path: root/include/pief.lpg

%%BeginResource: procset LoutPiePrependGraphic
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                    %
%  PostScript @SysPrependGraphic file for @Pie  Jeffrey H. Kingston  %
%  Version 1.0                                                       %
%                                                                    %
%  Jeffrey H. Kingston                                               %
%  October 2002                                                      %
%                                                                    %
%  To assist in avoiding name clashes, the names of all symbols      %
%  defined here begin with "lpie".                                   %
%                                                                    %
%  <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        %
%                                                                    %
%  The following invariant is maintained from the end of the         %
%  call to lpiebegin to the beginning of the call to lpieend:        %
%                                                                    %
%  lpiecentre        is an executable function which leaves the two  %
%                    coordinates of the centre of the pie on the     %
%                    operand stack (signature - lpiectr <x> <y>)     %
%                                                                    %
%  lpieradius        is the radius of the pie                        %
%                                                                    %
%  lpieinitangle     is the initial angle                            %
%                                                                    %
%  lpietotalweight   is the total weight of all slices               %
%                                                                    %
%  lpiecurrentweight is the total weight of all slices so far        %
%                                                                    %
%  The first four are constants set by lpiebegin; the last is        %
%  updated as each slice is printed.                                 %
%                                                                    %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% install error handler into error dictionary
errordict begin
   /handleerror
   {
      {  /Times-Roman findfont 8 pt scalefont setfont
	 0 setgray 4 pt 4 pt moveto
	 $error /errorname get
	 dup lpiedict exch known
	 { lpiedict exch get }
	 { 100 string cvs } ifelse
	 show
	 (  Command: ) show
	 $error /command get 100 string cvs show
      } stopped {} if
      showpage stop
   } def
end

% initial coordinates of debug output
/lpiedebugposy 432 def
/lpiedebugposx 72 def

% <string> <int> lpiedebugprint -
% must be defined outside lpiedict since used in arbitrary places
% print <string> plus count or <int> stack entries, whichever is the smaller
/lpiedebugprint
{
  exch
  gsave
  initgraphics
  lpiedebugposy 72 lt
  { /lpiedebugposx lpiedebugposx 144 add store
    /lpiedebugposy 432 store
  }
  {
    /lpiedebugposy lpiedebugposy 12 sub store
  } ifelse
  lpiedebugposx lpiedebugposy moveto
  /Times-Roman findfont 10 scalefont setfont
  0 setgray show
  count 1 sub 2 copy lt { pop } { exch pop } ifelse 1 sub
  0 exch 1 exch
  {
    /lpiedebugposy lpiedebugposy 12 sub store
    lpiedebugposx 12 add lpiedebugposy moveto
    index
    dup type (dicttype) eq
    {
      (begin dict) show
      {
        /lpiedebugposy lpiedebugposy 12 sub store
        lpiedebugposx 24 add lpiedebugposy moveto
	pop 100 string cvs show
      } forall
      /lpiedebugposy lpiedebugposy 12 sub store
      lpiedebugposx 12 add lpiedebugposy moveto
      (end dict) show
    }
    {
      dup type (arraytype) eq
      {
	dup xcheck { (executable array) } { (literal array) } ifelse show
	{
          /lpiedebugposy lpiedebugposy 12 sub store
          lpiedebugposx 24 add lpiedebugposy moveto
	  100 string cvs show
        } forall
        /lpiedebugposy lpiedebugposy 12 sub store
        lpiedebugposx 12 add lpiedebugposy moveto
        (end array) show
      }
      {
        dup xcheck { (ex: ) } { (lit: ) } ifelse show
        100 string cvs show
      } ifelse
    } ifelse
  } for
  grestore
} def

% name lpiedebugpoint -
/lpieshowpoint
{
  dup cvx exec moveto 20 string cvs show newpath
} def

% begin pie: <totalweight> <initialangle> lpiebegin -
% must be defined outside lpiedict since it loads it
/lpiebegin
{ lpiedict begin
  20 dict begin
  xmark ymark /lpiecentre lpiepointdef
  /lpieradius xmark def
  /lpieinitialangle exch def
  /lpietotalweight exch def
  /lpiecurrentweight 0 def
} def

% end pie: - lpieend -
/lpieend
{
  end
  end
} def

% pie dictionary
/lpiedict 200 dict def

% subsequent definitions are held within the pie dictionary
lpiedict begin

% error messages
/syntaxerror (syntaxerror error:  syntax error in text of pie chart?) def
/typecheck (typecheck error:  syntax error in text of pie chart?) def
/undefined (undefined error:  unknown or misspelt label?) def
/VMError (VMError error:  run out of memory?) def

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

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

% add two points:  <point> <point> lpiepadd <point>
/lpiepadd
{
  % (Entering padd) 4 lpiedebugprint
  exch 3 1 roll add 3 1 roll add exch
  % (Leaving padd) 2 lpiedebugprint
} def

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

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

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

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

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

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

% stroke a solid line:  <length> <dashlength> lpiesolid -
/lpiesolid
{ % (Entering lpiesolid) 2 lpiedebugprint
  gsave pop pop [] 0 setdash 1 setlinecap stroke grestore newpath
  % (Leaving lpiesolid) 0 lpiedebugprint
} def

% stroke a dashed line:   <length> <dashlength> lpiedashed -
/lpiedashed
{  gsave
   2 copy div 2 le 1 index 0 le or
   {  exch pop 1 pt lpiemax [ 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 0 setlinecap stroke
   grestore newpath
} def

% stroke a cdashed line:  <length> <dashlength> lpiecdashed -
/lpiecdashed
{  % (Entering lpiecdashed) 2 lpiedebugprint
   gsave
   2 copy le 1 index 0 le or
   { exch pop 1 pt lpiemax [ 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 0 setlinecap stroke
   grestore newpath
   % (Leaving lpiecdashed) 0 lpiedebugprint
} def

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

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

% label a point in current dictionary:  <point> /name lpiepointdef -
/lpiepointdef
{
  % (Entering lpiepointdef) 3 lpiedebugprint
  [ 4 2 roll transform /itransform cvx ] cvx def
  % (Leaving lpiepointdef) 0 lpiedebugprint
} def

% find the angle that the current slice starts at
% - lpiesliceangle1 <angle>
/lpiesliceangle1
{ lpiecurrentweight lpietotalweight div 360 mul lpieinitialangle add
} def

% find the angle that the current slice stops at
% - lpiesliceangle2 <angle>
/lpiesliceangle2
{ weight lpiecurrentweight add lpietotalweight div 360 mul lpieinitialangle add
} def

% find the angle that bisects the current slice
% - lpieslicemidangle <angle>
/lpieslicemidangle
{ weight 2 div lpiecurrentweight add lpietotalweight div 360 mul lpieinitialangle add
} def

% update the total weight
% - lpieupdateweight -
/lpieupdateweight
{ weight lpiecurrentweight add /lpiecurrentweight exch def
} def

% find the apex of the slice
% - lpiesliceapex <x> <y>
/lpiesliceapex
{ lpiecentre lpieradius detach mul lpieslicemidangle lpieatangle
} def

% find the end of the first arm of the slice
% - lpieslicearm1 <x> <y>
/lpieslicearm1
{ lpiesliceapex lpieradius lpiesliceangle1 lpieatangle
} def

% find the end of the second arm of the slice
% - lpieslicearm2 <x> <y>
/lpieslicearm2
{ lpiesliceapex lpieradius lpiesliceangle2 lpieatangle
} def

% set the whole closed path for the current slice
% - lpiesetslicepath -
/lpiesetslicepath
{ newpath lpiesliceapex moveto
  currentpoint lpieradius lpiesliceangle1 lpiesliceangle2 arc
  closepath
} def

% set the first segment of the current slice and return its length
% - lpiesetsegment1 <length>
/lpiesetsegment1
{ newpath lpiesliceapex moveto lpieslicearm1 lineto
  lpieradius
} def

% set the second segment of the current slice and return its length
% - lpiesetsegment2 <length>
/lpiesetsegment2
{ newpath lpiesliceapex moveto lpieslicearm2 lineto
  lpieradius
} def

% set the arc segment of the current slice and return its length
% - lpiesetarcsegment <length>
/lpiesetarcsegment
{ newpath
  lpiesliceapex lpieradius lpiesliceangle1 lpiesliceangle2 arc
  lpiesliceangle2 lpiesliceangle1 sub 180 div 3.14159 mul lpieradius mul
} def

% draw one slice
% <dashlength> [ <outlinecommand> ] <outlinewidth> { <paintcommand> }
% <weight> <detach> lpiedrawslice -
/lpiebeginslice
{
  % (Entering lpiebeginslice) 6 lpiedebugprint
  /detach exch def
  /weight exch def

  % paint the slice
  gsave lpiesetslicepath exec grestore

  % set the line width
  setlinewidth

  % stroke each segment separately to get dashes right
  2 copy lpiesetsegment1 3 1 roll
  dup length 0 exch mod get cvx
  % (Stroking segment1) count 1 sub lpiedebugprint
  exec

  2 copy lpiesetarcsegment 3 1 roll
  dup length 1 exch mod get cvx
  % (Stroking arc segment) count 1 sub lpiedebugprint
  exec

  lpiesetsegment2 3 1 roll
  dup length 2 exch mod get cvx
  % (Stroking segment2) count 1 sub lpiedebugprint
  exec

  % (Leaving lpiebeginslice) 0 lpiedebugprint
} def

% finish off one slice
/lpieendslice
{
  % (Entering lpieendslice) 0 lpiedebugprint

  % update current weight ready for next slice
  lpieupdateweight

  % (Leaving lpieendslice) 0 lpiedebugprint
} def

% translate label
% <xadjust> <yadjust> <labelradius> lpietranslatelabel -
/lpietranslatelabel
{
  % (Entering lpietranslatelabel) 3 lpiedebugprint 
  /labelradius exch def
  % lpiecentre (lpiecentre:) 2 lpiedebugprint pop pop
  % lpieradius (lpieradius:) 1 lpiedebugprint pop
  % labelradius (labelradius:) 1 lpiedebugprint pop
  % lpieslicemidangle (lpieslicemidangle:) 1 lpiedebugprint pop
  xsize 2 div ysize 2 div /labelcentre lpiepointdef
  labelcentre
  lpiesliceapex lpieradius labelradius mul lpieslicemidangle lpieatangle lpiepsub
  lpiepadd
  translate
  % (Leaving lpietranslatelabel) 0 lpiedebugprint 
} def

% fix an angle to 0 <= res < 360:  <angle> lpiefixangle <angle>
/lpiefixangle
{
  % (Entering lpiefixangle) 1 lpiedebugprint
  { dup 0 ge { exit } if
    360 add
  } loop
  { dup 360 lt { exit } if
    360 sub
  } loop
  % (Leaving lpiefixangle) 1 lpiedebugprint
} def

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

% find point on circumference of box:  alpha a b lpieboxcircum x y
/lpieboxcircum
{
  % (Entering lpieboxcircum) 3 lpiedebugprint
  4 dict begin
    /b exch def
    /a exch def
    lpiefixangle /alpha exch def
    0 0 a b lpieangleto /theta exch def
    % a (a:) 1 lpiedebugprint pop
    % b (b:) 1 lpiedebugprint pop
    % theta (theta:) 1 lpiedebugprint pop
    % alpha (alpha:) 1 lpiedebugprint pop

    % 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 lpieboxcircum) 2 lpiedebugprint
} def


% draw finger (will immediately follow lpietranslatelabel)
% <fingerdashlength> "[" <fingerstyle> "]" fingerwidth
% <fingeradjustx> <fingeradjusty> <fingerradius> lpiedrawfinger -
/lpiedrawfinger
{
  % (Entering lpidrawfinger) 6 lpiedebugprint
  % find inner endpoint of finger
  /fingerradius exch def
  lpiesliceapex lpieradius fingerradius mul
  lpieslicemidangle lpieatangle lpiepadd
  /fingerinner lpiepointdef
  xsize 2 div ysize 2 div /labelcentre lpiepointdef
  0 0 /labelorigin lpiepointdef

  % find outer endpoint of finger, on circumference of label
  labelcentre fingerinner lpieangleto
  xsize 2 div ysize 2 div
  lpieboxcircum labelcentre lpiepadd
  /fingerouter lpiepointdef

  % set the line width
  setlinewidth

  % draw line
  newpath fingerinner moveto fingerouter lineto
  fingerinner fingerouter lpiedistance 3 1 roll 0 get cvx exec
  % (Leaving lpiedrawfinger) 0 lpiedebugprint
} def

% draw arrowhead (will immediately follow lpiedrawfinger if reqd)
% <headlength> <headwidth> lpiedrawarrowhead
/lpiedrawarrowhead
{
  gsave
  /headwidth exch def
  /headlength exch def
  fingerinner translate
  fingerouter fingerinner lpieangleto rotate
  0 0 moveto
  headlength neg headwidth 2 div lineto
  0 headwidth neg rlineto
  closepath fill
  grestore
} def
end
%%EndResource