day 14, part 2 - endless pyramid

day14-scratch.lisp

@@ -350,3 +350,36 @@
        (drop-result (drop-sand-unit arena) (drop-sand-unit arena)))
       ((not drop-result)
        sand-units)))
+
+;;; PART 2
+;; let's not do floor infinite.
+;; let's just give it enough left-to-right?
+;; since the triangle is 2 right angle triangles, then bottom is 2x height
+;; so, let's add 4x height of the floor?
+;;
+;;  new bottommost =
+ (+ 2 bottommost)
+;;  new leftmost =
+(min leftmost
+     (- 500 (* 2 bottommost)))
+;; new rightmost =
+(max rightmost
+     (+ 500 (* 2 bottommost)))
+
+;; and add new rock-line?
+;; just through function that adds a rockline
+
+(slot-value *test-arena* 'grid)
+
+;; and now i'd like a more compact printing.
+;; how'd i do that?
+;; surely there's a way to get access ot a slice of the 2d array?
+
+(let* ((arena *test-arena*)
+       (array (slot-value arena 'grid)))
+  (dotimes (row (array-dimension array 0))
+    (dotimes (col (array-dimension array 1))
+      (format t "~a" (aref array row col)))
+    (terpri)))
+
+(drop-sand-unit *test-arena*)