Message-Id: <335DADA6.41A0@canvaslink.com>
Date: Wed, 23 Apr 1997 02:35:18 -0400
From: Tom Grandgent <tgrand AT canvaslink DOT com>
Reply-To: tgrand AT canvaslink DOT com
Organization: Canvas Link, Inc.
Mime-Version: 1.0
To: djgpp AT delorie DOT com
Subject: Measuring frame rate more often
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I am working on a game in which I need to measure the frame rate so
that I can compensate for it.  It's an overhead view and you fly a
ship around..  The idea is that I use the the measured frame rate
to modify the ship's visible amount of movement per frame.  This makes
it end up moving at the same speed through the game world no matter
what the frame rate is.

This would work beatifully except that I have only been able to
accurately measure the frame rate once per second.  I currently have
a frame counter which gets copied and reset once a second by a timer
function (I'm using Allegro).

I need some way to accurately measure the number of frames per second
(or milliseconds per frame or something?) more often than once per
second.  If anyone knows how I might be able to do this, I would be
very appreciative.

BTW, the formula I am using to calculate the corrected player speed is:
effective_speed = logical_speed * (1 / fps / TARGET_FPS);

This works great, except that the frame rate can change a lot in less
than a second, so the player might drastically slow down or speed up
and then "snap" back to the right speed once the new fps is measured.
And TARGET_FPS is just whatever fps I want the game to seem to run at.
It is set to 40.0 at the moment.

Thank you to those who will [hopefully] help me with this,

	Tom Grandgent
	tgrand AT canvaslink DOT com
	Canvas Link, Inc.