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From: Lewis_Evans@Playstation.sony.com
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: VSync return values
Date: 30 Mar 1998 11:58:56 +0100
Organization: Sony Computer Entertainment Europe - 119.SS5
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From: Lewis_Evans@Playstation.sony.com
To: news@playstation.co.uk

Are you getting any printf messages through to the
siocons console, eg 'GPU timeout' ? Is the whole
program non-interactive for a few seconds
just before the 30000 lines value appears?

GPU timeouts cause a stall of a few seconds, and are
caused by bad data being registered into
the GPU work area (Gs packet  area).

If it's not that, please describe situation more fully.

     Lewis
Help, something weird is happening...
I've hacked together a 3D starfield, and the first method of drawing the
stars I used (using a GsSortLine to draw a line of one pixel's length) was
a
bit slow, so I tried using a buffer in main RAM, drawing all the stars into
that, and then using LoadImage to shove it all into the current display
buffer.
This seems to work fine except for one thing. At the top of the screen I'm
using the built-in font to print the number of frames elapsed, the number
of
lines since the last VSync, and the maximum number of lines since VSync
that
has so far occurred. Occasionally, the text seems to glitch for one frame,
and the maximum number of lines leaps to some huge figure, like 30000
lines!
The stars don't seem to be affected by this at all.
Any ideas as to what's causing this?
Mark Wilson