New Random class for convenient random number generation.

1 files changed, 62 insertions, 0 deletions

diff --git a/src/random.h b/src/random.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            random.h
+ *
+ *  Wed Mar 23 19:17:24 CET 2016
+ *  Copyright 2016 André Nusser
+ *  andre.nusser@googlemail.com
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo 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 Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#pragma once
+
+#include <random>
+#include <vector>
+
+class Random
+{
+public:
+	Random();
+	Random(unsigned int seed);
+
+	//! \return random int in range [<lower_bound>, <upper_bound>].
+	int intInRange(int lower_bound, int upper_bound);
+
+	//! \return random float in range [<lower_bound>, <upper_bound>].
+	float floatInRange(float lower_bound, float upper_bound);
+
+	//! \return random float drawn from a normal distribution with mean <mean>
+	//! and standard deviation <stddev>.
+	float normalDistribution(float mean, float stddev);
+
+	//! \return uniformly at random chosen element from <vec>.
+	template <typename T>
+	T& choose(std::vector<T>& vec);
+
+private:
+	std::default_random_engine generator;
+};
+
+template <typename T>
+T& Random::choose(std::vector<T>& vec)
+{
+	std::uniform_int_distribution<size_t> distribution(0, vec.size()-1);
+	size_t rand_index = distribution(generator);
+	return vec[rand_index];
+}