[openbeos] Re: AppServer P4, FBC

  • From: DarkWyrm <bpmagic@xxxxxxxxxxxxxxx>
  • To: openbeos@xxxxxxxxxxxxx
  • Date: Mon, 28 Jan 2002 17:00:44 -0500

>> >Please allow for *everything* in the comm layer (non-rectangular 
>> > views, 
>> >transparency, etc.). The API is limited, but that's no reason to 
>> > limit 
>> >the app_server. Also, I would reccomend having window borders drawn 
>> > as 
>> >a non-rectangular view by BWindow, and *not* by the app_server to 
>> > make 
>> >things more flexible.
>> >-Nathan
>> 
>> There is no requirement for that. That is definately an R2 thing.
>
>That's the idea. Since the internal messaging protocol isn't a 
>compatibility issue, why not put it in now?
>-Nathan
Two reasons: (1)performance and (2) it's a major pain to pass a BRegion to 
the server.

I remember reading somewhere that using BRegions internally was something 
they considered, but it was too slow. There's a lot of overhead incurred when 
you use a BRegion because you can't assume that the thing is contiguous. 
There is suddenly a lot more clipping done when you use them, if for no other 
reason than each point must be clipped to the region before it is drawn. 
That's a serious performance hit, even with acceleration.

BRegions store their rectangles in a pointer list (obviously), so each 
rectangle must be copied three times if you utilize a PortLink and twice if 
you do it the Hard Way (tm).  Ouch.

Transparent windows boils down to another BView flag, which shouldn't be too 
bad to the API - there are already 2 reserved flags in the header, one of 
which we can un-reserve. It'll also be a change in the server's redraw code. 
Ah, another thing for R2...

--DarkWyrm

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