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+
+// InterpolNoise.h
+
+// Implements the cInterpolNoise class template representing a noise that interpolates the values between integer coords from a single set of neighbors
+
+
+
+
+
+#pragma once
+
+#include "Noise.h"
+
+#define FAST_FLOOR(x) (((x) < 0) ? (((int)x) - 1) : ((int)x))
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cInterpolCell2D:
+
+template <typename T>
+class cInterpolCell2D
+{
+public:
+ cInterpolCell2D(
+ const cNoise & a_Noise, ///< Noise to use for generating the random values
+ NOISE_DATATYPE * a_Array, ///< Array to generate into [x + a_SizeX * y]
+ int a_SizeX, int a_SizeY, ///< Count of the array, in each direction
+ const NOISE_DATATYPE * a_FracX, ///< Pointer to the array that stores the X fractional values
+ const NOISE_DATATYPE * a_FracY ///< Pointer to the attay that stores the Y fractional values
+ ):
+ m_Noise(a_Noise),
+ m_WorkRnds(&m_Workspace1),
+ m_CurFloorX(0),
+ m_CurFloorY(0),
+ m_Array(a_Array),
+ m_SizeX(a_SizeX),
+ m_SizeY(a_SizeY),
+ m_FracX(a_FracX),
+ m_FracY(a_FracY)
+ {
+ }
+
+
+ /** Generates part of the output noise array using the current m_WorkRnds[] values */
+ void Generate(
+ int a_FromX, int a_ToX,
+ int a_FromY, int a_ToY
+ )
+ {
+ for (int y = a_FromY; y < a_ToY; y++)
+ {
+ NOISE_DATATYPE Interp[2];
+ NOISE_DATATYPE FracY = T::coeff(m_FracY[y]);
+ Interp[0] = Lerp((*m_WorkRnds)[0][0], (*m_WorkRnds)[0][1], FracY);
+ Interp[1] = Lerp((*m_WorkRnds)[1][0], (*m_WorkRnds)[1][1], FracY);
+ int idx = y * m_SizeX + a_FromX;
+ for (int x = a_FromX; x < a_ToX; x++)
+ {
+ m_Array[idx++] = Lerp(Interp[0], Interp[1], T::coeff(m_FracX[x]));
+ } // for x
+ } // for y
+ }
+
+
+ /** Initializes m_WorkRnds[] with the specified values of the noise at the specified integral coords. */
+ void InitWorkRnds(int a_FloorX, int a_FloorY)
+ {
+ m_CurFloorX = a_FloorX;
+ m_CurFloorY = a_FloorY;
+ (*m_WorkRnds)[0][0] = m_Noise.IntNoise2D(m_CurFloorX, m_CurFloorY);
+ (*m_WorkRnds)[0][1] = m_Noise.IntNoise2D(m_CurFloorX, m_CurFloorY + 1);
+ (*m_WorkRnds)[1][0] = m_Noise.IntNoise2D(m_CurFloorX + 1, m_CurFloorY);
+ (*m_WorkRnds)[1][1] = m_Noise.IntNoise2D(m_CurFloorX + 1, m_CurFloorY + 1);
+ }
+
+
+ /** Updates m_WorkRnds[] for the new integral coords */
+ void Move(int a_NewFloorX, int a_NewFloorY)
+ {
+ // Swap the doublebuffer:
+ int OldFloorX = m_CurFloorX;
+ int OldFloorY = m_CurFloorY;
+ Workspace * OldWorkRnds = m_WorkRnds;
+ m_WorkRnds = (m_WorkRnds == &m_Workspace1) ? &m_Workspace2 : &m_Workspace1;
+
+ // Reuse as much of the old workspace as possible:
+ // TODO: Try out if simply calculating all 4 elements each time is faster than this monster loop
+ int DiffX = OldFloorX - a_NewFloorX;
+ int DiffY = OldFloorY - a_NewFloorY;
+ for (int x = 0; x < 2; x++)
+ {
+ int cx = a_NewFloorX + x;
+ int OldX = x - DiffX; // Where would this X be in the old grid?
+ for (int y = 0; y < 2; y++)
+ {
+ int cy = a_NewFloorY + y;
+ int OldY = y - DiffY; // Where would this Y be in the old grid?
+ if ((OldX >= 0) && (OldX < 2) && (OldY >= 0) && (OldY < 2))
+ {
+ (*m_WorkRnds)[x][y] = (*OldWorkRnds)[OldX][OldY];
+ }
+ else
+ {
+ (*m_WorkRnds)[x][y] = (NOISE_DATATYPE)m_Noise.IntNoise2D(cx, cy);
+ }
+ }
+ }
+ m_CurFloorX = a_NewFloorX;
+ m_CurFloorY = a_NewFloorY;
+ }
+
+protected:
+ typedef NOISE_DATATYPE Workspace[2][2];
+
+ /** The noise used for generating the values at integral coords. */
+ const cNoise & m_Noise;
+
+ /** The current random values; points to either m_Workspace1 or m_Workspace2 (doublebuffering) */
+ Workspace * m_WorkRnds;
+
+ /** Buffer 1 for workspace doublebuffering, used in Move() */
+ Workspace m_Workspace1;
+
+ /** Buffer 2 for workspace doublebuffering, used in Move() */
+ Workspace m_Workspace2;
+
+ /** Coords of the currently calculated m_WorkRnds[]. */
+ int m_CurFloorX, m_CurFloorY;
+
+ /** The output array to generate into. */
+ NOISE_DATATYPE * m_Array;
+
+ /** Dimensions of the output array. */
+ int m_SizeX, m_SizeY;
+
+ /** Arrays holding the fractional values of the coords in each direction. */
+ const NOISE_DATATYPE * m_FracX;
+ const NOISE_DATATYPE * m_FracY;
+} ;
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cInterpolCell3D:
+
+/** Holds a cache of the last calculated integral noise values and interpolates between them en masse.
+Provides a massive optimization for cInterpolNoise.
+Works by calculating multiple noise values (that have the same integral noise coords) at once. The underlying noise values
+needn't be recalculated for these values, only the interpolation is done within the unit cube. */
+template <typename T>
+class cInterpolCell3D
+{
+public:
+ cInterpolCell3D(
+ const cNoise & a_Noise, ///< Noise to use for generating the random values
+ NOISE_DATATYPE * a_Array, ///< Array to generate into [x + a_SizeX * y]
+ int a_SizeX, int a_SizeY, int a_SizeZ, ///< Count of the array, in each direction
+ const NOISE_DATATYPE * a_FracX, ///< Pointer to the array that stores the X fractional values
+ const NOISE_DATATYPE * a_FracY, ///< Pointer to the attay that stores the Y fractional values
+ const NOISE_DATATYPE * a_FracZ ///< Pointer to the array that stores the Z fractional values
+ ):
+ m_Noise(a_Noise),
+ m_WorkRnds(&m_Workspace1),
+ m_CurFloorX(0),
+ m_CurFloorY(0),
+ m_CurFloorZ(0),
+ m_Array(a_Array),
+ m_SizeX(a_SizeX),
+ m_SizeY(a_SizeY),
+ m_SizeZ(a_SizeZ),
+ m_FracX(a_FracX),
+ m_FracY(a_FracY),
+ m_FracZ(a_FracZ)
+ {
+ }
+
+
+ /** Generates part of the output array using current m_WorkRnds[]. */
+ void Generate(
+ int a_FromX, int a_ToX,
+ int a_FromY, int a_ToY,
+ int a_FromZ, int a_ToZ
+ )
+ {
+ for (int z = a_FromZ; z < a_ToZ; z++)
+ {
+ int idxZ = z * m_SizeX * m_SizeY;
+ NOISE_DATATYPE Interp2[2][2];
+ NOISE_DATATYPE FracZ = T::coeff(m_FracZ[z]);
+ for (int x = 0; x < 2; x++)
+ {
+ for (int y = 0; y < 2; y++)
+ {
+ Interp2[x][y] = Lerp((*m_WorkRnds)[x][y][0], (*m_WorkRnds)[x][y][1], FracZ);
+ }
+ }
+ for (int y = a_FromY; y < a_ToY; y++)
+ {
+ NOISE_DATATYPE Interp[2];
+ NOISE_DATATYPE FracY = T::coeff(m_FracY[y]);
+ Interp[0] = Lerp(Interp2[0][0], Interp2[0][1], FracY);
+ Interp[1] = Lerp(Interp2[1][0], Interp2[1][1], FracY);
+ int idx = idxZ + y * m_SizeX + a_FromX;
+ for (int x = a_FromX; x < a_ToX; x++)
+ {
+ m_Array[idx++] = Lerp(Interp[0], Interp[1], T::coeff(m_FracX[x]));
+ } // for x
+ } // for y
+ } // for z
+ }
+
+
+ /** Initializes m_WorkRnds[] with the specified Floor values. */
+ void InitWorkRnds(int a_FloorX, int a_FloorY, int a_FloorZ)
+ {
+ m_CurFloorX = a_FloorX;
+ m_CurFloorY = a_FloorY;
+ m_CurFloorZ = a_FloorZ;
+ (*m_WorkRnds)[0][0][0] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX, m_CurFloorY, m_CurFloorZ);
+ (*m_WorkRnds)[0][0][1] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX, m_CurFloorY, m_CurFloorZ + 1);
+ (*m_WorkRnds)[0][1][0] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX, m_CurFloorY + 1, m_CurFloorZ);
+ (*m_WorkRnds)[0][1][1] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX, m_CurFloorY + 1, m_CurFloorZ + 1);
+ (*m_WorkRnds)[1][0][0] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX + 1, m_CurFloorY, m_CurFloorZ);
+ (*m_WorkRnds)[1][0][1] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX + 1, m_CurFloorY, m_CurFloorZ + 1);
+ (*m_WorkRnds)[1][1][0] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX + 1, m_CurFloorY + 1, m_CurFloorZ);
+ (*m_WorkRnds)[1][1][1] = (NOISE_DATATYPE)m_Noise.IntNoise3D(m_CurFloorX + 1, m_CurFloorY + 1, m_CurFloorZ + 1);
+ }
+
+
+ /** Updates m_WorkRnds[] for the new Floor values. */
+ void Move(int a_NewFloorX, int a_NewFloorY, int a_NewFloorZ)
+ {
+ // Swap the doublebuffer:
+ int OldFloorX = m_CurFloorX;
+ int OldFloorY = m_CurFloorY;
+ int OldFloorZ = m_CurFloorZ;
+ Workspace * OldWorkRnds = m_WorkRnds;
+ m_WorkRnds = (m_WorkRnds == &m_Workspace1) ? &m_Workspace2 : &m_Workspace1;
+
+ // Reuse as much of the old workspace as possible:
+ // TODO: Try out if simply calculating all 8 elements each time is faster than this monster loop
+ int DiffX = OldFloorX - a_NewFloorX;
+ int DiffY = OldFloorY - a_NewFloorY;
+ int DiffZ = OldFloorZ - a_NewFloorZ;
+ for (int x = 0; x < 2; x++)
+ {
+ int cx = a_NewFloorX + x;
+ int OldX = x - DiffX; // Where would this X be in the old grid?
+ for (int y = 0; y < 2; y++)
+ {
+ int cy = a_NewFloorY + y;
+ int OldY = y - DiffY; // Where would this Y be in the old grid?
+ for (int z = 0; z < 2; z++)
+ {
+ int cz = a_NewFloorZ + z;
+ int OldZ = z - DiffZ;
+ if ((OldX >= 0) && (OldX < 2) && (OldY >= 0) && (OldY < 2) && (OldZ >= 0) && (OldZ < 2))
+ {
+ (*m_WorkRnds)[x][y][z] = (*OldWorkRnds)[OldX][OldY][OldZ];
+ }
+ else
+ {
+ (*m_WorkRnds)[x][y][z] = (NOISE_DATATYPE)m_Noise.IntNoise3D(cx, cy, cz);
+ }
+ } // for z
+ } // for y
+ } // for x
+ m_CurFloorX = a_NewFloorX;
+ m_CurFloorY = a_NewFloorY;
+ m_CurFloorZ = a_NewFloorZ;
+ }
+
+protected:
+ typedef NOISE_DATATYPE Workspace[2][2][2];
+
+ /** The noise used for generating the values at integral coords. */
+ const cNoise & m_Noise;
+
+ /** The current random values; points to either m_Workspace1 or m_Workspace2 (doublebuffering) */
+ Workspace * m_WorkRnds;
+
+ /** Buffer 1 for workspace doublebuffering, used in Move() */
+ Workspace m_Workspace1;
+
+ /** Buffer 2 for workspace doublebuffering, used in Move() */
+ Workspace m_Workspace2;
+
+ /** The integral coords of the currently calculated WorkRnds[] */
+ int m_CurFloorX, m_CurFloorY, m_CurFloorZ;
+
+ /** The output array where the noise is calculated. */
+ NOISE_DATATYPE * m_Array;
+
+ /** Dimensions of the output array. */
+ int m_SizeX, m_SizeY, m_SizeZ;
+
+ /** Arrays holding the fractional values of the coords in each direction. */
+ const NOISE_DATATYPE * m_FracX;
+ const NOISE_DATATYPE * m_FracY;
+ const NOISE_DATATYPE * m_FracZ;
+} ;
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cInterpolNoise:
+
+template <typename T>
+class cInterpolNoise
+{
+ /** Maximum size, for each direction, of the generated array. */
+ static const int MAX_SIZE = 256;
+
+public:
+ cInterpolNoise(int a_Seed):
+ m_Noise(a_Seed)
+ {
+ }
+
+
+ /** Sets a new seed for the generators. Relays the seed to the underlying noise. */
+ void SetSeed(int a_Seed)
+ {
+ m_Noise.SetSeed(a_Seed);
+ }
+
+
+ /** Fills a 2D array with the values of the noise. */
+ void Generate2D(
+ NOISE_DATATYPE * a_Array, ///< Array to generate into [x + a_SizeX * y]
+ int a_SizeX, int a_SizeY, ///< Count of the array, in each direction
+ NOISE_DATATYPE a_StartX, NOISE_DATATYPE a_EndX, ///< Noise-space coords of the array in the X direction
+ NOISE_DATATYPE a_StartY, NOISE_DATATYPE a_EndY ///< Noise-space coords of the array in the Y direction
+ ) const
+ {
+ ASSERT(a_SizeX > 0);
+ ASSERT(a_SizeY > 0);
+ ASSERT(a_SizeX < MAX_SIZE);
+ ASSERT(a_SizeY < MAX_SIZE);
+ ASSERT(a_StartX < a_EndX);
+ ASSERT(a_StartY < a_EndY);
+
+ // Calculate the integral and fractional parts of each coord:
+ int FloorX[MAX_SIZE];
+ int FloorY[MAX_SIZE];
+ NOISE_DATATYPE FracX[MAX_SIZE];
+ NOISE_DATATYPE FracY[MAX_SIZE];
+ int SameX[MAX_SIZE];
+ int SameY[MAX_SIZE];
+ int NumSameX, NumSameY;
+ CalcFloorFrac(a_SizeX, a_StartX, a_EndX, FloorX, FracX, SameX, NumSameX);
+ CalcFloorFrac(a_SizeY, a_StartY, a_EndY, FloorY, FracY, SameY, NumSameY);
+
+ cInterpolCell2D<T> Cell(m_Noise, a_Array, a_SizeX, a_SizeY, FracX, FracY);
+
+ Cell.InitWorkRnds(FloorX[0], FloorY[0]);
+
+ // Calculate query values using Cell:
+ int FromY = 0;
+ for (int y = 0; y < NumSameY; y++)
+ {
+ int ToY = FromY + SameY[y];
+ int FromX = 0;
+ int CurFloorY = FloorY[FromY];
+ for (int x = 0; x < NumSameX; x++)
+ {
+ int ToX = FromX + SameX[x];
+ Cell.Generate(FromX, ToX, FromY, ToY);
+ Cell.Move(FloorX[ToX], CurFloorY);
+ FromX = ToX;
+ } // for x
+ Cell.Move(FloorX[0], FloorY[ToY]);
+ FromY = ToY;
+ } // for y
+ }
+
+
+ /** Fills a 3D array with the values of the noise. */
+ void Generate3D(
+ NOISE_DATATYPE * a_Array, ///< Array to generate into [x + a_SizeX * y + a_SizeX * a_SizeY * z]
+ int a_SizeX, int a_SizeY, int a_SizeZ, ///< Count of the array, in each direction
+ NOISE_DATATYPE a_StartX, NOISE_DATATYPE a_EndX, ///< Noise-space coords of the array in the X direction
+ NOISE_DATATYPE a_StartY, NOISE_DATATYPE a_EndY, ///< Noise-space coords of the array in the Y direction
+ NOISE_DATATYPE a_StartZ, NOISE_DATATYPE a_EndZ ///< Noise-space coords of the array in the Z direction
+ ) const
+ {
+ // Check params:
+ ASSERT(a_SizeX > 1);
+ ASSERT(a_SizeY > 1);
+
+ ASSERT(a_SizeX < MAX_SIZE);
+ ASSERT(a_SizeY < MAX_SIZE);
+ ASSERT(a_SizeZ < MAX_SIZE);
+ ASSERT(a_StartX < a_EndX);
+ ASSERT(a_StartY < a_EndY);
+ ASSERT(a_StartZ < a_EndZ);
+
+ // Calculate the integral and fractional parts of each coord:
+ int FloorX[MAX_SIZE];
+ int FloorY[MAX_SIZE];
+ int FloorZ[MAX_SIZE];
+ NOISE_DATATYPE FracX[MAX_SIZE];
+ NOISE_DATATYPE FracY[MAX_SIZE];
+ NOISE_DATATYPE FracZ[MAX_SIZE];
+ int SameX[MAX_SIZE];
+ int SameY[MAX_SIZE];
+ int SameZ[MAX_SIZE];
+ int NumSameX, NumSameY, NumSameZ;
+ CalcFloorFrac(a_SizeX, a_StartX, a_EndX, FloorX, FracX, SameX, NumSameX);
+ CalcFloorFrac(a_SizeY, a_StartY, a_EndY, FloorY, FracY, SameY, NumSameY);
+ CalcFloorFrac(a_SizeZ, a_StartZ, a_EndZ, FloorZ, FracZ, SameZ, NumSameZ);
+
+ cInterpolCell3D<T> Cell(
+ m_Noise, a_Array,
+ a_SizeX, a_SizeY, a_SizeZ,
+ FracX, FracY, FracZ
+ );
+
+ Cell.InitWorkRnds(FloorX[0], FloorY[0], FloorZ[0]);
+
+ // Calculate query values using Cell:
+ int FromZ = 0;
+ for (int z = 0; z < NumSameZ; z++)
+ {
+ int ToZ = FromZ + SameZ[z];
+ int CurFloorZ = FloorZ[FromZ];
+ int FromY = 0;
+ for (int y = 0; y < NumSameY; y++)
+ {
+ int ToY = FromY + SameY[y];
+ int CurFloorY = FloorY[FromY];
+ int FromX = 0;
+ for (int x = 0; x < NumSameX; x++)
+ {
+ int ToX = FromX + SameX[x];
+ Cell.Generate(FromX, ToX, FromY, ToY, FromZ, ToZ);
+ Cell.Move(FloorX[ToX], CurFloorY, CurFloorZ);
+ FromX = ToX;
+ }
+ Cell.Move(FloorX[0], FloorY[ToY], CurFloorZ);
+ FromY = ToY;
+ } // for y
+ Cell.Move(FloorX[0], FloorY[0], FloorZ[ToZ]);
+ FromZ = ToZ;
+ } // for z
+ }
+
+protected:
+
+ /** The noise used for the underlying value generation. */
+ cNoise m_Noise;
+
+
+ /** Calculates the integral and fractional parts along one axis.
+ a_Floor will receive the integral parts (array of a_Size ints).
+ a_Frac will receive the fractional parts (array of a_Size floats).
+ a_Same will receive the counts of items that have the same integral parts (array of up to a_Size ints).
+ a_NumSame will receive the count of a_Same elements (total count of different integral parts). */
+ void CalcFloorFrac(
+ int a_Size,
+ NOISE_DATATYPE a_Start, NOISE_DATATYPE a_End,
+ int * a_Floor, NOISE_DATATYPE * a_Frac,
+ int * a_Same, int & a_NumSame
+ ) const
+ {
+ ASSERT(a_Size > 0);
+
+ // Calculate the floor and frac values:
+ NOISE_DATATYPE val = a_Start;
+ NOISE_DATATYPE dif = (a_End - a_Start) / (a_Size - 1);
+ for (int i = 0; i < a_Size; i++)
+ {
+ a_Floor[i] = FAST_FLOOR(val);
+ a_Frac[i] = val - a_Floor[i];
+ val += dif;
+ }
+
+ // Mark up the same floor values into a_Same / a_NumSame:
+ int CurFloor = a_Floor[0];
+ int LastSame = 0;
+ a_NumSame = 0;
+ for (int i = 1; i < a_Size; i++)
+ {
+ if (a_Floor[i] != CurFloor)
+ {
+ a_Same[a_NumSame] = i - LastSame;
+ LastSame = i;
+ a_NumSame += 1;
+ CurFloor = a_Floor[i];
+ }
+ } // for i - a_Floor[]
+ if (LastSame < a_Size)
+ {
+ a_Same[a_NumSame] = a_Size - LastSame;
+ a_NumSame += 1;
+ }
+ }
+};
+
+
+
+
+
+/** A fifth-degree curve for interpolating.
+Implemented as a functor for better chance of inlining. */
+struct Interp5Deg
+{
+ static NOISE_DATATYPE coeff(NOISE_DATATYPE a_Val)
+ {
+ return a_Val * a_Val * a_Val * (a_Val * (a_Val * 6 - 15) + 10);
+ }
+};
+
+typedef cInterpolNoise<Interp5Deg> cInterp5DegNoise;
+
+
+
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