Adding PerlinNoiseGenerator

include/easy/dsp/random/brown_noise_generator.hpp

@@ -29,8 +29,8 @@ namespace easy { namespace dsp { namespace random {
     template <typename T, typename Engine = std::mt19937>
     struct BrownNoiseGenerator {
         using result_type = T;
-        inline BrownNoiseGenerator(result_type mean, result_type std_dev) :
-            generator_(WhiteNoiseGenerator<result_type>(mean, std_dev)) {
+        inline BrownNoiseGenerator(result_type min, result_type max) :
+            generator_(WhiteNoiseGenerator<result_type>(min, max)) {
 
         }
 

include/easy/dsp/random/perlin_noise_generator.hpp

@@ -0,0 +1,93 @@
+/*
+ * EasyDSP, A cross-platform Digital Signal Processing library written in modern C++.
+ * Copyright (C) 2018 Mohammed Boujemaoui Boulaghmoudi
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of  MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along withº
+ * this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ * Filename: perlin_noise_generator.hpp
+ * Author: Mohammed Boujemaoui
+ * Date: 1/8/2018
+ */
+#ifndef EASYDSP_PERLIN_NOISE_GENERATOR_HPP
+#define EASYDSP_PERLIN_NOISE_GENERATOR_HPP
+
+#include <array>
+#include <random>
+#include <chrono>
+
+namespace easy { namespace dsp { namespace random {
+
+
+    namespace {
+
+        template <typename T>
+        constexpr T fade(T t) noexcept {
+            return t * t * t * (t * (t * 6 - 15) + 10);
+        }
+
+        template <typename T>
+        constexpr T lerp(T t, T a, T b) noexcept {
+            return a + t * (b - a);
+        }
+
+        template <typename Integer, typename T>
+        constexpr T grad(Integer hash, T x) noexcept {
+            return (hash & 1) == 0 ? x : -x;
+        }
+
+    }
+
+
+    template <typename T, typename Engine = std::mt19937>
+    struct PerlinNoiseGenerator {
+        using result_type = T;
+        inline PerlinNoiseGenerator() :
+            generator_(Engine(static_cast<std::size_t>(std::chrono::system_clock::now()
+                                                       .time_since_epoch()
+                                                       .count()))),
+            distribution_(std::uniform_int_distribution<T>(0, 511)) {
+
+        }
+
+        inline result_type operator()() {
+            const auto random_value = distribution_(generator_);
+            const auto index = static_cast<std::int64_t>(random_value) & 0xFF;
+            const auto floor_value = random_value - std::floor(random_value);
+            const auto fade_value = fade(random_value);
+            return lerp(fade_value,
+                        grad(permutation[index], floor_value),
+                        grad(permutation[index + 1], floor_value - 1)) * 2;
+        }
+    private:
+        Engine generator_;
+        std::uniform_int_distribution<T> distribution_;
+        static constexpr const std::array<T, 512> permutation = {{ 151,160,137,91,90,15,
+            131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
+            190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
+            88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
+            77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
+            102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
+            135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
+            5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
+            223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
+            129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
+            251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
+            49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
+            138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
+        }};
+    };
+
+
+}}}
+#endif // EASYDSP_PERLIN_NOISE_GENERATOR_HPP