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From: xiaofei@acsu.buffalo.edu (X. F. Wang)
Newsgroups: comp.lang.postscript
Subject: Re: 0 0 moveto (+) show: how to center the (+)?
Message-ID: <78801@eerie.acsu.Buffalo.EDU>
Date: 4 Jun 91 04:30:03 GMT
References: <9106020627.AA01346@einstein.physics.buffalo.edu> <1991Jun3.084911.20213@cs.nott.ac.uk>
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/* swx@cs.nott.ac.uk (Stephen Woolston) wrote */:
* In article <9106020627.AA01346@einstein.physics.buffalo.edu>
* xiaofei@EINSTEIN.PHYSICS.BUFFALO.EDU (X. F. Wang) writes:
* >I need something
* >
* >x y moveto 
* >( symbol ) show
* >
* >in drawing agraph. The probem is the symbol is not centered at
* >currentpoint [The lower left corner is at currentpoint]. How do I
* >symbol centered at currentpoint ?
* 
* Haven't tried it, but off the top of my head ...
* 
* 	x y moveto
* 	(symbol) dup	% stack[ (symbol) (symbol) ]
* 	stringwidth	% stack[ (symbol) xwid ywid ]
* 	2 div neg	% stack[ (symbol) xwid -ywid/2 ]
* 	exch		% stack[ (symbol) -ywid/2 xwid ]
* 	2 div neg	% stack[ (symbol) -ywid/2 -xwid/2 ]
* 	exch		% stack[ (symbol) -xwid/2 -ywid/2 ]
* 	rmoveto show	% stack[ ]
* 
* You might like to define {dup ... show} as a procedure.

Believe it or not, ywid is always 0. So (symbol) does not get vertically
centered. If it is (symbol), one can use charpath flattenpath pathbox
to get (symbol) vertically centered. However if it is a (string),
I pick up a letter, say (M), to calculate the height. But this is not a
perfect way of doing things. (abc) and (XYZ) do not have the same size
as (M). So the question is how to calculate (AbiTaRy) string height as
this? Or how to center an (aBItArY) string like this *vertically* ?
-- 
         (___) |              Xiaofei Wang                   | (___)
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