%!PS

/nextline {
  y linedist sub /y exch def
  % (page wrap handling could go here...)
} bind def

/block_justify {
  % expected args: x, y, string, width of block, line distance
  %   e.g.: 20 100 (...) 400 15 block_justify

  30 dict begin

  % configurable params
  %   (set those values to zero if you want to adjust
  %   nothing but inter-word spacings)
  /maxcondense 0.1 def             % max condense per glyph
  /maxstretch  0.3 def             % max stretch  per glyph

  % args
  /linedist exch def
  /blockwidth exch def
  dup length /txtlen exch def
  /txt exch def
  /y exch def  /x exch def
  
  /j    0 def
  /_i   0 def
  /_w   0 def
  /_len 0 def
  /nspaces 0 def
  
  0 1 txtlen 1 sub {                    % for each char/index of string
    /i exch def
    txt i get 32 eq {                   % word boundary?
      txt j i j sub getinterval         % substring to evaluate
      dup length /len exch def          % length of substring
      stringwidth pop /w exch def       % width of substring
      w blockwidth ge {                 % would exceed box border?
        /dleft blockwidth _w sub def    % distance to border from left side
        /dright w blockwidth sub def    % distance to border from right side
        /maxcondense_tot maxcondense len mul def
        /maxstretch_tot  maxstretch _len mul def
        dright maxcondense_tot le {
          /aw dright len div neg def    % neg value to apply to 'ashow'
          /cw 0 def
          txt j i j sub getinterval
          /j i 1 add def
        } {
          dleft maxstretch_tot le {
            /aw dleft _len div def      % pos value to apply to 'ashow'
            /cw 0 def
          } {
            /aw maxstretch def
            nspaces 1 gt {
              /cw dleft maxstretch_tot sub
              nspaces 1 sub div def     % value to apply to 'widthshow'
            } {
              /cw 0 def
            } ifelse
          } ifelse
          txt j _i j sub getinterval
          /j _i 1 add def
        } ifelse
        x y moveto cw 0 32 aw 0 6 -1 roll awidthshow
        nextline
        /_i j def
        /_w 0 def
        /nspaces 0 def
      } {                               % doesn't yet exceed...
        /_w w def
        /_i i def
        /_len len def
      } ifelse
      /nspaces nspaces 1 add def
    } if
  } for
  
  txtlen j sub 0 gt {
    % remainder / last line -- left-justified
    x y moveto txt j txtlen j sub getinterval show
    nextline
  } if
  end
} bind def

% -----

/text (Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do \
eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad \
minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip \
ex ea commodo consequat. Duis aute irure dolor in reprehenderit in \
voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur \
sint occaecat cupidatat non proident, sunt in culpa qui officia \
deserunt mollit anim id est laborum. ) def

/Helvetica findfont 15 scalefont setfont
50 700 text 500 20 block_justify

/Helvetica-BoldOblique findfont 12 scalefont setfont
50 550 text 450 17 block_justify

/Times-Roman findfont 15 scalefont setfont
50 400 text 450 18 block_justify

/Times-Italic findfont 15 scalefont setfont
50 250 text 400 18 block_justify

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