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%%
%% naive paragraph formatting for metapost. You get better results using
%% btex .. etex, since that will give you kerning, ligatures, and the
%% famous TeX paragraph breaking algorithm. This one is OK for me, though,
%%
%% Copyright 2001,2003 Patrick TJ McPhee
%% everyone is welcome to use this code for any purpose, to modify it, and
%% to copy it in whole or in part for use in other macro sets, with the
%% conditions that this copyright notice be preserved with any significant
%% portion of the code, and that modifications to this file be clearly
%% marked.
% arguments
% s - text to format
% w - maximum width
% b = baseline skip
vardef breaktowidth(expr s, w, b) =
save p;
picture p;
p := s infont defaultfont scaled defaultscale;
% if the string is too long to fit within bounds, we break it up on
% word boundaries.
if xpart(lrcorner p) > w:
save q, gq, offs, len, goodlen, gl, ls, sp;
picture q, gq;
numeric offs, len, goodlen, ls, gl;
string sp;
p := nullpicture;
offs := 0; % offset of current substring within s
len := 1; % most recent character examined
goodlen := 0; % most recent reasonable break point
ls := length(s);
forever:
if len < ls:
sp := substring(len, len+1) of s;
else:
sp := " ";
fi;
if (sp = " ") or (sp = "-") or (sp = "/"):
if sp <>" ":
len := len + 1;
fi;
% test to see if this is within the needed width
q := (substring(offs, len) of s) infont defaultfont scaled defaultscale;
if xpart (lrcorner q) > w:
% if there's no good break point, build up until we
% get something that fits -- can't use goodlen as the
% array index as it is reset to 0 after the loop ends
if goodlen <= offs:
for gl = (len-1) downto (offs+1):
goodlen := gl;
gq := (substring(offs, goodlen) of s) infont defaultfont scaled defaultscale;
exitunless xpart (lrcorner gq) > w;
endfor;
fi;
p := image(draw p shifted (0, b);
draw gq;);
offs := goodlen;
len := offs + 1;
% we still fit, so save the current position
else:
if sp <> " ":
goodlen := len;
else:
goodlen := len+1;
fi;
gq := q;
fi;
fi;
exitunless len < ls;
len := len + 1;
endfor;
if goodlen < ls:
gq := (substring(offs, ls) of s) infont defaultfont scaled defaultscale;
fi;
if goodlen <> ls:
p := image(draw p shifted (0, b);
draw gq;);
fi;
fi;
p
enddef;
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