From d4c162c1e0c41cbba96a09d8a251731bc5085fdb Mon Sep 17 00:00:00 2001
From: "C. J. Howard" <cjhoward@protonmail.com>
Date: Sat, 21 Nov 2020 22:11:20 +0800
Subject: [PATCH] Add initial genetics code

---
 src/game/genetics/allele.hpp   | 38 +++++++++++++++++++
 src/game/genetics/gene.hpp     | 33 +++++++++++++++++
 src/game/genetics/zygosity.hpp | 68 ++++++++++++++++++++++++++++++++++
 3 files changed, 139 insertions(+)
 create mode 100644 src/game/genetics/allele.hpp
 create mode 100644 src/game/genetics/gene.hpp
 create mode 100644 src/game/genetics/zygosity.hpp

diff --git a/src/game/genetics/allele.hpp b/src/game/genetics/allele.hpp
new file mode 100644
index 0000000..e39ed80
--- /dev/null
+++ b/src/game/genetics/allele.hpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2020  Christopher J. Howard
+ *
+ * This file is part of Antkeeper source code.
+ *
+ * Antkeeper source code 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.
+ *
+ * Antkeeper source code 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 with Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ANTKEEPER_ALLELE_HPP
+#define ANTKEEPER_ALLELE_HPP
+
+namespace dna
+{
+
+/// Enumerates allele types.
+enum class allele: bool
+{
+	/// Indicates an allele is recessive.
+	recessive = false,
+	
+	/// Indicates an allele is dominant.
+	dominant = true
+};
+
+} // namespace dna
+
+#endif // ANTKEEPER_ALLELE_HPP
diff --git a/src/game/genetics/gene.hpp b/src/game/genetics/gene.hpp
new file mode 100644
index 0000000..0de648e
--- /dev/null
+++ b/src/game/genetics/gene.hpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2020  Christopher J. Howard
+ *
+ * This file is part of Antkeeper source code.
+ *
+ * Antkeeper source code 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.
+ *
+ * Antkeeper source code 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 with Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ANTKEEPER_GENE_HPP
+#define ANTKEEPER_GENE_HPP
+
+#include "allele.hpp"
+
+namespace dna
+{
+
+/// A gene with two alleles.
+typedef std::array<allele, 2> gene;
+
+} // namespace dna
+
+#endif // ANTKEEPER_GENE_HPP
diff --git a/src/game/genetics/zygosity.hpp b/src/game/genetics/zygosity.hpp
new file mode 100644
index 0000000..549edca
--- /dev/null
+++ b/src/game/genetics/zygosity.hpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2020  Christopher J. Howard
+ *
+ * This file is part of Antkeeper source code.
+ *
+ * Antkeeper source code 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.
+ *
+ * Antkeeper source code 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 with Antkeeper source code.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef ANTKEEPER_ZYGOSITY_HPP
+#define ANTKEEPER_ZYGOSITY_HPP
+
+#include "gene.hpp"
+
+namespace dna
+{
+
+/// A homozygous recessive gene.
+static constexpr gene homozygous_recessive = {allele::recessive, allele::recessive};
+
+/// A homozygous dominant gene.
+static constexpr gene homozygous_dominant = {allele::recessive, allele::recessive};
+	
+/// Returns `true` if gene @p x is heterozygous, `false` otherwise.
+bool is_heterozygous(const gene& x);
+
+/// Returns `true` if gene @p x is homozygous, `false` otherwise.
+bool is_homozygous(const gene& x);
+
+/// Returns `true` if gene @p x is homozygous recessive, `false` otherwise.
+bool is_homozygous_recessive(const gene& x);
+
+/// Returns `true` if gene @p x is homozygous dominant, `false` otherwise.
+bool is_homozygous_dominant(const gene& x);
+
+inline bool is_heterozygous(const gene& x)
+{
+	return x[0] != x[1];
+}
+
+inline bool is_homozygous(const gene& x)
+{
+	return x[0] == x[1];
+}
+
+inline bool is_homozygous_recessive(const gene& x)
+{
+	return x == homozygous_recessive;
+}
+
+inline bool is_homozygous_dominant(const gene& x)
+{
+	return x == homozygous_dominant;
+}
+
+} // namespace dna
+
+#endif // ANTKEEPER_ZYGOSITY_HPP