;;;	brocard.lsp
;;;		Takaya Iwamoto   Oct 24,2001
;;;	added Vports 		Feb 15,2005
;;;	modified for doc	June 16,2005
;;;	added ndogs		June 17,2005
;;;	use make_polyline API for entmake POLYLINE
;;;***********************************************
;;;	copyright 2006		Takaya Iwamoto
;;;***********************************************
;;;Test for Brocard angle
;;;
(defun c:Brocard ()
  (setup_tri)
  (pursuit)
)
;;;BROCARD
(prompt "BROCARD  ")

;;;
(defun c:Brocard2_ccw ()
  (setup_tri_ccw)
  (command "_.point" pnt_br1)
  (alert "Hit OK to start")
  (command "_.vports" "2" "_V")
  (setvar "CVPORT" 3)
  (command "_.zoom" "_Extent")
  (setvar "CVPORT" 2)
  (command "_.zoom" "_Extent")
  (make_jpg)
  (pursuit2_ccw)
  (reset_sysvar)
)
;;;BROCARD
(prompt "BROCARD2_CCW  ")
;;;
;;;
;;;
(defun c:Brocard2_cw ()
  (setup_tri_cw)
  (command "_.point" pnt_br2)
  (alert "Hit OK to start")
  (command "_.vports" "2" "_V")
  (setvar "CVPORT" 3)
  (command "_.zoom" "_Extent")
  (setvar "CVPORT" 2)
  (command "_.zoom" "_Extent")
  (make_jpg)
  (pursuit2_cw)
  (reset_sysvar)
)
;;;BROCARD
(prompt "BROCARD2_CW  ")
;;;
;;;Test for 4-dogs
;;;
(defun c:4dogs ()
  (setup_sysvar)
  (setup_square)
  (pursuit_4dogs)
  (reset_sysvar)
)
;;;4dogs
(prompt "4dogs")

;;;
;;;SETUP_TRI_CCW     counter clockwise case  setup
;;;
(defun setup_tri_ccw ()
  (setup_sysvar)
  (setvar "PDMODE" 32)
  (setq	pnt_1 '(4.1838 0.382549 0.0)
	pnt_2 '(20.4652 0.382549 0.0)
	pnt_3 '(14.6504 13.3892 0.0)
	len_12 (distance pnt_1 pnt_2)
  )
  (mark_id pnt_1 "1" 4 0.5)
  (mark_id pnt_2 "2" 4 0.5)
  (mark_id pnt_3 "3" 3 0.5)
  (make_line_1 "0" 0 pnt_1 pnt_2)
  (make_line_1 "0" 1 pnt_1 pnt_2)
  (setq line_ab (entlast))
					
  (make_line_1 "0" 0 pnt_2 pnt_3)
  (make_line_1 "0" 2 pnt_2 pnt_3)
  (setq line_bc (entlast))
  (make_line_1 "0" 0 pnt_3 pnt_1)

  (setq	pnt_a pnt_1
	pnt_b pnt_2
	pnt_c pnt_3
	ncount 0
  )
  (command "_.zoom" "_EXTENT")
;;;compute Brocard angle omega omega_d  (in deg) omega_r (in radian)
  (c:omega)
;;;locate Brocard point (pnt_br1) for CCW rotation using omega value
;;; arc_length is the total travel path for a dog that sits at pnt_1 initially.
  (c:find_brocard_1)
  (setq	rate	 1.
;;;(getreal "\nSpecify distance as % of length AB:  ")
	delta	 (* (distance pnt_a pnt_b) (/ rate 100.))
	delta_bc (* delta ratio_ab)
	delta_ca (* delta ratio_ac)
	speed	 (getint
		   "\nSpecify speed (1-100) 1:veryfast 100:very slow (def = 50)"
		 )
  )
  (if (= speed nil)
    (setq speed 50)
  )
  (setq	d_ab  (distance pnt_a pnt_b)
	d_bc  (distance pnt_b pnt_c)
	d_ca  (distance pnt_c pnt_a)
	d_ref (/ d_ab len_12)
  )
  (entdel line_ab)
  (entdel line_bc)
;;;insert precision_meter
;;;display the value of the minimum distance between apexes = d_ref
	;block insert prec_meter.dwg 
	(setq ins_pnt '(7. -3) meter_scale 3.0 
		m_x (car ins_pnt) m_y (cadr ins_pnt)
		pm_factor (* 0.25 (/ 1. (log 10.)))
	)
	(my_block_insert "prec_meter" ins_pnt meter_scale)
	;display initial bar
	(my_block_insert "prec_bar" ins_pnt meter_scale)
	(setq old_bar (entlast))	;;;prec_bar just created
;;;
	(move_bar d_ref meter_scale)
)
;;;
;;;(prompt "SETUP_TRI_CW")
;;;SETUP_TR_CW   counter clockwise case setup
;;;
(defun setup_tri_cw ()
  (setup_sysvar)
  (setvar "PDMODE" 32)

  (setq	pnt_1 '(4.1838 0.382549 0.0)
	pnt_2 '(20.4652 0.382549 0.0)
	pnt_3 '(14.6504 13.3892 0.0)
	len_12 (distance pnt_1 pnt_2)
  )
  (mark_id pnt_1 "1" 4 0.5)
  (mark_id pnt_2 "2" 4 0.5)
  (mark_id pnt_3 "3" 3 0.5)

  (make_line_1 "0" 0 pnt_1 pnt_2)
  (make_line_1 "0" 1 pnt_1 pnt_2)
  (setq line_ab (entlast))

  (make_line_1 "0" 0 pnt_2 pnt_3)
  (make_line_1 "0" 2 pnt_2 pnt_3)
  (setq line_bc (entlast))
  (make_line_1 "0" 0 pnt_3 pnt_1)

  (setq	pnt_a pnt_1
	pnt_b pnt_2
	pnt_c pnt_3
	ncount 0
  )
  (command "_.zoom" "_EXTENT")
;;;compute Brocard angle omega   omega_d(deg) omega_r(radian)
  (c:omega)
;;;locate Brocard point for Clockwise chase case using omega angle--pnt_br2
;;;arc_length is the total travel path for a dog taht sits initially at pnt_1
  (c:find_brocard_2)
  (setq	rate	 1.
;;;(getreal "\nSpecify distance as % of length AB:  ")
	delta	 (* (distance pnt_a pnt_b) (/ rate 100.))
	delta_bc (* delta ratio_ab)
	delta_ca (* delta ratio_ac)
	speed	 (getint
		   "\nSpecify speed (1-100) 1:veryfast 100:very slow (def = 50)"
		 )
  )
  (if (= speed nil)
    (setq speed 50)
  )
  (setq	d_ab  (distance pnt_a pnt_b)
	d_bc  (distance pnt_b pnt_c)
	d_ca  (distance pnt_c pnt_a)
	d_ref (/ d_ab len_12)
  )
  (entdel line_ab)
  (entdel line_bc)
;;;insert precision_meter
;;;display the value of the minimum distance between apexes = d_ref
	;block insert prec_meter.dwg 
	(setq ins_pnt '(7. -3) meter_scale 3.0 
		m_x (car ins_pnt) m_y (cadr ins_pnt)
		pm_factor (* 0.25 (/ 1. (log 10.)))
	)
	(my_block_insert "prec_meter" ins_pnt meter_scale)
	;display initial bar
	(my_block_insert "prec_bar" ins_pnt meter_scale)
	(setq old_bar (entlast))	;;;prec_bar just created
;;;
	(move_bar d_ref meter_scale)
)
;;;
;;;(prompt "SETUP_SQUARE")
;;;
;;;
(defun setup_square ()

  (setq	pnt_1	'(-100. -100. 0)
	pnt_2	'(100. -100. 0)
	pnt_3	'(100. 100. 0)
	pnt_4	'(-100. 100. 0)
	Arc_len	200.
  )
  (command "_.pline" pnt_1 pnt_2 pnt_3 pnt_4 "cl")

  (mark_id pnt_1 "A" 3 10)
  (mark_id pnt_2 "B" 1 10)
  (mark_id pnt_3 "C" 1 10)
  (mark_id pnt_4 "D" 3 10)

  (setq	side_len (distance pnt_1 pnt_2)
	pnt_a	 pnt_1
	pnt_b	 pnt_2
	pnt_c	 pnt_3
	pnt_d	 pnt_4
	ncount	 0
  )
  (command "_.zoom" "_EXTENT")

  (setq	rate (getreal
	       "\nSpecify dog's stride as % of length AB:(def=10%)"
	     )
  )
  (if (= rate nil)
    (setq rate 10.)
  )
  (setq
    delta (* side_len (/ rate 100.))
    speed (getint
	    "\nSpecify display speed (1-100) 1:veryfast 100:very slow (def = 50)"
	  )
  )
  (if (= speed nil)
    (setq speed 50)
  )
  (setq	d_ref	 side_len
	n_repeat (+ 2 (fix (/ 100 rate)))
  )

)
;;;
;;;(prompt "PURSUIT")
;;;
;;;PURSUIT for a Triangle case
(defun pursuit ()
  (while (> d_ref delta)
    ;;(repeat n_repeat   
    (setq pnt_ab (pld pnt_a pnt_b delta)
	  pnt_bc (pld pnt_b pnt_c delta_bc)
	  pnt_ca (pld pnt_c pnt_a delta_ca)
    )
    (slow_line speed "0" 1 pnt_a pnt_ab)
    (slow_line speed "0" 3 pnt_b pnt_bc)
    (slow_line speed "0" 5 pnt_c pnt_ca)
    (command "_.pline" pnt_ab pnt_bc pnt_ca "c")
    (setq pnt_a	pnt_ab
	  pnt_b	pnt_bc
	  pnt_c	pnt_ca
    )
    (setq d_ab	(distance pnt_a pnt_b)
	  d_bc	(distance pnt_b pnt_c)
	  d_ca	(distance pnt_c pnt_a)
	  d_ref	(min d_ab d_bc d_ca)
    )
    (setq ncount (1+ ncount))

  )
;;;end of while(or repeat) loop

)
;;;PURSUIT
(prompt "PURSUIT  ")
;;;
;;;PURSUIT for a square case
(defun pursuit_4dogs ()
  (setvar "CECOLOR" "8")
  (while (> d_ref delta)
    ;;(repeat  n_repeat   
    (setq pnt_ab (pld pnt_a pnt_b delta)
	  pnt_bc (pld pnt_b pnt_c delta)
	  pnt_cd (pld pnt_c pnt_d delta)
	  pnt_da (pld pnt_d pnt_a delta)
    )
    (slow_line speed "layer1" 1 pnt_a pnt_ab)
    (slow_line speed "layer2" 2 pnt_b pnt_bc)
    (slow_line speed "layer3" 3 pnt_c pnt_cd)
    (slow_line speed "layer5" 5 pnt_d pnt_da)
    (command "_.pline" pnt_ab pnt_bc pnt_cd pnt_da "c")
    (setq pnt_a	pnt_ab
	  pnt_b	pnt_bc
	  pnt_c	pnt_cd
	  pnt_d	pnt_da
    )
    (setq d_ab	(distance pnt_a pnt_b)
	  d_bc	(distance pnt_b pnt_c)
	  d_cd	(distance pnt_c pnt_d)
	  d_da	(distance pnt_d pnt_a)
	  d_ref	(min d_ab d_bc d_cd d_da)
    )
    (setq ncount (1+ ncount))

  )
;;;end of while loop
  (setvar "CECOLOR" "BYLAYER")

)
;;;PURSUIT_4dogs
(prompt "PURSUIT_4dogs")
;;;
;;;PURSUIT for a Triangle case
(defun pursuit2_ccw ()
  (setq	total_count 0
	delta	    (* 0.01 arc_length)
	delta_bc    (* delta ratio_ab)
	delta_ca    (* delta ratio_ac)
	factor	    0.5075
  )

  (while (> d_ab delta)

    (setq pnt_ab (pld pnt_a pnt_b delta)
	  pnt_bc (pld pnt_b pnt_c delta_bc)
	  pnt_ca (pld pnt_c pnt_a delta_ca)
    )
    (slow_line speed "0" 1 pnt_a pnt_ab)
    (slow_line speed "0" 3 pnt_b pnt_bc)
    (slow_line speed "0" 5 pnt_c pnt_ca)
					;(command "_.pline" pnt_ab pnt_bc pnt_ca "c")
    (if	(= (rem total_count 10) 0) (make_jpg))
    
    (setq total_path (* ncount delta))
;;;total distance traveled
    (setq pnt_a	pnt_ab
	  pnt_b	pnt_bc
	  pnt_c	pnt_ca
    )
    (setq d_ab	(distance pnt_a pnt_b)
	  d_bc	(distance pnt_b pnt_c)
	  d_ca	(distance pnt_c pnt_a)
	  d_ref	(/ d_ab len_12)
    )
;;;precision bar display
	(move_bar d_ref meter_scale)
    (setq total_count (1+ total_count))
    (setq ncount (1+ ncount))
    (if	(= ncount 50)
      (progn
	(zoom_area_brocard)
	(setq ncount 1)
	(setq delta (* factor delta))
	(setq delta_bc (* factor delta_bc))
	(setq delta_ca (* factor delta_ca))
      )
    )

  )
;;;end of while loop

)
;;;PURSUIT2_ccw
(prompt "PURSUIT2_ccw  ")
;;;
;;;PURSUIT for a Triangle case
(defun pursuit2_cw ()
  (setq	total_count 0
	delta	    (* 0.01 arc_length)
	delta_b	    (* delta ratio_ab)
	delta_c	    (* delta ratio_ac)
	factor	    0.5075
  )

  (while (> d_ab delta)

    (setq pnt_ac (pld pnt_a pnt_c delta)
	  pnt_cb (pld pnt_c pnt_b delta_c)
	  pnt_ba (pld pnt_b pnt_a delta_b)
    )
    (slow_line speed "0" 1 pnt_a pnt_ac)
    (slow_line speed "0" 3 pnt_b pnt_ba)
    (slow_line speed "0" 5 pnt_c pnt_cb)
					;(command "_.pline" pnt_ab pnt_bc pnt_ca "c")
    (if	 (= (rem total_count 10) 0) (make_jpg) )

    (setq total_path (* ncount delta))
;;;total distance traveled
    (setq pnt_a	pnt_ac
	  pnt_b	pnt_ba
	  pnt_c	pnt_cb
    )
    (setq d_ab	(distance pnt_a pnt_b)
	  d_bc	(distance pnt_b pnt_c)
	  d_ca	(distance pnt_c pnt_a)
	  d_ref	(/ d_ab len_12)
    )
;;;precision bar display
	(move_bar d_ref meter_scale)
    (setq total_count (1+ total_count))
    (setq ncount (1+ ncount))
    (if	(= ncount 50)
      (progn
	(zoom_area_brocard)
	(setq ncount 1)
	(setq delta (* factor delta))
	(setq delta_b (* factor delta_b))
	(setq delta_c (* factor delta_c))
      )
    )

  )
;;;end of while loop

)
;;;PURSUIT2_cw
(prompt "PURSUIT2_cw  ")
;;;COPY_ROTATE
(defun C:copy_rotate ()
					;Copy the entity data points, layer, color	
  (setq	base_line (entsel "Select an object")
	line_list (entget (car base_line))
	new_ent	  (list
		    (assoc 0 line_list)
		    (assoc 8 line_list)
		    (assoc 10 line_list)
		    (assoc 11 line_list)
		  )
  )
					;Make a new entity
  (entmake new_ent)
  (setq new_obj (entlast))
					;specify a center of rotation
  (setq rot_pnt (entsel "\nSelect a center of rotation"))
  (setq	rot_angle (getreal "\nInput rotation angle in degrees: ")
  )
					;use ACAD rotate command to rotate	
  (command "_.rotate" new_obj "" (cadr rot_pnt) rot_angle)
)					;COPY_ROTATE
					;(prompt "COPY_ROTATE  ")
;;;
;;;Find the angle omega
(defun c:omega (/ inv_a inv_b inv_c sum_inv_tan)
  (setq	angle_a	    (angle_3p pnt_1 pnt_2 pnt_3)
	angle_b	    (angle_3p pnt_2 pnt_3 pnt_1)
	angle_c	    (angle_3p pnt_3 pnt_1 pnt_2)
	inv_a	    (/ 1. (tan angle_a))
	inv_b	    (/ 1. (tan angle_b))
	inv_c	    (/ 1. (tan angle_c))
	sum_inv_tan (/ 1. (+ inv_a inv_b inv_c))
	omega_r	    (atan sum_inv_tan)
	omega_d	    (rtd omega_r)
  )
					;(prin1 (rtos omega_d 2 8))
)
;;;OMEGA
					;(prompt "OMEGA ")(terpri)
;;;
;;;	Find Brocard points(ccw)
;;;
(defun c:find_brocard_1	()
  (command "_.rotate" line_ab "" pnt_a omega_d)
  (command "_.rotate" line_bc "" pnt_b omega_d)
					;(copy_rotate line_ab pnt_a omega_d)
					;(copy_rotate line_bc pnt_b omega_d)
;;;find intersection of these 2 lines  pnt_br1
  (setq	pnt_b_1	(cdr (assoc 11 (entget line_ab)))
	pnt_c_1	(cdr (assoc 11 (entget line_bc)))
	pnt_br1	(inters pnt_a pnt_b_1 pnt_b pnt_c_1 nil)
  )
;;;get distance from the apexes to this point
  (setq	d_a_br (distance pnt_a pnt_br1)
	d_b_br (distance pnt_b pnt_br1)
	d_c_br (distance pnt_c pnt_br1)
  )
;;;compute the ratios of these line lengths w.r.t. d_a_br
;;;These values will be used to set the speed
;;;arc_length is the actual distance traveled from A to BR_pnt
  (setq	ratio_ab   (/ d_b_br d_a_br)
	ratio_ac   (/ d_c_br d_a_br)
	arc_length (/ d_a_br (cos omega_r))
  )
)
;;;
;;;
;;;	Find Brocard points(cw)					;(prompt "c:find_brocard_1  ")
;;;
(defun c:find_brocard_2	()
  (command "_.rotate" line_ab "" pnt_b (- omega_d))
  (command "_.rotate" line_bc "" pnt_c (- omega_d))
					;(copy_rotate line_ab pnt_a omega_d)
					;(copy_rotate line_bc pnt_b omega_d)
;;;find intersection of these 2 lines  pnt_br2
  (setq	pnt_a_2	(cdr (assoc 10 (entget line_ab)))
	pnt_b_2	(cdr (assoc 10 (entget line_bc)))
	pnt_br2	(inters pnt_b pnt_a_2 pnt_c pnt_b_2 nil)
  )
;;;get distance from the apexes to this point
  (setq	d_a_br (distance pnt_a pnt_br2)
	d_b_br (distance pnt_b pnt_br2)
	d_c_br (distance pnt_c pnt_br2)
  )
;;;compute the ratios of these line lengths w.r.t. d_a_br
;;;These values will be used to set the speed
;;;arc_length is the actual distance traveled from A to BR_pnt
  (setq	ratio_ab   (/ d_b_br d_a_br)
	ratio_ac   (/ d_c_br d_a_br)
	arc_length (/ d_a_br (cos omega_r))
  )
)
;;;
					;(prompt "c:find_brocard_2  ")
;;;COPY_ROTATE
(defun copy_rotate (base_line rot_center rot_angle / line_list new_ent)
					;Copy the entity data points, layer, color	
  (setq	line_list (entget base_line)
	new_ent	  (list
		    (assoc 0 line_list)
		    (assoc 8 line_list)
		    (assoc 62 line_list)
		    (assoc 10 line_list)
		    (assoc 11 line_list)
		  )
  )
;;;;;;Make a new entity
  (entmake new_ent)
  (setq new_obj (entlast))
;;;;;;specify a center of rotation
;;;;;;use ACAD rotate command to rotate	
  (command "_.rotate" new_obj "" rot_center rot_angle)
)					;COPY_ROTATE
;;;
					;(prompt "COPY_ROTATE ")
;;;
;;;
(defun c:brocard_demo1 ()
  (setq	line_ab_t nil
	line_bc_t nil
	line_ca_t nil
  )
  (make_line_1 "0" 1 pnt_1 pnt_2)
  (setq line_ab (entlast))
  (make_line_1 "0" 2 pnt_2 pnt_3)
  (setq line_bc (entlast))
  (make_line_1 "0" 3 pnt_3 pnt_1)
  (setq line_ca (entlast))

  (command "_.block" "line_ab" pnt_1 line_ab "")
  (command "_.block" "line_bc" pnt_2 line_bc "")
  (command "_.block" "line_ca" pnt_3 line_ca "")

  (alert "Pick the end of red line to rotate")

  (while (setq pnt_temp (cadr (grread)))
    (setq rot_deg (rtd (angle_3p pnt_1 pnt_2 pnt_temp)))
    (if	(/= line_ab_t nil)
      (entdel line_ab_t)
    )
    (if	(/= line_bc_t nil)
      (entdel line_bc_t)
    )
    (if	(/= line_ca_t nil)
      (entdel line_ca_t)
    )
    (command "_.insert" "line_ab" pnt_1 "" "" rot_deg)
    (setq line_ab_t (entlast))
    (command "_.insert" "line_bc" pnt_2 "" "" rot_deg)
    (setq line_bc_t (entlast))
    (command "_.insert" "line_ca" pnt_3 "" "" rot_deg)
    (setq line_ca_t (entlast))
  )
  ;;end of while loop
  (setq	line_ab_t nil
	line_bc_t nil
	line_ca_t nil
  )

)
;;;
(prompt "c:brocard_demo1  ")
;;;
;;;
;;;
(defun c:brocard_demo2 ()
  (setq	line_ab_t nil
	line_bc_t nil
	line_ca_t nil
  )
  (make_line_1 "0" 1 pnt_1 pnt_2)
  (setq line_ab (entlast))
  (make_line_1 "0" 2 pnt_2 pnt_3)
  (setq line_bc (entlast))
  (make_line_1 "0" 3 pnt_3 pnt_1)
  (setq line_ca (entlast))

  (command "_.block" "line_ab" pnt_1 line_ab "")
  (command "_.block" "line_bc" pnt_2 line_bc "")
  (command "_.block" "line_ca" pnt_3 line_ca "")

  (alert "Pick the end of red line to rotate")

  (while (setq pnt_temp (cadr (grread T)))
    (setq rot_deg (rtd (angle_3p pnt_1 pnt_2 pnt_temp)))
    (if	(/= line_ab_t nil)
      (entdel line_ab_t)
    )
    (if	(/= line_bc_t nil)
      (entdel line_bc_t)
    )
    (if	(/= line_ca_t nil)
      (entdel line_ca_t)
    )
    (command "_.insert" "line_ab" pnt_1 "" "" rot_deg)
    (setq line_ab_t (entlast))
    (command "_.insert" "line_bc" pnt_2 "" "" rot_deg)
    (setq line_bc_t (entlast))
    (command "_.insert" "line_ca" pnt_3 "" "" rot_deg)
    (setq line_ca_t (entlast))
  )
  ;;end of while loop
  (setq	line_ab_t nil
	line_bc_t nil
	line_ca_t nil
  )

)
;;;
(prompt "c:brocard_demo2  ")

;;;
;;;
(defun c:brocard_demo3 ()
  (setq	line_ab_t nil
	line_bc_t nil
	line_ca_t nil
	status_change nil
  )
  (make_line_1 "0" 1 pnt_1 pnt_2)
  (setq line_ab (entlast))
  (make_line_1 "0" 2 pnt_2 pnt_3)
  (setq line_bc (entlast))
  (make_line_1 "0" 3 pnt_3 pnt_1)
  (setq line_ca (entlast))

  (command "_.block" "line_ab" pnt_1 line_ab "")
  (command "_.block" "line_bc" pnt_2 line_bc "")
  (command "_.block" "line_ca" pnt_3 line_ca "")

  (alert "Pick the end of red line to rotate")
  (while (and (setq key (grread T)) (= (car key) 5))
    (setq pnt_temp (cadr key))
					;(while (setq pnt_temp (cadr (grread T)))
    (setq rot_deg (rtd (angle_3p pnt_1 pnt_2 pnt_temp)))
    (if	(/= line_ab_t nil)
      (entdel line_ab_t)
    )
    (if	(/= line_bc_t nil)
      (entdel line_bc_t)
    )
    (if	(/= line_ca_t nil)
      (entdel line_ca_t)
    )
    (command "_.insert" "line_ab" pnt_1 "" "" rot_deg)
    (setq line_ab_t (entlast))
    (command "_.insert" "line_bc" pnt_2 "" "" rot_deg)
    (setq line_bc_t (entlast))
    (command "_.insert" "line_ca" pnt_3 "" "" rot_deg)
    (setq line_ca_t (entlast))
    (if	(= status_change T)
      (zoom_area_brocard)
    )					;zoom for easy picking
  )
  ;;end of while loop
  (setq	line_ab_t nil
	line_bc_t nil
	line_ca_t nil
  )

)
;;;
(prompt "c:brocard_demo3  ")
;;;
;;;ZOOM_AREA
;;;zoom the transition area for detail search
;;;
(defun ZOOM_AREA_brocard
       (/ x_a x_b x_c y_a y_b y_c lower_left upper_right)

  (setq	x_a	    (car pnt_a)
	y_a	    (cadr pnt_a)
	x_b	    (car pnt_b)
	y_b	    (cadr pnt_b)
	x_c	    (car pnt_c)
	y_c	    (cadr pnt_c)
	min_x	    (min x_a x_b x_c)
	min_y	    (min y_a y_b y_c)
	max_x	    (max x_a x_b x_c)
	max_y	    (max y_a y_b y_c)
	lower_left  (list min_x min_y)
	upper_right (list max_x max_y)
  )
  (command "_.zoom" "_w" lower_left upper_right)
  (command "_.regen")
)					;ZOOM_AREA_brocard
;;;
;;;Test for n-dogs
;;;
(defun c:ndogs ()
  (setup_sysvar)
  (setup_npolygon)
  (if (= JPG_YES 1)
    (command "_.jpgout" (strcat "6dogs_" (itoa 0)) "")
  )
					;(setq new_list apex_list)	;;copy apex_list
  (pursuit_ndogs)
  (reset_sysvar)
)
;;;Ndogs
(prompt "ndogs")
;;;
;;;PURSUIT for n-polygon case
(defun pursuit_ndogs ()
  (setvar "CECOLOR" "8")
  (while (<= total_path (- arc_len tol_val))
					;(while (> d_ref delta)		;;;old criteria
    (setq n_apex    0
	  pnt_a_old (nth 0 new_list)
	  ncol	    1
    )
    (repeat n_poly
      (setq pnt_start (nth n_apex new_list)
	    pnt_dest  (nth (1+ n_apex) new_list)
	    pnt_s_old pnt_start
	    pnt_s_new (pld pnt_start pnt_dest delta)
	    color_id  ncol
      )
      (slow_line speed "0" color_id pnt_start pnt_s_new)

      (setq new_list (repl_nth new_list n_poly n_apex pnt_s_new))
      (setq n_apex (1+ n_apex)
	    ncol   (1+ ncol)
      )
    )
    (setq pnt_a_new (nth 0 new_list)
	  pnt_b_new (nth 1 new_list)
	  new_list  (repl_nth new_list n_poly n_apex pnt_a_new)
	  d_ref	    (distance pnt_a_new pnt_b_new)
    )
					;(princ new_list)(terpri)	
    (make_polyline "layer8" 8 "Continuous" new_list 0)
    (if	(and (= (rem ncount 10) 0) (= JPG_YES 1))
      (command "_.jpgout" (strcat "6dogs_" (itoa ncount)) "")
    )
;;;end of if loop
    (setq ncount (1+ ncount))
    (setq total_path (* ncount delta))
;;;total distance traveled
					;(princ "total_path =")(princ total_path)(terpri)
  )
;;;end of while loop
  (setvar "CECOLOR" "BYLAYER")
  (princ "total_path =")
  (princ total_path)
  (terpri)
)
;;;PURSUIT_ndogs
(prompt "PURSUIT_ndogs")
;;;
;;;SETUP for N-polygon case
;;;
(defun setup_npolygon ()
  (setq rad 1.0)
  (setq N_poly (getint "\nNumber of sides in polygon<def = 4>"))
  (if (= n_poly nil)
    (setq n_poly 4)
  )
  (setq	theta	  (/ pi n_poly)
	sine	  (sin theta)
	cosine	  (cos theta)
	height	  (* rad cosine)
	half_base (* rad sine)
	arc_len	  (/ rad sine)
;;;S = rad/(cos (pi/2 -theta) )=rad/sin(theta)
	pnt_1	  (list (- half_base) (- height))
	pnt_2	  (list half_base (- height))
	side_len  (* 2 half_base)
	ncount	  0
	tol_val	  1.e-6
  )
  (command "_.polygon" N_poly "_Edge" pnt_1 pnt_2)

  (setq apex_list (pl_vertices (entlast)))
  ;;list of apex data
					;(setq apex_list (append apex_list (list (nth 0 apex_list))) )
  (mark_id pnt_1 "A" 3 0.1)
  (mark_id pnt_2 "B" 1 0.1)

					;(make_polyline "0" 5 "_Continuous" apex_list 1)		;;closed polyline

  (command "_.zoom" "_EXTENT")
  (setq apex_list (append apex_list (list (nth 0 apex_list))))
  (setq new_list apex_list)
  ;;copy apex_list
  (princ new_list)
  (terpri)
  (setq
    rate (getreal
	   "\nSpecify dog's stride as % of side length AB:(def=1%)"
	 )
  )
  (if (= rate nil)
    (setq rate 1.)
  )
  (setq
    delta (* side_len (/ rate 100.))
    speed (getint
	    "\nSpecify display speed (1-100) 1:veryfast 100:very slow (def = 50)"
	  )
  )
  (if (= speed nil)
    (setq speed 50)
  )
  (setq	d_ref	   side_len
	total_path 0.
	n_repeat   (+ 2 (fix (/ 100 rate)))
  )

)
;;;
(prompt "SETUP_NPLOYGON")
;;;
;;;Replace the n-th element in the list by the user given element
;;;
(defun repl_nth	(list_in list_size n_th new_elem / new_list npos)
  (setq	new_list nil
	npos 0
  )
  (repeat (1+ list_size)
    (if	(= npos n_th)
      (setq elem new_elem)
      (setq elem (nth npos list_in))
    )
;;;end_if loop

    (setq npos (1+ npos))
    (setq new_list (append new_list (list elem)))

  )
;;;end of repeat loop

)
;;;repl_nth
;;;
;;;Equiangular curve parameters
;;;
(defun c:equi_angular()
	(setup_equi_angular)
  (alert "\nCopy , move and rotate two colored sets")
  (copy_move_rot)
  (alert "\nScale two sets to see if they match the curve.")
  (scale_sets)

);;;
;;;
(defun setup_equi_angular()
	(setq 
		qtr_pi (/ pi 4.)
		th_d (* 3 qtr_pi)
		th_c  qtr_pi
		th_a (- th_d)
		th_b (- th_c)
		k_a (/ 1. (exp th_a))
		k_b (/ 1. (exp th_b))
		k_c (/ 1. (exp th_c))
		k_d (/ 1. (exp th_d))
		pnt_org '(0 0)
		pnt_org_2 '(-0.5 0)
		pnt_cr11 '(-0.001 0.1)
		pnt_cr12 '(-0.1 0.001)
		pnt_cr21 '(0.1 0.1)
		pnt_cr22 '(0.001 0.001)
		pnt_cr31 '(0.3 0)
		pnt_cr32 '(0 -0.5)
		pnt_cr41 '(-0.48 -0.0001) pnt_cr42 '(-0.49999 -0.05)
		pnt_cr51 '(-0.45 -0.0001) pnt_cr52 '(-0.49999 -0.1)
		ss1 (ssadd)
		ss2 (ssadd)
		ss3 (ssadd)
		ss1a (ssadd)
		ss2a (ssadd)
	)
	(make_pt "0" 0 pnt_org_2)
	(alert "\nChange colors of the first and second sets")
;;change the color of the first and second sets
	(setq ss1 (ssget "_C" pnt_cr11 pnt_cr12))
	(command "_.chprop" ss1 "" "c" "yellow" "")
	(setq ss2 (ssget "_C" pnt_cr21 pnt_cr22))
  	(command "_.chprop" ss2 "" "_C" "green" "")
);;;

;;;
;;;
(defun copy_move_rot()
	
  (alert "\nCopy , move and rotate two colored sets")
;;copy.move and rotate the first set(yellow)
	
  
  (command "_.copy" ss1 "" pnt_org pnt_org)
  (command "_.move" ss1 "" pnt_org pnt_org_2)
  (command "_.rotate" ss1 "" pnt_org_2 -180.)
  (setq ss1a (ssget "C" pnt_cr41 pnt_cr42))
  (command "_.copy" ss1a "" pnt_org_2 pnt_org_2)

;;copy,move and rotate the second set(cyan)
	
  (command "_.copy" ss2 "" pnt_org pnt_org)
  (command "_.move" ss2 "" pnt_org pnt_org_2)
  (command "_.rotate" ss2 "" pnt_org_2 -90.)
  (setq ss2a (ssget "C" pnt_cr51 pnt_cr52))
  (command "_.copy" ss2a "" pnt_org_2 pnt_org_2)
  
;;copy and move the third set(red)
	(setq ss3 (ssget "_C" pnt_cr31 pnt_cr32))
  (command "_.copy" ss3 "" pnt_org pnt_org)
  (command "_.move" ss3 "" pnt_org pnt_org_2)

);;;
;;;
;;;
(defun scale_sets()
	(command "_.scale" ss1a ss2a "" pnt_org_2 4.8)
)
;;;
;;;DRAW equiangular spiral corresponding to square chase case.
;;;
;;;
(defun c:draw_equiangular_spiral()
	(setq theta_0 (* 0.75 pi)
		sqrt_2 (sqrt 2.)
		inv_sqrt_2 (/ 1. sqrt_2)
		theta_s 0.
		theta_e (* 2. pi)
		del_theta (/ theta_e 100.)
		nth_turn  1
		nstep 0
		pnt_old (list (- inv_sqrt_2) (- inv_sqrt_2))
		col_id 1
		pnt_org '(0 0)
		scale_factor 0.075
		cur_scale 1.0
	)
 (make_line_1 "0" 8 '(0 -0.7) '(0 0.1))
 (make_line_1 "0" 8 '(-0.1 0) '(0.1 0))
 (command "_.zoom" "_E")
 (while (= (Yes_or_No "Go to next step ?") "_Y") 
     (setq nstep 0  )
	(repeat 100
		(setq theta (+ theta_s (* del_theta nstep)) 
			m_theta (- theta)
			f_val (exp m_theta)
			theta2 (- theta theta_0)
			x_val (* f_val (cos theta2))
			y_val (* f_val (sin theta2))
			pnt_new (list x_val y_val)
		)
	  (make_line_1 "0" col_id pnt_old pnt_new)
	  (setq pnt_old pnt_new
		nstep (1+ nstep)
	  )
	);;;inner loop
	(setq cur_scale (* cur_scale scale_factor))
	(if (= col_id 1) (command "_.zoom" "_E")
	 (command "_.zoom" "_C" pnt_org cur_scale)
        )
     (setq theta_s (+ theta_s theta_e) col_id  (1+ col_id))
     (make_jpg)
     (command "_.delay" 500)
 );;while loop
  

);;;
;;;
;;;How the brocard points are defined.
;;;
;;;BROCARD_DEF
(prompt "brocard_def")
;;;
(defun C:brocard_def()
	(setup_brocard_def)
	(command "_.zoom" "_E")
;;copy line segment
	(copy_line_seg)
;;rotate line segment inward by 10 degrees
	(alert "\nRotate line segments inward by a given angle")
	(setq rot_ang 0.5)
  (while (> dist_bc min_dist)
	(rot_lineseg_in rot_ang)
;;compute 3 intersecting points & draw a triangle
	(draw_temp_triangle)
	
	(command "_.delay" 100)
  );;while loop

;(alert "\nRotate line segmnets outward by the same given angle")
;	(rot_lineseg_out rot_ang)


	(reset_sysvar)
);;
;;;BROCARD_DEF
;;;
(prompt "brocard_defa")
;;;BROCARD_DEFA
;;;
(defun C:brocard_defa()
	(setup_brocard_def)
	(command "_.zoom" "_W" lower_left upper_right)
;;copy line segment
	(copy_line_seg)
;;rotate line segment inward by 10 degrees
	(alert "\nRotate line segments inward by a given angle")
	(setq rot_ang 1.0)
	(setvar "CECOLOR" "8")
  (repeat 180
	
	(rot_lineseg_in rot_ang)
;;compute 3 intersecting points & draw a triangle
	(draw_temp_triangle)
	(make_jpg)
	(command "_.delay" 100)
  );;while loop
	(command "_.draworder" line_ab line_bc line_ca text_a text_b text_c "" "_F")

;(alert "\nRotate line segmnets outward by the same given angle")
;	(rot_lineseg_out rot_ang)


	(reset_sysvar)
);;
;;;BROCARD_DEFA
;;;BROCARD_DEFB
(prompt "brocard_defb")
;;;
(defun C:brocard_defb()
	(setup_brocard_def)
	(command "_.zoom" "_E")
;;copy line segment
	(copy_line_seg)
;;rotate line segment inward by 10 degrees
	(alert "\nRotate line segments inward by a given angle")
	(setq rot_ang 1.0)
  (while (> dist_bc min_criteria)
  (while (> dist_bc half_bc)
	(rot_lineseg_in rot_ang)
;;compute 3 intersecting points & draw a triangle
	(draw_temp_triangle)
	
	(command "_.delay" 100)
  );;while loop
	(setq half_bc (* 0.5 dist_bc)
		rot_ang (* 0.5 rot_ang)
	)
  );;outer while loop

(command "_.draworder" line_ab line_bc line_ca text_a text_b text_c "" "_F")

	(reset_sysvar)
);;
;;;BROCARD_DEFB
;;;
;;;SETUP_BROCARD_DEF
(prompt "setup_brocard_def")
;;;
(defun setup_brocard_def()
	(setup_sysvar)
	(command "_.zoom" "_C" '(0 0) 1.0)
	(setq pnt_a (getpoint "\nLocate point A of triangle ABC"))
	(if (= pnt_a nil) (setq pnt_a '(0.03125 0.39125 0.0)) )
	(textdisplay "A" (shift_pnt pnt_a '(0.02 0.02)) 0.1 0.)
		(setq text_a (entlast))
	(setq pnt_b (getpoint pnt_a "\nLocate point B of triangle ABC"))
	(if (= pnt_b nil) (setq pnt_b '(-0.44625 -0.02875 0.0)) )
	(textdisplay "B" (shift_pnt pnt_b '(-0.1 0.)) 0.1 0.)
		(setq text_b (entlast))
	
	(make_line_1 "0" 0 pnt_a pnt_b)
		(setq line_ab (entlast))

	(setq pnt_c (getpoint pnt_b "\nLocate point C of triangle ABC"))
	(if (= pnt_c nil) (setq pnt_c '(0.28125 -0.02875 0.0)) )
	(textdisplay "C" pnt_c 0.1 0.)
		(setq text_c (entlast))
	(make_line_1 "0" 0 pnt_b pnt_c)
		(setq line_bc (entlast))
	(make_line_1 "0" 0 pnt_c pnt_a)
		(setq line_ca (entlast))
	(setq dist_ab (distance pnt_a pnt_b)
		dist_bc (distance pnt_b pnt_c)
		dist_ca (distance pnt_c pnt_a)
		half_bc (* 0.5 dist_bc)
		len_max (max dist_ab dist_bc dist_ca)
		min_dist (* len_max 0.05)
		min_criteria (* 0.0001 len_max)
		mlen_max (- len_max)
	)
	(setq lower_left (shift_pnt pnt_b (list mlen_max mlen_max) )
		upper_right (shift_pnt pnt_a (list len_max len_max) )
	)
	 

)
;;;SETUP_BROCARD_DEF
;;;
;;;copy line segment for rotation
;;;
(prompt "copy_line_seg")
;;;COPY_LINE_SEG
;;;
(defun copy_line_seg()
	(command "_.copy" line_ab "" pnt_a pnt_a "")
	(setq line_ab_copy (entlast))

	(command "_.copy" line_bc "" pnt_b pnt_b "")
	(setq line_bc_copy (entlast))

	(command "_.copy" line_ca "" pnt_c pnt_c "")
	(setq line_ca_copy (entlast))

)
;;;COPY_LINE_SEG
;;;
;;;Rotate 3 line segments inward (counter clockwise)
;;;ROT_LINESEG_IN
(prompt "rot_lineseg_in")
;;;
(defun rot_lineseg_in(rot_ang)
	(command "_.rotate" line_ab_copy "" pnt_a rot_ang)
 	(command "_.rotate" line_bc_copy "" pnt_b rot_ang)
	(command "_.rotate" line_ca_copy "" pnt_c rot_ang)
)
;;;ROT_LINESEG_IN
;;;
;;;
;;;Rotate 3 line segments outward ( clockwise)
;;;ROT_LINESEG_IN
(prompt "rot_lineseg_out")
;;;
(defun rot_lineseg_out(rot_ang)
	;(command "_.copy" line_ab "" pnt_a pnt_a "")
	;(setq line_ab_copy2 (entlast))

	;(command "_.copy" line_bc "" pnt_b pnt_b "")
	;(setq line_bc_copy2 (entlast))

	;(command "_.copy" line_ca "" pnt_c pnt_c "")
	;(setq line_ca_copy2 (entlast))
	;(command "_.rotate" line_ab_copy2 "" pnt_a (- rot_ang))
 	;(command "_.rotate" line_bc_copy2 "" pnt_b (- rot_ang))
	;(command "_.rotate" line_ca_copy2 "" pnt_c (- rot_ang))

	(command "_.rotate" line_ab_copy "" pnt_a (- rot_ang))
 	(command "_.rotate" line_bc_copy "" pnt_b (- rot_ang))
	(command "_.rotate" line_ca_copy "" pnt_c (- rot_ang))

)
;;;ROT_LINESEG_out
(prompt "draw_temp_triangle")
;;;
;;;DRAW_TEMP_TRIANGLE
;;;compute the 3 intersecting points and draw a triangle
;;;
(defun draw_temp_triangle()
;;compute the other ends of 3 line segments
	(setq pnt_ab_b (cdr (assoc 11 (entget line_ab_copy)))
		pnt_bc_c (cdr (assoc 11 (entget line_bc_copy)))
		pnt_ca_a (cdr (assoc 11 (entget line_ca_copy)))
	)
;;compute the intersecting points
	(setq  pnt_bc (inters pnt_a pnt_ab_b pnt_b pnt_bc_c nil)
		pnt_ca (inters pnt_b pnt_bc_c pnt_c pnt_ca_a nil)
		pnt_ab (inters pnt_c pnt_ca_a pnt_a pnt_ab_b nil)
	)
	(make_line_1 "0" 1 pnt_bc pnt_ca)
	(make_line_1 "0" 3 pnt_ca pnt_ab)
	(make_line_1 "0" 5 pnt_ab pnt_bc)
	;(command "_.pline" pnt_bc pnt_ca pnt_ab "cl")
	(setq dist_bc (distance pnt_bc pnt_ca))
)
;;;DRAW_TEMP_TRIANGLE