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need more noise features

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Yggdrasil75
2025-11-07 14:27:40 -05:00
parent 90a34cd433
commit 18b03fbdac
7 changed files with 521 additions and 50 deletions
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util/noise/pnoise.hpp Normal file
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#ifndef PERLIN_NOISE_HPP
#define PERLIN_NOISE_HPP
#include <vector>
#include <cmath>
#include <random>
#include <algorithm>
#include <functional>
class PerlinNoise {
private:
std::vector<int> permutation;
// Fade function as defined by Ken Perlin
static double fade(double t) {
return t * t * t * (t * (t * 6 - 15) + 10);
}
// Linear interpolation
static double lerp(double t, double a, double b) {
return a + t * (b - a);
}
// Gradient function
static double grad(int hash, double x, double y, double z) {
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);
}
public:
// Constructor with optional seed
PerlinNoise(unsigned int seed = 0) {
permutation.resize(256);
// Initialize with values 0-255
for (int i = 0; i < 256; ++i) {
permutation[i] = i;
}
// Shuffle using the seed
std::shuffle(permutation.begin(), permutation.end(), std::default_random_engine(seed));
// Duplicate the permutation vector
permutation.insert(permutation.end(), permutation.begin(), permutation.end());
}
// 1D Perlin noise
double noise(double x) const {
return noise(x, 0.0, 0.0);
}
// 2D Perlin noise
double noise(double x, double y) const {
return noise(x, y, 0.0);
}
// 3D Perlin noise (main implementation)
double noise(double x, double y, double z) const {
// Find unit cube that contains the point
int X = (int)floor(x) & 255;
int Y = (int)floor(y) & 255;
int Z = (int)floor(z) & 255;
// Find relative x, y, z of point in cube
x -= floor(x);
y -= floor(y);
z -= floor(z);
// Compute fade curves for x, y, z
double u = fade(x);
double v = fade(y);
double w = fade(z);
// Hash coordinates of the 8 cube corners
int A = permutation[X] + Y;
int AA = permutation[A] + Z;
int AB = permutation[A + 1] + Z;
int B = permutation[X + 1] + Y;
int BA = permutation[B] + Z;
int BB = permutation[B + 1] + Z;
// Add blended results from 8 corners of cube
double res = lerp(w, lerp(v, lerp(u, grad(permutation[AA], x, y, z),
grad(permutation[BA], x - 1, y, z)),
lerp(u, grad(permutation[AB], x, y - 1, z),
grad(permutation[BB], x - 1, y - 1, z))),
lerp(v, lerp(u, grad(permutation[AA + 1], x, y, z - 1),
grad(permutation[BA + 1], x - 1, y, z - 1)),
lerp(u, grad(permutation[AB + 1], x, y - 1, z - 1),
grad(permutation[BB + 1], x - 1, y - 1, z - 1))));
return (res + 1.0) / 2.0; // Normalize to [0,1]
}
// Fractal Brownian Motion (fBm) - multiple octaves of noise
double fractal(size_t octaves, double x, double y = 0.0, double z = 0.0) const {
double value = 0.0;
double amplitude = 1.0;
double frequency = 1.0;
double maxValue = 0.0;
for (size_t i = 0; i < octaves; ++i) {
value += amplitude * noise(x * frequency, y * frequency, z * frequency);
maxValue += amplitude;
amplitude *= 0.5;
frequency *= 2.0;
}
return value / maxValue;
}
// Turbulence - absolute value of noise for more dramatic effects
double turbulence(size_t octaves, double x, double y = 0.0, double z = 0.0) const {
double value = 0.0;
double amplitude = 1.0;
double frequency = 1.0;
double maxValue = 0.0;
for (size_t i = 0; i < octaves; ++i) {
value += amplitude * std::abs(noise(x * frequency, y * frequency, z * frequency));
maxValue += amplitude;
amplitude *= 0.5;
frequency *= 2.0;
}
return value / maxValue;
}
// Ridged multi-fractal - creates ridge-like patterns
double ridgedMultiFractal(size_t octaves, double x, double y = 0.0, double z = 0.0,
double lacunarity = 2.0, double gain = 0.5, double offset = 1.0) const {
double value = 0.0;
double amplitude = 1.0;
double frequency = 1.0;
double prev = 1.0;
double weight;
for (size_t i = 0; i < octaves; ++i) {
double signal = offset - std::abs(noise(x * frequency, y * frequency, z * frequency));
signal *= signal;
signal *= prev;
weight = std::clamp(signal * gain, 0.0, 1.0);
value += signal * amplitude;
prev = weight;
amplitude *= weight;
frequency *= lacunarity;
}
return value;
}
};
// Utility functions for common noise operations
namespace PerlinUtils {
// Create a 1D noise array
static std::vector<double> generate1DNoise(int width, double scale = 1.0, unsigned int seed = 0) {
PerlinNoise pn(seed);
std::vector<double> result(width);
for (int x = 0; x < width; ++x) {
result[x] = pn.noise(x * scale);
}
return result;
}
// Create a 2D noise array
static std::vector<std::vector<double>> generate2DNoise(int width, int height,
double scale = 1.0, unsigned int seed = 0) {
PerlinNoise pn(seed);
std::vector<std::vector<double>> result(height, std::vector<double>(width));
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
result[y][x] = pn.noise(x * scale, y * scale);
}
}
return result;
}
// Create a 3D noise array
static std::vector<std::vector<std::vector<double>>> generate3DNoise(int width, int height, int depth,
double scale = 1.0, unsigned int seed = 0) {
PerlinNoise pn(seed);
std::vector<std::vector<std::vector<double>>> result(
depth, std::vector<std::vector<double>>(
height, std::vector<double>(width)));
for (int z = 0; z < depth; ++z) {
for (int y = 0; y < height; ++y) {
for (int x = 0; x < width; ++x) {
result[z][y][x] = pn.noise(x * scale, y * scale, z * scale);
}
}
}
return result;
}
}
#endif