path: root/src/Generating/IntGen.h

// IntGen.h

// Declares the cIntGen class and descendants for generating and filtering various 2D arrays of ints

/*
The integers generated may be interpreted in several ways:
- land/see designators
	- 0 = ocean
	- >0 = land
- biome group designators
	- 0 = ocean
	- 1 = desert biomes
	- 2 = temperate biomes
	- 3 = mountains (hills and forests)
	- 4 = jungle
	- 5 = ice biomes
- biome IDs
The interpretation depends on the generator used and on the position in the chain.

The generators can be chained together - one produces data that another one consumes.
Some of such chain connections require changing the data dimensions between the two, which is handled automatically
by using templates.
*/





#pragma once

#include "../BiomeDef.h"





/** Constants representing the biome group designators. */
const int bgOcean     = 0;
const int bgDesert    = 1;
const int bgTemperate = 2;
const int bgMountains = 3;
const int bgJungle    = 4;
const int bgIce       = 5;
const int bgMax       = 5;  // Maximum biome group value





/** Interface that all the generator classes provide. */
template <int SizeX, int SizeZ = SizeX>
class cIntGen
{
public:
	/** Holds the array of values generated by this class (descendant). */
	typedef int Values[SizeX * SizeZ];

	/** Generates the array of templated size into a_Values, based on given min coords. */
	virtual void GetInts(int a_MinX, int a_MinZ, Values & a_Values) = 0;
};

template <int SizeX, int SizeZ = SizeX>
using cIntGenPtr = std::shared_ptr<cIntGen<SizeX, SizeZ>>;






/** Provides additional cNoise member and its helper functions. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenWithNoise :
	public cIntGen<SizeX, SizeZ>
{
	typedef cIntGen<SizeX, SizeZ> super;

public:
	cIntGenWithNoise(int a_Seed) :
		m_Noise(a_Seed)
	{
	}

protected:
	cNoise m_Noise;

	/** Chooses one of a_Val1 or a_Val2, based on m_Noise and the coordinates for querying the noise. */
	int ChooseRandomOne(int a_RndX, int a_RndZ, int a_Val1, int a_Val2)
	{
		int rnd = m_Noise.IntNoise2DInt(a_RndX, a_RndZ) / 7;
		return ((rnd & 1) == 0) ? a_Val1 : a_Val2;
	}

	/** Chooses one of a_ValN, based on m_Noise and the coordinates for querying the noise. */
	int ChooseRandomOne(int a_RndX, int a_RndZ, int a_Val1, int a_Val2, int a_Val3, int a_Val4)
	{
		int rnd = m_Noise.IntNoise2DInt(a_RndX, a_RndZ) / 7;
		switch (rnd % 4)
		{
			case 0:  return a_Val1;
			case 1:  return a_Val2;
			case 2:  return a_Val3;
			default: return a_Val4;
		}
	}
};






/** Generates a 2D array of random integers in the specified range [0 .. Range). */
template <int Range, int SizeX, int SizeZ = SizeX>
class cIntGenChoice :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;

public:
	cIntGenChoice(int a_Seed) :
		super(a_Seed)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		for (int z = 0; z < SizeZ; z++)
		{
			int BaseZ = a_MinZ + z;
			for (int x = 0; x < SizeX; x++)
			{
				a_Values[x + SizeX * z] = (super::m_Noise.IntNoise2DInt(a_MinX + x, BaseZ) / 7) % Range;
			}
		}  // for z
	}
};






/** Decides between the ocean and landmass biomes.
Has a threshold (in percent) of how much land, the larger the threshold, the more land.
Generates 0 for ocean, biome group ID for landmass. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenLandOcean :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;

public:
	cIntGenLandOcean(int a_Seed, int a_Threshold) :
		super(a_Seed),
		m_Threshold(a_Threshold)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		for (int z = 0; z < SizeZ; z++)
		{
			int BaseZ = a_MinZ + z;
			for (int x = 0; x < SizeX; x++)
			{
				int rnd = (m_Noise.IntNoise2DInt(a_MinX + x, BaseZ) / 7);
				a_Values[x + SizeX * z] = ((rnd % 100) < m_Threshold) ? ((rnd / 128) % bgMax + 1) : 0;
			}
		}

		// If the centerpoint of the world is within the area, set it to bgTemperate, always:
		if ((a_MinX <= 0) && (a_MinZ <= 0) && (a_MinX + SizeX > 0) && (a_MinZ + SizeZ > 0))
		{
			a_Values[-a_MinX - a_MinZ * SizeX] = bgTemperate;
		}
	}

protected:
	int m_Threshold;
};





template <int SizeX, int SizeZ = SizeX>
class cIntGenZoom :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;

protected:
	static const int m_LowerSizeX = (SizeX / 2) + 2;
	static const int m_LowerSizeZ = (SizeZ / 2) + 2;

public:
	typedef cIntGenPtr<m_LowerSizeX, m_LowerSizeZ> Underlying;


	cIntGenZoom(int a_Seed, Underlying a_UnderlyingGen) :
		super(a_Seed),
		m_UnderlyingGen(a_UnderlyingGen)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Generate the underlying data with half the resolution:
		int lowerMinX = a_MinX >> 1;
		int lowerMinZ = a_MinZ >> 1;
		int Underlying[m_LowerSizeX * m_LowerSizeZ];
		m_UnderlyingGen->GetInts(lowerMinX, lowerMinZ, Underlying);
		const int lowStepX = (m_LowerSizeX - 1) * 2;
		const int lowStepZ = (m_LowerSizeZ - 1) * 2;
		int Cache[lowStepX * lowStepZ];

		// Discreet-interpolate the values into twice the size:
		for (int z = 0; z < m_LowerSizeZ - 1; ++z)
		{
			int idx = (z * 2) * lowStepX;
			int PrevZ0 = Underlying[z * m_LowerSizeX];
			int PrevZ1 = Underlying[(z + 1) * m_LowerSizeX];

			for (int x = 0; x < m_LowerSizeX - 1; ++x)
			{
				int ValX1Z0 = Underlying[x + 1 + z * m_LowerSizeX];
				int ValX1Z1 = Underlying[x + 1 + (z + 1) * m_LowerSizeX];
				int RndX = (x + lowerMinX) * 2;
				int RndZ = (z + lowerMinZ) * 2;
				Cache[idx] = PrevZ0;
				Cache[idx + lowStepX] = ChooseRandomOne(RndX, RndZ, PrevZ0, PrevZ1);
				idx++;
				Cache[idx] = ChooseRandomOne(RndX, RndZ, PrevZ0, ValX1Z0);
				Cache[idx + lowStepX] = ChooseRandomOne(RndX, RndZ, PrevZ0, ValX1Z0, PrevZ1, ValX1Z1);
				idx++;
				PrevZ0 = ValX1Z0;
				PrevZ1 = ValX1Z1;
			}
		}

		// Copy from Cache into a_Values; take into account the even/odd offsets in a_Min:
		for (int z = 0; z < SizeZ; ++z)
		{
			memcpy(a_Values + z * SizeX, Cache + (z + (a_MinZ & 1)) * lowStepX + (a_MinX & 1), SizeX * sizeof(int));
		}
	}

protected:
	Underlying m_UnderlyingGen;
};





template <int SizeX, int SizeZ = SizeX>
class cIntGenSmooth :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;
	static const int m_UnderlyingSizeX = SizeX + 2;
	static const int m_UnderlyingSizeZ = SizeZ + 2;

public:
	typedef cIntGenPtr<m_UnderlyingSizeX, m_UnderlyingSizeZ> Underlying;


	cIntGenSmooth(int a_Seed, Underlying a_Underlying) :
		super(a_Seed),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Generate the underlying values:
		int Cache[(SizeX + 2) * (SizeZ + 2)];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, Cache);

		// Smooth - for each square check if the surroundings are the same, if so, expand them diagonally.
		// Also get rid of single-pixel irregularities (A-B-A):
		for (int z = 0; z < SizeZ; z++)
		{
			int NoiseZ = a_MinZ + z;
			for (int x = 0; x < SizeX; x++)
			{
				int val   = Cache[x + 1 + (z + 1) * m_UnderlyingSizeX];
				int Above = Cache[x + 1 +  z      * m_UnderlyingSizeX];
				int Below = Cache[x + 1 + (z + 2) * m_UnderlyingSizeX];
				int Left  = Cache[x     + (z + 1) * m_UnderlyingSizeX];
				int Right = Cache[x + 2 + (z + 1) * m_UnderlyingSizeX];

				if ((Left == Right) && (Above == Below))
				{
					if (((m_Noise.IntNoise2DInt(a_MinX + x, NoiseZ) / 7) % 2) == 0)
					{
						val = Left;
					}
					else
					{
						val = Above;
					}
				}
				else
				{
					if (Left == Right)
					{
						val = Left;
					}

					if (Above == Below)
					{
						val = Above;
					}
				}

				a_Values[x + z * SizeX] = val;
			}
		}
	}

protected:
	Underlying m_Underlying;
};





template<int SizeX, int SizeZ = SizeX>
class cIntGenBeaches :
	public cIntGen<SizeX, SizeZ>
{
	typedef cIntGen<SizeX, SizeZ> super;
	static const int m_UnderlyingSizeX = SizeX + 2;
	static const int m_UnderlyingSizeZ = SizeZ + 2;

public:
	typedef cIntGenPtr<m_UnderlyingSizeX, m_UnderlyingSizeZ> Underlying;


	cIntGenBeaches(Underlying a_Underlying) :
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Map for biome -> its beach:
		static const int ToBeach[] =
		{
			/* biOcean            */ biOcean,
			/* biPlains           */ biBeach,
			/* biDesert           */ biBeach,
			/* biExtremeHills     */ biStoneBeach,
			/* biForest           */ biBeach,
			/* biTaiga            */ biColdBeach,
			/* biSwampland        */ biSwampland,
			/* biRiver            */ biRiver,
			/* biNether           */ biNether,
			/* biEnd              */ biEnd,
			/* biFrozenOcean      */ biColdBeach,
			/* biFrozenRiver      */ biColdBeach,
			/* biIcePlains        */ biColdBeach,
			/* biIceMountains     */ biColdBeach,
			/* biMushroomIsland   */ biMushroomShore,
			/* biMushroomShore    */ biMushroomShore,
			/* biBeach            */ biBeach,
			/* biDesertHills      */ biBeach,
			/* biForestHills      */ biBeach,
			/* biTaigaHills       */ biColdBeach,
			/* biExtremeHillsEdge */ biStoneBeach,
			/* biJungle           */ biBeach,
			/* biJungleHills      */ biBeach,
			/* biJungleEdge       */ biBeach,
			/* biDeepOcean        */ biOcean,
			/* biStoneBeach       */ biStoneBeach,
			/* biColdBeach        */ biColdBeach,
			/* biBirchForest      */ biBeach,
			/* biBirchForestHills */ biBeach,
			/* biRoofedForest     */ biBeach,
			/* biColdTaiga        */ biColdBeach,
			/* biColdTaigaHills   */ biColdBeach,
			/* biMegaTaiga        */ biStoneBeach,
			/* biMegaTaigaHills   */ biStoneBeach,
			/* biExtremeHillsPlus */ biStoneBeach,
			/* biSavanna          */ biBeach,
			/* biSavannaPlateau   */ biBeach,
			/* biMesa             */ biMesa,
			/* biMesaPlateauF     */ biMesa,
			/* biMesaPlateau      */ biMesa,
		};

		// Generate the underlying values:
		int Cache[m_UnderlyingSizeX * m_UnderlyingSizeZ];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, Cache);

		// Add beaches between ocean and biomes:
		for (int z = 0; z < SizeZ; z++)
		{
			for (int x = 0; x < SizeX; x++)
			{
				int val = Cache[x + 1 + (z + 1) * m_UnderlyingSizeX];
				int Above = Cache[x + 1 + z * m_UnderlyingSizeX];
				int Below = Cache[x + 1 + (z + 2) * m_UnderlyingSizeX];
				int Left  = Cache[x     + (z + 1) * m_UnderlyingSizeX];
				int Right = Cache[x + 2 + (z + 1) * m_UnderlyingSizeX];
				if (!IsBiomeOcean(val))
				{
					if (IsBiomeOcean(Above) || IsBiomeOcean(Below) || IsBiomeOcean(Left) || IsBiomeOcean(Right))
					{
						val = ToBeach[(val % 128) % ARRAYCOUNT(ToBeach)];
					}
				}
				a_Values[x + z * SizeX] = val;
			}
		}
	}

protected:
	Underlying m_Underlying;
};





/** Generates the underlying numbers and then randomly changes some zeroes into nonzeroes. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenAddIslands :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;

public:
	typedef cIntGenPtr<SizeX, SizeZ> Underlying;


	cIntGenAddIslands(int a_Seed, int a_Threshold, Underlying a_Underlying) :
		super(a_Seed),
		m_Threshold(a_Threshold),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		m_Underlying->GetInts(a_MinX, a_MinZ, a_Values);
		for (int z = 0; z < SizeZ; z++)
		{
			for (int x = 0; x < SizeX; x++)
			{
				if (a_Values[x + z * SizeX] == bgOcean)
				{
					int rnd = m_Noise.IntNoise2DInt(a_MinX + x, a_MinZ + z) / 7;
					if (rnd % 100 < m_Threshold)
					{
						a_Values[x + z * SizeX] = (rnd / 100) % bgMax;
					}
				}
			}
		}
	}

protected:
	int m_Threshold;

	Underlying m_Underlying;
};





/** A filter that adds an edge biome group between two biome groups that need an edge between them. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenBiomeGroupEdges :
	public cIntGen<SizeX, SizeZ>
{
	typedef cIntGen<SizeX, SizeZ> super;

	static const int m_UnderlyingSizeX = SizeX + 2;
	static const int m_UnderlyingSizeZ = SizeZ + 2;

public:

	typedef cIntGenPtr<m_UnderlyingSizeX, m_UnderlyingSizeZ> Underlying;

	cIntGenBiomeGroupEdges(Underlying a_Underlying) :
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values)
	{
		// Generate the underlying biome groups:
		int Cache[m_UnderlyingSizeX * m_UnderlyingSizeZ];
		m_Underlying->GetInts(a_MinX, a_MinZ, Cache);

		// Change the biomes on incompatible edges into an edge biome:
		for (int z = 0; z < SizeZ; z++)
		{
			for (int x = 0; x < SizeX; x++)
			{
				int v = Cache[x + 1 + (z + 1) * m_UnderlyingSizeX];
				int Above = Cache[x + 1 + z * m_UnderlyingSizeX];
				int Below = Cache[x + 1 + (z + 2) * m_UnderlyingSizeX];
				int Left  = Cache[x     + (z + 1) * m_UnderlyingSizeX];
				int Right = Cache[x + 2 + (z + 1) * m_UnderlyingSizeX];
				switch (v)
				{
					// Desert should neighbor only oceans, desert and temperates; change to temperate when another:
					case bgDesert:
					{
						if (
							!IsDesertCompatible(Above) ||
							!IsDesertCompatible(Below) ||
							!IsDesertCompatible(Left) ||
							!IsDesertCompatible(Right)
						)
						{
							v = bgTemperate;
						}
						break;
					}

					// Ice should not neighbor deserts; change to temperate:
					case bgIce:
					{
						if (
							(Above == bgDesert) ||
							(Below == bgDesert) ||
							(Left == bgDesert) ||
							(Right == bgDesert)
						)
						{
							v = bgTemperate;
						}
						break;
					}

					// Jungle should not neighbor Desert or Ice; change to temperate:
					case bgJungle:
					{
						if (
							!IsJungleCompatible(Above) ||
							!IsJungleCompatible(Below) ||
							!IsJungleCompatible(Left) ||
							!IsJungleCompatible(Right)
						)
						{
							v = bgTemperate;
						}
					}
				}
				a_Values[x + z * SizeX] = v;
			}  // for x
		}  // for z
	}

protected:
	Underlying m_Underlying;


	inline bool IsDesertCompatible(int a_BiomeGroup)
	{
		return ((a_BiomeGroup == bgOcean) || (a_BiomeGroup == bgDesert) || (a_BiomeGroup == bgTemperate));
	}

	inline bool IsJungleCompatible(int a_BiomeGroup)
	{
		return ((a_BiomeGroup != bgDesert) && (a_BiomeGroup != bgIce));
	}
};





template <int SizeX, int SizeZ = SizeX>
class cIntGenBiomes :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;

public:
	typedef cIntGenPtr<SizeX, SizeZ> Underlying;


	cIntGenBiomes(int a_Seed, Underlying a_Underlying) :
		super(a_Seed),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Define the per-biome-group biomes:
		static const int OceanBiomes[] =
		{
			biOcean, // biDeepOcean,
		};

		static const int DesertBiomes[] =
		{
			biDesert, biDesert, biSavanna, biPlains,
		};

		static const int TemperateBiomes[] =
		{
			biForest, biRoofedForest, biExtremeHills, biPlains, biBirchForest, biSwampland,
		};

		static const int MountainBiomes[] =
		{
			biExtremeHills, biForest, biTaiga, biPlains,
		};

		static const int JungleBiomes[] =
		{
			biJungle, biJungle, biForest,
		};

		static const int IceBiomes[] =
		{
			biIcePlains, biIcePlains, biColdTaiga,
		};

		static const cBiomesInGroups BiomesInGroups[] =
		{
			{ static_cast<int>(ARRAYCOUNT(OceanBiomes)),     OceanBiomes},
			{ static_cast<int>(ARRAYCOUNT(DesertBiomes)),    DesertBiomes},
			{ static_cast<int>(ARRAYCOUNT(TemperateBiomes)), TemperateBiomes},
			{ static_cast<int>(ARRAYCOUNT(MountainBiomes)),  MountainBiomes},
			{ static_cast<int>(ARRAYCOUNT(JungleBiomes)),    JungleBiomes},
			{ static_cast<int>(ARRAYCOUNT(IceBiomes)),       IceBiomes},
		};

		// Generate the underlying values, representing biome groups:
		m_Underlying->GetInts(a_MinX, a_MinZ, a_Values);

		// Overwrite each biome group with a random biome from that group:
		for (int z = 0; z < SizeZ; z++)
		{
			int IdxZ = z * SizeX;
			for (int x = 0; x < SizeX; x++)
			{
				int val = a_Values[x + IdxZ];
				const cBiomesInGroups & Biomes = BiomesInGroups[val % ARRAYCOUNT(BiomesInGroups)];
				int rnd = (m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7);
				a_Values[x + IdxZ] = Biomes.Biomes[rnd % Biomes.Count];
			}
		}
	}

protected:

	struct cBiomesInGroups
	{
		const int Count;
		const int * Biomes;
	};


	/** The underlying int generator */
	Underlying m_Underlying;
};





template <int SizeX, int SizeZ = SizeX>
class cIntGenReplaceRandomly :
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;

public:
	typedef cIntGenPtr<SizeX, SizeZ> Underlying;


	cIntGenReplaceRandomly(int a_From, int a_To, int a_Chance, int a_Seed, Underlying a_Underlying) :
		super(a_Seed),
		m_From(a_From),
		m_To(a_To),
		m_Chance(a_Chance),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Generate the underlying values:
		m_Underlying->GetInts(a_MinX, a_MinZ, a_Values);

		// Replace some of the values:
		for (int z = 0; z < SizeZ; z++)
		{
			int idxZ = z * SizeX;
			for (int x = 0; x < SizeX; x++)
			{
				int idx = x + idxZ;
				if (a_Values[idx] == m_From)
				{
					int rnd = m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7;
					if (rnd % 100 < m_Chance)
					{
						a_Values[idx] = m_To;
					}
				}
			}
		}  // for z
	}


protected:
	int m_From;
	int m_To;
	int m_Chance;
	Underlying m_Underlying;
};





/** Mixer that joins together finalized biomes and rivers.
It first checks for oceans; if there's no ocean, it checks for a river. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenMixRivers:
	public cIntGen<SizeX, SizeZ>
{
	typedef cIntGen<SizeX, SizeZ> super;

public:
	typedef cIntGenPtr<SizeX, SizeZ> Underlying;


	cIntGenMixRivers(Underlying a_Biomes, Underlying a_Rivers):
		m_Biomes(a_Biomes),
		m_Rivers(a_Rivers)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Generate the underlying data:
		m_Biomes->GetInts(a_MinX, a_MinZ, a_Values);
		typename super::Values Rivers;
		m_Rivers->GetInts(a_MinX, a_MinZ, Rivers);

		// Mix the values:
		for (int z = 0; z < SizeZ; z++)
		{
			int idxZ = z * SizeX;
			for (int x = 0; x < SizeX; x++)
			{
				int idx = x + idxZ;
				if (IsBiomeOcean(a_Values[idx]))
				{
					// Oceans are kept without any changes
					continue;
				}
				if (Rivers[idx] != biRiver)
				{
					// There's no river, keep the current value
					continue;
				}

				// There's a river, change the output to a river or a frozen river, based on the original biome:
				if (IsBiomeVeryCold((EMCSBiome)a_Values[idx]))
				{
					a_Values[idx] = biFrozenRiver;
				}
				else
				{
					a_Values[idx] = biRiver;
				}
			}  // for x
		}  // for z
	}

protected:
	Underlying m_Biomes;
	Underlying m_Rivers;
};





/** Generates a river based on the underlying data.
This is basically an edge detector over the underlying data. The rivers are the edges where the underlying data
changes from one pixel to its neighbor. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenRiver:
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;
	static const int UnderlyingSizeX = SizeX + 2;
	static const int UnderlyingSizeZ = SizeZ + 2;

public:
	typedef cIntGenPtr<UnderlyingSizeX, UnderlyingSizeZ> Underlying;


	cIntGenRiver(int a_Seed, Underlying a_Underlying):
		super(a_Seed),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Generate the underlying data:
		int Cache[UnderlyingSizeX * UnderlyingSizeZ];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, Cache);

		// Detect the edges:
		for (int z = 0; z < SizeZ; z++)
		{
			for (int x = 0; x < SizeX; x++)
			{
				int Above = Cache[x + 1 + z * UnderlyingSizeX];
				int Below = Cache[x + 1 + (z + 2) * UnderlyingSizeX];
				int Left  = Cache[x +     (z + 1) * UnderlyingSizeX];
				int Right = Cache[x + 2 + (z + 1) * UnderlyingSizeX];
				int val   = Cache[x + 1 + (z + 1) * UnderlyingSizeX];

				if ((val == Above) && (val == Below) && (val == Left) && (val == Right))
				{
					val = 0;
				}
				else
				{
					val = biRiver;
				}
				a_Values[x + z * SizeX] = val;
			}  // for x
		}  // for z
	}

protected:
	Underlying m_Underlying;
};





/** Turns some of the oceans into the specified biome. Used for mushroom and deep ocean.
The biome is only placed if at least 3 of its neighbors are ocean and only with the specified chance. */
template <int SizeX, int SizeZ = SizeX>
class cIntGenAddToOcean:
	public cIntGenWithNoise<SizeX, SizeZ>
{
	typedef cIntGenWithNoise<SizeX, SizeZ> super;
	static const int UnderlyingSizeX = SizeX + 2;
	static const int UnderlyingSizeZ = SizeZ + 2;

public:
	typedef cIntGenPtr<UnderlyingSizeX, UnderlyingSizeZ> Underlying;


	cIntGenAddToOcean(int a_Seed, int a_Chance, int a_ToValue, Underlying a_Underlying):
		super(a_Seed),
		m_Chance(a_Chance),
		m_ToValue(a_ToValue),
		m_Underlying(a_Underlying)
	{
	}


	virtual void GetInts(int a_MinX, int a_MinZ, typename super::Values & a_Values) override
	{
		// Generate the underlying data:
		int Cache[UnderlyingSizeX * UnderlyingSizeZ];
		m_Underlying->GetInts(a_MinX - 1, a_MinZ - 1, Cache);

		// Add the mushroom islands:
		for (int z = 0; z < SizeZ; z++)
		{
			for (int x = 0; x < SizeX; x++)
			{
				int val = Cache[x + 1 + (z + 1) * UnderlyingSizeX];
				if (!IsBiomeOcean(val))
				{
					a_Values[x + z * SizeX] = val;
					continue;
				}

				// Count the ocean neighbors:
				int Above = Cache[x + 1 + z * UnderlyingSizeX];
				int Below = Cache[x + 1 + (z + 2) * UnderlyingSizeX];
				int Left  = Cache[x +     (z + 1) * UnderlyingSizeX];
				int Right = Cache[x + 2 + (z + 1) * UnderlyingSizeX];
				int NumOceanNeighbors = 0;
				if (IsBiomeOcean(Above))
				{
					NumOceanNeighbors += 1;
				}
				if (IsBiomeOcean(Below))
				{
					NumOceanNeighbors += 1;
				}
				if (IsBiomeOcean(Left))
				{
					NumOceanNeighbors += 1;
				}
				if (IsBiomeOcean(Right))
				{
					NumOceanNeighbors += 1;
				}

				// If at least 3 ocean neighbors and the chance is right, change:
				if ((NumOceanNeighbors >= 3) && ((m_Noise.IntNoise2DInt(x + a_MinX, z + a_MinZ) / 7) % 1000 < m_Chance))
				{
					a_Values[x + z * SizeX] = m_ToValue;
				}
				else
				{
					a_Values[x + z * SizeX] = val;
				}
			}  // for x
		}  // for z
	}

protected:
	/** Chance, in permille, of changing the biome. */
	int m_Chance;

	/** The value to change the ocean into. */
	int m_ToValue;

	Underlying m_Underlying;
};