A TCP server implementing a simple protocol very loosely inspired by LOGO. When a client connects, it will be able to send simple commands to the server to draw on a canvas. It will also call ask the server to render the current canvas.

When a client connects, the server will allocate a canvas. The state of the canvas is defined by:

• The canvas itself: a 30x30 buffer.
• The cursor, which is initially located at (15,15).
• The current direction, which is initially set to top.

The server opens a local TCP socket on port 8124. The server accepts commands separated by newlines (\r\n). All server responses are also terminated by \r\n.

• steps <n>: move the cursor n steps in the current direction.
• left <n>, right <n>: change the direction (see “Directions” below).
• hover, draw, eraser: set the brush mode (see “Drawing” below).
• coord: print the current coordinates of the cursor with the format (x,y).
• render: print the current canvas.
• clear: erase the current canvas, while keeping the current cursor and direction.
• quit: closes the current connection.

• The server contains a 2d (30 x 30) array that represents the canvas.
• The cursor starts at index [15,15].
• There is a directions array that represents all the 8 directions the cursor can move in. The values in the directions array are 2d array of the format [y, x]. The value in [y] represents which direction y-axis or row direction to move the cursor. Whereas the value in [x] represents which direction in the x-axis or column direction to move the cursor. As a result the 8 values stored in the directions array are:
  • up = [-1, 0]
  • up_right = [-1, 1]
  • right = [0, 1]
  • down_right = [1, 1]
  • down = [1, 0]
  • down_left = [1, -1]
  • left = [0, -1]
  • up_left = [-1, -1]
• There is a current_direction variable that stores the current direction the cursor should move in. current_direction is mapped to an index in the directions array. So for example, if current_direction = 0 and the directions arrray is [[-1, 0], [-1, 1], [0, 1], [1, 1], [1, 0], [1, -1], [0, -1], [-1, -1]]then it means the current direction of cursor is [-1, 0] which is equal to top.
• The current_direction variable wraps around the directions array. So if for example current_direction = 0 and a user types in right 9, the current_direction will be 9 % 8 = [1] in the directions array.

• To run the server, open a terminal and cd into this project's directory. Then simply run: python3 socket_server.py -i.
  • Caveat: For unit tests, just run python3 socket_server.py --> Removes the verbose prompting sent to the user indicating that an action was completed.

• To close server just enter Ctrl + C or cmd + C in the terminal