; pocket_circ - circular pocket cut with an outward spiral from center.
; Requires globals: #<_z_top>, #<_z_bot>
; Requires tool loaded (uses #5410 for diameter)
; Optional globals: #<_z_clearance>, #<_rampang>, #<_stepover>
o<pocket_circ> sub
	; o<pocket_circ> call [mode] [x][y] [diameter] [fincut]
	; #1=mode #2=x #3=y #4=diameter #5=fincut

	#<M_CONVENTIONAL> = [FIX[#1/1] MOD 2 EQ 1]
	#<M_PLUNGE>       = [FIX[#1/4] MOD 2 EQ 1]
	#<M_CLIMB>        = [FIX[#1/1] MOD 2 EQ 0]
	#<M_HELIX>        = [FIX[#1/4] MOD 2 EQ 0]

	G90
	G90.1
	M101
	G17

	#<td> = #5410
	#<tr> = [#<td>/2]
	o1 if [EXISTS[#<_z_clearance>]]
		#<z_clearance> = #<_z_clearance>
	o1 else
		#<z_clearance> = #<_z_top>
	o1 endif
	o2 if [EXISTS[#<_rampang>]]
		#<rampang> = #<_rampang>
	o2 else
		#<rampang> = 5
	o2 endif
	o3 if [EXISTS[#<_stepover>]]
		#<stepover> = #<_stepover>
	o3 else
		#<stepover> = [#<td>*0.4]
	o3 endif

	o4 if [#<td> GT #4]
		o5 return  ; tool bigger than pocket
	o4 endif

	#<a> = 0
	#<r> = 0
	o100 if [#<M_HELIX>]
		#<r> = [#<td>*0.3]
		o115 if [[[#4-#<td>]/2-ABS[#5]] LE #<r>]
			#<r> = [[[#4-#<td>]/2-ABS[#5]]*0.8]
		o115 endif

		#<z_step> = [#<r>*2*3.14*TAN[#<rampang>]]
		; guard: if z_step is tiny, avoid infinite loop
		o116 if [#<z_step> LT 0.0001]
			#<z_step> = 0.0001
		o116 endif

		G0 Z#<z_clearance>
		G0 X[#2+#<r>] Y[#3]
		G0 Z#<_z_top>

		#<z> = [#<_z_top>-#<z_step>]
		o101 while [#<z> GT #<_z_bot>]
			o102 if [#<M_CLIMB>]
				G3 X[#2+#<r>] Y[#3] I[#2] J[#3] Z[#<z>] P1
			o102 else
				G2 X[#2+#<r>] Y[#3] I[#2] J[#3] Z[#<z>] P1
			o102 endif
			#<z> = [#<z> - #<z_step>]
		o101 endwhile

		; finish plunge to exact depth
		; guard: avoid division by zero if z_top == z_bot
		o117 if [ABS[#<_z_top>-#<_z_bot>] GT 0.0001]
			#<a> = [[#<z>-#<_z_bot>]/[#<_z_top>-#<_z_bot>]*360]
		o117 else
			#<a> = 0
		o117 endif
		o103 if [#<M_CLIMB>]
			G3 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>] I[#2] J[#3] Z[#<_z_bot>]
			G3 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>] I[#2] J[#3] Z[#<_z_bot>]
		o103 else
			G2 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>] I[#2] J[#3] Z[#<_z_bot>]
			G2 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>] I[#2] J[#3] Z[#<_z_bot>]
		o103 endif

	o100 elseif [#<M_PLUNGE>]
		G0 Z#<z_clearance>
		G0 X[#2] Y[#3]
		G0 Z[#<_z_top>]
		G1 Z[#<_z_bot>]
	o100 endif

	; spiral outward
	#<r_base> = #<r>
	#<a_base> = #<a>
	#<iter> = 0
	o105 while [#<r> LT [[#4-#<td>]/2-ABS[#5]]]
		o106 if [#<M_CLIMB>]
			G1 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>]
		o106 else
			G1 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>]
		o106 endif
		#<a> = [#<a>+1]
		#<r> = [#<r_base>+[#<a>-#<a_base>]/360*#<stepover>]
		#<iter> = [#<iter>+1]
		o109 if [#<iter> GT 360000]
			o105 BREAK  ; safety limit
		o109 endif
	o105 endwhile

	; pre-finish circle
	#<r> = [[#4-#<td>]/2-ABS[#5]]
	o107 if [#<M_CLIMB>]
		G1 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>]
		G3 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>] I[#2] J[#3]
	o107 else
		G1 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>]
		G2 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>] I[#2] J[#3]
	o107 endif

	; finish cut
	o104 if [ABS[#5] GT 0.0]
		#<r> = [[#4-#<td>]/2]
		o108 if [#<M_CLIMB>]
			G1 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>]
			G3 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>] I[#2] J[#3]
			#<r> = [[#4-#<td>]/2*0.9]
			G1 X[#2+COS[#<a>]*#<r>] Y[#3+SIN[#<a>]*#<r>]
		o108 else
			G1 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>]
			G2 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>] I[#2] J[#3]
			#<r> = [[#4-#<td>]/2*0.9]
			G1 X[#2+COS[#<a>]*#<r>] Y[#3-SIN[#<a>]*#<r>]
		o108 endif
	o104 endif

	G0 Z#<z_clearance>

o<pocket_circ> endsub

M2