Welcome to DAR tanks! This project is dedicated to server of tanks game that is hosted by DAR Tech and available to anyone interested. The server employs client-server model. Using current documentation a client can make calls and interact with the server. Enjoy the game!
Game concepts rooms – there are 30 game rooms available to players. One client can play only in one room. Room IDs are as follows: room-1, room-2, …, room-30 Maximum 12 tanks may join a room at any given time
game field – each room has one game field. Game field is 2D field with width and height. Tanks and bullets are located on the game field
timed rounds – in order to avoid endless games and to make the game rapid, games are run in rounds
a round starts when game field is empty and a new player joins the game via registration
each round lasts 120 seconds (2 minutes)
when round ends, if there are players left on the game field, losers are winners are decided
authentication – before starting the game, a client must register on the server and receive a token. Client should use that token when sending commands to server
tank – tank is a moving object in the game. One player can control only 1 tank. Player’s goal is to score points by firing bullets and hitting opponents
bullet – bullet is a moving object in the game that is fired by a tank. A player can send a request to DAR tanks to fire a bullet. In order to limit unfair play, each tank is limited to fire one bullet per second
hit – a hit happens when a bullet collides with a tank that is not the owner of the bullet. Tank cannot hit itself with a bullet, it can hit opponents. When hit, tank loses health and bullet that hit the tank disappears
loser – loser is tank whose health decreased and changed to zero. When losing the game, tank’s corresponding session is closed and player can no longer control the tank
winner – a tank can win in the following conditions:
when it is the last tank left on the game field and score is bigger than or equal to 3
when game timed round ends, and the tank has the highest score. If there are multiple tanks left with same maximum score, then the winners are tanks that have more health points
kicked – a tank is kicked from the game if does not send any commands for 30 seconds. This done in order to avoid unfair score farming and freeing player slots if the player is AFK (away from keyboard). When tank is kicked, tank’s token is deleted and player can no longer control the tank
RabbitMQ client-server architecture RabbitMQ in DAR tanks consists of one topic exchange called X:routing.topic. DAR tanks server has a server queue that binds to X:routing.topic via binding-keys of AMQP endpoints. In order to send a request to DAR tanks server, a client must produce a message to X:routing.topic with proper body and routing-key. It is strongly advised to review RPC tutorial to recall how client-server model is implemented in RabbitMQ. General design of client-server interaction in DAR tanks looks as follows:
Requests Each request should have body (if required) and the following properties: routing-key, reply_to and correlation ID.
routing-key is required for each request. routing-key is used to route the request message to server queue via X:routing.topic exchange
some requests require request body. request body must be in JSON format
client must add reply_to property to request (if it wants to receive response from DAR tanks server). DAR tanks server puts reply_to as routing_key of response
client may add optional correlation ID property in order to correlate responses on client side. DAR tanks does not alter correlation ID received from client and puts it into response
Server messages All messages that DAR tanks server produces to RabbitMQ have type property set according to table below
Server errors For every request, DAR tanks server may respond with an Error. Errors consist of two fields: status (Integer) and message (String). status employs HTTP status codes (400, 500, 404 ,etc.), while message has a short description of the error. Error may arise when request body is not valid, when a client tries to register a room that already has maximum number of players, etc. Commonly encountered errors and their formats are listed below
Server events In order to allow clients to visualize the state of the room, DAR tanks server emits state of room every 100 milliseconds. Room state is emitted as event and DAR tanks server does not expect any replies to emitted event. Event body is in JSON format. Clients should subscribe to game state events according to roomId.
Room state body:
Room state body is represented in JSON format. Body of the event and it’s content is described in the tables below
