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- >>>>> "Sang Jin" == Sang Jin Hong <sangjin+@CMU.EDU> writes:
-
- Sang Jin> Excerpts from mail: 6-Jul-95 executor-digest V1 #203 by
- Sang Jin> owner-executor-diges@nac
- >> 5. For some reason you have it drawing the whole background
- >> behind the mouse when it is moved! This slows the system down
- >> considerably. Why not just draw the cursor?
-
- Sang Jin> Really? This is just opposite... My 'Executor' only
- Sang Jin> draws the cursor. The problem is, there are times when
- Sang Jin> it *only* updates the cursor (a shareware game called
- Sang Jin> 'BalderDoush', for example). And the cursor is updated
- Sang Jin> (that is, the background where the cursor is), while the
- Sang Jin> the rest of the background is still not updated. After
- Sang Jin> a while, if everything goes well, the whole screen gets
- Sang Jin> updated. The latter happens *all* the time.
-
- Here's what's happening: In most cases, due to underlying OS
- constraints, Executor can not map the screen in and use that as the
- only screen. Instead it has to keep a screen in RAM and periodically
- copy portions of this screen to the real screen. When the cursor is
- redrawn, it is fastest to just redraw from the internal screen and to
- redraw the rectangle surrounding the cursor rather than to take the
- cursor and read in some parts of the real screen, modify some of them
- to have the cursor and write them back out. NOTE: I did say
- *faster*. Mat is pretty clever about making things go fast and he
- didn't make a performance mistake here.
-
- However, transferring from the offscreen to the real screen is a
- performance hit, so we schedule the transfers (in normal mode -- you
- can alter this in the preferences panel) to only occur when the
- program is ready to accept events again.
-
- Everyone is right, this particular combination is ugly. It doesn't
- happen in Linux land, because cursors are handled by X. I'll discuss
- this with Mat, but probably we'll just update the realscreen
- completely when the cursor is moved. This is a slight performance
- hit, but it will only happen when the cursor is moved.
-
- Sang Jin> Reading the mailing-list, it seems like I am the only
- Sang Jin> one having this problem though (right, wrong? anyone
- Sang Jin> else?)
-
- I think all the DOS users are seeing this, unless they have a VESA
- level 2 compliant video card that can be mapped linearly. Executor
- will now try to map the screen in entirely and not use an offscreen
- copy (although it needs one for "-refresh") if you have a VESA level 2
- video card. This is *much* faster, too.
-
- Sang Jin> While we are on the subject, my Executor sometimes don't
- Sang Jin> recognize files on DOS drive that are not on the root
- Sang Jin> directory. I can change the directory (i.e. folder)
- Sang Jin> from the root, but it brings up an empty folder. This
- Sang Jin> is sort of on/off thingi. I don't know when it does
- Sang Jin> happen/not happen. But once it happens, my only option
- Sang Jin> is to exit Executor and restart (it usually doesn't work
- Sang Jin> though... after doing something else for a while, it
- Sang Jin> behaves correctly, like I said, it's voodoo).
-
- OK. We haven't been able to reproduce this problem in house, but
- we've heard enough people are having it that we'll try to get some
- test code out to figure out what's going on. This may take a few
- days.
-
- Sang Jin> FYI, I am running E/D 1.99n on my 486DX100 laptop with
- Sang Jin> Win95 installed.
-
- Yay! The more people running Executor on laptops, the more exposure
- Executor gets. One more reason for us to get all those nasty bugs
- fixed.
-
- You should see if getting uvbe51a speeds up Executor. If you're
- seeing the mouse cruft, Executor probably could be sped up with
- uvbe51a. I'd be real interested in knowing if I'm right.
-
- Sang Jin> Thanks in advance for any comments. I havn't seen any
- Sang Jin> software/hardware company with such a great QA, fast,
- Sang Jin> accurate, detailed answers for every little single
- Sang Jin> questions on the list/email deserve some applause...
-
- You're welcome. Thank you for the bug reports.
-
- --Cliff
-
-