% ps library to draw various shapes with lines eg. grids, lattice, box, etc.
%
% To draw a grid
% x1 y1 x2 y2 sep grid
%
% To draw a line
% x1 y1 x2 y2 line
%
% To draw a path connected with points
% x1 y1 x2 y2 x3 y3 ... x_n y_n path stroke
%
% To draw a polygon from points
% x1 y1 x2 y2 x3 y3 ... x_n y_n path closepath stroke
%
% To draw a filled polygon from points
% x1 y1 x2 y2 x3 y3 ... x_n y_n path closepath fill
%
% To draw a box
% x1 y1 x2 y2 box fill/stroke
% x1 y1 x2 y2 rect fill/stroke      % 'rect' is a synonym of 'box' 
%
% To draw a box with width and height
% x1 y1 w h rbox fill/stroke
%
% To draw a box with center coordinates, width and height
% cx1 cy1 w h cbox fill/stroke
%
% To draw a round-corner rectangle
% x1 y1 x2 y2 corner_size roundrect
%
% To draw a parallelo
% x1 y1 x2 y2 dx parallelo fill/stroke
% 
% To draw a circle
% x1 y1 rad  circle fill/stroke
%
% To draw an ellipse
% x1 y1 a b ellipse fill/stroke
%
% To draw a bent curve connecing two lines 
% x1 y1 x2 y2 x3 y3 x4 y4 r bendto     %  r: 0 - 1
%
% To draw a rectangular lattice 
% x1 y1 x2 y2 width lattice
 


% Calc average xM, yM from x1, y1 and x2, y2
/average{
exch 4 3 roll add 2 div 3 1 roll add 2 div
}
def

/line{
moveto lineto stroke
}def

/path{
    moveto count
    2 div cvi
    {lineto} repeat
}def

/griddic 1 dict def
/grid {
    griddic begin
    currentlinewidth 
    /lw exch def
    currentrgbcolor 3 array astore
    /rgb exch def
    /sep exch def
    /sep5 {sep 5 mul} def
    /y2 exch def
    /x2 exch def
    /y1 exch def
    /x1 exch def
    0.1 setlinewidth
    0.4 1.0 0.7 setrgbcolor
    x1 sep x2{
	dup y1 exch y2
	moveto lineto stroke
    }for
    y1 sep y2 {
	dup x1 3 1 roll
	x2 exch
	moveto lineto stroke
    }for
    0.5 setlinewidth
    0 0.8 0.2 setrgbcolor
    x1 sep5 x2{
	dup y1 exch y2
	moveto lineto stroke
    }for
    y1 sep5 y2 {
	dup x1 3 1 roll
	x2 exch
	moveto lineto stroke
    }for
    lw setlinewidth
    rgb aload pop setrgbcolor
    end
} def

% define box
/boxdict 1 dict def
/box {
    boxdict begin
    /y2 exch def
    /x2 exch def
    /y1 exch def
    /x1 exch def
    x1 y1 x2 y1 x2 y2 x1 y2 
    moveto lineto lineto lineto closepath
    end
} def


% define box with xL, yD, width, height
/rboxdict 1 dict def
/rbox {
    rboxdict begin
    /h exch def
    /w exch def
    /y1 exch def
    /x1 exch def
    x1 y1 moveto 
    w 0 rlineto
    0 h rlineto
    w neg 0 rlineto
    closepath 
    end
} def


% define box with center x y and  width, height
/cboxdict 1 dict def
/cbox {
    rboxdict begin
    /h exch def
    /w exch def
    /y1 exch def
    /x1 exch def
    x1 w 0.5 mul sub y1 h 0.5 mul sub moveto 
    w 0 rlineto
    0 h rlineto
    w neg 0 rlineto
    closepath 
    end
} def


/rect {
    box
}def

/rrect {
    rbox
}def

/crect {
    cbox
}def

% define parallelo
/trapdic 1 dict def
/parallelo {
    trapdic begin
    /dy exch def
    /dx exch def
    /y2 exch def
    /x2 exch def
    /y1 exch def
    /x1 exch def
    x1 y1 moveto
    x2 dx sub y1  dy add lineto
    x2  y2  lineto
    x1 dx add y2 dy sub lineto
    closepath
    end
} def

/circle{
   0 360 arc
} def

/ellipse {
  newpath 4 2 roll 2 copy
  neg exch neg exch  6 2 roll translate
  2 copy exch div 1 exch scale  exch dup
  0 0 3 2 roll 0 360 arc
  exch div 1 exch scale translate
}def

/bendtodict 1 dict def
/bendto{
  bendtodict begin
  /r1 exch def
  /y3 exch def
  /x3 exch def
  /y4 exch def
  /x4 exch def
  /y2 exch def
  /x2 exch def
  /y1 exch def
  /x1 exch def
%   x1 y1 x2 y2 x4 y4 x3 y3 path s
  /a {x2 x1 sub} def
  /b {y2 y1 sub} def
  /c {x4 x3 sub} def
  /d {y4 y3 sub} def
  /det {b c mul a d mul sub}def
  /x {b c x2 mul mul
      a c y2 mul mul sub
      a  d  x4 mul mul sub
      a  c  y4 mul mul add
      det div} def
  /y {b d x2 mul mul
      a d y2 mul mul sub
      b d x4 mul mul sub
      b c y4 mul mul add
      det div} def
  /r2 {1 r1 sub} def
  /rx1 {x2 r1 mul x r2 mul add} def
  /ry1 {y2 r1 mul y r2 mul add} def
  /rx2 {x4 r1 mul x r2 mul add} def
  /ry2 {y4 r1 mul y r2 mul add} def

  x1 y1 moveto
  x2 y2 lineto
  rx1  ry1 lineto
  x y rx2 ry2 x4 y4 curveto
  x3 y3 lineto
  stroke
  end
}def

/rndrectdict 1 dict def
/roundrect {
    rndrectdict begin
    /rc exch def
    /y2 exch def
    /x2 exch def
    /y1 exch def
    /x1 exch def
    /rch{rc 0.5 mul}def
    x1 x2  add 2 div y1 m
    x2 rc sub y1 lineto
    x2 rch sub y1
    x2 y1 rch add
    x2 y1 rc add
    curveto
    x2 y2 rc sub lineto
    x2 y2 rch sub
    x2 rch sub y2
    x2 rc sub y2
    curveto
    x1 rc add y2 lineto
    x1 rch add y2
    x1 y2 rch sub
    x1 y2 rc sub
    curveto
    x1 y1 rc add lineto
    x1 y1 rch add
    x1 rch add y1
    x1 rc add y1
    curveto
    closepath
    end
} def

/crndrectdict 1 dict def
/croundrect {
    rndrectdict begin
    /rc exch def
    /height1 exch def
    /width1 exch def
    /yc exch def
    /xc exch def
    /rch{rc 0.5 mul}def
    /x1{xc width1 2 div sub} def
    /y1{yc height1 2 div sub} def
    /x2{xc width1 2 div add} def
    /y2{yc height1 2 div add} def
    x1 x2  add 2 div y1 m
    x2 rc sub y1 lineto
    x2 rch sub y1
    x2 y1 rch add
    x2 y1 rc add
    curveto
    x2 y2 rc sub lineto
    x2 y2 rch sub
    x2 rch sub y2
    x2 rc sub y2
    curveto
    x1 rc add y2 lineto
    x1 rch add y2
    x1 y2 rch sub
    x1 y2 rc sub
    curveto
    x1 y1 rc add lineto
    x1 y1 rch add
    x1 rch add y1
    x1 rc add y1
    curveto
    closepath
    end
} def

/latticedic 1 dict def
/lattice {
    latticedic begin
    currentlinewidth 
    /lw exch def
    /sep exch def
    /y2 exch def
    /x2 exch def
    /y1 exch def
    /x1 exch def
    0.4 setlinewidth
    x1 sep x2{
	dup y1 exch y2
	moveto lineto stroke
    }for
    y1 sep y2 {
	dup x1 3 1 roll
	x2 exch
	moveto lineto stroke
    }for
    lw setlinewidth
    end
} def