[josm-dev] JOSM Mappaint - major improvements

[Frederik Ramm]

Hi,

Rolf Bode-Meyer wrote:
> What I don't understand - with your change and before - is that paint
> speed seems to depend on the amount of data in the layer even if it's
> outside the view.

That's not difficult to understand. Whether or not something is outside 
the view is not known to JOSM before drawing. JOSM goes through the full 
list of objects, always. So: The more objects, the slower a redraw.

One could try and record the information whether an object is visible or 
not, and draw only those that are visible. This would make anything that 
changes the viewport (zooming, panning, window resizing) slower because 
a new list of objects to be drawn would have to be compiled, and would 
make redrawing without changes to the viewport faster.

Bye
Frederik