;; ****************************************
;; *  Csu 211 : 1/16/2008
;; *  Lecture #4 Code
;; *  Booleans and Conditional Expressions
;; ****************************************


;; The 'empty-scene', only need to create once
(define EMPTY (empty-scene 400 400))

;; Create the Window to display our world
(big-bang 400 400 1 false)

;; dist: Number Number -> Number
;; Compute the Distance from (0,0) to (x,y)
(define (dist x y)
  (sqrt (+ (sqr x) (sqr y))))

"Distance Tests"
(= (dist 3 4) 5)
(= (dist 0 0) 0)
(= (dist 9 12) 15)
(= (dist -3 4) 5)


;; Definitions for our Circle
(define R 150)
(define CCX 200)
(define CCY 200)

;; test-circ: Number Number Number Number -> Boolean
;; Is the given point (x,y) within our circle
;;   centered at (cx,cy)?
(define (test-circ x y cx cy)
  (> R (dist (- cx x) (- cy y))))

;; image-circ: Boolean -> Scene
;; Draw our circle in an empty scene, based on
;;   whether or not the mouse is 'in' the circle
(define (image-circ in)
  (place-image (circle R (cond [in "solid"]
                               [else "outline"])
                       "purple")
               CCX CCY EMPTY))

;; mouse-circ: Boolean Number Number Symbol -> Boolean
;; Use a Mouse event to update our World
(define (mouse-circ in x y sym)
  (test-circ x y CCX CCY))

;;** Setup after the big-bang
;(on-redraw image-circ)
;(on-mouse-event mouse-circ)




;; Definitions for our Rectangle
(define WIDTH 250)
(define HEIGHT 200)
(define RCX 200)
(define RCY 200)

;; image-rect: Boolean -> Scene
;; Draw our rectangle in an empty scene, based on
;;   whether or not the mouse is 'in' the rectangle
(define (image-rect in)
  (place-image (rectangle WIDTH HEIGHT "solid"
                          (cond (in "red")
                                (else "blue")))
               RCX RCY EMPTY))

;; test-rect: Number Number Number Number -> Boolean
;; Is the given point (x,y) within our rectangle
;;   centered at (cx,cy)?
(define (test-rect x y cx cy)
  (and (and (> x (- cx (/ WIDTH 2))) 
            (< x (+ cx (/ WIDTH 2))))
       (and (> y (- cy (/ HEIGHT 2)))
            (< y (+ cy (/ HEIGHT 2))))))

;; mouse-rect: Boolean Number Number Symbol -> Boolean
;; Use a Mouse event to update our World
(define (mouse-rect in x y sym)
  (test-rect x y RCX RCY))

;;** Setup after the big-bang
(on-redraw image-rect)
(on-mouse-event mouse-rect)