From 187bdab4fa90fbfa5b1979ea529dc9c0deac89d9 Mon Sep 17 00:00:00 2001
From: Tiger Wang <ziwei.tiger@hotmail.co.uk>
Date: Tue, 25 Nov 2014 23:03:33 +0000
Subject: Merge remote-tracking branch 'origin-master' into c++11

---
 src/Generating/HeiGen.h | 98 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 66 insertions(+), 32 deletions(-)

(limited to 'src/Generating/HeiGen.h')

diff --git a/src/Generating/HeiGen.h b/src/Generating/HeiGen.h
index b3c9483fb..62bb227c6 100644
--- a/src/Generating/HeiGen.h
+++ b/src/Generating/HeiGen.h
@@ -2,10 +2,12 @@
 // HeiGen.h
 
 /*
-Interfaces to the various height generators:
+Interfaces to the various height-based terrain shape generators:
 	- cHeiGenFlat
 	- cHeiGenClassic
 	- cHeiGenBiomal
+
+Also implements the heightmap cache
 */
 
 
@@ -21,26 +23,7 @@ Interfaces to the various height generators:
 
 
 
-class cHeiGenFlat :
-	public cTerrainHeightGen
-{
-public:
-	cHeiGenFlat(void) : m_Height(5) {}
-	
-protected:
-
-	int m_Height;
-
-	// cTerrainHeightGen overrides:
-	virtual void GenHeightMap(int a_ChunkX, int a_ChunkZ, cChunkDef::HeightMap & a_HeightMap) override;
-	virtual void InitializeHeightGen(cIniFile & a_IniFile) override;
-} ;
-
-
-
-
-
-/// A simple cache that stores N most recently generated chunks' heightmaps; N being settable upon creation
+/** A simple cache that stores N most recently generated chunks' heightmaps; N being settable upon creation */
 class cHeiGenCache :
 	public cTerrainHeightGen
 {
@@ -50,15 +33,11 @@ public:
 	
 	// cTerrainHeightGen overrides:
 	virtual void GenHeightMap(int a_ChunkX, int a_ChunkZ, cChunkDef::HeightMap & a_HeightMap) override;
-	virtual void InitializeHeightGen(cIniFile & a_IniFile) override;
 	
-	/// Retrieves height at the specified point in the cache, returns true if found, false if not found
+	/** Retrieves height at the specified point in the cache, returns true if found, false if not found */
 	bool GetHeightAt(int a_ChunkX, int a_ChunkZ, int a_RelX, int a_RelZ, HEIGHTTYPE & a_Height);
 	
 protected:
-
-	cTerrainHeightGenPtr m_HeiGenToCache;
-	
 	struct sCacheData
 	{
 		int m_ChunkX;
@@ -66,6 +45,9 @@ protected:
 		cChunkDef::HeightMap m_HeightMap;
 	} ;
 	
+	/** The terrain height generator that is being cached. */
+	cTerrainHeightGenPtr m_HeiGenToCache;
+	
 	// To avoid moving large amounts of data for the MRU behavior, we MRU-ize indices to an array of the actual data
 	int          m_CacheSize;
 	int *        m_CacheOrder;  // MRU-ized order, indices into m_CacheData array
@@ -81,6 +63,57 @@ protected:
 
 
 
+/** Caches heightmaps in multiple underlying caches to improve the distribution and lower the chain length. */
+class cHeiGenMultiCache:
+	public cTerrainHeightGen
+{
+public:
+	cHeiGenMultiCache(cTerrainHeightGenPtr a_HeightGenToCache, size_t a_SubCacheSize, size_t a_NumSubCaches);
+
+	// cTerrainHeightGen overrides:
+	virtual void GenHeightMap(int a_ChunkX, int a_ChunkZ, cChunkDef::HeightMap & a_HeightMap) override;
+	
+	/** Retrieves height at the specified point in the cache, returns true if found, false if not found */
+	bool GetHeightAt(int a_ChunkX, int a_ChunkZ, int a_RelX, int a_RelZ, HEIGHTTYPE & a_Height);
+
+protected:
+	typedef SharedPtr<cHeiGenCache> cHeiGenCachePtr;
+	typedef std::vector<cHeiGenCachePtr> cHeiGenCachePtrs;
+
+
+	/** The coefficient used to turn Z coords into index (x + Coeff * z). */
+	static const size_t m_CoeffZ = 5;
+
+	/** Number of sub-caches, pulled out of m_SubCaches.size() for performance reasons. */
+	size_t m_NumSubCaches;
+
+	/** The individual sub-caches. */
+	cHeiGenCachePtrs m_SubCaches;
+};
+
+
+
+
+
+class cHeiGenFlat :
+	public cTerrainHeightGen
+{
+public:
+	cHeiGenFlat(void) : m_Height(5) {}
+	
+protected:
+
+	int m_Height;
+
+	// cTerrainHeightGen overrides:
+	virtual void GenHeightMap(int a_ChunkX, int a_ChunkZ, cChunkDef::HeightMap & a_HeightMap) override;
+	virtual void InitializeHeightGen(cIniFile & a_IniFile) override;
+} ;
+
+
+
+
+
 class cHeiGenClassic :
 	public cTerrainHeightGen
 {
@@ -137,7 +170,11 @@ public:
 		m_BiomeGen(a_BiomeGen)
 	{
 	}
-	
+
+	// cTerrainHeightGen overrides:
+	virtual void GenHeightMap(int a_ChunkX, int a_ChunkZ, cChunkDef::HeightMap & a_HeightMap) override;
+	virtual void InitializeHeightGen(cIniFile & a_IniFile) override;
+
 protected:
 
 	typedef cChunkDef::BiomeMap BiomeNeighbors[3][3];
@@ -154,11 +191,8 @@ protected:
 		float m_BaseHeight;
 	} ;
 	static const sGenParam m_GenParam[256];
-	
-	// cTerrainHeightGen overrides:
-	virtual void GenHeightMap(int a_ChunkX, int a_ChunkZ, cChunkDef::HeightMap & a_HeightMap) override;
-	virtual void InitializeHeightGen(cIniFile & a_IniFile) override;
-	
+
+
 	NOISE_DATATYPE GetHeightAt(int a_RelX, int a_RelZ, int a_ChunkX, int a_ChunkZ, const BiomeNeighbors & a_BiomeNeighbors);
 } ;
 
-- 
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