[haiku-appserver] Re: BView::ClipToPicture

  • From: "DarkWyrm" <bpmagic@xxxxxxxxxxxxxxx>
  • To: haiku-appserver@xxxxxxxxxxxxx
  • Date: Sun, 07 Nov 2004 07:37:13 -0500 EST

> 
>                       
> 
> >Excellent work. :D Unless Adi has any objections, why don't you >
> > check it in?
> 
> Ok, though you'll have to wait till monday at least. Unless you 
> decide to check it in yourself  (and I would be ok with that) :))
> 
> On a side note, before someone jumps out screaming we should optimize 
> it using ASM.... :))))
> 
> The test takes ~5000 usecs on my system.
> The main bottleneck seems to be the creation of the BBitmap (~2300 
> usecs here) and the drawing of the BPicture on the bitmap itself.
> 
> I tried to add spans instead of 1x1 pixels, and beside a small issue 
> that I'll fix as soon as possible, I got a nice 30/40% speed 
improvement, though, to be able to reach the speed of the beos version 
(less than 50 usecs here), we'll need to change the way its' done now 
(for example, calculating the region server side, after we  will have 
drawn the BPicure on a "special" bitmap/canvas, maybe a custom 
DisplayDriver subclass, I dunno).
I've been wondering about using spans for calculating clipping regions 
myself. IIRC, QuickDraw (for Macs) did it this way.  As an optimization 
down the road, it might be nice to see if a class with the same API 
could be used to speed things up. I think I remember reading somewhere 
that Be didn't use regions in the server for performance reasons or 
something like that..

Have you thought about the possibility of generating the BBitmap on the 
server side?
 
> Anyway, for the moment I think we can keep it as is. At least it 
> works :))
Yep. Chalk up one less thing for the team, and thanks. :)

--DW

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