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stupidsimcpp/util/noise/pnoise2.hpp

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20 KiB
C++

#ifndef PNOISE2_HPP
#define PNOISE2_HPP
#include <vector>
#include <cmath>
#include <algorithm>
#include <functional>
#include <random>
#include "../../eigen/Eigen/Core"
#include "../timing_decorator.hpp"
class PNoise2 {
private:
std::vector<int> permutation;
std::default_random_engine rng;
using Vector2f = Eigen::Vector2f;
using Vector3f = Eigen::Vector3f;
using Vector4f = Eigen::Vector4f;
/// @brief Linear interpolation between two values
/// @param t Interpolation factor [0,1]
/// @param a1 First value
/// @param a2 Second value
/// @return Interpolated value between a1 and a2
/// @note Changing interpolation method affects noise smoothness
float lerp(float t, float a1, float a2) {
return a1 + t * (a2 - a1);
}
/// @brief Fade function for smooth interpolation
/// @param t Input parameter
/// @return Smoothed t value using 6t^5 - 15t^4 + 10t^3
/// @note Critical for gradient continuity; changes affect noise smoothness
static double fade(double t) {
return t * t * t * (t * (t * 6 - 15) + 10);
}
/// @brief Get constant gradient vector for 2D Perlin noise
/// @param v Hash value (0-3)
/// @return One of four 2D gradient vectors
/// @note Changing vectors affects noise pattern orientation
Vector2f GetConstantVector(int v) {
int h = v & 3;
if (h == 0) return Vector2f(1,1);
else if (h == 1) return Vector2f(-1,1);
else if (h == 2) return Vector2f(-1,-1);
else return Vector2f(1,-1);
}
/// @brief Get constant gradient vector for 3D Perlin noise
/// @param v Hash value (0-11)
/// @return One of twelve 3D gradient vectors
/// @note Vector selection affects 3D noise patterns
Vector3f GetConstantVector3(int v) {
int h = v & 11;
switch(h) {
case 0: return Vector3f( 1, 1, 0);
case 1: return Vector3f(-1, 1, 0);
case 2: return Vector3f( 1,-1, 0);
case 3: return Vector3f(-1,-1, 0);
case 4: return Vector3f( 1, 0, 1);
case 5: return Vector3f(-1, 0, 1);
case 6: return Vector3f( 1, 0,-1);
case 7: return Vector3f(-1, 0,-1);
case 8: return Vector3f( 0, 1, 1);
case 9: return Vector3f( 0,-1, 1);
case 10: return Vector3f( 0, 1,-1);
case 11: return Vector3f( 0,-1,-1);
default: return Vector3f(0,0,0);
}
}
/// @brief Gradient function for 2D/3D Perlin noise
/// @param hash Hash value for gradient selection
/// @param x X coordinate
/// @param y Y coordinate
/// @param z Z coordinate (default 0 for 2D)
/// @return Dot product of gradient vector and distance vector
/// @note Core of Perlin noise; changes affect basic noise character
static double grad(int hash, double x, double y, double z = 0.0) {
int h = hash & 15;
double u = h < 8 ? x : y;
double v = h < 4 ? y : (h == 12 || h == 14 ? x : z);
return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
}
/// @brief Initialize permutation table with shuffled values
/// @note Called on construction; changing seed or shuffle affects all noise patterns
void initializePermutation() {
permutation.clear();
std::vector<int> permutationt;
permutationt.reserve(256);
for (int i = 0; i < 256; i++){
permutationt.push_back(i);
}
std::ranges::shuffle(permutationt, rng);
permutation.insert(permutation.end(), permutationt.begin(), permutationt.end());
permutation.insert(permutation.end(), permutationt.begin(), permutationt.end());
}
/// @brief Normalize noise value from [-1,1] to [0,1]
/// @param point Input coordinate
/// @return Normalized noise value in [0,1] range
/// @note Useful for texture generation; changes affect output range
float normalizedNoise(const Vector2f& point) {
return (permute(point) + 1.0f) * 0.5f;
}
/// @brief Normalize 3D noise value from [-1,1] to [0,1]
/// @param point Input coordinate
/// @return Normalized noise value in [0,1] range
float normalizedNoise(const Vector3f& point) {
return (permute(point) + 1.0f) * 0.5f;
}
/// @brief Map value from one range to another
/// @param value Input value
/// @param inMin Original range minimum
/// @param inMax Original range maximum
/// @param outMin Target range minimum
/// @param outMax Target range maximum
/// @return Value mapped to new range
/// @note Useful for post-processing; changes affect output scaling
float mapRange(float value, float inMin, float inMax, float outMin, float outMax) {
return (value - inMin) * (outMax - outMin) / (inMax - inMin) + outMin;
}
/// @brief Blend two noise values
/// @param noise1 First noise value
/// @param noise2 Second noise value
/// @param blendFactor Blending factor [0,1]
/// @return Blended noise value
/// @note Changes affect multi-layer noise combinations
float blendNoises(float noise1, float noise2, float blendFactor) {
return lerp(blendFactor, noise1, noise2);
}
/// @brief Add two noise values with clamping
/// @param noise1 First noise value
/// @param noise2 Second noise value
/// @return Sum clamped to [-1,1]
/// @note Clamping prevents overflow; changes affect combined noise magnitude
float addNoises(float noise1, float noise2) {
return std::clamp(noise1 + noise2, -1.0f, 1.0f);
}
/// @brief Multiply two noise values
/// @param noise1 First noise value
/// @param noise2 Second noise value
/// @return Product of noise values
/// @note Creates modulation effects; changes affect combined noise character
float multiplyNoises(float noise1, float noise2) {
return noise1 * noise2;
}
/// @brief Hash function for 2D coordinates
/// @param x X coordinate integer
/// @param y Y coordinate integer
/// @return Hash value in [-1,1] range
/// @note Core of value noise; changes affect random distribution
float hash(int x, int y) {
return (permutation[(x + permutation[y & 255]) & 255] / 255.0f) * 2.0f - 1.0f;
}
/// @brief Hash function for 3D coordinates
/// @param x X coordinate integer
/// @param y Y coordinate integer
/// @param z Z coordinate integer
/// @return Hash value in [-1,1] range
/// @note 3D version of hash function
float hash(int x, int y, int z) {
return (permutation[(z + permutation[(y + permutation[x & 255]) & 255]) & 255] / 255.0f) * 2.0f - 1.0f;
}
public:
/// @brief Default constructor with random seed
/// @note Uses random_device for seed; different runs produce different noise
PNoise2() : rng(std::random_device{}()) {
initializePermutation();
}
/// @brief Constructor with specified seed
/// @param seed Random seed value
/// @note Same seed produces identical noise patterns across runs
PNoise2(unsigned int seed) : rng(seed) {
initializePermutation();
}
/// @brief Generate 2D Perlin noise at given point
/// @param point 2D coordinate
/// @return Noise value in [-1,1] range
/// @note Core 2D noise function; changes affect all 2D noise outputs
float permute(const Vector2f& point) {
TIME_FUNCTION;
float x = point.x();
float y = point.y();
int X = (int)floor(x);
int xmod = X & 255;
int Y = (int)floor(y);
int ymod = Y & 255;
float xf = x - X;
float yf = y - Y;
Vector2f BL(xf-0, yf-0);
Vector2f BR(xf-1, yf-0);
Vector2f TL(xf-0, yf-1);
Vector2f TR(xf-1, yf-1);
int vBL = permutation[permutation[xmod+0]+ymod+0];
int vBR = permutation[permutation[xmod+1]+ymod+0];
int vTL = permutation[permutation[xmod+0]+ymod+1];
int vTR = permutation[permutation[xmod+1]+ymod+1];
// float dBL = BL.dot(GetConstantVector(vBL));
// float dBR = BR.dot(GetConstantVector(vBR));
// float dTL = TL.dot(GetConstantVector(vTL));
// float dTR = TR.dot(GetConstantVector(vTR));
float u = fade(xf);
float v = fade(yf);
float x1 = lerp(u, grad(vBL, xf, yf), grad(vBR, xf - 1, yf));
float x2 = lerp(u, grad(vTL, xf, yf - 1), grad(vTR, xf - 1, yf - 1));
float retval = lerp(v, x1, x2);
return retval;
}
/// @brief Generate 3D Perlin noise at given point
/// @param point 3D coordinate
/// @return Noise value in [-1,1] range
float permute(const Vector3f& point) {
TIME_FUNCTION;
float x = point.x();
float y = point.y();
float z = point.z();
int X = (int)floor(x) & 255;
int Y = (int)floor(y) & 255;
int Z = (int)floor(z) & 255;
float xf = x - X;
float yf = y - Y;
float zf = z - Z;
// Distance vectors from corners
Vector3f FBL(xf-0, yf-0, zf-0);
Vector3f FBR(xf-1, yf-0, zf-0);
Vector3f FTL(xf-0, yf-1, zf-0);
Vector3f FTR(xf-1, yf-1, zf-0);
Vector3f RBL(xf-0, yf-0, zf-1);
Vector3f RBR(xf-1, yf-0, zf-1);
Vector3f RTL(xf-0, yf-1, zf-1);
Vector3f RTR(xf-1, yf-1, zf-1);
int vFBL = permutation[permutation[permutation[Z+0]+X+0]+Y+0];
int vFBR = permutation[permutation[permutation[Z+0]+X+1]+Y+0];
int vFTL = permutation[permutation[permutation[Z+0]+X+0]+Y+1];
int vFTR = permutation[permutation[permutation[Z+0]+X+1]+Y+1];
int vRBL = permutation[permutation[permutation[Z+1]+X+0]+Y+0];
int vRBR = permutation[permutation[permutation[Z+1]+X+1]+Y+0];
int vRTL = permutation[permutation[permutation[Z+1]+X+0]+Y+1];
int vRTR = permutation[permutation[permutation[Z+1]+X+1]+Y+1];
// float dFBL = FBL.dot(GetConstantVector3(vFBL));
// float dFBR = FBR.dot(GetConstantVector3(vFBR));
// float dFTL = FTL.dot(GetConstantVector3(vFTL));
// float dFTR = FTR.dot(GetConstantVector3(vFTR));
// float dRBL = RBL.dot(GetConstantVector3(vRBL));
// float dRBR = RBR.dot(GetConstantVector3(vRBR));
// float dRTL = RTL.dot(GetConstantVector3(vRTL));
// float dRTR = RTR.dot(GetConstantVector3(vRTR));
float u = fade(xf);
float v = fade(yf);
float w = fade(zf);
float x1 = lerp(u, grad(vFBL, xf, yf + 0, zf + 0), grad(vFBR, xf - 1, yf + 0, zf + 0));
float x2 = lerp(u, grad(vFTL, xf, yf - 1, zf + 0), grad(vFTR, xf - 1, yf - 1, zf + 0));
float y1 = lerp(v, x1, x2);
float x3 = lerp(u, grad(vRBL, xf, yf - 1, zf + 1), grad(vRBR, xf - 1, yf - 1, zf + 1));
float x4 = lerp(u, grad(vRTL, xf, yf - 1, zf + 1), grad(vRTR, xf - 1, yf - 1, zf + 1));
float y2 = lerp(v, x3, x4);
float retval = lerp(w, y1, y2);
return retval;
}
/// @brief Generate 2D value noise (simpler alternative to Perlin)
/// @param point 2D coordinate
/// @return Noise value in [-1,1] range
/// @note Different character than Perlin; changes affect value-based textures
float valueNoise(const Vector2f& point) {
int xi = (int)std::floor(point.x());
int yi = (int)std::floor(point.y());
float tx = point.x() - xi;
float ty = point.y() - yi;
int rx0 = xi & 255;
int rx1 = (xi + 1) & 255;
int ry0 = yi & 255;
int ry1 = (yi + 1) & 255;
// Random values at corners
float c00 = hash(rx0, ry0);
float c10 = hash(rx1, ry0);
float c01 = hash(rx0, ry1);
float c11 = hash(rx1, ry1);
// Interpolation
float sx = fade(tx);
float sy = fade(ty);
float nx0 = lerp(c00, c10, sx);
float nx1 = lerp(c01, c11, sx);
return lerp(nx0, nx1, sy);
}
/// @brief Generate 3D value noise
/// @param point 3D coordinate
/// @return Noise value in [-1,1] range
float valueNoise(const Vector3f& point) {
int xi = (int)std::floor(point.x());
int yi = (int)std::floor(point.y());
int zi = (int)std::floor(point.z());
float tx = point.x() - xi;
float ty = point.y() - yi;
float tz = point.z() - zi;
int rx0 = xi & 255;
int rx1 = (xi + 1) & 255;
int ry0 = yi & 255;
int ry1 = (yi + 1) & 255;
int rz0 = zi & 255;
int rz1 = (zi + 1) & 255;
// Random values at corners
float c000 = hash(rx0, ry0, rz0);
float c100 = hash(rx1, ry0, rz0);
float c010 = hash(rx0, ry1, rz0);
float c110 = hash(rx1, ry1, rz0);
float c001 = hash(rx0, ry0, rz1);
float c101 = hash(rx1, ry0, rz1);
float c011 = hash(rx0, ry1, rz1);
float c111 = hash(rx1, ry1, rz1);
// Interpolation
float sx = fade(tx);
float sy = fade(ty);
float sz = fade(tz);
float nx00 = lerp(c000, c100, sx);
float nx10 = lerp(c010, c110, sx);
float nx01 = lerp(c001, c101, sx);
float nx11 = lerp(c011, c111, sx);
float ny0 = lerp(nx00, nx10, sy);
float ny1 = lerp(nx01, nx11, sy);
return lerp(ny0, ny1, sz);
}
/// @brief Generate RGBA color from 3D noise with offset channels
/// @param point 3D coordinate
/// @return Vector4f containing RGBA noise values
/// @note Each channel uses different offset; changes affect color patterns
Vector4f permuteColor(const Vector3f& point) {
TIME_FUNCTION;
float noiseR = permute(point);
float noiseG = permute(Vector3f(point + Vector3f(100.0f, 100.0f, 100.0f)));
float noiseB = permute(Vector3f(point + Vector3f(200.0f, 200.0f, 200.0f)));
float noiseA = permute(Vector3f(point + Vector3f(300.0f, 300.0f, 300.0f)));
float rNormalized = (noiseR + 1.0f) * 0.5f;
float gNormalized = (noiseG + 1.0f) * 0.5f;
float bNormalized = (noiseB + 1.0f) * 0.5f;
float aNormalized = (noiseA + 1.0f) * 0.5f;
rNormalized = std::clamp(rNormalized, 0.0f, 1.0f);
gNormalized = std::clamp(gNormalized, 0.0f, 1.0f);
bNormalized = std::clamp(bNormalized, 0.0f, 1.0f);
aNormalized = std::clamp(aNormalized, 0.0f, 1.0f);
return Vector4f(rNormalized, gNormalized, bNormalized, aNormalized);
}
/// @brief Generate fractal (octave) noise for natural-looking patterns
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @param persistence Amplitude multiplier per octave
/// @param lacunarity Frequency multiplier per octave
/// @return Combined noise value
/// @note Parameters control noise character: octaves=detail, persistence=roughness, lacunarity=frequency change
float fractalNoise(const Vector2f& point, int octaves, float persistence, float lacunarity) {
float total = 0.0f;
float frequency = 1.f;
float amplitude = 1.f;
float maxV = 0.f;
Vector2f scaledPoint = point * frequency;
for (int i = 0; i < octaves; i++) {
total += permute(scaledPoint) * amplitude;
maxV += amplitude;
amplitude *= persistence;
frequency *= lacunarity;
}
return total / maxV;
}
/// @brief Generate 3D fractal (octave) noise
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @param persistence Amplitude multiplier per octave
/// @param lacunarity Frequency multiplier per octave
/// @return Combined noise value
float fractalNoise(const Vector3f& point, int octaves, float persistence, float lacunarity) {
float total = 0.0f;
float frequency = 1.f;
float amplitude = 1.f;
float maxV = 0.f;
Vector3f scaledPoint = point * frequency;
for (int i = 0; i < octaves; i++) {
total += permute(scaledPoint) * amplitude;
maxV += amplitude;
amplitude *= persistence;
frequency *= lacunarity;
}
return total / maxV;
}
/// @brief Generate turbulence noise (absolute value of octaves)
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @return Turbulence noise value
/// @note Creates swirling, turbulent patterns; changes affect visual complexity
float turbulence(const Vector2f& point, int octaves) {
float value = 0.0f;
Vector2f tempPoint = point;
for (int i = 0; i < octaves; i++) {
value += std::abs(permute(tempPoint)) / (1 << i);
tempPoint *= 2.f;
}
return value;
}
/// @brief Generate 3D turbulence noise
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @return Turbulence noise value
float turbulence(const Vector3f& point, int octaves) {
float value = 0.0f;
Vector3f tempPoint = point;
for (int i = 0; i < octaves; i++) {
value += std::abs(permute(tempPoint)) / (1 << i);
tempPoint *= 2.f;
}
return value;
}
/// @brief Generate ridged (ridged multifractal) noise
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @param offset Weighting offset for ridge formation
/// @return Ridged noise value
/// @note Creates sharp ridge-like patterns; offset controls ridge prominence
float ridgedNoise(const Vector2f& point, int octaves, float offset = 1.0f) {
float result = 0.f;
float weight = 1.f;
Vector2f p = point;
for (int i = 0; i < octaves; i++) {
float signal = 1.f - std::abs(permute(p));
signal *= signal;
signal *= weight;
weight = signal * offset;
result += signal;
p *= 2.f;
}
return result;
}
/// @brief Generate 3D ridged noise
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @param offset Weighting offset for ridge formation
/// @return Ridged noise value
float ridgedNoise(const Vector3f& point, int octaves, float offset = 1.0f) {
float result = 0.f;
float weight = 1.f;
Vector3f p = point;
for (int i = 0; i < octaves; i++) {
float signal = 1.f - std::abs(permute(p));
signal *= signal;
signal *= weight;
weight = signal * offset;
result += signal;
p *= 2.f;
}
return result;
}
/// @brief Generate billow (cloud-like) noise
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @return Billow noise value
/// @note Creates soft, billowy patterns like clouds
float billowNoise(const Vector2f& point, int octaves) {
float value = 0.0f;
float amplitude = 1.0f;
float frequency = 1.0f;
Vector2f scaledPoint = point * frequency;
for (int i = 0; i < octaves; i++) {
value += std::abs(permute(scaledPoint)) * amplitude;
amplitude *= 0.5f;
frequency *= 2.0f;
}
return value;
}
/// @brief Generate 3D billow noise
/// @param point Input coordinate
/// @param octaves Number of noise layers
/// @return Billow noise value
float billowNoise(const Vector3f& point, int octaves) {
float value = 0.0f;
float amplitude = 1.0f;
float frequency = 1.0f;
Vector3f scaledPoint = point * frequency;
for (int i = 0; i < octaves; i++) {
value += std::abs(permute(scaledPoint)) * amplitude;
amplitude *= 0.5f;
frequency *= 2.0f;
}
return value;
}
};
#endif