clipping 
> independently from translation/transformation?

Yes, we need, and especially without any clipping but with stenciling.

Maybe we should make all clipping and stenciling explicit for now,
i.e. so that the view calls an utility routine that constructs
the clipped thing?

> b) How do we implement it? I.e., what code does set the clip area? (In 
> AWT, the vob asks the VobRenderInfo for the clipping rectangle, then 
> issues the clipping command itself, but somehow I got the feeling you 
> won't like that for GL.)

No, since with stencils, it can be of *any* shape, even defined 
by a shaded texture.

> >>But how do we draw the connection? I know how to draw something in 
> >>the first coordsys, but I have no idea how to draw a line between the 
> >>first and second coordsys of a vob.
> >
> >See renderables.py: it's all in there. 
> >
> 
> (Do you realize renderables.py is REALLY hard to understand in its 
> undocumented state?)

Yes, unfortunately, I do.

> >There are vobs that take two
> >coordinate systems. Then, inside the vob, you just get the coordinates
> >appropriately. Naturally, this can't be done using callgl since
> >the coordinates have to be calculated on the C++ side.
> >
> 
> Achso. So what do I use?

LineConnector or SmoothConnector

> Is there some vob constructor in renderables.py I should use? Where do 
> I find out how to call it?
> 
> It would be nice if renderables.py would insert Javadoc for every 
> renderable into GZZGL...

renderables.py is scheduled for rewrite later.

> >Actually, a good stopgap measure might be simply to render the 
> >characters
> >at size 2^n instead of something like "40" currently. That could
> >improve it considerably. Also, have you tried __GL_FSAA_MODE ?
> >It helps a little.
> 
> I don't know how to turn it on...

At the point where the actual GZZGL font is created it is given a pixel
size (texel size).

        Tuomas