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cuberite-2a/src/VoronoiMap.h

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// VoronoiMap.h
// Declares the cVoronoiMap class that implements a Voronoi algorithm over a noise to produce a map
#pragma once
#include "Noise/Noise.h"
class cVoronoiMap
{
public:
cVoronoiMap(int a_Seed, int a_CellSize = 128, int a_JitterSize = 128);
/** Sets both the cell size and jitter size used for generating the Voronoi seeds. */
void SetCellSize(int a_CellSize);
/** Sets the jitter size. Clamps it to current cell size. */
void SetJitterSize(int a_JitterSize);
/** Sets the offset that is added to each odd row of cells.
This offset makes the voronoi cells align to a non-grid.
Clamps the value to [-m_CellSize, +m_CellSize]. */
void SetOddRowOffset(int a_OddRowOffset);
/** Returns the value in the cell into which the specified point lies. */
int GetValueAt(int a_X, int a_Y);
/** Returns the value in the cell into which the specified point lies,
and the distance to the nearest Voronoi seed. */
int GetValueAt(int a_X, int a_Y, int & a_MinDistance);
/** Returns the value in the cell into which the specified point lies,
and the distances to the 2 nearest Voronoi seeds. Uses a cache. */
int GetValueAt(
int a_X, int a_Y, // Coords to query
int & a_NearestSeedX, int & a_NearestSeedY, // Coords of the closest cell's seed
int & a_MinDist2 // Distance to the second closest cell's seed
);
/** Finds the nearest and second nearest seeds, returns their coords. */
void FindNearestSeeds(
int a_X, int a_Y,
int & a_NearestSeedX, int & a_NearestSeedY,
int & a_SecondNearestSeedX, int & a_SecondNearestSeedY
);
protected:
/// The noise used for generating Voronoi seeds
cNoise m_Noise1;
cNoise m_Noise2;
cNoise m_Noise3;
/** Size of the Voronoi cells (avg X / Y distance between the seeds). Expected to be at least 2. */
int m_CellSize;
/** The amount that the cell seeds may be offset from the grid.
Expected to be at least 1 and less than m_CellSize. */
int m_JitterSize;
/** The constant amount that the cell seeds of every odd row will be offset from the grid.
This allows us to have non-rectangular grids.
Expected to be between -m_CellSize and +m_CellSize. */
int m_OddRowOffset;
/** The X coordinate of the currently cached cell neighborhood */
int m_CurrentCellX;
/** The Z coordinate of the currently cached cell neighborhood */
int m_CurrentCellZ;
/** The seeds of cells around m_CurrentCellX, m_CurrentCellZ, X-coords */
int m_SeedX[5][5];
/** The seeds of cells around m_CurrentCellX, m_CurrentCellZ, X-coords */
int m_SeedZ[5][5];
/** Updates the cached cell seeds to match the specified cell. Noop if cell pos already matches.
Updates m_SeedX and m_SeedZ. */
void UpdateCell(int a_CellX, int a_CellZ);
} ;