Web Adapter

The web adapater provides a TCP interface to the engine using websockets.

A single game can be created per connection. Attempts to create more than one game per connection will simply return the currently existing game.

The server will push state messages to the client when it computes a state change. This will be correlated to the tick rate of the game.

API

Endpoint: /ws Method: GET Response Upgrade to websocket connection

Messages

Valid types are: new, destroy, input, state.

Server Receive

• new: Create a singleton game for connection and respond with an acknowledgement of a game being created.

snd > { "type": "new", "width": [int], "height": [int], "tick": [int] }
rec > {
  "type": "ack",
  "data": "ok" | "error",
  "err"?: [error string]
}

• destroy: End the currently running game early and remove it from the engine.

snd > { "type": "destroy" }
rec > {
  "type": "ack",
  "data": "ok" | "error",
  "err"?: [error string]
}

• input: Send an input command to the game running on the current engine.

type direction = "left" | "right" | "up" | "down"

snd > { "type": "input", "direction": [direction] }

Client Receive

• ack: Receive confirmation of the message being successful. Otherwise receive an error message.

snd > { "type": "new" }
rec > {
  "type": "ack",
  "data": "ok" | "error",
  "err"?: [error string]
}

snd > { "type": "destroy" }
rec > {
  "type": "ack",
  "data": "ok" | "error",
  "err"?: [error string]
}

• state: Receive the game state from the server.

type Part = {
  x: int
  y: int
}

type Snake = {
  parts: []Part
}

type Fruit {
  value: int
  x:     int
  y:     int
}

type GameState = {
  width:  int
  height: int
  snake:  Snake
  fruit:  []Fruit
  score:  int
}

rcv > { "type": "state", "data": [GameState] }

License

Licensed under MIT or GPLv3.0, whichever you prefer.