Path: utzoo!attcan!uunet!husc6!uwvax!vanvleck!uwmcsd1!ig!agate!.berkeley.edu!chernoff
From: chernoff@cartan.berkeley.edu
Newsgroups: comp.graphics
Subject: Sun pixrect rops
Message-ID: <11115@agate.BERKELEY.EDU>
Date: 19 Jun 88 02:57:38 GMT
Sender: usenet@agate.BERKELEY.EDU
Reply-To: chernoff@cartan.berkeley.edu (Paul R. Chernoff)
Distribution: na
Organization: Math Dept., UC Berkeley
Lines: 20


I would like to know why the Sun pixrect operation
for copying a "vertical" rectangle of a given size
(say 1 by 500) takes much longer than the corresponding
operation for copying a "horizontal" rectangle (say 500x1).

For example, the obvious c program to flip the screen
top-bottom by reshuffling horizontal lines runs much,
much faster than the analogous program to flip the
screen left-right by reshuffling vertical lines.

(I imagine this has something to do with hardware; I
am using a Sun 3/50 (without any special graphics
hardware).)

*********************************************************
* Paul R. Chernoff                       chernoff@cartan.berkeley.edu   *
* Department of Mathematics              ucbvax!cartan!chernoff         *
* University of California                                              *
* Berkeley, CA  94720                                                   *