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;;Lab 4
;;Purpose: The purpose of this lab is to create moving shapes using, draw-shapes, clear-shapes, sleep-for-a-while and structures such as (make-posn.. . and our own defined structures such as "circle".  We may have overdid the comments, please leave a comment if this is true.  Also during this lab we are using solid-disks and calling them circles because its shorter.
(start 450 450);; Opens Canvas for Drawing
(define-struct circle (center radius color))
;; Defines a structure that allows us to use (make-circle. . . function to define circles.
(define (draw-circ a-circle x y);;Function that Draws a Solid Disk.
  (draw-solid-disk ;Pre-loaded function
   (make-posn      ;Pre-loaded structure
               (+ x (posn-x (circle-center a-circle))) ;Alters x-value.
               (+ y (posn-y (circle-center a-circle))));Alters y-value.
               (circle-radius a-circle) ;Keeps Radius the same.
               (circle-color a-circle)  ;Keeps Color the same.
  ));;The purpose of this function is to take a pre-defined circle defined using a (make-circle. . . function and then draws the same shape in a different location given by x and y.  X and Y represent the difference in those values from the original shape.
(define (clear-circ a-circle x y);;Function that Clears a Solid Disk.
  (clear-solid-disk ;Pre-loaded function
   (make-posn
               (+ x (posn-x (circle-center a-circle)))  ;Alters x-value.
               (+ y (posn-y (circle-center a-circle)))) ;Alters y-value.
               (circle-radius a-circle) ;Keeps Radius the same.
               (circle-color a-circle)  ;Keeps Color the same.
  ));;This function does exactly the same thing as the draw-circ function except that it clears the shape instead of drawing it.
(define 
  (draw-and-clear-circle circle x y delay)
  (and
      (draw-circ circle x y) ;Pre-defined function
      (sleep-for-a-while delay);;Pre-loaded delay function.
      (clear-circ circle x y) ;Pre-defined function
  ));; This function pieces the two previous functions together and adds a delay inbetween drawing and clearing the shapes.  Useful since we want the shapes to have the appearance of moving.
(define (translate circle x y delay times time);Times is the number of translations and time is a value that needs to start out at 1, it allows the function to keep track of how many translations it has done to keep the shape moving.
  (cond    ;Condition that causes it to loop untill it completes the correct number of moves.
      [(= times 1) 
       (draw-and-clear-circle circle (* time x) (* time y) delay)]
      [(>= times 2)
       (and 
        (draw-and-clear-circle circle (* time x) (* time y) delay)
        (translate circle x y delay (- times 1) (+ time 1))
        )
       ]
      [else 'InvalidTranslation]
   ));;This function is a little bit unneccesary but I wanted to piece it together.  It takes a pre-defined circle, x and y values, a delay, how many times it translates and a number time that has to be 1 at the start for the function to work correctly.  This function takes the pre-defined circle and translates it a certain x and y value based on imput, a certain number of times based on imput.  If used correctly it can, with limited other code, create circles flying across the screen.  In order to keep this Lab simple shorter I will not define this many functions for the other shapes.

(draw-solid-rect (make-posn 29 250) 9 85 'darkblue);Draws Bumper 1, Blue Rectangle.
(draw-solid-rect (make-posn 421 40) 9 85 'darkblue);Draws Bumber 2, Blue Rectangle.
(draw-solid-rect (make-posn 300 0) 85 8 'darkblue) ;Draws Bumper 3, Blue Rectangle.
(draw-solid-line (make-posn 65 380) (make-posn 90 415) 'darkgreen) ;Makes left Line of Cup.
(draw-solid-line (make-posn 90 415) (make-posn 115 395) 'darkgreen);Makes bottom Line of Cup.
(draw-solid-line (make-posn 115 395) (make-posn 93 360) 'darkgreen);Makes right Line of Cup.
(define circle1 (make-circle (make-posn 225 225) 9 'red));Defines Circle 1, Red, starts in the middle.
(translate circle1 5 -4 .023 37 1)                       ;Slides Circle 1 to new position against Bumper 2.
(define circle2 (make-circle (make-posn 410 77) 9 'red)) ;Defines Circle 2, Red, starts where Circle 1 left off.
(translate circle2 -4 -4 .02 15 1)                       ;Starts where Circle 1 ended, against Bumper 2 and slides to Bumper 3. 
(define circle3 (make-circle (make-posn 342 17) 9 'red)) ;Defines Circle 3, Red, starts where Circle 2 left off.
(translate circle3 -5 5 .015 59 1)                       ;Starts where Circle 2 ended, against Bumper 3 and slides to Bumper 1.
(define circle4 (make-circle (make-posn 47 312) 9 'red)) ;Defines Circle 4, Red, starts where Circle 3 left off.
(translate circle4 3 5 .01 16 1)                         ;Starts where Circle 3 ended, against Bumper 1 and slides into Cup.
(draw-solid-disk (make-posn 95 392) 9 'red)              ;Creates visible circle that is not cleared in the cup at the end of the motion.
(translate circle4 3 3 .01 -1 1)                         ;Test for 'InvalidTranslation.