Article View: comp.sys.amiga.tech
Article #2094Re: Fast/smooth/easy vertical scrolling
From: Eduardo Horvath
Date: Sun, 12 Nov 1989 20:35
Date: Sun, 12 Nov 1989 20:35
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1804 bytes
In article <993@mit-amt.MEDIA.MIT.EDU> dlleigh@media-lab.media.mit.edu.UUCP (Darren Leigh) writes:
>I'm looking for various ways to do fast and smooth vertical scrolling
>of text. Both up and down scrolling are necessary. Prefereably the
>scrolling should take as little CPU time as possible. I also need to
>have the sprites usable over the entire screen.
>
You could consider creating a really big bitmap, and changing the
modulo for the start of the bitmap. This takes almost zero cpu time. If
the bitmap is 3x the height (width) of the screen, you can do a quick blit
to copy the bottom of the screen to the top, change the modulo to the top
of the screen, and then continue.
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/// \ Try: 33014-18@sjsumcs.SJSU.EDU = I just tell myself `cheer
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!shadooby!samsung!usc!apple!excelan!sjsumcs!33014-18 From: 33014-18@sjsumcs.sjsu.edu (Eduardo Horvath) Newsgroups: comp.sys.amiga.tech Subject: Re: Fast/smooth/easy vertical scrolling Message-ID: <1989Nov12.203553.18251@sjsumcs.sjsu.edu> Date: 12 Nov 89 20:35:53 GMT References: <993@mit-amt.MEDIA.MIT.EDU> Reply-To: 33014-18@sjsumcs.SJSU.EDU (Eduardo Horvath) Distribution: na Organization: San Jose State University Lines: 23