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Problem ... very slow scrolling.
From: |
Richard Frith-Macdonald |
Subject: |
Problem ... very slow scrolling. |
Date: |
Thu, 31 Jan 2002 09:18:33 +0000 |
I work with non-gui stuff, so I don't look at the GNUstep gui stuff as
much as I should,
and when I do, it's on a fast machine.
I just started using GWorkspace with the icon view, and when scrolling a
window full of
icons is can clearly see the display updating.
Now, a scrollview is supposed to do a fast copy using NSCopyBits() so
that slow updates
should not be seen.
Looking at the code for NSCopyBits(), it uses DPScomposite, which (in
the xgps backend)
grabs an image from the source, manipulates it (alpha support etc), puts
the result in
another image and writes that to the destination. This means that, far
from NSCopyBits()
being a fast function to shift parts of a view around, it's actually
rather slow.
Would it be possible to check for the case of a simple copy operation,
and optimise this
case (perhaps using XCopyArea()) so that scrolling was quick?
Anyone with the appropriate skills want to volunteer to do this?
- Problem ... very slow scrolling.,
Richard Frith-Macdonald <=