Planning Rock Rain Live in Font

Painting DataMatrix in Font Planning Rock Rain Live

Rock Rain Live!

he game in 4 mainly showed a playability change, allowing a match between two players on the same PC or on the same Xbox 360 console. This is nice, but how about being able to play with your friend on the other side of the world And what about matches with one player running on a PC and another one on an Xbox 360 Wouldn t that be cool We ll use the concepts in the previous chapter and add a networked multiplayer feature to Rock Rain, called Multiplayer Online. We ll call this new version Rock Rain Live.

Rock Rain Enhanced already implements many of the features that you need for a new Multiplayer Online version of Rock Rain. What you ll do is add a new item in the game s starting screen menu that leads to another scene with the options of network games (create a game, join a game s session, and so on). With this new scene, the start scene will look like Figure 6-1. Still, you have to think a little beforehand about how your game will work in a network. You saw in the previous chapter that XNA offers all the support for data transport between the players through a network, be it a local network or through LIVE. It s simple to send and receive data in a synchronized and safe way, but the main question is: what should you send or receive between the two players to create a network match Remember that Rock Rain is a game in which you must dodge the meteors (and the other player) and try to get the energy source to remain as long as possible in the game. So, the two players must be synchronized so that they see the same meteors, the other player s score, the energy source, and so on. That is, they must share the same state of the game. Remember 2 There, we talked a little about game state; controlling this state is one of the most important tasks in any game. In Rock Rain Live s case, besides controlling this state, you also have to think about how to synchronize this state between the two players who will be playing a match through a local network or through the LIVE network from Microsoft.

CHAPTER 6 s ROCK RAIN LIVE!

In this game, you ll use a client/server architecture, described in the previous chapter, where one of the players is the game s server, offering the synchrony services of the game state itself. You ll call that player the local player. The other player is the game s client, consuming the data from the server to show the correct status of the game to the other player. You ll call that player the remote player. It seems obvious, then, that the remote player will always consume information from the local player to obtain the game state. The remote player will always ask the state of the game, obtaining from the local player the score of the game, the meteors positions, and so on. That is, the local player will always have control of the game state, and it s up to him or her to change this state (add a new meteor, for instance). However, the remote player controls a new game state: its own position on the screen. So, you ll also have to inform the local player of the remote player s position, so that the game state stays synchronized between the two players. This information exchange indeed involves a lot of code, but it s not complicated. Next, you ll create all the communication protocols to send the game state information between the players in a simple but powerful way, which can be changed or extended to other games.

CHAPTER 6 s ROCK RAIN LIVE!