Patch that speed things up (brain dump)

[Boudewijn Rempt]

On Friday 27 February 2004 12:43, Roger Larsson wrote:
> This patch speeds things up enough for most brushes (even the paprika).
>
> It is really a multi part...
> 1) An attempt to speed up drawing itself (not finished, has bugs)
> 	Guess why I started to look into other image libraries :-)

:-). I haven't found any library that's as versatile as we want Krita's design 
to be -- so we'll have to roll our own, I fear. I think we're near the moment 
when it would be wise to do some actual profiling to check where the worst 
bottlenecks are, currenlty.

> 2) Rethink of m_dirtyRect and screen redraws
> 	let m_dirtyRect accumulate changes!
> 	notify on:
> 	a) mouse release
> 	b) timeout  (kis_notify_limit [ms])
> 		The timeout is global to simplify modifications.
> 		kis_notify_limit = 0 gives you back the current behaviour.
> 		kis_notify_limit = 10 gives about one update per monitor refresh (100Hz).
> 		kis_notify_limit = 50 X is no longer the problem - krita/brushes are.
>

It looks pretty interesting: I have been thinking about the timed notify 
lately, too. I think it would be pretty cool to absolve all tools and drawing 
code from the obligation to notify, and put the timer in KisView, and store 
the dirty rect in KisImage. Then whenever the timer fires, the view can be 
repainted, possibly in another thread so drawing operations are not disrupted 
-- you'd need to synchronize on tiles, of course, but I think it would give 
both a speed-up and a better design.

-- 
Boudewijn Rempt | http://www.valdyas.org/fading/index.cgi