src/Math/Perlin.hpp


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#pragma once

#include "Common.hpp"

namespace Math::Perlin {

float raw(Vector<2> pos);
float raw(Vector<3> pos);

template <size_t D>
struct Noise {
    static_assert(D > 1 && D < 4);

    Vector<D> offset{20000.0f};
    float scale = 15.0f;

    uint octaves = 3;
    float persistence = 0.3f;

    float at(Vector<D> pos) const {
        float result = 0;
        float max = 0;
        float frequency = 1;
        float amplitude = 1;

        for (uint octave = 0; octave < octaves; octave++) {
            result += raw((pos + offset).abs() / scale * frequency) * amplitude;
            max += amplitude;

            frequency *= 2;
            amplitude *= persistence;
        }

        return result / max;
    }
};

}