Ok, after the finalizing the annoying chatting view, I finally went into a programming frenzy and forgot all about this blog. Yes, this is something good. Very good. From the very first post, I admitted, I don’t care about the reader :P.
Well, what’s with this programming frenzy? It’s a Packet’s Life.
Initially, before thinking about implementing the chat, all the packets I sent through Game Center to play the game online were structs. Here is an example:
#pragma mark -
#pragma mark Network Packets
struct ColorPacket {
BOOL isBlack;
};
typedef struct ColorPacket ColorPacket;
struct MovePacket {
NSInteger size;
Block blocks[16];
Block eaten[16];
};
typedef struct MovePacket MovePacket;
Why structs? They are lightweight, they can be used without memory management hassle, and best of all, it can be sent through the network as raw data. To send a struct packet, all you had to do is initialize it, then send it’s memory content (&packet) with it’s length (sizeof(packet)) .. Something like that. (Please request the specifics if you are interested). On the other hand, objects must implement the NSCoding protocol and then are encoded/decoded using the NSKeyedArchiver/Unarchiver.
BUT! How the heck am I suppose to stick a string inside the struct!! Adding an NSString* won’t do, since only the pointer will be sent. Well, I did some research, and it turned out ugly… Just like that, I jumped to Objects. Obviously, the coolest thing about classes is the inheritance. A superclass MMPacket and subclasses MMPacketChat, MMPacketMove, … etc.
This step REALLY helped me organize my code A LOT better. The class that was responsible for sending and receiving packets was a complete mess. Sometimes it would receive a packet and send it to a certain class. Sometimes it would process it itself. UGLY!
So, how about now? Well, Mr. MMPacket just refuses to be handled by other than his own dedicated handler. How cheap! :P This introduced the following classes:
id<GKHGameInitDelegate> delegateInit;
id<GKHGameMoveDelegate> delegateMove;
id<GKHGameChatDelegate> delegateChat;
id<GKHGameRematchDelegate> delegateRematch;
...
- (BOOL)sendPacket:(MMPacket *)aPacket
{
if (!isGameCenterAvailable)
return FALSE;
NSError* error = nil;
NSData* data = [NSKeyedArchiver archivedDataWithRootObject:aPacket];
BOOL didSendSuccessfully = [currentMatch sendDataToAllPlayers:data
withDataMode:GKMatchSendDataReliable
error:&error];
return didSendSuccessfully;
}
- (void)match:(GKMatch *)match didReceiveData:(NSData *)data fromPlayer:(NSString *)playerID
{
MMPacket* receivedPacket = [NSKeyedUnarchiver unarchiveObjectWithData:data];
if ([receivedPacket isKindOfClass:[MMPacketInit class]])
{
MMPacketInit* packetInit = (MMPacketInit*)receivedPacket;
[delegateInit receivedInitPacket:packetInit fromPeer:playerID];
}
else if ([receivedPacket isKindOfClass:[MMPacketMove class]])
{
MMPacketMove* packetMove = (MMPacketMove*)receivedPacket;
[delegateMove receivedMovePacket:packetMove fromPeer:playerID];
}
else if ([receivedPacket isKindOfClass:[MMPacketChat class]])
{
MMPacketChat* packetChat = (MMPacketChat*)receivedPacket;
[delegateChat receivedChatPacket:packetChat fromPeer:playerID];
}
else if ([receivedPacket isKindOfClass:[MMPacketRematch class]])
{
MMPacketRematch* packetRematch = (MMPacketRematch*)receivedPacket;
[delegateRematch receivedRematchPacket:packetRematch fromPeer:playerID];
}
else
{
//ignore packet =/
}
Am really lazy right now to explain that code, but it should show you how awesome this design is!! :D
That’s all folks ! More coming, hopefully!!