path: root/include/figf.lpg

%%BeginResource: procset LoutFigPrependGraphic
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                    %
%  PostScript @SysPrependGraphic file for @Fig  Jeffrey H. Kingston  %
%  Version 2.0 (includes CIRCUM label)                 January 1992  %
%                                                                    %
%  Although Fig is now obsolete I have updated it 20 October 2002    %
%  to work with textures, i.e. replacing setrgbcolor with            %
%  LoutSetRGBColor.                                                  %
%                                                                    %
%  To assist in avoiding name clashes, the names of all symbols      %
%  defined here begin with "lfig".  However, this is not feasible    %
%  with user-defined labels and some labels used by users.           %
%                                                                    %
%  <point>      is two numbers, a point.                             %
%  <length>     is one number, a length                              %
%  <angle>      is one number, an angle in degrees                   %
%  <dashlength> is one number, the preferred length of a dash        %
%                                                                    %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

errordict begin
   /handleerror
   {
      {  /Times-Roman findfont 8 pt scalefont setfont
	 0 setgray 4 pt 4 pt moveto
	 $error /errorname get
	 dup lfigdict exch known
	 { lfigdict exch get }
	 { 30 string cvs } ifelse
	 show
	 (  Command: ) show
	 $error /command get 30 string cvs show
      } stopped {} if
      showpage stop
   } def
end

% concat strings: <string> <string> lfigconcat <string>
% must be defined outside lfigdict since used in lfigpromotelabels
/lfigconcat
{ 2 copy length exch length add string
  dup 0 4 index putinterval
  dup 3 index length 3 index putinterval
  3 1 roll pop pop
} def

% <string> lfigdebugprint -
% must be defined outside lfigdict since used in arbitrary places
% /lfigdebugprint
% { print
%   (;  operand stack:\n) print
%   count copy
%   count 2 idiv
%   { ==
%     (\n) print
%   } repeat
%   (\n) print
% } def

/lfigdict 120 dict def
lfigdict begin

% error messages
/dictfull (dictfull error:  too many labels?) def
/dictstackoverflow (dictstackoverflow error:  labels nested too deeply?) def
/execstackoverflow (execstackoverflow error:  figure nested too deeply?) def
/limitcheck (limitcheck error:  figure nested too deeply or too large?) def
/syntaxerror (syntaxerror error:  syntax error in text of figure?) def
/typecheck (typecheck error:  syntax error in text of figure?) def
/undefined (undefined error:  unknown or misspelt label?) def
/VMError (VMError error:  run out of memory?) def

% push pi onto stack:  - lfigpi <num>
/lfigpi 3.14159 def

% arc directions
/clockwise     false def
/anticlockwise true  def

% maximum of two numbers:  <num> <num> lfigmax <num>
/lfigmax { 2 copy gt { pop } { exch pop } ifelse } def

% minimum of two numbers:  <num> <num> lfigmin <num>
/lfigmin { 2 copy lt { pop } { exch pop } ifelse } def

% add two points:  <point> <point> lfigpadd <point>
/lfigpadd { exch 3 1 roll add 3 1 roll add exch } def

% subtract first point from second:  <point> <point> lfigpsub <point>
/lfigpsub { 3 2 roll sub 3 1 roll exch sub exch } def

% max two points:  <point> <point> lfigpmax <point>
/lfigpmax { exch 3 1 roll lfigmax 3 1 roll lfigmax exch } def

% min two points:  <point> <point> lfigpmin <point>
/lfigpmin { exch 3 1 roll lfigmin 3 1 roll lfigmin exch } def

% scalar multiplication: <point> <num> lfigpmul <point>
/lfigpmul { dup 3 1 roll mul 3 1 roll mul exch } def

% point at angle and distance:  <point> <length> <angle> lfigatangle <point>
/lfigatangle { 2 copy cos mul 3 1 roll sin mul lfigpadd } def

% angle from one point to another:  <point> <point> lfigangle <angle>
/lfigangle { lfigpsub 2 copy 0 eq exch 0 eq and {pop} {exch atan} ifelse } def

% distance between two points:  <point> <point> lfigdistance <length>
/lfigdistance { lfigpsub dup mul exch dup mul add sqrt } def

% difference in x coords: <point> <point> lfigxdistance <length>
/lfigxdistance { pop 3 1 roll pop sub } def

%difference in y coords: <point> <point> lfigydistance <length>
/lfigydistance { 3 1 roll pop sub exch pop } def

% stroke a solid line:  <length> <dashlength> lfigsolid -
/lfigsolid
{  pop pop [] 0 setdash stroke
} def

% stroke a lfigdashed line:   <length> <dashlength> lfigdashed -
/lfigdashed
{  2 copy div 2 le 1 index 0 le or
   {  exch pop 1 pt lfigmax [ exch dup ] 0 setdash }
   {  dup [ exch 4 2 roll 2 copy div
      1 sub 2 div ceiling dup 4 1 roll
      1 add mul sub exch div ] 0 setdash
   } ifelse stroke
} def

% stroke a lfigcdashed line:  <length> <dashlength> lfigcdashed -
/lfigcdashed
{  2 copy le 1 index 0 le or
   { exch pop 1 pt lfigmax [ exch dup ] dup 0 get 2 div setdash }
   { dup [ 4 2 roll exch 2 copy exch div
     2 div ceiling div 1 index sub
     ] exch 2 div setdash
   } ifelse stroke
} def

% stroke a dotted line:  <length> <dashlength> lfigdotted -
/lfigdotted
{  2 copy le 1 index 0 le or
   { exch pop 1 pt lfigmax [ exch 0 exch ] 0 setdash }
   { 1 index exch div ceiling div
     [ 0 3 2 roll ] 0 setdash
   } ifelse stroke
} def

% stroke a noline line:  <length> <dashlength> lfignoline -
/lfignoline
{ pop pop
} def

% painting (i.e. filling): - lfigwhite - (etc.)
/lfignopaint		{			           } def
/lfignochange		{ 			      fill } def
/lfigdarkblue		{ 0.0 0.0 0.5 LoutSetRGBColor fill } def
/lfigblue		{ 0.0 0.0 1.0 LoutSetRGBColor fill } def
/lfiglightblue		{ 0.5 0.5 1.0 LoutSetRGBColor fill } def
/lfigdarkgreen		{ 0.0 0.5 0.0 LoutSetRGBColor fill } def
/lfiggreen		{ 0.0 1.0 0.0 LoutSetRGBColor fill } def
/lfiglightgreen		{ 0.5 1.0 0.5 LoutSetRGBColor fill } def
/lfigdarkred		{ 0.5 0.0 0.0 LoutSetRGBColor fill } def
/lfigred		{ 1.0 0.0 0.0 LoutSetRGBColor fill } def
/lfiglightred		{ 1.0 0.5 0.5 LoutSetRGBColor fill } def
/lfigdarkcyan		{ 0.0 0.5 0.5 LoutSetRGBColor fill } def
/lfigcyan		{ 0.0 1.0 1.0 LoutSetRGBColor fill } def
/lfiglightcyan		{ 0.5 1.0 1.0 LoutSetRGBColor fill } def
/lfigdarkmagenta	{ 0.5 0.0 0.5 LoutSetRGBColor fill } def
/lfigmagenta		{ 1.0 0.0 1.0 LoutSetRGBColor fill } def
/lfiglightmagenta	{ 1.0 0.5 1.0 LoutSetRGBColor fill } def
/lfigdarkyellow		{ 0.5 0.5 0.0 LoutSetRGBColor fill } def
/lfigyellow		{ 1.0 1.0 0.0 LoutSetRGBColor fill } def
/lfiglightyellow	{ 1.0 1.0 0.5 LoutSetRGBColor fill } def
/lfigdarkgray		{ 0.2 0.2 0.2 LoutSetRGBColor fill } def
/lfiggray		{ 0.5 0.5 0.5 LoutSetRGBColor fill } def
/lfiglightgray		{ 0.8 0.8 0.8 LoutSetRGBColor fill } def
/lfigdarkgrey		{ 0.2 0.2 0.2 LoutSetRGBColor fill } def
/lfiggrey		{ 0.5 0.5 0.5 LoutSetRGBColor fill } def
/lfiglightgrey		{ 0.8 0.8 0.8 LoutSetRGBColor fill } def
/lfigblack		{ 0.0 0.0 0.0 LoutSetRGBColor fill } def
/lfigwhite		{ 1.0 1.0 1.0 LoutSetRGBColor fill } def

% line caps (and joins, not currently used)
/lfigbutt       0 def
/lfiground      1 def
/lfigprojecting 2 def
/lfigmiter      0 def
/lfigbevel      2 def

% shape and labels of the @Box symbol
/lfigbox
{
   0     0     /SW  lfigpointdef
   xsize 0     /SE  lfigpointdef
   xsize ysize /NE  lfigpointdef
   0     ysize /NW  lfigpointdef
   SE 0.5 lfigpmul /S   lfigpointdef
   NW 0.5 lfigpmul /W   lfigpointdef
   W SE lfigpadd   /E   lfigpointdef
   S NW lfigpadd   /N   lfigpointdef
   NE 0.5 lfigpmul /CTR lfigpointdef
   [ CTR NE lfigpsub /lfigboxcircum cvx ] lfigcircumdef
   SW SE NE NW SW
} def

% shape and labels of the @CurveBox symbol
/lfigcurvebox
{

   xsize 0.5 mul	ysize 0.5 mul	/CTR lfigpointdef
   xsize 0.5 mul	0		/S   lfigpointdef
   xsize		ysize 0.5 mul	/E   lfigpointdef
   xsize 0.5 mul	ysize		/N   lfigpointdef
   0			ysize 0.5 mul	/W   lfigpointdef

   xmark 0.293 mul		xmark 0.293 mul		  /SW  lfigpointdef
   xsize xmark 0.293 mul sub	xmark 0.293 mul		  /SE  lfigpointdef
   xsize xmark 0.293 mul sub	ysize xmark 0.293 mul sub /NE  lfigpointdef
   xmark 0.293 mul		ysize xmark 0.293 mul sub /NW  lfigpointdef

   [ xsize ysize 0.5 lfigpmul xmark /lfigcurveboxcircum cvx ] lfigcircumdef

   xmark		0
   xsize xmark sub	0
   [ xsize xmark sub	xmark		]
   xsize		xmark
   xsize		ysize xmark sub
   [ xsize xmark sub	ysize xmark sub	]
   xsize xmark sub	ysize
   xmark		ysize
   [ xmark		ysize xmark sub	]
   0			ysize xmark sub
   0			xmark
   [ xmark		xmark		]
   xmark		0
} def

% shadow of the @ShadowBox symbol
% its shape and labels are done, somewhat inaccurately, with lfigbox
/lfigshadow
{ xmark 2 mul 0 moveto xsize 0 lineto
  xsize ysize xmark 2 mul sub lineto
  xsize xmark sub ysize xmark 2 mul sub lineto
  xsize xmark sub xmark lineto
  xmark 2 mul xmark lineto closepath fill
} def

% shape and labels of the @Square symbol
/lfigsquare
{
   xsize ysize 0.5 lfigpmul /CTR lfigpointdef
   CTR xsize xsize ysize ysize lfigpmax 0.5 lfigpmul lfigpadd /NE lfigpointdef
   CTR 0 0 CTR NE lfigdistance 135 lfigatangle lfigpadd /NW lfigpointdef
   CTR 0 0 CTR NE lfigdistance 225 lfigatangle lfigpadd /SW lfigpointdef
   CTR 0 0 CTR NE lfigdistance 315 lfigatangle lfigpadd /SE lfigpointdef
   SW 0.5 lfigpmul SE 0.5 lfigpmul lfigpadd /S lfigpointdef
   NW 0.5 lfigpmul NE 0.5 lfigpmul lfigpadd /N lfigpointdef
   SW 0.5 lfigpmul NW 0.5 lfigpmul lfigpadd /W lfigpointdef
   SE 0.5 lfigpmul NE 0.5 lfigpmul lfigpadd /E lfigpointdef
   [ CTR NE lfigpsub /lfigboxcircum cvx ] lfigcircumdef
   SW SE NE NW SW
} def

% shape and labels of the @Diamond symbol
/lfigdiamond
{
   xsize 0 0.5 lfigpmul /S   lfigpointdef
   0 ysize 0.5 lfigpmul /W   lfigpointdef
   S W         lfigpadd /CTR lfigpointdef
   CTR W       lfigpadd /N   lfigpointdef
   CTR S       lfigpadd /E   lfigpointdef
   [ xsize ysize 0.5 lfigpmul /lfigdiamondcircum cvx ] lfigcircumdef
   S E N W S
} def

% shape and labels of the @Ellipse symbol
/lfigellipse
{
   xsize 0 0.5 lfigpmul /S   lfigpointdef
   0 ysize 0.5 lfigpmul /W   lfigpointdef
   S W         lfigpadd /CTR lfigpointdef
   CTR W       lfigpadd /N   lfigpointdef
   CTR S       lfigpadd /E   lfigpointdef
   CTR xsize 0 0.3536 lfigpmul lfigpadd 0 ysize 0.3536 lfigpmul lfigpadd /NE lfigpointdef
   0 ysize 0.3536 lfigpmul CTR xsize 0 0.3536 lfigpmul lfigpadd lfigpsub /SE lfigpointdef
   xsize 0 0.3536 lfigpmul CTR lfigpsub 0 ysize 0.3536 lfigpmul lfigpadd /NW lfigpointdef
   0 ysize 0.3536 lfigpmul xsize 0 0.3536 lfigpmul CTR lfigpsub lfigpsub /SW lfigpointdef
   [ xsize ysize 0.5 lfigpmul /lfigellipsecircum cvx ] lfigcircumdef
   S [ CTR ] E [ CTR ] N [ CTR ] W [ CTR ] S
} def

% shape and labels of the @Circle symbol
/lfigcircle
{
   xsize ysize 0.5 lfigpmul /CTR lfigpointdef
   CTR xsize 0 ysize 0 lfigpmax 0.5 lfigpmul lfigpadd /E lfigpointdef
   CTR 0 0 CTR E lfigdistance 45 lfigatangle lfigpadd /NE lfigpointdef
   CTR 0 0 CTR E lfigdistance 90 lfigatangle lfigpadd /N lfigpointdef
   CTR 0 0 CTR E lfigdistance 135 lfigatangle lfigpadd /NW lfigpointdef
   CTR 0 0 CTR E lfigdistance 180 lfigatangle lfigpadd /W lfigpointdef
   CTR 0 0 CTR E lfigdistance 225 lfigatangle lfigpadd /SW lfigpointdef
   CTR 0 0 CTR E lfigdistance 270 lfigatangle lfigpadd /S lfigpointdef
   CTR 0 0 CTR E lfigdistance 315 lfigatangle lfigpadd /SE lfigpointdef
   [ S E lfigpsub /lfigellipsecircum cvx ] lfigcircumdef
   S [ CTR ] E [ CTR ] N [ CTR ] W [ CTR ] S
} def

% shape and labels of the @HLine and @HArrow symbols
/lfighline
{
   0 ymark lfigprevious /FROM lfigpointdef
   xsize ymark lfigprevious /TO lfigpointdef
} def

% shape and labels of the @VLine and @VArrow symbols
/lfigvline
{
   xmark ysize lfigprevious /FROM lfigpointdef
   xmark 0 lfigprevious /TO lfigpointdef
} def

% points of a polygon around base with given no of sides, vert init angle:
% <sides> <angle> figpolygon <point> ... <point>
/lfigpolygon
{  xsize ysize 0.5 lfigpmul /CTR lfigpointdef
   90 sub CTR 2 copy lfigmax 5 3 roll
   [ 4 copy pop /lfigpolycircum cvx ] lfigcircumdef
   exch dup 360 exch div exch
   1 1  3 2 roll
   {  4 string cvs (P) exch lfigconcat cvn
      6 copy pop pop lfigatangle 2 copy 10 2 roll
      3 2 roll lfigpointdef
      dup 3 1 roll add exch
   }  for
   pop lfigatangle
} def

% next array element:  <array> <index> lfiggetnext <array> <index> <any> true
%                                               or <array> <index> false
/lfiggetnext
{  2 copy exch length ge
   { false }
   { 2 copy get exch 1 add exch true } ifelse
} def

% check whether thing is number:  <any> lfigisnumbertype <any> <bool>
/lfigisnumbertype
{  dup type dup
   /integertype eq exch /realtype eq or
} def

% check whether thing is an array:  <any> lfigisarraytype <any> <bool>
/lfigisarraytype { dup type /arraytype eq } def

% get next item:  <array> <index> lfiggetnextitem <array> <index> 0
%                                              or <array> <index> <array> 1
%                                              or <array> <index> <point> 2
/lfiggetnextitem
{   lfiggetnext
    {	lfigisarraytype
	{   1
	}
	{   lfigisnumbertype
	    {	3 1 roll
		lfiggetnext
		{   lfigisnumbertype
		    {	4 3 roll exch  2
		    }
		    {	pop 3 2 roll pop  0
		    } ifelse
		}
		{   3 2 roll pop  0
		} ifelse
	    }
	    {	pop 0
	    } ifelse
	} ifelse
    }
    {	0
    } ifelse
} def

% set arc path:  bool x1 y1  x2 y2  x0 y0  lfigsetarc  <angle> <angle> <dist>
% the path goes from x1 y1 to x2 y2 about centre x0 y0,
% anticlockwise if bool is true else clockwise.
% The orientations of backwards pointing and forwards pointing
% arrowheads are returned in the two angles, and
% the length of the arc is returned in <dist>.
/lfigsetarc
{
  20 dict begin
     matrix currentmatrix 8 1 roll
     2 copy translate 2 copy 8 2 roll
     4 2 roll lfigpsub 6 2 roll lfigpsub
     dup /y1 exch def dup mul /y1s exch def
     dup /x1 exch def dup mul /x1s exch def
     dup /y2 exch def dup mul /y2s exch def
     dup /x2 exch def dup mul /x2s exch def

     y1s y2s eq
     {	-1
     }
     {	y1s x2s mul y2s x1s mul sub y1s y2s sub div
     } ifelse
     /da exch def

     x1s x2s eq
     {	-1
     }
     {	x1s y2s mul x2s y1s mul sub x1s x2s sub div
     } ifelse
     /db exch def

     da 0 gt db 0 gt and
     {	/LMax da sqrt db sqrt lfigmax def
	/scalex da sqrt LMax div def
	/scaley db sqrt LMax div def
	scalex scaley scale
	0 0 LMax
	0 0 x1 scalex mul y1 scaley mul lfigangle
	0 0 x2 scalex mul y2 scaley mul lfigangle
	2 copy eq { 360 add } if
	2 copy 8 2 roll
	5 index { arc } { arcn } ifelse
	2 index 1 index
	{ 90 sub } { 90 add } ifelse
	dup sin scaley mul exch cos scalex mul atan
	2 index 2 index
	{ 90 add } { 90 sub } ifelse
	dup sin scaley mul exch cos scalex mul atan
	5 2 roll  % res1 res2 ang1 ang2 anticlockwise
	{ exch sub } { sub } ifelse
	dup 0 le { 360 add } if  lfigpi mul LMax mul 180 div
     }
     {	0 0 x1 y1 lfigdistance 0 0 x2 y2 lfigdistance eq
	0 0 x1 y1 lfigdistance 0 gt and
	{	0 0
		0 0 x1 y1 lfigdistance
		0 0 x1 y1 lfigangle
		0 0 x2 y2 lfigangle
		2 copy eq { 360 add } if
		2 copy 8 2 roll
		5 index { arc } { arcn } ifelse
		2 index 1 index
		{ 90 sub } { 90 add } ifelse
		2 index 2 index
		{ 90 add } { 90 sub } ifelse
		5 2 roll % res1 res2 ang1 ang2 clockwise
		{ exch sub } { sub } ifelse
		dup 0 le { 360 add } if lfigpi mul 0 0 x1 y1 lfigdistance mul 180 div
	}
	{	x2 y2 lineto pop
		x2 y2 x1 y1 lfigangle
		x1 y1 x2 y2 lfigangle
		x1 y1 x2 y2 lfigdistance
	} ifelse
     } ifelse
     4 -1 roll setmatrix
   end
} def

% lfigsetcurve: set up a Bezier curve from x0 y0 to x3 y3
% and return arrowhead angles and length of curve (actually 0)
% x0 y0 x1 y1 x2 y2 x3 y3 lfigsetcurve <angle> <angle> <length>
/lfigsetcurve
{ 8 copy curveto pop pop
  lfigangle
  5 1 roll
  4 2 roll lfigangle
  exch
  0
} def

% lfigpaintpath: paint a path of the given shape
% /paint [ shape ] lfigpaintpath -
/lfigpaintpath
{
  10 dict begin
    0 newpath
    /prevseen false def
    /curveseen false def
    { lfiggetnextitem
      dup 0 eq { pop exit }
      { 1 eq
        { /curveseen true def
	  /curve exch def
	  curve length 0 eq { /curveseen false def } if
        }
        { /ycurr exch def
	  /xcurr exch def
	  prevseen
	  { curveseen
	    { curve length 4 eq
	      { xprev yprev
		curve 0 get curve 1 get
		curve 2 get curve 3 get
		xcurr ycurr
		lfigsetcurve pop pop pop
	      }
	      { xprev yprev xcurr ycurr
	        curve length 1 ge { curve 0 get } { 0 } ifelse
	        curve length 2 ge { curve 1 get } { 0 } ifelse
	        curve length 3 ge { curve 2 get } { true } ifelse
	        7 1 roll
	        lfigsetarc pop pop pop
	      } ifelse
	    }
	    { xcurr ycurr lineto
	    } ifelse
	  }
	  { xcurr ycurr moveto
	  } ifelse
	  /xprev xcurr def
	  /yprev ycurr def
	  /prevseen true def
	  /curveseen false def
        } ifelse
      } ifelse
    } loop pop pop cvx exec
  end
} def

% stroke a path of the given shape in the given linestyle and dash length.
% Return the origin and angle of the backward and forward arrow heads.
% dashlength /linestyle [shape] lfigdopath  [<point> <angle>] [<point> <angle>] 
/lfigdopath
{
  10 dict begin
    0
    /prevseen  false def
    /curveseen false def
    /backarrow []    def
    /fwdarrow  []    def
    {
	lfiggetnextitem
	dup 0 eq { pop exit }
	{
	    1 eq
	    {	/curveseen true def
		/curve exch def
		curve length 0 eq { /prevseen false def } if
	    }
	    {	/ycurr exch def
		/xcurr exch def
		prevseen
		{   newpath xprev yprev moveto
		    curveseen
		    {	curve length 4 eq
			{   xprev yprev
			    curve 0 get curve 1 get
			    curve 2 get curve 3 get
			    xcurr ycurr lfigsetcurve
			}
			{   xprev yprev xcurr ycurr
			    curve length 1 ge { curve 0 get } { 0 } ifelse
			    curve length 2 ge { curve 1 get } { 0 } ifelse
			    curve length 3 ge { curve 2 get } { true } ifelse
			    7 1 roll
			    lfigsetarc
			} ifelse
		    }
		    {	xcurr ycurr lineto
			xcurr ycurr xprev yprev lfigangle dup 180 sub
			xprev yprev xcurr ycurr lfigdistance
		    } ifelse
		    6 index 6 index cvx exec
		    [ xprev yprev 5 -1 roll ]
		    backarrow length 0 eq
		    { /backarrow exch def }
		    { pop } ifelse
		    [ xcurr ycurr 4 -1 roll ] /fwdarrow exch def
		} if
		/xprev xcurr def
		/yprev ycurr def
		/prevseen true def
		/curveseen false def
	    } ifelse
	} ifelse
    } loop
    pop pop pop pop
    backarrow length 0 eq { [ 0 0 0 ] } { backarrow } ifelse
    fwdarrow  length 0 eq { [ 0 0 0 ] } { fwdarrow  } ifelse
  end
} def

% lfigdoarrow: draw an arrow head of given form
% dashlength /lstyle /pstyle hfrac height width [ <point> <angle> ] lfigdoarrow -
/lfigdoarrow
{  matrix currentmatrix 8 1 roll
   dup 0 get 1 index 1 get translate
   2 get rotate
   [ 2 index neg 2 index 0 0
     3 index 3 index neg
     1 index 10 index mul 0
     7 index 7 index ]
   4 1 roll pop pop pop
   dup 3 1 roll
   gsave lfigpaintpath grestore lfigdopath pop pop
   setmatrix
} def

% arrow head styles
/lfigopen     0.0 def
/lfighalfopen 0.5 def
/lfigclosed   1.0 def

% stroke no arrows, forward, back, and both
/lfignoarrow { pop pop pop pop pop pop pop pop                        } def
/lfigforward { 7 -1 roll lfigdoarrow pop                              } def
/lfigback    { 8 -2 roll pop lfigdoarrow                              } def
/lfigboth    { 8 -1 roll 7 copy lfigdoarrow pop 7 -1 roll lfigdoarrow } def

% lfigprevious: return previous point on path
/lfigprevious
{ lfigisnumbertype
  { 2 copy }
  { lfigisarraytype
    { 2 index 2 index }
    { 0 0 }
    ifelse
  } ifelse
} def

% label a point in 2nd top dictionary:  <point> /name lfigpointdef -
/lfigpointdef
{
  % (Entering lfigpointdef) lfigdebugprint
  [ 4 2 roll transform
    /itransform cvx ] cvx
    currentdict end
    3 1 roll
    % currentdict length currentdict maxlength lt
    % { def }
    % { exec moveto (too many labels) show stop }
    % ifelse
    def
    begin
  % (Leaving lfigpointdef) lfigdebugprint
} def

% promote labels from second top to third top dictionary
% <string> lfigpromotelabels -
/lfigpromotelabels
{
  % (Entering lfigpromotelabels) lfigdebugprint
  currentdict end exch currentdict end
  { exch 20 string cvs 2 index
    (@) lfigconcat exch lfigconcat cvn exch def
  } forall pop begin
  % (Leaving lfigpromotelabels) lfigdebugprint
} def

% show labels (except CIRCUM): - lfigshowlabels -
/lfigshowlabels
{
  % (Entering lfigshowlabels) lfigdebugprint
  currentdict end
    currentdict
    { 1 index 20 string cvs (CIRCUM) search % if CIRCUM in key
      { pop pop pop pop pop }
      { pop cvx exec 2 copy
        newpath 1.5 pt 0 360 arc
        0 setgray fill
        /Times-Roman findfont 8 pt scalefont setfont
        moveto 0.2 cm 0.1 cm rmoveto 20 string cvs show
      }
      ifelse
    } forall
  begin
  % (Leaving lfigshowlabels) lfigdebugprint
} def

% fix an angle to 0 <= res < 360:  <angle> lfigfixangle <angle>
/lfigfixangle
{
  % (Entering lfigfixangle) lfigdebugprint
  { dup 0 ge { exit } if
    360 add
  } loop
  { dup 360 lt { exit } if
    360 sub
  } loop
  % (Leaving lfigfixangle) lfigdebugprint
} def

% find point on circumference of box:  alpha a b lfigboxcircum x y
/lfigboxcircum
{
  % (Entering lfigboxcircum) lfigdebugprint
  4 dict begin
    /b exch def
    /a exch def
    lfigfixangle /alpha exch def
    0 0 a b lfigangle /theta exch def

    % if alpha <= theta, return (a, a*tan(alpha))
    alpha theta le
    { a  a alpha sin mul alpha cos div }
    {
      % else if alpha <= 180 - theta, return (b*cot(alpha), b)
      alpha 180 theta sub le
      { b alpha cos mul alpha sin div  b }
      {
        % else if alpha <= 180 + theta, return (-a, -a*tan(alpha))
        alpha 180 theta add le
        { a neg  a neg alpha sin mul alpha cos div }
        {
	  % else if alpha <= 360 - theta, return (-b*cot(alpha), -b)
	  alpha 360 theta sub le
          { b neg alpha cos mul alpha sin div  b neg }
	  {
	    % else 360 - theta <= alpha, return (a, a*tan(alpha))
	    a  a alpha sin mul alpha cos div
	  } ifelse
        } ifelse
      } ifelse
    } ifelse
  end
  % (Leaving lfigboxcircum) lfigdebugprint
} def

% find quadratic roots (assume a != 0): a b c lfigqroots x1 x2 2
%                                                     or    x2 1
%                                                     or       0
/lfigqroots
{
  4 dict begin
    /c exch def
    /b exch def
    /a exch def
    /disc b b mul 4 a c mul mul sub def
    disc 0 lt
    { 0
    }
    { disc 0 eq
      { b neg 2 a mul div
	1
      }
      { b neg disc sqrt add 2 a mul div
        b neg disc sqrt sub 2 a mul div
	2
      }
      ifelse
    }
    ifelse
  end
} def

% work our which quadrant: <angle> lfigquadrant <0-3>
/lfigquadrant
{ dup 90 lt
  { pop 0
  }
  { dup 180 lt
    { pop 1
    }
    { 270 lt
      { 2
      }
      { 3
      } ifelse
    } ifelse
  } ifelse
} def

% find curvebox circum, assuming upper right quadrant: alpha a b xmk lfigcb x y
/lfigcb
{
  6 dict begin
    /xmk exch def
    /b exch def
    /a exch def
    /alpha exch def
    /theta1 0 0 a b xmk sub lfigangle def
    /theta2 0 0 a xmk sub b lfigangle def
    alpha theta1 le
    { % if alpha <= theta1, return (a, a*tan(alpha))
      a  a alpha sin mul alpha cos div
    }
    { alpha theta2 ge
      { % else if alpha > theta2, return (b*cot(alpha), b)
	b alpha cos mul alpha sin div  b
      }
      {
	% else, return the intersection of line and circle
	a xmk sub b xmk sub xmk  0 0 alpha lfigcircleintersect
	dup 0 eq
	{ % should never happen, just return any reasonable point
	  pop
	  a b 0.5 lfigpmul
	}
	{ 1 eq
	  { % should never happen, just return the point on top of stack
	  }
	  { % the usual case, two points on stack, return the larger
	    lfigpmax
	  } ifelse
	} ifelse
      } ifelse
    } ifelse
  end
} def

% find point on circumference of curvebox: alpha a b xmk lfigcurveboxcircum x y
/lfigcurveboxcircum
{
  % (Entering lfigcurveboxcircum) lfigdebugprint
  5 dict begin
    /xmk exch def
    /b exch def
    /a exch def
    lfigfixangle /alpha exch def

    % work out which quadrant we are in, and reflect accordingly
    /quad alpha lfigquadrant def
    quad 0 eq
    { alpha a b xmk lfigcb
    }
    { quad 1 eq
      { 180 alpha sub a b xmk lfigcb exch neg exch
      }
      { quad 2 eq
	{ alpha 180 sub a b xmk lfigcb neg exch neg exch
	}
	{ 360 alpha sub a b xmk lfigcb neg
	} ifelse
      } ifelse
    } ifelse
  end
  % (Leaving lfigcurveboxcircum) lfigdebugprint
} def

% find point on circumference of diamond:  alpha a b lfigdiamondcircum x y
/lfigdiamondcircum
{
  % (Entering lfigdiamondcircum) lfigdebugprint
  4 dict begin
    /b exch def
    /a exch def
    lfigfixangle /alpha exch def
    b alpha cos abs mul  a alpha sin abs mul  add  /denom exch def
    a b mul alpha cos mul denom div
    a b mul alpha sin mul denom div
  end
  % (Leaving lfigdiamondcircum) lfigdebugprint
} def

% find point on circumference of ellipse:  alpha a b lfigellipsecircum x y
/lfigellipsecircum
{
  % (Entering lfigellipsecircum) lfigdebugprint
  4 dict begin
    /b exch def
    /a exch def
    lfigfixangle /alpha exch def
    b alpha cos mul dup mul  a alpha sin mul dup mul  add sqrt /denom exch def
    a b mul alpha cos mul denom div
    a b mul alpha sin mul denom div
  end
  % (Leaving lfigellipsecircum) lfigdebugprint
} def

% find point of intersection of two lines each defined by two points
% x1 y1 x2 y2  x3 y3 x4 y4  lfiglineintersect x y
/lfiglineintersect
{
  % (Entering lfiglineintersect) lfigdebugprint
  13 dict begin
    /y4 exch def
    /x4 exch def
    /y3 exch def
    /x3 exch def
    /y2 exch def
    /x2 exch def
    /y1 exch def
    /x1 exch def
    x2 x1 sub /x21 exch def
    x4 x3 sub /x43 exch def
    y2 y1 sub /y21 exch def
    y4 y3 sub /y43 exch def
    y21 x43 mul y43 x21 mul sub /det exch def
  
    % calculate x 
    y21 x43 mul x1 mul
    y43 x21 mul x3 mul sub
    y3 y1 sub x21 mul x43 mul add
    det div

    % calculate y
    x21 y43 mul y1 mul
    x43 y21 mul y3 mul sub
    x3 x1 sub y21 mul y43 mul add
    det neg div

  end
  % (Leaving lfiglineintersect) lfigdebugprint
} def

% find point on circumference of polygon
% alpha radius num theta lfigpolycircum x y
/lfigpolycircum
{
  % (Entering lfigpolycircum) lfigdebugprint
  13 dict begin
    /theta exch def
    /num exch def
    /radius exch def
    /alpha exch def

    % calculate delta, the angle from theta to alpha
    alpha theta sub lfigfixangle

    % calculate the angle which is the multiple of 360/num closest to delta
    360 num div div truncate 360 num div mul theta add /anglea exch def

    % calculate the next multiple of 360/num after anglea
    anglea 360 num div add /angleb exch def

    % intersect the line through these two points with the alpha line
    anglea cos anglea sin  angleb cos angleb sin
    0 0  alpha cos 2 mul alpha sin 2 mul
    lfiglineintersect radius lfigpmul

  end
  % (Leaving lfigpolycircum) lfigdebugprint
} def

% find point of intersection of a point and a circle
% x0 y0 r  x1 y1 theta  lfigcircleintersect xa ya xb yb 2
%                                        or       xb yb 1
%                                        or             0
/lfigcircleintersect
{
  % (Entering lfigcircleintersect) lfigdebugprint
  15 dict begin
    /theta exch def
    /y1    exch def
    /x1    exch def
    /r     exch def
    /y0    exch def
    /x0    exch def

    % if sin(theta) = 0 then line is horizontal and y must be y1
    theta sin abs 0.00001 lt
    { 
      /a 1 def
      /b -2 x0 mul def
      /c x0 dup mul y1 y0 sub dup mul add r dup mul sub def
      a b c lfigqroots dup
      0 eq
      { pop
	0
      }
      { 1 eq
	{ y1 1
	}
	{ y1 exch y1 2
	} ifelse
      } ifelse
    }
    {
      /ct theta cos theta sin div def
      /a ct ct mul 1 add def
      /b ct x1 x0 sub mul y1 add y0 sub 2 mul def
      /c x1 x0 sub dup mul y1 y0 sub dup mul add r dup mul sub def
      a b c lfigqroots dup
      0 eq
      { pop
	0
      }
      { 1 eq
	{ y1 add /yb exch def
	  yb y1 sub ct mul x1 add /xb exch def
	  xb yb 1
	}
	{ y1 add /ya exch def
	  ya y1 sub ct mul x1 add /xa exch def
	  y1 add /yb exch def
	  yb y1 sub ct mul x1 add /xb exch def
	  xa ya xb yb 2
	} ifelse
      } ifelse
    } ifelse
  end
  % (Leaving lfigcircleintersect) lfigdebugprint
} def

% add CIRCUM operator with this body:  <array> lfigcircumdef -
/lfigcircumdef
{   % (Entering lfigcircumdef) lfigdebugprint
    /CIRCUM exch cvx
    currentdict end
    3 1 roll
    % currentdict length currentdict maxlength lt
    % { def }
    % { exec moveto (too many labels) show stop }
    % ifelse
    def
    begin
    % (Leaving lfigcircumdef) lfigdebugprint
} def

end
%%EndResource