Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!ucbvax!agate!shelby!labrea!cdp!jwhiting
From: jwhiting@cdp.UUCP
Newsgroups: comp.lang.postscript
Subject: Snap to Pixel Question
Message-ID: <134400007@cdp>
Date: 17 Aug 89 11:03:27 GMT
Lines: 42
Nf-ID: #N:cdp:134400007:000:1300
Nf-From: cdp.UUCP!jwhiting    Aug 16 10:20:00 1989


%% the following PostScript code has me baffled
%%
%% inch procedure
/in {72 mul } def
%%
%% procedure for line w/o snap procedure
%%
/NoSnap { 0 .125 in rlineto .045 in -.125 in rmoveto } bind def
%%
%% snap to pixel procedure from p148 Green Book
%%
/snap { transform round exch round exch itransform } bind def
%%
%% procedure for line w/Green Book snap procedure
%%
/WithSnap { 0 .125 in snap rlineto .045 in -.125 in snap rmoveto } bind def
%%
%% Aldus Prep snap trick
/Snap2
	{
	transform 2 div round 2 mul exch 2 div round 2 mul exch itransform
	} bind def
%%
%% procedure for line w/Aldus Prep snap
%%
/WithAldusSnap { 0 .125 in Snap2 rlineto .045 in -.125 in Snap2 rmoveto } bind
def
%%
200 200 moveto 35 { NoSnap } repeat
200 250 moveto 35 { WithSnap } repeat
200 300 moveto 35 { WithAldusSnap } repeat
.02 in setlinewidth stroke showpagesnap procedure?
%% this is no better: { transform .25 sub round .25 add round exch
%% .25 sub round .25 add round exchange itransform } bind def
%% the Aldus Prep snap trick gives a wiggle to the lines
%% what am I doing wrong?  I just want the lines & spaces to be even.
%% thanks           jwhiting
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