;Version: 121.4d
;Date   : 29 December 1999
;
;This program now handles two dimensional lay out.
;Okay, before I forget I'll quickly explain what goes on in this edition.
;I finished off last time with 121.3 (or 121z.lsp) which could
;automatically detect lying and standing rectangular rooms and place
;one and only one row of desirable number of lights across the middle.
;121.4 can now position numerous number of rows in a 2-D manner if you like
;to see this as.
;
;Mechanism: I took 121.3 and removed its Lying part, keeping the Standing
;part. This program breaks up the big room into many small standing rectangular
;rooms and then feeds appropriate coordinates into the old standing().
;Everything is basically the same as before, except we've now added the
;outerloop and removed the lying part.
;
;Bug Fix: In previous versions, the background always seemed to interfere
;with our positioning for some unknown reason. I figured out it
;must be due to osnap. That problem has been fixed in this version.
;
;Future development: I think one purpose of LSP is to minimize the number of
;questions the user needs to answer. 121.4 already asks 5 questions,
;and I am reluctant to make it worse. However if I do come back and improve
;on this edition, I look forward to including (1) a rotation function
;and (2) default/memory for previous corners (3) automatically calculate from
;the dimensions how many lights to place and how to place them and then place
;them automatically (4) Rather than needing to select two opposite corner points ;of the room, I hope to let the user click any where inside the room once and ;only once, and leave it to the program to detect the corners and dimensions.


(defun c:121()
  (setq p1 (getpoint "\n1st corner:"))
  (setq p3 (getpoint "\n2nd corner (furthest opposite):"))

  ;set default for r to light.dwg
  (if (= r nil) (setq r "light.dwg"))



  ;default or memory recall
  (princ "\nWhat block <")
  (princ r)
  (princ ">?")
  (setq s (getstring " "))

  ;this renews previous setting
  ;provides default and memory function
  (setq r0 r)
  (if (/= r s) (setq r s))
  (if (= s "") (setq r r0))



  ;n is number of lights to fit into each vertical row
  (setq n (getint "\nHow many in each vertical row? "))
  ;m is number of lights to fit into each horizontal row
  (setq m (getint "\nHow many in each horizontal row? "))

  (setq x1 (car  p1))
  (setq y1 (cadr p1))
  (setq x9 (car  p3))
  (setq y3 (cadr p3))


;It is important that we clear the osnap before we start inserting blocks
;because any ON osnap attribute can interact with the background structures
;and stuff up our coordinates.

;Memorizing osnap status into the variable ostatus before we clear osnap
  (setq ostatus (getvar "osmode") )
;Clearing osnap
  (setvar "osmode" 0)


;START OF OUTER LOOP

;dd is the absolute width of the corridor
 (setq dd (- x9 x1))

;tt is the distance of first light from wall, ie. unit distance.
;2m comes from 2(m-1)+2
 (setq tt (/ dd (* 2 m)))

;qq1 represents the absolute x value of lights in specific vertical row
;We in effect, wish to feed qq1-tt and qq1+tt into standing() for it to
;complete the content of each vertical row for us

;Here we go, this is the x value for lights in the first vertical row
 (setq qq1 (+ x1 tt))

         ;for a=0 to m
         (setq a 0)
         (setq b 1)
         (while b
           (setq x1 (- qq1 tt))
           (setq x3 (+ qq1 tt))
           (standing)
           (setq qq1 (+ qq1 (* tt 2) ) )
           (setq a (+ a 1))
           (if (= a m) (setq b nil))
         )
         ;next a
; END OF OUTER LOOP




;Returning initial osnap settings
(setvar "osmode" ostatus)

;get rid of end nil
(princ)
)   ;main program ends here








; START OF INNER LOOP

;start of function standing
(defun standing()
            (setq xmid (/ (+ x1 x3) 2))
            ;d is the height of the corridor
            (setq d (- y3 y1))


           ;t is the distance of first light from wall, ie. unit distance.
           ;2n comes from 2(n-1)+2
           (setq t (/ d (* 2 n)))

           ;q1 is an arbitary point in the corridor with xmid as its x value
           (setq q1 (+ y1 t))

         ;for j=0 to n-2
         (setq j 0)
         (setq w 1)
         (while w
           (setq q (+ q1 (* (* 2 t) j)))
           (setq j (+ j 1))
           (if (= j n) (setq w nil))
           (setq z (list xmid q))
           (command "insert" r z "" "" "")
         )
         ;next j
)

; END OF INNER LOOP