fixup

1 files changed, 61 insertions, 0 deletions

diff --git a/shared/pict.rkt b/shared/pict.rkt
new file mode 100644
index 0000000..7c7a74e
--- /dev/null
+++ b/shared/pict.rkt
@@ -0,0 +1,61 @@
+#lang racket
+(provide
+  make-vect
+  xcor-vect
+  ycor-vect
+  add-vect
+  sub-vect
+  scale-vect
+  test-vect
+  make-frame
+  origin-frame
+  edge1-frame
+  edge2-frame
+  test-frame
+  make-segment
+  start-segment
+  end-segment)
+(require sicp-pict)
+(require "lists.rkt")
+
+(define (make-vect x y)
+  (cons x y))
+(define (xcor-vect v)
+  (car v))
+(define (ycor-vect v)
+  (cdr v))
+
+(define (add-vect . v)
+  (make-vect 
+    (fold-right + 0 (map xcor-vect v))
+    (fold-right + 0 (map ycor-vect v))))
+(define (sub-vect . v)
+  (let ((xcors (map xcor-vect v))
+        (ycors (map ycor-vect v)))
+   (make-vect
+     (- (car xcors) (fold-right + 0 (cdr xcors)))
+     (- (car ycors) (fold-right + 0 (cdr ycors))))))
+(define (scale-vect s v)
+  (make-vect (* s (xcor-vect v))
+             (* s (ycor-vect v))))
+(define test-vect (make-vect 1 2))
+
+(define (make-frame origin edge1 edge2)
+  (list origin edge1 edge2))
+(define (origin-frame frame)
+  (car frame))
+(define (edge1-frame frame)
+  (cadr frame))
+(define (edge2-frame frame)
+  (caddr frame))
+(define test-frame (make-frame
+                     (make-vect 1 2)
+                     (make-vect 2 4)
+                     (make-vect 3 6)))
+
+(define (make-segment start end)
+  (cons start end))
+(define (start-segment s)
+  (car s))
+(define (end-segment s)
+  (cdr s))