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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.

    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

    } forall

} bind def

%%EndProlog