nanogui: How pixmaps will work
Subject:
Re: How pixmaps will work
From:
"Vidar Hokstad" ####@####.####
Date:
15 Oct 1999 19:24:29 -0000
Message-Id: <19991015192219.10919.qmail@mail.relight.com>
On Fri, 15 Oct 1999 14:39:47 -0400 (EDT) you wrote:
>>
>> One of the conclusions people using X a lot have reached is you want both
>> video memory and client side pixmaps depending on the purpose. I dont think
>> its actually a big issue for nanogui as most low end onboard lcd devices
>> and the like tend not to have acceleration and also to be UMA
>>
>
>I was referring more to the time/space tradeoff. Keeping bitmaps offscreen
>will require more memory, doing redraws will require more CPUs. This
>decision is more important in embedded systems than in larger machines.
It's not as if it's something that is forced on you. But for many applications
offscreen pixmaps is a must to get decent performance.
If you're thinking about keeping window bitmaps offscreen when the window isn't
mapped, or when it is obscured, then I agree that it might hog resources.
And that's not something I would advocate for NanoGUI.
However, supporting off screen server side pixmaps is important for cases
such as when you use the networked version, and want to draw on a canvas
that will be copied to screen frequently, but that may be fully or
partially obscured by other windows, and that will be partially updated
frequently. In those cases you certainly wouldn't want to draw client
side, and send the entire image over the socket every time it should be
updated.
Regards,
Vidar Hokstad
VP of R&D,
Screen Media
