Article View: comp.sys.amiga.tech
Article #2447Re: Fast Scrolling
From: Michael Jansson
Date: Fri, 01 Dec 1989 10:13
Date: Fri, 01 Dec 1989 10:13
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2103 bytes
This is a related question to the previous ones.
I am currently trying to implement a classic game called 'Moon lander'
where I want to be able to scroll a landscape (implemented as a sort of
fractal) in which a space craft should try to land.
One of my goals is to do this inside a workbench window (It's much more
fun to do it this way, and probably harder too ;-).
The big prob|em with this is that I can't use ScrollVPort because I don't
have a ViewPort with a RasInfo to modify, and that using a ScrollRaster
would make the window flicker because the bitplanes will scroll one at a
time and not all at once.
In my crrent solution I create a fake RastPort which is a exact copy of
the original RastPort in the window, except for the bitmap which only have
one bitplane. In this way I won't get any flicker because ScrollRaster
will only scroll one plane and it will be much faster then with the
original RastPort, BUT I only have two colors to play with now.
THE BIG QUESTION: Is there a better way to scroll a window in the
Workbench Screen (better == faster, using all colors and no flicker)? I
assume that this could be done with the coper or blitter, but what about
concurrency of other windows on the Workbench screen (I heard that
LockLayer and LockIBase have a few bugs!? ;-)
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<1449@majestix.ida.liu.se>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!eru!luth!sunic!liuida!micjaReferences:
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!eru!luth!sunic!liuida!micja From: micja@majestix.ida.liu.se (Michael Jansson) Newsgroups: comp.sys.amiga.tech Subject: Re: Fast Scrolling Summary: Fast scrolling in a workbench window!? Message-ID: <1449@majestix.ida.liu.se> Date: 1 Dec 89 10:13:17 GMT References: <13939@eerie.acsu.Buffalo.EDU> Organization: CIS Dept, Univ of Linkoping, Sweden Lines: 35