Re: [Gzz] View2D enhancing.

[Matti Katila]

On Tue, 8 Jul 2003, Tuomas Lukka wrote:
> On Tue, Jul 08, 2003 at 01:19:02AM +0300, Matti Katila wrote:
> > I run into problems with View2D. I would like to make it use faster way 
> > to change scene i.e., through setParams. As you already know we have more 
> > than one main node with FenPDF. I have made a simple interface to change 
> > scene's parameters but it doesn't work because no one keeps track of all 
> > possible coordinate systems since recursive view2ds can be just one 
> > instance in the whole view. 
> > 
> > So can we add a new parameter to View2D?
> > 
> >     public abstract void render(VobScene vs, 
> > -           Object plane,
> > +           Object plane, Object key,
> >             int matchingParent,
> >                 int box2screen, int box2plane
> >                     );
> > 
> > 
> > With this change and simple helper class:
> 
> Umm, I'm not at all in the clear about what you're trying to achieve
> and how.

View2D is one big instance and it renders all viewports shown in screen, 
main nodes and buoys currently. Dragging of main node can be made fast 
because we can save the coordsys number in the main node instance.
We can't use fast dragging(using the same vobscene and changing coordsys 
parameters) with: moving notes, selecting area because they are a part of 
View2D chain instance and saving the coordsys number there is ridiculous 
in the current View2D chain layer as I noticed it. So if we want speed - 
we need to save that coordsystem to somewhere.


> > /** Very simple util to save integer in map.
> >  */
> > public class CoordsysCache {
> >     private Map coords = new WeakHashMap(10);
> >     public void set(Object key, int cs) {
> >     coords.put(key, new Integer(cs));
> >     }
> >     
> >     public int get(Object key) {
> >     return ((Integer)coords.get(key)).intValue();
> >     }
> > }
> > 
> > 
> > We could use setParams easily and make things faster.
> 
> This is very bad on Kaffe and possibly others, creating lots of
> Integer objects for the GC to worry about.

Other possibility is to create a new View2D chain instance for every 
viewport.


   -Matti