From 0681ec7ba5ee4807591929d07f8a37488f986396 Mon Sep 17 00:00:00 2001
From: nihilazo <nico@itwont.work>
Date: Fri, 1 Apr 2022 23:11:42 +0100
Subject: [PATCH] add count-square function

---
 main-test.rkt | 14 +++++++++-----
 main.rkt      | 14 +++++++++++++-
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/main-test.rkt b/main-test.rkt
index bdcf749..f709c0e 100644
--- a/main-test.rkt
+++ b/main-test.rkt
@@ -56,7 +56,12 @@
  (check-true (forwards? (line (point 0 1) (point 1 1) 1)))
  (check-false (forwards? (line (point 1 1) (point 0 0) 0))))
 
-; TODO
+(test-case
+ "point+"
+ (check-equal? (point+ (point 0 0) (point 1 2)) (point 1 2))
+ (check-equal? (point+ (point 2 4) (point 5 0)) (point 7 4))
+ (check-equal? (point+ (point 0 0) (point 0 0)) (point 0 0)))
+
 (test-case
  "count-square"
   (define grid (list
@@ -70,11 +75,10 @@
                 (line (point 3 3) (point 3 4) 0)
                 (line (point 3 3) (point 4 3) 0)
                 (line (point 4 3) (point 4 4) 0)
-                (line (point 3 4) (point 4 4) 0)
-                ))
+                (line (point 3 4) (point 4 4) 0)))
   (check-equal? (count-square (point 0 0) grid) 4)
-  (check-equal? (count-square (point 0 1) grid) 3)
-  (check-equal? (count-square (point 0 2) grid) 2)
+  (check-equal? (count-square (point 1 0) grid) 3)
+  (check-equal? (count-square (point 2 0) grid) 2)
   (check-equal? (count-square (point 3 2) grid) 1)
   (check-equal? (count-square (point 0 4) grid) 0)
 )
\ No newline at end of file
diff --git a/main.rkt b/main.rkt
index 80bbf58..c89fe0b 100644
--- a/main.rkt
+++ b/main.rkt
@@ -40,9 +40,21 @@
     (equal? (line-to l1) (line-from l2))
     (equal? (line-from l1) (line-to l2)))))
 
+; Point Point -> Point
+; adds two points together.
+(define (point+ p1 p2)
+  (point (+ (point-x p1) (point-x p2)) (+ (point-y p1) (point-y p2))))
+
 ; Point Grid -> Number
 ; given a point that is the top-left corner of a square on the grid, returns the amount of edges surrounding that square.
-(define (count-square p g) 0)
+(define (count-square p g)
+  ; explanation:
+  ; for every item in the grid (g), test it against every edge of the box 
+  (length
+   (filter (lambda (item) (foldl (lambda (x y) (or x y)) #f
+         (for/list ([x (list (point 0 0) (point 0 1) (point 1 0) (point 0 0))]
+                    [y (list (point 0 1) (point 1 1) (point 1 1) (point 1 0))]) 
+           (same-position? item (line (point+ x p) (point+ y p) 0))))) g))) ; for every position in the square, check if there's a line there
 
 ; Line -> Bool
 ; returns #t if the line is forwards (with forwards being moving right and down, higher end coord than start)