; Circular pocket - clears a round pocket using spiral toolpath
; Params: #1=x, #2=y, #3=diameter, #4=ztop, #5=zbot, #6=finishcut, #7=mode
; Mode bitmask: bit0=conventional, bit1=bothways, bit2=plunge(vs helix), bit3=outside
o<pocket_circ> sub
	; o<pocket_circ> call [x][y] [diameter] [ztop][zbot] [finishcut] [mode]

	#<M_CONVENTIONAL> = [FIX[#7/1] MOD 2 EQ 1]
	#<M_BOTHWAYS>     = [FIX[#7/2] MOD 2 EQ 1]
	#<M_PLUNGE>       = [FIX[#7/4] MOD 2 EQ 1]
	#<M_OUTSIDE>      = [FIX[#7/8] MOD 2 EQ 1]
	#<M_CLIMB>        = [FIX[#7/1] MOD 2 EQ 0]
	#<M_ONEWAY>       = [FIX[#7/2] MOD 2 EQ 0]
	#<M_HELIX>        = [FIX[#7/4] MOD 2 EQ 0]
	#<M_INSIDE>       = [FIX[#7/8] MOD 2 EQ 0]

	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> = #4
	o1 endif
	o2 if [EXISTS[#<_rampang>]]
		#<rampang> = #<_rampang>
	o2 else
		#<rampang> = 5 ; degrees
	o2 endif
	o3 if [EXISTS[#<_stepover>]]
		#<stepover> = #<_stepover>
	o3 else
		#<stepover> = [#<td>*0.4]
	o3 endif

	o4 if [#<td> GT #3] ; tool bigger than pocket, bail out
		o5 return
	o4 endif

	#<a> = 0
	#<r> = 0
	o100 if [#<M_HELIX>] ; helical plunge
		#<r> = [#<td>*0.3] ; helix radius = 30% of tool diameter
		o115 if [[[#3-#<td>]/2-ABS[#6]] LE #<r>] ; shrink if helix would exceed pocket wall
			#<r> = [[[#3-#<td>]/2-ABS[#6]]*0.8]
		o115 endif

		#<z_step>  = [#<r>*2*3.14*TAN[#<rampang>]]

		G0 Z#<z_clearance>
		G0 X[#1+#<r>] Y[#2]
		G0 Z#4

		; helical plunge
		#<z> = [#4-#<z_step>]
		o101 while [#<z> GT #5]
			o102 if [#<M_CLIMB>]
				G3 X[#1+#<r>] Y[#2] I[#1] J[#2] Z[#<z>] P1
			o102 else
				G2 X[#1+#<r>] Y[#2] I[#1] J[#2] Z[#<z>] P1
			o102 endif
			#<z> = [#<z> - #<z_step>]
		o101 endwhile

		; finish the helical plunge
		#<a> = [[#<z>-#5]/[#4-#5]*360] ; TODO: what the heck is the denominator here doing?
		o103 if [#<M_CLIMB>]
			G3 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>] I[#1] J[#2] Z[#5]
			G3 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>] I[#1] J[#2] Z[#5]
		o103 else
			G2 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>] I[#1] J[#2] Z[#5]
			G2 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>] I[#1] J[#2] Z[#5]
		o103 endif

	o100 elseif [#<M_PLUNGE>] ; straight plunge
		

		G0 Z#<z_clearance>
		G0 X[#1] Y[#2]
		G0 Z[#4]
		G1 Z[#5]

	o100 endif

	; spiral outward from center to clear pocket, stopping short by finishcut amount
	#<r_base> = #<r>
	#<a_base> = #<a>
	o105 while [#<r> LT [[#3-#<td>]/2-ABS[#6]]]

		o106 if [#<M_CLIMB>]
			G1 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>]
		o106 else
			G1 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>]
		o106 endif
		#<a> = [#<a>+1] ; advance 1 degree per step

		#<r> = [#<r_base>+[#<a>-#<a_base>]/360*#<stepover>] ; radius grows by stepover each revolution
	o105 endwhile

	; pre-finish cut: full circle at pocket wall minus finishcut allowance
	#<r> = [[#3-#<td>]/2-ABS[#6]]
	o107 if [#<M_CLIMB>]
		G1 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>]
		G3 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>] I[#1] J[#2]
	o107 else
		G1 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>]
		G2 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>] I[#1] J[#2]
	o107 endif

	; finish cut: full circle at final pocket wall radius
	o104 if [ABS[#6] GT 0.0]
		#<r> = [[#3-#<td>]/2]
		o108 if [#<M_CLIMB>]
			G1 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>]
			G3 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>] I[#1] J[#2]
			#<r> = [[#3-#<td>]/2*0.9] ; retract slightly inward before rapid out
			G1 X[#1+COS[#<a>]*#<r>] Y[#2+SIN[#<a>]*#<r>]
		o108 else
			G1 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>]
			G2 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>] I[#1] J[#2]
			#<r> = [[#3-#<td>]/2*0.9] ; retract slightly inward before rapid out
			G1 X[#1+COS[#<a>]*#<r>] Y[#2-SIN[#<a>]*#<r>]
		o108 endif
	o104 endif

	G0 Z#<z_clearance>


o<pocket_circ> endsub

M2