Guidelines for Writing Multiuser Shockwave Movies

  1. Minimize message frequency

    2. Send only what you need to send. For example, if you are tracking the position of another players sprite, only send position information when the sprite's position changes.

    For some applications, it makes sense collect a set of very small messages and send them together. For example: Collect several points in a brush stroke for shared drawing and send them together. Send entire chat messages after the user presses return instead of sending every character.

  2. Prioritize receiving over sending

    3. Increase framerate

    Make sure that the Multiuser Xtra is getting enough time to process incoming messages. Since the Multiuser Xtra processes messages on idle, this means you need to make sure that there is at least one idle called for every message you expect to receive. The easiest way to do that is to increase the framerate of your movie (either through the control panel or use the tempo channel of the score if you want the framerate to be different for different parts of the score). By default, message processing happens between frames. You can also set the idleHandlerPeriod to 0 for maximum idles

    CheckNetMessages

    If you don't want to depend on built-in idle handling or you want messages to be processed at other times, you can call CheckNetMessage(numMessages). This command will process up to numMessages that may be waiting in the queue. Note: during the CheckNetMessage call your callback handlers will be called to process the incoming messages.

    One way you can make sure you receive messages before you send new ones is by calling GetNumberOutgoingMessages and then calling CheckNetMessages with the number of messages returned, before sending a message.

  3. Minimize Screen Updates

    In general, drawing to the screen is much more time consuming than sending, receiving, or processing messages. So, you don't necessarily want to update the screen for every message you receive. For example, if every player in a game sends their status, you may want to collect that information and then update the graphics on stage all at once.

  4. Only send messages to people who need it

    5. If only one user needs the information, don't broadcast it to the whole group.

  5. Use SetNetMessageHandler

    Use SetNetMessageHandler to dispatch and help process incoming messages depending on subject and/or sender. The native Xtra message dispatching is more efficient than similar code written in Lingo.