Sem.I Final 2021

Part A

You are working in people coordinates to determine if a point is inside this 200x100 shape. People coordinates in this problem means $(0,0)$ in the lower left. The rounded corners are quarters of radius 50 circles. There is an animation to demonstrate, but you do not need to write the animation!

1. Create this shape in DrRacket.
2. The purpose of in-shape?: number(x) number(y) -> boolean is to return true if the point (x,y) is inside this shape. Write:
   1. Write a check-expect that returns true.
   2. Write a check-expect that returns false even though the point (x,y) is inside the rectangle with $0\le x \le 200$ and $0 \le y \le 100$.
3. Write the in-shape? function.

Part B

1. Simplify as much as possible.

(define (clean-teeth? minutes-brushing toothbrush? sugar-toothpaste?)
  (and (boolean=? true toothbrush?)
       (and (boolean=? sugar-toothpaste? false)
            (boolean=? (not (< minutes-brushing 2))
                        true))))

2. Identify the type of model and write the draw handler (only!). A radius 10 solid red circle rotates around just inside the perimeter of a solid yellow circle of radius 100. The red circle should be able to follow the mouse around the circle.

3. Make an animation that will show a given word until you click again.

• The background is 300x200.
• Clicking on a 50x50 square the lower right corner shows “woof”.
• Clicking on the same sized square in the lower left corner shows “rowr”.
• Clicking anywhere else shows nothing (blank).

The red dots below show where the clicks occurred.