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+%%BeginProlog
+50 dict begin
+
+% This is a standard prolog for Postscript generated by Tk's canvas
+% widget.
+% SCCS: @(#) prolog.ps 1.7 96/07/08 17:52:14
+
+% The definitions below just define all of the variables used in
+% any of the procedures here.  This is needed for obscure reasons
+% explained on p. 716 of the Postscript manual (Section H.2.7,
+% "Initializing Variables," in the section on Encapsulated Postscript).
+
+/baseline 0 def
+/stipimage 0 def
+/height 0 def
+/justify 0 def
+/lineLength 0 def
+/spacing 0 def
+/stipple 0 def
+/strings 0 def
+/xoffset 0 def
+/yoffset 0 def
+/tmpstip null def
+
+% Define the array ISOLatin1Encoding (which specifies how characters are
+% encoded for ISO-8859-1 fonts), if it isn't already present (Postscript
+% level 2 is supposed to define it, but level 1 doesn't).
+
+systemdict /ISOLatin1Encoding known not {
+    /ISOLatin1Encoding [
+	/space /space /space /space /space /space /space /space
+	/space /space /space /space /space /space /space /space
+	/space /space /space /space /space /space /space /space
+	/space /space /space /space /space /space /space /space
+	/space /exclam /quotedbl /numbersign /dollar /percent /ampersand
+	    /quoteright
+	/parenleft /parenright /asterisk /plus /comma /minus /period /slash
+	/zero /one /two /three /four /five /six /seven
+	/eight /nine /colon /semicolon /less /equal /greater /question
+	/at /A /B /C /D /E /F /G
+	/H /I /J /K /L /M /N /O
+	/P /Q /R /S /T /U /V /W
+	/X /Y /Z /bracketleft /backslash /bracketright /asciicircum /underscore
+	/quoteleft /a /b /c /d /e /f /g
+	/h /i /j /k /l /m /n /o
+	/p /q /r /s /t /u /v /w
+	/x /y /z /braceleft /bar /braceright /asciitilde /space
+	/space /space /space /space /space /space /space /space
+	/space /space /space /space /space /space /space /space
+	/dotlessi /grave /acute /circumflex /tilde /macron /breve /dotaccent
+	/dieresis /space /ring /cedilla /space /hungarumlaut /ogonek /caron
+	/space /exclamdown /cent /sterling /currency /yen /brokenbar /section
+	/dieresis /copyright /ordfeminine /guillemotleft /logicalnot /hyphen
+	    /registered /macron
+	/degree /plusminus /twosuperior /threesuperior /acute /mu /paragraph
+	    /periodcentered
+	/cedillar /onesuperior /ordmasculine /guillemotright /onequarter
+	    /onehalf /threequarters /questiondown
+	/Agrave /Aacute /Acircumflex /Atilde /Adieresis /Aring /AE /Ccedilla
+	/Egrave /Eacute /Ecircumflex /Edieresis /Igrave /Iacute /Icircumflex
+	    /Idieresis
+	/Eth /Ntilde /Ograve /Oacute /Ocircumflex /Otilde /Odieresis /multiply
+	/Oslash /Ugrave /Uacute /Ucircumflex /Udieresis /Yacute /Thorn
+	    /germandbls
+	/agrave /aacute /acircumflex /atilde /adieresis /aring /ae /ccedilla
+	/egrave /eacute /ecircumflex /edieresis /igrave /iacute /icircumflex
+	    /idieresis
+	/eth /ntilde /ograve /oacute /ocircumflex /otilde /odieresis /divide
+	/oslash /ugrave /uacute /ucircumflex /udieresis /yacute /thorn
+	    /ydieresis
+    ] def
+} if
+
+% font ISOEncode font
+% This procedure changes the encoding of a font from the default
+% Postscript encoding to ISOLatin1.  It's typically invoked just
+% before invoking "setfont".  The body of this procedure comes from
+% Section 5.6.1 of the Postscript book.
+
+/ISOEncode {
+    dup length dict begin
+	{1 index /FID ne {def} {pop pop} ifelse} forall
+	/Encoding ISOLatin1Encoding def
+	currentdict
+    end
+
+    % I'm not sure why it's necessary to use "definefont" on this new
+    % font, but it seems to be important; just use the name "Temporary"
+    % for the font.
+
+    /Temporary exch definefont
+} bind def
+
+% StrokeClip
+%
+% This procedure converts the current path into a clip area under
+% the assumption of stroking.  It's a bit tricky because some Postscript
+% interpreters get errors during strokepath for dashed lines.  If
+% this happens then turn off dashes and try again.
+
+/StrokeClip {
+    {strokepath} stopped {
+	(This Postscript printer gets limitcheck overflows when) =
+	(stippling dashed lines;  lines will be printed solid instead.) =
+	[] 0 setdash strokepath} if
+    clip
+} bind def
+
+% desiredSize EvenPixels closestSize
+%
+% The procedure below is used for stippling.  Given the optimal size
+% of a dot in a stipple pattern in the current user coordinate system,
+% compute the closest size that is an exact multiple of the device's
+% pixel size.  This allows stipple patterns to be displayed without
+% aliasing effects.
+
+/EvenPixels {
+    % Compute exact number of device pixels per stipple dot.
+    dup 0 matrix currentmatrix dtransform
+    dup mul exch dup mul add sqrt
+
+    % Round to an integer, make sure the number is at least 1, and compute
+    % user coord distance corresponding to this.
+    dup round dup 1 lt {pop 1} if
+    exch div mul
+} bind def
+
+% width height string StippleFill --
+%
+% Given a path already set up and a clipping region generated from
+% it, this procedure will fill the clipping region with a stipple
+% pattern.  "String" contains a proper image description of the
+% stipple pattern and "width" and "height" give its dimensions.  Each
+% stipple dot is assumed to be about one unit across in the current
+% user coordinate system.  This procedure trashes the graphics state.
+
+/StippleFill {
+    % The following code is needed to work around a NeWSprint bug.
+
+    /tmpstip 1 index def
+
+    % Change the scaling so that one user unit in user coordinates
+    % corresponds to the size of one stipple dot.
+    1 EvenPixels dup scale
+
+    % Compute the bounding box occupied by the path (which is now
+    % the clipping region), and round the lower coordinates down
+    % to the nearest starting point for the stipple pattern.  Be
+    % careful about negative numbers, since the rounding works
+    % differently on them.
+
+    pathbbox
+    4 2 roll
+    5 index div dup 0 lt {1 sub} if cvi 5 index mul 4 1 roll
+    6 index div dup 0 lt {1 sub} if cvi 6 index mul 3 2 roll
+
+    % Stack now: width height string y1 y2 x1 x2
+    % Below is a doubly-nested for loop to iterate across this area
+    % in units of the stipple pattern size, going up columns then
+    % across rows, blasting out a stipple-pattern-sized rectangle at
+    % each position
+
+    6 index exch {
+	2 index 5 index 3 index {
+	    % Stack now: width height string y1 y2 x y
+
+	    gsave
+	    1 index exch translate
+	    5 index 5 index true matrix tmpstip imagemask
+	    grestore
+	} for
+	pop
+    } for
+    pop pop pop pop pop
+} bind def
+
+% -- AdjustColor --
+% Given a color value already set for output by the caller, adjusts
+% that value to a grayscale or mono value if requested by the CL
+% variable.
+
+/AdjustColor {
+    CL 2 lt {
+	currentgray
+	CL 0 eq {
+	    .5 lt {0} {1} ifelse
+	} if
+	setgray
+    } if
+} bind def
+
+% x y strings spacing xoffset yoffset justify stipple DrawText --
+% This procedure does all of the real work of drawing text.  The
+% color and font must already have been set by the caller, and the
+% following arguments must be on the stack:
+%
+% x, y -	Coordinates at which to draw text.
+% strings -	An array of strings, one for each line of the text item,
+%		in order from top to bottom.
+% spacing -	Spacing between lines.
+% xoffset -	Horizontal offset for text bbox relative to x and y: 0 for
+%		nw/w/sw anchor, -0.5 for n/center/s, and -1.0 for ne/e/se.
+% yoffset -	Vertical offset for text bbox relative to x and y: 0 for
+%		nw/n/ne anchor, +0.5 for w/center/e, and +1.0 for sw/s/se.
+% justify -	0 for left justification, 0.5 for center, 1 for right justify.
+% stipple -	Boolean value indicating whether or not text is to be
+%		drawn in stippled fashion.  If text is stippled,
+%		procedure StippleText must have been defined to call
+%		StippleFill in the right way.
+%
+% Also, when this procedure is invoked, the color and font must already
+% have been set for the text.
+
+/DrawText {
+    /stipple exch def
+    /justify exch def
+    /yoffset exch def
+    /xoffset exch def
+    /spacing exch def
+    /strings exch def
+
+    % First scan through all of the text to find the widest line.
+
+    /lineLength 0 def
+    strings {
+	stringwidth pop
+	dup lineLength gt {/lineLength exch def} {pop} ifelse
+	newpath
+    } forall
+
+    % Compute the baseline offset and the actual font height.
+
+    0 0 moveto (TXygqPZ) false charpath
+    pathbbox dup /baseline exch def
+    exch pop exch sub /height exch def pop
+    newpath
+
+    % Translate coordinates first so that the origin is at the upper-left
+    % corner of the text's bounding box. Remember that x and y for
+    % positioning are still on the stack.
+
+    translate
+    lineLength xoffset mul
+    strings length 1 sub spacing mul height add yoffset mul translate
+
+    % Now use the baseline and justification information to translate so
+    % that the origin is at the baseline and positioning point for the
+    % first line of text.
+
+    justify lineLength mul baseline neg translate
+
+    % Iterate over each of the lines to output it.  For each line,
+    % compute its width again so it can be properly justified, then
+    % display it.
+
+    strings {
+	dup stringwidth pop
+	justify neg mul 0 moveto
+	stipple {
+
+	    % The text is stippled, so turn it into a path and print
+	    % by calling StippledText, which in turn calls StippleFill.
+	    % Unfortunately, many Postscript interpreters will get
+	    % overflow errors if we try to do the whole string at
+	    % once, so do it a character at a time.
+
+	    gsave
+	    /char (X) def
+	    {
+		char 0 3 -1 roll put
+		currentpoint
+		gsave
+		char true charpath clip StippleText
+		grestore
+		char stringwidth translate
+		moveto
+	    } forall
+	    grestore
+	} {show} ifelse
+	0 spacing neg translate
+    } forall
+} bind def
+
+%%EndProlog