(prompt "\nAngle Trisection by AutoCAD - MACLAURIN.LSP")
(prompt "\nCommands:  TEST MACLAURIN")
(prompt "\nFunctions: (LOCATE) (PL_DISPLAY) (MACL_SETUP)")
(prompt "\n           ")
;----------------------------------------------------------
;;;Tri_section by Colin Maclaurin---Trisectrix
;;;
;;;1/20/00  added geometric construction macl
;;;
;;;TEST
(defun c:test()
	(setup_sysvar)
	(macl_setup)
	(command "_osnap" "nearest")
	(while (and (setq key (grread T)) (= (car key) 5) )
		(setq pnt_temp (cadr key))
		(locate pnt_temp)	;compute all points
		(pl_display)		;display the polyline
	)
	(reset_sysvar)

);MACL
;;;
;;;LOCATE
;;;
(defun locate (pnt_temp / )
	(setq two_theta (angle pnt_origin pnt_temp)
		x_0 (cos two_theta)
		y_0 (sin two_theta)
		pnt_temp (list x_0 y_0)
		x_mid (* 0.5 x_0)
		y_mid (* 0.5 y_0)
		pnt_mid (list x_mid y_mid)
		pnt_perp (polar pnt_mid (+ half_pi two_theta) 0.5)
		pnt_x (inters pnt_ref pnt_temp pnt_mid pnt_perp nil)
	)
);LOCATE
;;;
;;;PL_DISPLAY
;;;
(defun pl_display()
	(if (/= last_pline nil) (entdel last_pline))
	(make_pt "0" 4 pnt_x)
	(command "_.pline" pnt_ref pnt_temp pnt_origin pnt_x pnt_mid "")
	(setq last_pline (entlast))
)
;;;
;;;MACLAURIN
(defun c:maclaurin( )
	(setup_sysvar)
	(macl_setup)
	(while (<= (setq theta_new (+ theta_old del_theta)) theta_end)
		(setq rad_1 (* 2.0 (cos theta_new))
			rad_2 (/ 1.0 rad_1)
			radius (- rad_1 rad_2)
			pnt_new (polar pnt_ref theta_new radius)
		)
		(command "_.line" pnt_start pnt_new "")
		(setq pnt_start pnt_new
			theta_old theta_new
		)
	);while loop
	;;;
	(setq pick_line (entlast))
	(command "_pedit" pick_line "Y" "_Join" "all" "" "_X")

	;(command "_.point" pnt_origin)
	;(command "_.point" pnt_ref)
	;(command "_.line" x_left x_right "")
	;(command "_.line" y_down y_up "")
	(command "_.zoom" "e")
	(command "_.line" pnt_ref pnt_new "")
	(reset_sysvar)

)
;;;
;;;
;;;DRAW_MACLAURIN
(defun c:draw_maclaurin( )
	(setup_sysvar)
	(macl_setup2)
	(while (<= (setq theta_new (+ theta_old del_theta)) theta_end)
		(setq pnt_p (list (cos theta_new) (sin theta_new))
			rad_1 (distance pnt_c pnt_p)
			pnt_q (inters pnt_c pnt_p pnt_e pnt_f nil)
			rad_2 (distance pnt_c pnt_q)
			radius (- rad_1 rad_2)
			pnt_new (pld pnt_c pnt_p radius)
		)
		(setq dist (distance pnt_start pnt_new))
		
		(command "_.line" pnt_start pnt_new "")
		(setq pnt_start pnt_new
			theta_old theta_new
		)
	);while loop
	;;;
	(setq pick_line (entlast))
	(command "_.pedit" pick_line "Y" "_Join" "all" "" "_X")

	;(command "_.point" pnt_origin)
	;(command "_.point" pnt_ref)
	;(command "_.line" x_left x_right "")
	;(command "_.line" y_down y_up "")
	(command "_.zoom" "e")
	;(command "_.line" pnt_ref pnt_new "")
	(reset_sysvar)

)
;;;
;;;
;;;DRAW_MACLAURIN_ONLY
(defun c:draw_maclaurin_only( )
	(setup_sysvar)
	(macl_setup2)
	(alert "\nStart drawing curve.")
	(setq step 0)
	(while (<= (setq theta_new (+ theta_old del_theta)) theta_end)
		(setq pnt_p (list (cos theta_new) (sin theta_new))
			rad_1 (distance pnt_c pnt_p)
			pnt_q (inters pnt_c pnt_p pnt_e pnt_f nil)
			rad_2 (distance pnt_c pnt_q)
			radius (- rad_1 rad_2)
			pnt_new (pld pnt_c pnt_p radius)
		)
		(make_line_1 "layer2" 2  pnt_start pnt_new )
		(setq pnt_start pnt_new
			theta_old theta_new
		)
		(if (and (= jpg_yes 1) (= (rem step 20) 0)) (make_jpg))	;;jpgout for animation
		(command "_.delay" 50)
		(setq step (1+ step))
	);while loop
	;;;
	(setq pick_line (entlast))
	(command "_.pedit" pick_line "Y" "_Join" "all" "" "")
		(setq half_curve (entlast))
	(make_jpg)		;;jpgout command
	(alert "\nMake a mirror image")
	(command "_.mirror" half_curve "" pnt_c pnt_b "")
	;(command "_.point" pnt_origin)
	;(command "_.point" pnt_ref)
	;(command "_.line" x_left x_right "")
	;(command "_.line" y_down y_up "")
	;(command "_.zoom" "e")
	;(command "_.line" pnt_ref pnt_new "")
	;(reset_sysvar)

)
;;;
;;;MACL_SETUP
(defun macl_setup()
	(setq x_left '(-1.25 0) x_right '(1.25 0)
		y_up '(0 1.25) y_down '(0 -0.25)
		half_pi (* 0.5 pi)
		pnt_origin '(0 0) pnt_org '(0 0)
		pnt_ref '(-1 0) pnt_c '(-1 0) pnt_b '(1 0)
		;theta_end (/ pi 3.0)
		theta_end (* 0.4 pi)	;;
		del_theta (/ theta_end 1000) 	;0.001
		theta_old 0.0
		radius 1.0
		pnt_start '(0.5 0)
		
	)
	(setvar "PDMODE" 32)
	(setvar "PDSIZE" -2)
	(make_line_1 "0" 8 y_up y_down)
	(make_line_1 "0" 8 x_left x_right)
	(make_pt "0" 0 pnt_org)
	(make_pt "0" 0 pnt_b)
	(make_pt "0" 0 pnt_c)
	(command "_.arc" "_C" pnt_origin '(1 0) pnt_ref)
	(command "_.zoom" "e")
	(command "_.regen")

);MACL_SETUP
;;;
;;;MACL_SETUP2
(defun macl_setup2()
	(setq x_left '(-1.5 0) x_right '(1. 0)
		y_up '(0 1.25) y_down '(0 -0.25)
		half_pi (* 0.5 pi)
		pnt_origin '(0 0) pnt_org '(0 0)
		pnt_ref '(-1 0) pnt_c '(-1 0) pnt_b '(1 0)
		;theta_end (/ pi 3.0)
		theta_end (* 0.90 pi)	;;
		del_theta (/ pi 180.) 	;every one degree
		theta_old 0.0
		radius 1.0
		pnt_start '(0.5 0)
		pnt_e '(-0.5 0) pnt_f '(-0.5 1.5)
		yl_up '(-1.5 1.25) yl_down '(-1.5 -2.85)
		chr_size 0.1 txt_angle 0.
	)
	(setvar "PDMODE" 32)
	(setvar "PDSIZE" -2)
	(make_line_1 "0" 8 y_up y_down)
	(make_line_1 "0" 8 x_left x_right)
	(make_line_1 "0" 8 yl_down yl_up)
	(textdisplay "C" pnt_c chr_size txt_angle)
	(textdisplay "O" pnt_org chr_size txt_angle)
	(textdisplay "B" pnt_b chr_size txt_angle)
	(make_pt "0" 0 pnt_org)
	(make_pt "0" 0 pnt_b)
	(make_pt "0" 0 pnt_c)
	(command "_.arc" "_C" pnt_origin '(1 0) pnt_ref)
	(command "_.zoom" "e")
	(command "_.regen")

);MACL_SETUP
;;--------------------------------------------------------------------------
(princ)