floating Coord round-off

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#366

From: Paul Calder
Date: Sun, 06 Sep 1992 04:30

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Donn Cave writes ...

  In 3.0.1, it sometimes seems that the actual size and position of
  elements on the screen is slightly more variable than one would expect,
  and I have been thinking that this is because of round-off errors between
  InterViews' floating point coordinate system, and X's integer screen
  coordinates.

This behaviour is an unavoidable consequence of round-off; to call it
an 'error' is a bit strong.  Mark Linton's paper on device-independent
rendering addresses the issue in more detail.  (The paper was
presented at XTech92 and is available from sgi.com as xconf92.ps.Z.)

You can avoid the 'undulation' on scrolling if you always scroll by
exact pixel-sized amounts.

Paul Calder

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Path: arc1-ca.pugleaf.net!sparky!uunet!stanford.edu!NURB.JRC.FLINDERS.EDU.AU!calder
From: calder@NURB.JRC.FLINDERS.EDU.AU (Paul Calder)
Subject: floating Coord round-off
Message-ID: <9209060430.AA09946@nurb.jrc.flinders.edu.au>
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Date: Sun, 6 Sep 1992 04:30:16 GMT
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