Lisp tính cao độ

;TINH CAO DO NHAP KHOANG CACH VA VIET VAO DIEM CHON (tạo một block caodo.dwg)
(defun c:tcd1 ()
(c:setupdesign)
(setq luu (getvar "osmode"))
(setvar "osmode" 33)
(initget 3)
(setq pt1 (getpoint "\nChon diem goc da biet cao do: " ))
(setq pt2 (getpoint "\nChon diem can tim cao do: " pt1))

; (setq pt3 (getreal "\nVao cao do diem da biet:" ))
(setvar "blipmode" 0)
(while (null (setq chon (entsel "\nChon so cao do diem truoc:"))))
(setq dt (entget (car chon)))
(setq loai (cdr (assoc 0 dt)))
(if (= loai "TEXT")
(progn
(setq gtri (cdr (assoc 1 dt)))

(setq pt3 (atof gtri))
(initget 0)
)
(progn
)
)

; (setq B (getreal "\nCao do ghi ben trai (0) hay phai (1) ? : "))
(setq B 1)
(setq dau1 (car pt1))
(setq cuoi1 (cadr pt1))
(setq dau2 (car pt2))
(setq cuoi2 (cadr pt2))
(setq l (abs (- dau1 dau2)))
(Setq phia (- 0 0))
(setq xt (+ dau2 1.10))
(setq yt (- cuoi2 0.45))
(setq cht (list xt yt))
(setq xp (- dau2 1.10))
(setq yp (- cuoi2 0.45))
(setq chp (list xp yp))

(if ( = B phia )
(command "insert" "cdt" pt2 "" "" "0")
(command "text" "J" "M" cht "0.36" "0" (rtos (+ pt3 (/ (- cuoi2 cuoi1) ntl)) 2 tphan))
)
(if ( > B phia )
(command "insert" "cdo" pt2 "" "" "0")
(command "text" "J" "M" chp "0.36" "0" (rtos (+ pt3 (/ (- cuoi2 cuoi1) ntl)) 2 tphan))
)
(setvar "osmode" luu)
; (setvar "blipmode" luublipmode)

(setq pt3 nil)
(princ)
)
;het tcd