Add emerge.cpp, initial EmergeThread changes

- Neatly placed all emerge related code into a new file, emerge.cpp
- Greatly cleaned up the code in EmergeThread::Thread()
- Reworked Emerge queue.  Now an actual std::queue of v3s16 block positions
- Removed the completely unnecessary map of peer ids requesting blocks

src/emerge.h

@@ -0,0 +1,122 @@
+#ifndef EMERGE_HEADER
+#define EMERGE_HEADER
+
+#include <map>
+#include <queue>
+#include "util/thread.h"
+
+#define BLOCK_EMERGE_ALLOWGEN (1<<0)
+
+class Mapgen;
+class MapgenParams;
+class MapgenFactory;
+class Biome;
+class BiomeDefManager;
+class EmergeThread;
+class ManualMapVoxelManipulator;
+//class ServerMap;
+//class MapBlock;
+
+#include "server.h"
+
+struct BlockMakeData {
+	bool no_op;
+	ManualMapVoxelManipulator *vmanip;
+	u64 seed;
+	v3s16 blockpos_min;
+	v3s16 blockpos_max;
+	v3s16 blockpos_requested;
+	UniqueQueue<v3s16> transforming_liquid;
+	INodeDefManager *nodedef;
+
+//	BlockMakeData();
+//	~BlockMakeData();
+	
+BlockMakeData():
+	no_op(false),
+	vmanip(NULL),
+	seed(0),
+	nodedef(NULL)
+{}
+
+~BlockMakeData()
+{
+	delete vmanip;
+}
+};
+
+class EmergeManager {
+public:
+	std::map<std::string, MapgenFactory *> mglist;
+
+	//settings
+	MapgenParams *params;
+
+	JMutex queuemutex;
+	std::map<v3s16, u8> blocks_enqueued; //change to a hashtable later
+	Mapgen *mapgen;
+	EmergeThread *emergethread;
+
+	//biome manager
+	BiomeDefManager *biomedef;
+
+	EmergeManager(IGameDef *gamedef, BiomeDefManager *bdef);
+	~EmergeManager();
+
+	void initMapgens(MapgenParams *mgparams);
+	Mapgen *createMapgen(std::string mgname, int mgid,
+						MapgenParams *mgparams, EmergeManager *emerge);
+	MapgenParams *createMapgenParams(std::string mgname);
+	Mapgen *getMapgen();
+	bool enqueueBlockEmerge(u16 peer_id, v3s16 p, bool allow_generate);
+	bool popBlockEmerge(v3s16 *pos, u8 *flags);
+	
+	bool registerMapgen(std::string name, MapgenFactory *mgfactory);
+	MapgenParams *getParamsFromSettings(Settings *settings);
+	void setParamsToSettings(Settings *settings);
+	
+	//mapgen helper methods
+	Biome *getBiomeAtPoint(v3s16 p);
+	int getGroundLevelAtPoint(v2s16 p);
+	bool isBlockUnderground(v3s16 blockpos);
+	u32 getBlockSeed(v3s16 p);
+};
+
+class EmergeThread : public SimpleThread
+{
+	Server *m_server;
+	ServerMap *map;
+	EmergeManager *emerge;
+	Mapgen *mapgen;
+	bool enable_mapgen_debug_info;
+	
+public:
+	Event qevent;
+	std::queue<v3s16> blockqueue;
+	
+	EmergeThread(Server *server):
+		SimpleThread(),
+		m_server(server),
+		map(NULL),
+		emerge(NULL),
+		mapgen(NULL)
+	{
+		enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
+	}
+
+	void *Thread();
+
+	void trigger()
+	{
+		setRun(true);
+		if(IsRunning() == false)
+		{
+			Start();
+		}
+	}
+
+	bool getBlockOrStartGen(v3s16 p, MapBlock **b, 
+							BlockMakeData *data, bool allow_generate);
+};
+
+#endif