Path: chuka.playstation.co.uk!news
From: Majik <majik@127.0.0.1>
Newsgroups: scee.yaroze.programming.3d_graphics
Subject: Re: split-screen?
Date: Mon, 23 Feb 1998 18:02:26 +0000
Organization: Sinclair MicroComputer Museum
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References: <6cjs0r$m1u1@emeka.playstation.co.uk> <34ED8958.2773@mdx.ac.uk> <34F15DA4.5CE9@127.0.0.1> <34F174A7.1DA0@mdx.ac.uk>
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Robert Swan wrote:
> 1) Um, I might have put up the version that doesn't work properly!
>    I'll check this later tonight (Monday)
Your demo works okay, I can't make your demo do what my code does.

> 2) The routine doesn't take into account the positions of your
>    double buffers in memory. To make the program sipler, I
>    assumed (probably unfairly) that the buffer screens were of
>    res (320, 240) and located at (0,0) and (0,240) in VRAM. Even
>    if this isn't the problem, I'll rewrite it to automaticaly
>    read the location of these screens. Also, trying to edit the
>    InitSplitScreen() function coudl cause problems like that.
I'm not directly using your actual code, merely the sequence of events
in the
render loop, I'll take a closer look at you InitSplitScreen() the
differences might be there.

> 3) Does the updating of the game take more than one Vsync? (ie,
>    updates less than 50 times a second) I'm not sure if that would
>    cause a problem as I haven't tested it extensively, but I'll check
No. I thought this aswell, but it isnt that.

> 4) There might be other synchronisation problems with such things as
>    queuing the drawing of more than one OT. (Notice I don't have a
>    command to wait for the drawing of the first OT to finish before I
>    tell it to draw the 2nd OT) I can check this easily.
This maybe it, although I use DrawSync() after the DrawOT()'s

> 
> Other than those... um, not sure!
> Because I have a problem with attachments from email, you could put up
> the code onto your web page, Email me, and I'll have download tham
> and have a look and try to sort it out (if it isn't problems 1 or
> 2 above). I'll be checking probs 3 and 4 tonight, so there might be a
> solution on Tuesday
I'll play about with it tonight again, then I can probably upload some
stuff
tomorrow.. It may be worth while writing a quick demo just to test split
screen...

ttfn,

Majik.

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-- Majik - Owner/Curator of the Sinclair Microcomputer Museum
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