o<spquircle_boss> sub
	; o<spquircle_boss> call [x][y] [square_width] [boss_diamter] [ztop][zbot] [finishcut] [mode]

	#<M_CONVENTIONAL> = [FIX[#8/1] MOD 2 EQ 1]
	#<M_BOTHWAYS>     = [FIX[#8/2] MOD 2 EQ 1]
	#<M_PLUNGE>       = [FIX[#8/4] MOD 2 EQ 1]
	#<M_OUTSIDE>      = [FIX[#8/8] MOD 2 EQ 1]
	#<M_CLIMB>        = [FIX[#8/1] MOD 2 EQ 0]
	#<M_ONEWAY>       = [FIX[#8/2] MOD 2 EQ 0]
	#<M_HELIX>        = [FIX[#8/4] MOD 2 EQ 0]
	#<M_INSIDE>       = [FIX[#8/8] MOD 2 EQ 0]

	;G10 L0 ; re-read tool data
	G90	  ; absolute x,y,z
	G90.1 ; absolute i,j,k
	M101  ; enable Z-axis (M102 disables)
	G17   ; select XY plane for arcs

	#<td> = #<_td>
	#<tr> = [#<td>/2]
	o1 if [EXISTS[#<_z_clearance>]]
		#<z_clearance> = #<_z_clearance>
	o1 else
		#<z_clearance> = #5
	o1 endif
	o3 if [EXISTS[#<_stepover>]]
		#<stepover> = [#<_stepover>*0.8]
	o3 else
		#<stepover> = [#<td>*0.4*0.8]
	o3 endif


	G0 Z#<z_clearance>


	#<dist> = [[#3-#4]/2-#7]
	#<n_steps> = [FIX[#<dist>/#<stepover>]-1]
	#<n_steps_total> = [#<n_steps>+1]

	#<ys> = +1
	o10 if [#<M_CONVENTIONAL>]
		#<ys> = [-1]
	o10 endif


	G0 X[#1 + #4/2 + #<tr> + #7 + #<n_steps_total>*#<stepover>] Y[#2 + #4/2 + #<tr> + #7 + #<n_steps_total>*#<stepover>*#<ys>]
	G0 Z#5
	G1 Z#6
	G1 Y#2

	o30 while [#<n_steps> GE 0]

		#<a> = 0
		o20 while [#<a> LE 360]
			#<pow> = [1-[#<n_steps>-#<a>/360+0.95]/#<n_steps_total>]
			#<r> = [#4/2 + #<tr> + #7 + [1+#<n_steps>-#<a>/360]*#<stepover>]

			o201 if [#<a> LT 90]
				G1 X[#1+ABS[COS[#<a>]]**#<pow>*#<r>] Y[#2-ABS[SIN[#<a>]]**#<pow>*#<r>*#<ys>]
			o201 elseif [#<a> LT 180]
				G1 X[#1-ABS[COS[#<a>]]**#<pow>*#<r>] Y[#2-ABS[SIN[#<a>]]**#<pow>*#<r>*#<ys>]
			o201 elseif [#<a> LT 270]
				G1 X[#1-ABS[COS[#<a>]]**#<pow>*#<r>] Y[#2+ABS[SIN[#<a>]]**#<pow>*#<r>*#<ys>]
			o201 else
				G1 X[#1+ABS[COS[#<a>]]**#<pow>*#<r>] Y[#2+ABS[SIN[#<a>]]**#<pow>*#<r>*#<ys>]
			o201 endif

			#<a> = [#<a>+1]
		o20 endwhile

		#<n_steps> = [#<n_steps>-1]
	o30 endwhile

	G1 X[#1+#4/2+#<tr>] Y[#2]
	
	o40 if [#<M_CONVENTIONAL>]
		G3 X[#1+#4/2+#<tr>] Y[#2] I#1 J#2
	o40 else
		G2 X[#1+#4/2+#<tr>] Y[#2] I#1 J#2
	o40 endif

	

	G0 Z#<z_clearance>


o<spquircle_boss> endsub

M2