Semester Project (part 2)

Server->Client protocol

• Server sends periodic updates of all objects in simulation
• Server sends notification of ship destruction

Server->Client messages

• SIGNON_ACK
• PLAYER_ID
• KILLED
• STATUS

SIGNON_ACK

• Acknowledges SIGNON and returns player's unique identifier
• Only sent once (after player SIGNON)
• Format:

PLAYER_ID

• Gives name and ID for new player (opponent)
• Sent once for each player when they join
• (You might also see a similar message when a player dies, but with a playerid with the high bit set to 1.)
• Format:

KILLED

• Sent when ship destroyed
• Client must sent RESTART message to get new ship
• Format:

STATUS

• Sent periodically to distribute location and status of all objects in simulation
• One entry for each object
• Message header:

• Message for each object:

• If bit 31 of score is 1, object is a torpedo
• If bit 31 of score is 0, object is a ship
• If bit 30 of ship's score is 1, ship is firing thrusters

Processing Server->Client protocol

• Client processes incoming mesages in a loop
• Reads message type (one byte) first, then reads remainder of message (if necessary)
• Process contents of message
• switch statement useful:

     while (true) {
       read next message type
       switch (message type) {
       case SIGNON_ACK:
         read player id
         break
       case PLAYER_ID
         read player information
         break
       case KILLED:
         restart new ship
         break
       case STATUS:
         read n
         for (i = 0; i < n; i++) {
           read object status
         }
       }
     }