Task $1(0$ points$)$

Your first task is to run the starter code. If you are doing this on Windows, see the section above. You need to install an extra library before starting it$.$ To run the starter code, execute this in a terminal or command shell.

python$3$ play.py

Notice that it doesn$$t do very much.

The room is drawn with the top wall on the top edge of the screen.

The other $3$ walls are missing.

There is no snake and no apple.

The game enters an infinite loop waiting for user input.

Press Control$-$C to interrupt the game.

You may press Control$-$C at any time to interrupt the game while you are testing and developing the game.

Task $2(2$ points$)$

Your next task is to detect when the user presses a $\text{'}$q$\text{'}.$ When the user presses a $\text{'}$q$\text{'},$ the game should quit gracefully.

Hint:

Start by reading the main program in play.py$.$

The program is heavily commented.

The main loop has a section that reads a user keypress.

Add code to that section to break out of the main loop when the user presses $$q$.$

Remember to test your changes after each step!

Task $3(2$ points$)$

Your next task is to fully implement the Room. Modify the Room class so that the four walls of the room are drawn when Room.draw$()$ is called.

Hint:

You can see how the top wall of the room is drawn in the code for Room.draw$().$

Follow that example and draw the left, bottom and right walls of the room.

Task $4(2$ points$)$

Your next task is to implement a basic Snake. The Snake$$s head $($denoted by $>)$ should start out at the center of the screen, and it should initially be three characters long, like so:

$`++>`$

The Snake doesn$$t have to move in this step. It just has to show up on the screen when the Snake.draw$()$ method is called.

Hint:

The Snake object needs to know where the center of the screen is$.$ Modify the constructor for Snake so that the center of the screen is passed to it when the Snake object is constructed.

In the constructor:

The Snake is represented as a list of positions.

The head$$s position is at index $0.$ Create a position for the head, and add it to the list.

The tail$$s position is represented by the rest of the list. Create two other positions that represent the tail, and add it to the list

The Snake.draw$()$ method should loop over all positions.

Draw the head with a $>,$ and tail section with $+$ using the Gui object.

Task $5(3$ points$)$

The Snake$$s default direction to move is to the right, since it starts as $++>.$ Next, you should make the snake move right one step at a time. At each step, the snake moves one step to the right.

When you complete this step, the snake moves right one step at each iteration of the main loop, until it eventually runs off the edge of the screen on the right hand side. That$$s ok for now.

Hint:

Add a move$()$ method to the Snake class that takes no arguments.

Call snake.move$()$ in the main loop.

The Snake is represented as a list, with the head at index $0$ of the list.

Starting from the end of the tail, each element of the snake steps into the place of the element before it$.$ That is$,$ each element at index i should get the value at index i $-1.$

The head then moves right by adding $1$ to the x coordinate of the head.

Task $6(5$ points$)$

Make the Snake change directions when the user presses the up$,$ down, left, or right arrow keys.

When the Snake goes right, the head is $>.$

When it goes down, the head is V$.$

When it goes up$,$ the head is $^.$

When it goes left, the head is

Hint:

Add a member variable called direction to the Snake class. The variable tells the snake which direction the head should move.

Add a change$\_$direction method to the Snake class that takes a string direction as an argument. The argument can be either $$RIGHT$,$LEFT$,$UP$$ or $$DOWN$.$

When the user presses an arrow key, call change$\_$direction from the main loop. The change$\_$direction should set the direction member variable to the new direction of movement.

The head moves in the direction of motion. Edit the Snake.move$()$ method so that:

If the direction is $$RIGHT$,$ add $1$ to the x$-$coordinate of the head

If the direction is $$LEFT$,$ subtract $1$ from the x$-$coordinate of the head

If the direction is $$UP$,$ subtract $1$ from the y$-$coordinate of the head

If the direction is $$DOWN$,$ add $1$ to the y$-$coordinate of the head

Edit the Snake.draw$()$ method to draw the head correctly, depending on the value of direction.

Task $7(3$ points$)$

The Snake shouldn$$t be able to double back on itself. For example, when it$$s going right, the only valid direction change is up or down. Left is not valid. Add to the code in change$\_$direction$()$ to make sure that the snake can$$t double back on itself.

Task $8(3$ points$)$

Your next task is to implement Apple. The Apple should be red and green in color, drawn with the $*($asterisk$)$ character, and show up in a random position on the screen.