Re: [Gzz] OrthoCoordsys???

[Benja Fallenstein]

Tuomas Lukka wrote:

> No, that's not the problem. The problem is the *HIERARCHICAL*
> coordinate systems, which changed a lot of APIs (and also made 
> a lot of jython GL-using code not work any more).

Ah, I see. This doesn't have anything to do with OrthoCoordsys-- I 
implemented the hierarchical coord systems before I implemented the 
latter. OrthoCoordsys is just to make it faster (so that we don't need 
to be so worried about creating many coord systems).

There are four issues involved here.

1. Coordinates

OrthoCoorder stores the coordinates (and depth) absolute, not relative 
to the parent coordsys, even though it gets the coordinates relative to 
the parent. It simply adds the parent's x, y, and depth coordinates to 
its own.

2. Interpolation

The current semantics are: Interpolate only inside the parent coordset, 
i.e., interpolate A to B only if they have the same key *and* their 
parents are interpolated to each other.

This means that you need to do lookups by key *and parent*, and that 
means java.util.Maps won't suffice. I've implemented my own in 
OrthoCoordsysMap, which is tightly coupled to OrthoCoordsys.

3. Clipping

In OrthoCoorder, the clip rect is found by going through all parents of 
a coordsys and taking the maximum left and upper and the minimum right 
and lower coordinates of all ExtRects. (OrthoCoorder doesn't do this 
right during interpolation, yet.)

4. Depth sorting

In depth sorting, we draw first a coord system, then (above that) all 
coord systems in it, the (above that) the next coord system on the same 
level. The algorithm to do that takes some figuring out; see 
OrthoDepthSorter.cmp().

Hm. Actually... I guess you could use OrthoCoordsys, in fact; you'd 
simply need to store the coordinates you need in it (neither 
OrthoCoordsysMap nor OrthoDepthSorter depend on the coords, I think).

You could make OrthoCoordsys an abstract superclass (AbstractCoordsys), 
and remove the w and h arrays from it. Then you could make two 
subclasses, OrthoCoordsys (adding the w and h arrays), and 
AffineCoordsys (adding xx, xy, yx and yy arrays). Would that work for you?

-b.