Le 28.06.2013 15:50, Alexandre Bergel a écrit :

ROView puts its elements in an OrderedCollection, doesn't it?

Yes. But actually there are two collections. One for the existing elements, and another for the elements that are currently visible.

Might using a QuadTree help?

It would slightly help. This is a feedback I've heard from expert in the field. 

Well, there is an OrderedCollection with all the elements and kinda set of association of int (zOrdering) and orderedCollection for the elements to be rendered.

For now the problem is that all the elements are to be rendered.

The idea is then to choose the good elements to be drawn.

Here are proposals, tell me what you prefer:

1) Quadtree

+ you compute it one time, you only update it when dragging an element ;

- you have to deal with element overlapping several quadrants.

2) set of association

+ just like now, but with a lot less elements in the collections (fast to handle events, fast to draw) ;

- have to take more than just the visible elements so that we can translate the visualisation ; have to update when translating, zooming ;

3) fixed picture ( with the set of associations for events)

+ very fast to draw, very light, translation and zoom really easy,

- have to be deeply implemented, update when dragging an element
 

Please tell me what you prefer and I will do it.

Maybe quadtree is not the best solution here, and we can begin by solution 2  and then see if we need more speed.

Regards

Mathieu