;Change list:
;Toggle extrusion while keeping smooth movement
;Modify to se x0 and xf to arbitrary functions of step or another parameter

; Hello World

G21 (mm)
G90 (Absolute distance mode)
G55 (Machine Plane Coordinates) 
G64 (Turn off exact stop check)
M5 (Stop the spindle if it's left on)

; Variables for controlling the model

; Movement speed
#<_speed> = 1100 (450)(300)
#<_mss> = 1  (1.28) (Margin Speed Scalar: the return speed on the margin)

#<_ccws> = 0.0006 ;extrude: extruder motor counter clockwise from top (0.005 to 0.007) 
#<_cws> = 0.005 (extruder back up, used before inter-layer pauses)

#<_corners> = 0 (1 extrude on corners, 0 no extrude on corners)
#<_margin> = 8
#<_lo> = 2 ; loop offset, used to prevent errors from turn-arounds at row ends	

#<_pause> = .0001 (wait time, used at corners)

;work dimensions
#<_l> = 36 (mm length)
#<_width> = 36 (mm width)
#<_delta> = .75 (mm inter-row&column spacing)
#<_layerH> = .08 (mm layer height)

;coordinates
#<_z0> = 0  (Initial Height of Needle Tip) (5)
#<_zz> = #<_z0>

#<_x0> = 0 (initial x)
#<_xx> = #<_x0> (x)

#<_y0> = 0 (initial y)
#<_yy> = #<_y0> (y) 

;counters
#<_zstep> = 0
#<_step> = 0

;counter maximums
#<_layers> = 40
#<_ystepf> = FIX[#<_l>/#<_delta>](_____-[#<_l> MOD #<_delta>]/#<_delta>])
#<_xstepf> = FIX[#<_width>/#<_delta>]([_____-[#<_width> MOD #<_delta>]/#<_delta>])

;#<_yy> = [#<_yy> + #<_l> + 20]     ;position purge routine (y)
#<_xx> = [#<_xx> - #<_width>+7] ;position purge routine (x)
G0 X[#<_xx>] Y[#<_yy>] Z10         ;position purge routine

M3 S0.005                            ;literal purge
o100 while [#<_step> LE 0]         ;'timer' for purge
	;#<_yy> = [#<_yy> + #<_delta>] (shows iterations for debugging)
	#<_xx> = [#<_xx> + 0.25*#<_width>*[2*[#<_step> MOD 2]-1]]    ;remind linuxcnc how to dance
	G1 X[#<_xx>] F#<_speed>                                     ;travel (the real time filler)
	#<_step>=[#<_step> + 1]                                     ;linuxcnc doesn't like infinity...
o100 endwhile

M4 S0.05                            ;back up extruder to relieve excess pressure 
o101 while [#<_step> LE 0]         ;'timer' for purge
	;#<_yy> = [#<_yy> + #<_delta>] (shows iterations for debugging)
	#<_xx> = [#<_xx> + 0.25*#<_width>*[2*[#<_step> MOD 2]-1]]    ;remind linuxcnc how to dance
	G1 X[#<_xx>] F#<_speed>                                     ;travel (the real time filler)
	#<_step>=[#<_step> + 1]                                     ;linuxcnc doesn't like infinity...
o101 endwhile
M3

S#<_ccws>       ;slow down the extruder and allow the pressure to equilibrate
o105 while [#<_step> LE 35]
	;G1 X[#<_xx> - #<_margin>*[2*[#<_step> MOD 2]-1]] F#<_speed> ;margin code (equilibration)
	;G0 Y[#<_yy>] F#<_speed>                                     ;margin code (equilibration)
	;G1 X[#<_xx>] F#<_speed>                                     ;margin code (equilibration)
	;#<_yy> = [#<_yy> + #<_delta>] (shows iterations for debugging)
	#<_xx> = [#<_xx> + 0.5*#<_width>*[2*[#<_step> MOD 2]-1]]
	G1 X[#<_xx>] F#<_speed>
	#<_step>=[#<_step> + 1]
o105 endwhile
#<_xx> = #<_x0> ;reset variables assumed to have previously stated initial values
#<_yy> = #<_y0> ;reset variables assumed to have previously stated initial values
#<_step> = 0    ;reset variables assumed to have previously stated initial values
M5

G1 X[#<_xx>] Y[#<_yy>] Z[#<_zz>] F#<_speed>
M3 S#<_ccws>
o110 while [#<_zstep> LE FIX[[#<_layers> - 1]/2]] (4)
		
	;G1 Y[#<_yy> + #<_margin>+5] F#<_speed>
	;G1 X[#<_x0> - #<_margin>-5] F#<_speed>

	;G1 Y[#<_y0>]  F#<_speed>
	#<_xx> = [#<_l> + #<_margin>*0.5]
	#<_yy> = [#<_y0> + [[0.5*#<_delta>]*[#<_zstep> MOD 2]]] ; causes layers to stager
	
	o115 while[#<_step> LE [[#<_ystepf>/2]-1]]
		#<_step> = [#<_step> + 1]
		o120 if [#<_corners> EQ 0]
			(M5) (Causes stop in spite of G64 will need something else.)
		o120 endif
		;G4 P#<_pause>		
		G1 X[[#<_xx> - #<_width> - [#<_margin>]]] F#<_speed>
		#<_yy> = [#<_yy>+[0.5*#<_l>]]
		
		G4 P[#<_pause>]
		;margin
		G0 Y[#<_yy>] X[[#<_xx> - #<_width> - [#<_margin>]*1.5]] F[#<_speed> * #<_mss>]
		G4 P#<_pause>
		
		G1 X[#<_xx> ] F#<_speed>
		#<_yy> = [#<_yy>-[[0.5*#<_l>]-#<_delta>]]
		
		G4 P#<_pause>
		;margin
		G0 Y[#<_yy>] X[#<_xx> + [#<_margin>/2]] F[#<_speed>*#<_mss>]
		G4 P#<_pause>
		
	o115 endwhile	
	#<_zz> = [#<_zz>+#<_layerH>]
	G0 Z[#<_zz>]
	;#<_step> = 0
	#<_xx> = #<_x0>
	#<_xx> = [#<_x0> + [[0.5*#<_delta>]*[#<_zstep> MOD 2]]] ; causes layers to stager
	#<_yy> = [#<_y0> - #<_margin>]	
	
;These three lines may turn out to be important	
	;G1 X[#<_x0> - #<_margin>-5] Y[#<_yy> + #<_margin>+5] F#<_speed>
	;G1 X[#<_x0> - #<_margin>-5] Y[#<_yy> + #<_margin>+5] F#<_speed>
	;G1 Y[#<_y0>] F#<_speed>

	#<_step> = 0

	o125 while[#<_step> LE [[#<_xstepf>/2]-1]]
		#<_step> = [#<_step> + 1]
		o130 if [#<_corners> EQ 0]
			(M5)  (Causes stop in spite of G64)
		o130 endif
		;G4 P#<_pause>		
		G1 Y[[#<_yy> + #<_l> +[#<_margin>*1.5]]] F#<_speed>
		#<_xx> = [#<_xx>+[0.5*#<_width>]]
		
		G4 P[#<_pause>/2]
		;margin		
		G0 X[#<_xx>] Y[[#<_yy> + #<_l> + [2*#<_margin>]]] F[#<_speed>*#<_mss>]

		;G4 P#<_pause>		
		G1 Y[#<_yy> + [#<_margin>/2]] F#<_speed>
		
		#<_xx> = [#<_xx>-[[0.5*#<_width>]-#<_delta>]]
		
		G4 P#<_pause>
		;margin		
		G0 X[#<_xx>] Y[#<_yy>] F[#<_speed>*#<_mss>]
		
	o125 endwhile
		
	#<_zz> = [#<_zz>+#<_layerH>]
	G0 Z[#<_zz>]
	#<_step> = 0
	
	(z++)

#<_zstep> = [#<_zstep> + 1]	
o110 endwhile	
G0 X-20 Y-20 Z 20
M5

M30