Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: Kemp@dockmaster.arpa
Newsgroups: comp.sys.sun
Subject: Re: pixrect help
Keywords: Windows
Message-ID: <890302021522.345124@DOCKMASTER.ARPA>
Date: 9 Mar 89 03:22:10 GMT
Sender: usenet@rice.edu
Organization: Sun-Spots
Lines: 17
Approved: Sun-Spots@rice.edu
Original-Date: Wed, 1 Mar 89 21:15 EST
X-Sun-Spots-Digest: Volume 7, Issue 189, message 3 of 17

>> Question on *slow* operation of pw_put > Advice on proper use of
batch and lock

Proper batching/locking is necessary for performance, but even then
writing individual pixels with pw_put is going to be slow.  If at all
possible, you should create a memory pixrect that points to your array of
data and then copy the whole array to your pixwin.  Of course this assumes
that you want to manipulate a compact region, not scatter a thousand
points of light randomly about the screen.

We have gotten acceptable speed from a 3/60 and excellent speed from a
3/160 with Graphics Processor in an application that scrolls an image (a
spectrogram in this case) by copying the pixwin to itself with a
horizontal offset and then copying in the new data from a memory pixrect.
A 4/280 should be able to do even better.

  Dave Kemp