Files
stupidsimcpp/util/noise/pnoise2.hpp
2026-01-16 13:37:13 -05:00

304 lines
9.9 KiB
C++

#ifndef PNOISE2_HPP
#define PNOISE2_HPP
#include <vector>
#include <cmath>
#include <algorithm>
#include <functional>
#include <random>
#include "../vectorlogic/vec2.hpp"
#include "../vectorlogic/vec3.hpp"
#include "../vectorlogic/vec4.hpp"
#include "../timing_decorator.hpp"
class PNoise2 {
private:
std::vector<int> permutation;
std::default_random_engine rng;
float lerp(float t, float a1, float a2) {
return a1 + t * (a2 - a1);
}
static double fade(double t) {
return t * t * t * (t * (t * 6 - 15) + 10);
}
Vec2f GetConstantVector(int v) {
int h = v & 3;
if (h == 0) return Vec2f(1,1);
else if (h == 1) return Vec2f(-1,1);
else if (h == 2) return Vec2f(-1,-1);
else return Vec2f(1,-1);
}
Vec3ui8 GetConstantVector3(int v) {
int h = v & 7;
if (h == 0) return Vec3ui8(1,1,1);
else if (h == 1) return Vec3ui8(-1,1, 1);
else if (h == 2) return Vec3ui8(-1,-1, 1);
else if (h == 3) return Vec3ui8(-1,-1, 1);
else if (h == 4) return Vec3ui8(-1,-1,-1);
else if (h == 5) return Vec3ui8(-1,-1, -1);
else if (h == 6) return Vec3ui8(-1,-1, -1);
else return Vec3ui8(1,-1, -1);
}
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);
}
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());
}
float normalizedNoise(const Vec2<float>& point) {
return (permute(point) + 1.0f) * 0.5f;
}
float mapRange(float value, float inMin, float inMax, float outMin, float outMax) {
return (value - inMin) * (outMax - outMin) / (inMax - inMin) + outMin;
}
float blendNoises(float noise1, float noise2, float blendFactor) {
return lerp(noise1, noise2, blendFactor);
}
float addNoises(float noise1, float noise2) {
return std::clamp(noise1 + noise2, -1.0f, 1.0f);
}
float multiplyNoises(float noise1, float noise2) {
return noise1 * noise2;
}
float hash(int x, int y) {
return (permutation[(x + permutation[y & 255]) & 255] / 255.0f) * 2.0f - 1.0f;
}
public:
PNoise2() : rng(std::random_device{}()) {
initializePermutation();
}
PNoise2(unsigned int seed) : rng(seed) {
initializePermutation();
}
template<typename T>
float permute(Vec2<T> point) {
TIME_FUNCTION;
float x = static_cast<float>(point.x);
float y = static_cast<float>(point.y);
int X = (int)floor(x);
int xmod = X & 255;
int Y = (int)floor(point.y);
int ymod = Y & 255;
float xf = point.x - X;
float yf = point.y - Y;
Vec2 BL = Vec2(xf-0, yf-0);
Vec2 BR = Vec2(xf-1, yf-0);
Vec2 TL = Vec2(xf-0, yf-1);
Vec2 TR = Vec2(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);
//std::cout << "returning: " << retval << std::endl;
return retval;
}
template<typename T>
float permute(Vec3<T> point) {
TIME_FUNCTION;
int X = (int)floor(point.x) & 255;
int Y = (int)floor(point.y) & 255;
int Z = (int)floor(point.z) & 255;
float xf = point.x - X;
float yf = point.y - Y;
float zf = point.z - Z;
Vec3ui8 FBL = Vec3ui8(xf-0, yf-0, zf-0);
Vec3ui8 FBR = Vec3ui8(xf-1, yf-0, zf-0);
Vec3ui8 FTL = Vec3ui8(xf-0, yf-1, zf-0);
Vec3ui8 FTR = Vec3ui8(xf-1, yf-1, zf-0);
Vec3ui8 RBL = Vec3ui8(xf-0, yf-0, zf-1);
Vec3ui8 RBR = Vec3ui8(xf-1, yf-0, zf-1);
Vec3ui8 RTL = Vec3ui8(xf-0, yf-1, zf-1);
Vec3ui8 RTR = Vec3ui8(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);
//std::cout << "returning: " << retval << std::endl;
return retval;
}
float valueNoise(const Vec2<float>& 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);
}
Vec4ui8 permuteColor(const Vec3<float>& point) {
TIME_FUNCTION;
float noiseR = permute(point);
float noiseG = permute(point + Vec3<float>(100.0f, 100.0f, 100.0f));
float noiseB = permute(point + Vec3<float>(200.0f, 200.0f, 200.0f));
float noiseA = permute(point + Vec3<float>(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);
uint8_t r = static_cast<uint8_t>(noiseR * 255.0f);
uint8_t g = static_cast<uint8_t>(noiseG * 255.0f);
uint8_t b = static_cast<uint8_t>(noiseB * 255.0f);
uint8_t a = static_cast<uint8_t>(noiseA * 255.0f);
return Vec4ui8(r, g, b, a);
}
template<typename T>
float fractalNoise(const Vec2<T>& point, int octaves, float persistence, float lacunarity) {
float total = 0.0f;
float frequency = 1.f;
float amplitude = 1.f;
float maxV = 0.f;
for (int i = 0; i < octaves; i++) {
total += permute(point*frequency) * amplitude;
maxV += amplitude;
amplitude *= persistence;
frequency *= lacunarity;
}
return total / maxV;
}
template<typename T>
float turbulence(const Vec2<T>& point, int octaves) {
float value = 0.0f;
Vec2<float> tempPoint = point;
for (int i = 0; i < octaves; i++) {
value += std::abs(permute(tempPoint));
tempPoint *= 2.f;
}
return value;
}
float ridgedNoise(const Vec2<float>& point, int octaves, float offset = 1.0f) {
float result = 0.f;
float weight = 1.f;
Vec2<float> 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;
}
float billowNoise(const Vec2<float>& point, int octaves) {
float value = 0.0f;
float amplitude = 1.0f;
float frequency = 1.0f;
for (int i = 0; i < octaves; i++) {
value += std::abs(permute(point * frequency)) * amplitude;
amplitude *= 0.5f;
frequency *= 2.0f;
}
return value;
}
};
#endif