[haiku-appserver] Re: Going "back" to partially hardware accelerated drawing

  • From: "Rudolf" <drivers.be-hold@xxxxxxxxxxxx>
  • To: haiku-appserver@xxxxxxxxxxxxx
  • Date: Thu, 21 Apr 2005 11:54:17 +0200 CEST

Hi,

> Sure, scrolling in particular would be better moved to the graphics 
> card, although I don't see a big problem with it, anyway (even for 
> the 
> back buffer case), since you should only update the rectangles that 
> you 
> change.
> That of course requires the "only draw from the looper's thread" 
> design 
> we already have.

I want to define scrolling from the accelerants perspective (think 
textfile for example):
-scrolling down:
->blit top-second text line downto last textline one textline up.
->app_server will send new last line using software copying from main 
mem.

-scroling up:
->well, you can guess ;-)

It's just using local blits (mainly)! Which makes it so damn fast.
And again: no retrace syncing is used. trust me on that ;-)

I don't know about non-accelerated drawing though: but it seems 
unlikely that that would be retrace synced. retrace syncing comes at a 
huge performance penaltly. (let's say you need 20 times the time of non
-synced drawing on high loads)


Rudolf.


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