NetNews Usenet Archive 1992 #19/NN_1992_19.iso/spool/comp/sys/amiga/graphics/5840

Text File | 1992-08-31 | 1.6 KB | 39 lines

Newsgroups: comp.sys.amiga.graphics
Path: sparky!uunet!munnari.oz.au!newsroom.utas.edu.au!bruny.cc.utas.edu.au!u894793
From: [e-mail] (Timothy D Little)
Subject: How do I double-buffer an Intuition screen?
Message-ID: <u894793.715312894@bruny>
Sender: [e-mail]
Organization: University of Tasmania, Australia.
Date: Tue, 1 Sep 1992 02:01:34 GMT
Lines: 28


I am writing a 3D game, which must should run under Intuition reasonably
nicely.  (Multitasking, screen dragging, etc)  I have Kickstart ROM 1.3

My problems arose when I tried to remove the flicker from my test program
using double-buffering.

1) I tried allocating a spare bitmap, and switching the BitMap structures
between the Screen and my private one.  Didn't work - I had forgotten about
the copperlists requiring update.

2) As a test, I tried the above, and calling RethinkDisplay.  As I thought, it
took too long to complete for my purposes.

3) I tried making two copies of the View structure, one for each bitmap, and
switching using LoadView.
This wasn't good enough either - I can't move the screen without horrible
effects.

4) I had a look in the graphics.library for suitable routines.  MakeVPort
looked OK, but needs to be linked with the other VPort copperlists, and
where do I get those?

At this point, I decided I'd just fire up the modem and ask for advice.
After all, I only want to change a single set of addresses in the copperlist,
and if I took over the system, it would only take 3 machine code instructions.
--
Timothy D Little   a.k.a.   [e-mail]