Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!ut-emx!mentat
From: mentat@walt.cc.utexas.edu (Robert Dorsett)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Stupid QuickDraw question
Message-ID: <10637@ut-emx.UUCP>
Date: 19 Feb 89 23:48:35 GMT
References: <71976CXT105@PSUVM> <3695@ucdavis.ucdavis.edu> <19810@santra.UUCP>
Sender: csdq122@ut-emx.UUCP
Reply-To: mentat@walt.cc.utexas.edu (Robert Dorsett)
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In article <19810@santra.UUCP> jmunkki@kampi.UUCP (Juri Munkki) writes:
>>In article <71976CXT105@PSUVM> CXT105@PSUVM.BITNET (Christopher Tate) writes:
>>>What is the best way to plot a single point in a given GrafPort
>>>
>The fastest way to draw multiple
>pixels is to create an offscreen bitmap and write directly to this bitmap. You
>can then copy this bitmap to your grafport.

That's not entirely true: while it will give you the fastest APPEARANCE of 
drawing on the screen, it won't be the FASTEST, since you're adding a third
step--copying a (potentially large) bitmap to the screen, after making the
drawing commands.  One need only fool around with a Supermac monitor, copying
color bitmaps around, to see the potential problems here.

But for flicker-free animation, or to make things "look nice," yes, the use
of offscreen bitmaps can make software look really spiffy.

The old LSC documentation (and, I believe, the old Megamax documentation) had
examples a plenty of drawing directly onto the screen memory, which is the
fastest way of plotting of all...:-)  




Robert Dorsett
Internet: mentat@walt.cc.utexas.edu (Robert Dorsett)
UUCP: ...cs.utexas.edu!walt.cc.utexas.edu!mentat