129 lines
2.7 KiB
C++
129 lines
2.7 KiB
C++
|
|
// VoronoiMap.cpp
|
|
|
|
// Implements the cVoronoiMap class that implements a Voronoi algorithm over a noise to produce a map
|
|
|
|
#include "Globals.h"
|
|
#include "VoronoiMap.h"
|
|
|
|
|
|
|
|
|
|
|
|
cVoronoiMap::cVoronoiMap(int a_Seed, int a_CellSize) :
|
|
m_Noise1(a_Seed + 1),
|
|
m_Noise2(a_Seed + 2),
|
|
m_Noise3(a_Seed + 3),
|
|
m_CellSize(a_CellSize),
|
|
m_CurrentCellX(9999999), // Cell coords that are definitely out of the range for normal generator, so that the first query will overwrite them
|
|
m_CurrentCellZ(9999999)
|
|
{
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
void cVoronoiMap::SetCellSize(int a_CellSize)
|
|
{
|
|
m_CellSize = a_CellSize;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int cVoronoiMap::GetValueAt(int a_X, int a_Y)
|
|
{
|
|
int MinDist1, MinDist2;
|
|
return GetValueAt(a_X, a_Y, MinDist1, MinDist2);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int cVoronoiMap::GetValueAt(int a_X, int a_Y, int & a_MinDist)
|
|
{
|
|
int MinDist2;
|
|
return GetValueAt(a_X, a_Y, a_MinDist, MinDist2);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
int cVoronoiMap::GetValueAt(int a_X, int a_Y, int & a_MinDist1, int & a_MinDist2)
|
|
{
|
|
// Note that due to historical reasons, the algorithm uses XZ coords, while the input uses XY coords.
|
|
// This is because the algorithm was first implemented directly in the biome generators which use MC coords.
|
|
|
|
int CellX = a_X / m_CellSize;
|
|
int CellZ = a_Y / m_CellSize;
|
|
|
|
UpdateCell(CellX, CellZ);
|
|
|
|
// Get 5x5 neighboring cell seeds, compare distance to each. Return the value in the minumim-distance cell
|
|
int MinDist = m_CellSize * m_CellSize * 16; // There has to be a cell closer than this
|
|
int MinDist2 = MinDist;
|
|
int res = 0; // Will be overriden
|
|
for (int x = 0; x < 5; x++)
|
|
{
|
|
for (int z = 0; z < 5; z++)
|
|
{
|
|
int SeedX = m_SeedX[x][z];
|
|
int SeedZ = m_SeedZ[x][z];
|
|
|
|
int Dist = (SeedX - a_X) * (SeedX - a_X) + (SeedZ - a_Y) * (SeedZ - a_Y);
|
|
if (Dist < MinDist)
|
|
{
|
|
MinDist2 = MinDist;
|
|
MinDist = Dist;
|
|
res = m_Noise3.IntNoise2DInt(x + CellX - 2, z + CellZ - 2);
|
|
}
|
|
else if (Dist < MinDist2)
|
|
{
|
|
MinDist2 = Dist;
|
|
}
|
|
} // for z
|
|
} // for x
|
|
|
|
a_MinDist1 = MinDist;
|
|
a_MinDist2 = MinDist2;
|
|
return res;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
void cVoronoiMap::UpdateCell(int a_CellX, int a_CellZ)
|
|
{
|
|
// If the specified cell is currently cached, bail out:
|
|
if ((a_CellX == m_CurrentCellX) && (a_CellZ == m_CurrentCellZ))
|
|
{
|
|
return;
|
|
}
|
|
|
|
// Update the cell cache for the new cell position:
|
|
int NoiseBaseX = a_CellX - 2;
|
|
int NoiseBaseZ = a_CellZ - 2;
|
|
for (int x = 0; x < 5; x++)
|
|
{
|
|
int BaseX = (NoiseBaseX + x) * m_CellSize;
|
|
for (int z = 0; z < 5; z++)
|
|
{
|
|
int OffsetX = (m_Noise1.IntNoise2DInt(NoiseBaseX + x, NoiseBaseZ + z) / 8) % m_CellSize;
|
|
int OffsetZ = (m_Noise2.IntNoise2DInt(NoiseBaseX + x, NoiseBaseZ + z) / 8) % m_CellSize;
|
|
m_SeedX[x][z] = BaseX + OffsetX;
|
|
m_SeedZ[x][z] = (NoiseBaseZ + z) * m_CellSize + OffsetZ;
|
|
} // for z
|
|
} // for x
|
|
m_CurrentCellX = a_CellX;
|
|
m_CurrentCellZ = a_CellZ;
|
|
}
|
|
|
|
|
|
|
|
|