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- //----------------------------------------------------------------------------------------
- //
- // siv::PerlinNoise
- // Perlin noise library for modern C++
- //
- // Copyright (C) 2013-2018 Ryo Suzuki <reputeless@gmail.com>
- //
- // Permission is hereby granted, free of charge, to any person obtaining a copy
- // of this software and associated documentation files(the "Software"), to deal
- // in the Software without restriction, including without limitation the rights
- // to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
- // copies of the Software, and to permit persons to whom the Software is
- // furnished to do so, subject to the following conditions :
- //
- // The above copyright notice and this permission notice shall be included in
- // all copies or substantial portions of the Software.
- //
- // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
- // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- // THE SOFTWARE.
- //
- //----------------------------------------------------------------------------------------
-
- # pragma once
- # include <cstdint>
- # include <numeric>
- # include <algorithm>
- # include <random>
-
- namespace siv
- {
- class PerlinNoise
- {
- private:
-
- std::uint8_t p[512];
-
- static double Fade(double t) noexcept
- {
- return t * t * t * (t * (t * 6 - 15) + 10);
- }
-
- static double Lerp(double t, double a, double b) noexcept
- {
- return a + t * (b - a);
- }
-
- static double Grad(std::uint8_t hash, double x, double y, double z) noexcept
- {
- const std::uint8_t h = hash & 15;
- const double u = h < 8 ? x : y;
- const double v = h < 4 ? y : h == 12 || h == 14 ? x : z;
- return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
- }
-
- public:
-
- explicit PerlinNoise(std::uint32_t seed = std::default_random_engine::default_seed)
- {
- reseed(seed);
- }
-
- template <class URNG>
- explicit PerlinNoise(URNG& urng)
- {
- reseed(urng);
- }
-
- void reseed(std::uint32_t seed)
- {
- for (size_t i = 0; i < 256; ++i)
- {
- p[i] = static_cast<std::uint8_t>(i);
- }
-
- std::shuffle(std::begin(p), std::begin(p) + 256, std::default_random_engine(seed));
-
- for (size_t i = 0; i < 256; ++i)
- {
- p[256 + i] = p[i];
- }
- }
-
- template <class URNG>
- void reseed(URNG& urng)
- {
- for (size_t i = 0; i < 256; ++i)
- {
- p[i] = static_cast<std::uint8_t>(i);
- }
-
- std::shuffle(std::begin(p), std::begin(p) + 256, urng);
-
- for (size_t i = 0; i < 256; ++i)
- {
- p[256 + i] = p[i];
- }
- }
-
- double noise(double x) const
- {
- return noise(x, 0.0, 0.0);
- }
-
- double noise(double x, double y) const
- {
- return noise(x, y, 0.0);
- }
-
- double noise(double x, double y, double z) const
- {
- const std::int32_t X = static_cast<std::int32_t>(std::floor(x)) & 255;
- const std::int32_t Y = static_cast<std::int32_t>(std::floor(y)) & 255;
- const std::int32_t Z = static_cast<std::int32_t>(std::floor(z)) & 255;
-
- x -= std::floor(x);
- y -= std::floor(y);
- z -= std::floor(z);
-
- const double u = Fade(x);
- const double v = Fade(y);
- const double w = Fade(z);
-
- const std::int32_t A = p[X] + Y, AA = p[A] + Z, AB = p[A + 1] + Z;
- const std::int32_t B = p[X + 1] + Y, BA = p[B] + Z, BB = p[B + 1] + Z;
-
- return Lerp(w, Lerp(v, Lerp(u, Grad(p[AA], x, y, z),
- Grad(p[BA], x - 1, y, z)),
- Lerp(u, Grad(p[AB], x, y - 1, z),
- Grad(p[BB], x - 1, y - 1, z))),
- Lerp(v, Lerp(u, Grad(p[AA + 1], x, y, z - 1),
- Grad(p[BA + 1], x - 1, y, z - 1)),
- Lerp(u, Grad(p[AB + 1], x, y - 1, z - 1),
- Grad(p[BB + 1], x - 1, y - 1, z - 1))));
- }
-
- double octaveNoise(double x, std::int32_t octaves) const
- {
- double result = 0.0;
- double amp = 1.0;
-
- for (std::int32_t i = 0; i < octaves; ++i)
- {
- result += noise(x) * amp;
- x *= 2.0;
- amp *= 0.5;
- }
-
- return result;
- }
-
- double octaveNoise(double x, double y, std::int32_t octaves) const
- {
- double result = 0.0;
- double amp = 1.0;
-
- for (std::int32_t i = 0; i < octaves; ++i)
- {
- result += noise(x, y) * amp;
- x *= 2.0;
- y *= 2.0;
- amp *= 0.5;
- }
-
- return result;
- }
-
- double octaveNoise(double x, double y, double z, std::int32_t octaves) const
- {
- double result = 0.0;
- double amp = 1.0;
-
- for (std::int32_t i = 0; i < octaves; ++i)
- {
- result += noise(x, y, z) * amp;
- x *= 2.0;
- y *= 2.0;
- z *= 2.0;
- amp *= 0.5;
- }
-
- return result;
- }
-
- double noise0_1(double x) const
- {
- return noise(x) * 0.5 + 0.5;
- }
-
- double noise0_1(double x, double y) const
- {
- return noise(x, y) * 0.5 + 0.5;
- }
-
- double noise0_1(double x, double y, double z) const
- {
- return noise(x, y, z) * 0.5 + 0.5;
- }
-
- double octaveNoise0_1(double x, std::int32_t octaves) const
- {
- return octaveNoise(x, octaves) * 0.5 + 0.5;
- }
-
- double octaveNoise0_1(double x, double y, std::int32_t octaves) const
- {
- return octaveNoise(x, y, octaves) * 0.5 + 0.5;
- }
-
- double octaveNoise0_1(double x, double y, double z, std::int32_t octaves) const
- {
- return octaveNoise(x, y, z, octaves) * 0.5 + 0.5;
- }
- };
- }
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