(outside traverse arbitrary quadrangle)
(computes direction for polygon cw or ccw and swaps if required)

(info: oquad: outside quadrilateral, specify four x,y points)
o<oquad>  sub

#<toolno>   =  #1 (=1)
#<rpm>      =  #2 (=1)
#<dir>      =  #3 (=2 2conv|3climb)
#<feedrate> =  #4 (=10)
#<cutdepth> =  #5
#<zincr>    =  #6
#<zsafe>    =  #7 (=0.2)
#<zstart>   =  #8 (=0)
#<x1>       =  #9
#<y1>       = #10
#<x2>       = #11
#<y2>       = #12
#<x3>       = #13
#<y3>       = #14
#<x4>       = #15
#<y4>       = #16
#<scale>    = #17 (=1)
#<rotate>   = #18 (=0)
#<xoff>     = #19 (=0)
#<yoff>     = #20 (=0)
#<spin_notify> = #21 (=0)
#<use_g43>     = #22 (=1)
#<h_for_g43>   = #23 (=0)
#<verbose>     = #24 (=0)

o<i0> if [#<scale> EQ 0]
        #<scale> = 1.0
        (debug, scale was 0, setting #<scale>)
o<i0> endif

o<loadtool> call [#<toolno>][#<use_g43>][#<h_for_g43>][#<verbose>]
#<tooldiam> = [#5410 + .001]

o<l00> if [[#<dir> NE 2] AND [#<dir> NE 3]]
         (debug, oquad: bogus direction #<dir> - EXITING)
         (print, oquad: bogus direction #<dir> - EXITING)
         (AXIS,notify, oquad: bogus direction - EXITING)
         m2
o<l00> endif

       (determine direction eg cw or ccw of points)
o<dir> call [4][#<x1>][#<y1>][#<x2>][#<y2>][#<x3>][#<y3>][#<x4>][#<y4>]
       #<pointsdir> = #<_dir:>

o<l20> if [#<pointsdir> NE #<dir>]
         (swap 1234 --> 1432)
         #<xt> = #<x2>
         #<yt> = #<y2>
         #<x2> = #<x4>
         #<y2> = #<y4>
         #<x4> = #<xt>
         #<y4> = #<yt>
o<l20> endif

(apply scale, rotate, then offset to all input points)
o<move> call [#<x1>][#<y1>][#<rotate>][#<scale>][#<xoff>][#<yoff>]
#<x1>      = #<_move:x>
#<y1>      = #<_move:y>
o<move> call [#<x2>][#<y2>][#<rotate>][#<scale>][#<xoff>][#<yoff>]
#<x2>      = #<_move:x>
#<y2>      = #<_move:y>
o<move> call [#<x3>][#<y3>][#<rotate>][#<scale>][#<xoff>][#<yoff>]
#<x3>      = #<_move:x>
#<y3>      = #<_move:y>
o<move> call [#<x4>][#<y4>][#<rotate>][#<scale>][#<xoff>][#<yoff>]
#<x4>      = #<_move:x>
#<y4>      = #<_move:y>

#<r>        = [#<tooldiam>/2]
#<cutdepth> = [0 - #<cutdepth>]
#<zincr>    = [0 - #<zincr>]

(get lengths and angles for connecting lines)
o<line> call [#<x1>][#<y1>][#<x2>][#<y2>]
#<phi12>    = #<_line:phi>

         g40 (cutter radius compensation off)
         f #<feedrate>
         s #<rpm> m3 (spindle cw)
o<if1>   if [#<spin_notify> GT 0]
o<spin>    call [#<rpm>]
o<if1>   endif
         g0 z#<zsafe>
         #<zcurrent> = #<zstart>
         #<pass>     = 1

o<wh010> while [#<zcurrent> GT #<cutdepth>]
           #<zcurrent> = [#<zcurrent> + #<zincr>]
o<wh020>   if [#<zcurrent> LT #<cutdepth>]
             #<zcurrent> = #<cutdepth>
o<wh020>   endif
o<wh030>   if [#<pass> GT 100]
             (debug, oquad: too many passes - EXITING)
             (print, oquad: too many passes - EXITING)
             (AXIS,notify, oquad: too many passes - EXITING)
             m2
o<wh030>   endif

o<pas00>   if [#<pass> EQ 1]
o<dir00>     if [#<dir> EQ 2]
               #<bx>  = [#<x1> -  #<r> * sin[#<phi12>] - #<r> * cos[#<phi12>]]
               #<by>  = [#<y1> +  #<r> * cos[#<phi12>] - #<r> * sin[#<phi12>]]
               #<vx>  = [         #<r> * cos[#<phi12>]] (b to arc center)
               #<vy>  = [         #<r> * sin[#<phi12>]]
               g0  x #<bx> y #<by>
/              g41 (cutter radius comp left of path)
               g3  x #<x1> y #<y1> i #<vx> j #<vy> (arc entry)
o<dir00>     else (dir EQ 3 CCW)
               #<bx>  = [#<x1> +  #<r> * sin[#<phi12>] - #<r> * cos[#<phi12>]]
               #<by>  = [#<y1> -  #<r> * cos[#<phi12>] - #<r> * sin[#<phi12>]]
               #<vx>  = [         #<r> * cos[#<phi12>]] (b to arc center)
               #<vy>  = [         #<r> * sin[#<phi12>]]
               g0  x #<bx> y #<by>
/              g42 (cutter radius comp right of path)
               g2  x #<x1> y #<y1> i #<vx> j #<vy> (arc entry)
o<dir00>     endif
             #<xfinal> = #<x2>
             #<yfinal> = #<y2>
             g1 z #<zstart> (plunge to start height todo:g0)
o<pas00>   endif
           x #<x2> y #<y2> z#<zcurrent> (ramp down to zcurrent)
           x #<x3> y #<y3>
           x #<x4> y #<y4>
           x #<x1> y #<y1>
           #<pass> = [#<pass> + 1]
o<wh010> endwhile
         g1  x #<xfinal> y #<yfinal>
         g0  z #<zsafe>
         g40
o<oquad> endsub