68 lines
2.5 KiB
Groff
68 lines
2.5 KiB
Groff
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.\" $NetBSD: intro.4,v 1.5 2003/08/07 16:44:28 agc Exp $
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.\"
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.\" Copyright (c) 1980, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)intro.4 8.1 (Berkeley) 6/4/93
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.\"
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.sh 1 "Cursor Movement Optimizations"
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.pp
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One of the most difficult things to do properly is motion optimization.
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After using
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.Fn gettmode
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and
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.Fn setterm
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to get the terminal descriptions,
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the function
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.Fn mvcur
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deals with this task.
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It usage is simple:
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simply tell it where you are now and where you want to go.
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For example
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.(l
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mvcur(0\*,0\*,LINES/2\*,COLS/2);
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.)l
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.lp
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would move the cursor from the home position (0\*,0)
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to the middle of the screen.
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If you wish to force absolute addressing,
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you can use the function
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.Fn tgoto
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from the
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.b termlib (7)
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routines,
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or you can tell
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.Fn mvcur
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that you are impossibly far away,
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For example,
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to absolutely address the lower left hand corner of the screen
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from anywhere
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just claim that you are in the upper right hand corner:
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.(l
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mvcur(0\*,COLS\-1\*,LINES\-1\*,0);
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.)l
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