Re: performance of goocanvas

[Damon Chaplin <damonachaplin gmail com>]

On Wed, 2013-11-20 at 22:46 +0900, D M German wrote:
> Ed, Damon, 
>
> I really want to thank you both. I was able to find the reason for the
> performance hit. As you indicated, we were "moving" items to the same
> location where they were _for the entire document_. I have found some
> redundancy in some operations during scrolling (and probably in other
> places too) that I'll remove.

I think your test file created about 330,000 GooCanvasPolyline items,
which is a bit too much really!

Ideally I think you should use custom canvas items for your stroke
items, to handle all the segments in one canvas item. You can optimize
it to calculate the bounds quickly, and you can avoid using object
properties which are pretty slow. The file will load a lot quicker that
way.


The test file with the handwriting and sketches looks cool! Do you use a
graphics tablet to do that?

Damon