// Noise.h
// Declares the cNoise, cCubicNoise and cPerlinNoise classes for generating noise
#pragma once
#include <cmath>
/** The datatype used by all the noise generators. */
typedef float NOISE_DATATYPE;
#include "OctavedNoise.h"
#include "RidgedNoise.h"
class cNoise
{
public:
cNoise(int a_Seed);
cNoise(const cNoise & a_Noise);
// The following functions, if not marked INLINE, are about 20 % slower
inline NOISE_DATATYPE IntNoise1D(int a_X) const;
inline NOISE_DATATYPE IntNoise2D(int a_X, int a_Y) const;
inline NOISE_DATATYPE IntNoise3D(int a_X, int a_Y, int a_Z) const;
// Return a float number in the specified range:
inline NOISE_DATATYPE IntNoise2DInRange(int a_X, int a_Y, float a_Min, float a_Max) const
{
return a_Min + std::abs(IntNoise2D(a_X, a_Y)) * (a_Max - a_Min);
}
// Note: These functions have a mod8-irregular chance - each of the mod8 remainders has different chance of occurrence. Divide by 8 to rectify.
inline int IntNoise1DInt(int a_X) const;
inline int IntNoise2DInt(int a_X, int a_Y) const;
inline int IntNoise3DInt(int a_X, int a_Y, int a_Z) const;
NOISE_DATATYPE LinearNoise1D(NOISE_DATATYPE a_X) const;
NOISE_DATATYPE CosineNoise1D(NOISE_DATATYPE a_X) const;
NOISE_DATATYPE CubicNoise1D (NOISE_DATATYPE a_X) const;
NOISE_DATATYPE SmoothNoise1D(int a_X) const;
NOISE_DATATYPE CubicNoise2D (NOISE_DATATYPE a_X, NOISE_DATATYPE a_Y) const;
NOISE_DATATYPE CubicNoise3D (NOISE_DATATYPE a_X, NOISE_DATATYPE a_Y, NOISE_DATATYPE a_Z) const;
void SetSeed(int a_Seed) { m_Seed = a_Seed; }
inline static NOISE_DATATYPE CubicInterpolate (NOISE_DATATYPE a_A, NOISE_DATATYPE a_B, NOISE_DATATYPE a_C, NOISE_DATATYPE a_D, NOISE_DATATYPE a_Pct);
inline static NOISE_DATATYPE CosineInterpolate(NOISE_DATATYPE a_A, NOISE_DATATYPE a_B, NOISE_DATATYPE a_Pct);
inline static NOISE_DATATYPE LinearInterpolate(NOISE_DATATYPE a_A, NOISE_DATATYPE a_B, NOISE_DATATYPE a_Pct);
private:
int m_Seed;
} ;
class cCubicNoise
{
public:
/** Maximum size of each dimension of the query arrays. */
static const int MAX_SIZE = 512;
/** Creates a new instance with the specified seed. */
cCubicNoise(int 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;
/** 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;
protected:
/** Noise used for integral random values. */
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;
} ;
/** Improved noise, as described by Ken Perlin: http://mrl.nyu.edu/~perlin/paper445.pdf
Implementation adapted from Perlin's Java implementation: http://mrl.nyu.edu/~perlin/noise/ */
class cImprovedNoise
{
public:
/** Constructs a new instance of the noise obbject.
Note that this operation is quite expensive (the permutation array being constructed). */
cImprovedNoise(int 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;
/** 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;
/** Returns the value at the specified integral coords. Used for raw speed measurement. */
NOISE_DATATYPE GetValueAt(int a_X, int a_Y, int a_Z);
protected:
/** The permutation table used by the noise function. Initialized using seed. */
int m_Perm[512];
/** Calculates the fade curve, 6 * t^5 - 15 * t^4 + 10 * t^3. */
inline static NOISE_DATATYPE Fade(NOISE_DATATYPE a_T)
{
return a_T * a_T * a_T * (a_T * (a_T * 6 - 15) + 10);
}
/** Returns the gradient value based on the hash. */
inline static NOISE_DATATYPE Grad(int a_Hash, NOISE_DATATYPE a_X, NOISE_DATATYPE a_Y, NOISE_DATATYPE a_Z)
{
int hash = a_Hash % 16;
NOISE_DATATYPE u = (hash < 8) ? a_X : a_Y;
NOISE_DATATYPE v = (hash < 4) ? a_Y : (((hash == 12) || (hash == 14)) ? a_X : a_Z);
return (((hash & 1) == 0) ? u : -u) + (((hash & 2) == 0) ? v : -v);
}
};
typedef cOctavedNoise<cCubicNoise> cPerlinNoise;
typedef cOctavedNoise<cRidgedNoise<cCubicNoise>> cRidgedMultiNoise;
////////////////////////////////////////////////////////////////////////////////
// Inline function definitions:
// These need to be in the header, otherwise linker error occur in MSVC
NOISE_DATATYPE cNoise::IntNoise1D(int a_X) const
{
int x = ((a_X * m_Seed) << 13) ^ a_X;
return (1 - (NOISE_DATATYPE)((x * (x * x * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824);
// returns a float number in the range of [-1, 1]
}
NOISE_DATATYPE cNoise::IntNoise2D(int a_X, int a_Y) const
{
int n = a_X + a_Y * 57 + m_Seed * 57 * 57;
n = (n << 13) ^ n;
return (1 - (NOISE_DATATYPE)((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824);
// returns a float number in the range of [-1, 1]
}
NOISE_DATATYPE cNoise::IntNoise3D(int a_X, int a_Y, int a_Z) const
{
int n = a_X + a_Y * 57 + a_Z * 57 * 57 + m_Seed * 57 * 57 * 57;
n = (n << 13) ^ n;
return ((NOISE_DATATYPE)1 - (NOISE_DATATYPE)((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0f);
// returns a float number in the range of [-1, 1]
}
int cNoise::IntNoise1DInt(int a_X) const
{
int x = ((a_X * m_Seed) << 13) ^ a_X;
return ((x * (x * x * 15731 + 789221) + 1376312589) & 0x7fffffff);
}
int cNoise::IntNoise2DInt(int a_X, int a_Y) const
{
int n = a_X + a_Y * 57 + m_Seed * 57 * 57;
n = (n << 13) ^ n;
return ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff);
}
int cNoise::IntNoise3DInt(int a_X, int a_Y, int a_Z) const
{
int n = a_X + a_Y * 57 + a_Z * 57 * 57 + m_Seed * 57 * 57 * 57;
n = (n << 13) ^ n;
return ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff);
}
NOISE_DATATYPE cNoise::CubicInterpolate(NOISE_DATATYPE a_A, NOISE_DATATYPE a_B, NOISE_DATATYPE a_C, NOISE_DATATYPE a_D, NOISE_DATATYPE a_Pct)
{
NOISE_DATATYPE P = (a_D - a_C) - (a_A - a_B);
NOISE_DATATYPE Q = (a_A - a_B) - P;
NOISE_DATATYPE R = a_C - a_A;
NOISE_DATATYPE S = a_B;
return ((P * a_Pct + Q) * a_Pct + R) * a_Pct + S;
}
NOISE_DATATYPE cNoise::CosineInterpolate(NOISE_DATATYPE a_A, NOISE_DATATYPE a_B, NOISE_DATATYPE a_Pct)
{
const NOISE_DATATYPE ft = a_Pct * (NOISE_DATATYPE)3.1415927;
const NOISE_DATATYPE f = (NOISE_DATATYPE)((NOISE_DATATYPE)(1 - cos(ft)) * (NOISE_DATATYPE)0.5);
return a_A * (1 - f) + a_B * f;
}
NOISE_DATATYPE cNoise::LinearInterpolate(NOISE_DATATYPE a_A, NOISE_DATATYPE a_B, NOISE_DATATYPE a_Pct)
{
return a_A * (1 - a_Pct) + a_B * a_Pct;
}
////////////////////////////////////////////////////////////////////////////////
// Global functions:
/** Exports the noise array into a file.
a_Coeff specifies the value that each array value is multiplied by before being converted into a byte. */
extern void Debug2DNoise(const NOISE_DATATYPE * a_Array, int a_SizeX, int a_SizeY, const AString & a_FileNameBase, NOISE_DATATYPE a_Coeff = 32);
/** Exports the noise array into a set of files, ordered by XY and XZ.
a_Coeff specifies the value that each array value is multiplied by before being converted into a byte. */
extern void Debug3DNoise(const NOISE_DATATYPE * a_Array, int a_SizeX, int a_SizeY, int a_SizeZ, const AString & a_FileNameBase, NOISE_DATATYPE a_Coeff = 32);
/** Linearly interpolates between two values.
Assumes that a_Ratio is in range [0, 1]. */
inline NOISE_DATATYPE Lerp(NOISE_DATATYPE a_Val1, NOISE_DATATYPE a_Val2, NOISE_DATATYPE a_Ratio)
{
return a_Val1 + (a_Val2 - a_Val1) * a_Ratio;
}
/** Linearly interpolates between two values, clamping the ratio to [0, 1] first. */
inline NOISE_DATATYPE ClampedLerp(NOISE_DATATYPE a_Val1, NOISE_DATATYPE a_Val2, NOISE_DATATYPE a_Ratio)
{
if (a_Ratio < 0)
{
return a_Val1;
}
if (a_Ratio > 1)
{
return a_Val2;
}
return Lerp(a_Val1, a_Val2, a_Ratio);
}
