1 files changed, 70 insertions, 0 deletions
diff --git a/c++/ico.hpp b/c++/ico.hpp
new file mode 100644
index 0000000..0ac1a91
--- /dev/null
+++ b/c++/ico.hpp
@@ -0,0 +1,70 @@
+#pragma once
+
+#include <array>
+#include <cstdint>
+
+namespace kel {
+namespace impl {
+struct ico_surface_helper {
+	/**
+	 * On each triangle we assume a ccw order and we start on the top-left part of the
+	 * triangle. The orientation of the triangle is determined by the horizontal line
+	 * (on the 2D foldout of the icosahedron) which is the down direction.  
+	 */
+	static constexpr std::array<std::array<uint8_t,3u>, 20u> neighbour_map {
+		{1,4,5},//0
+		{2,0,6},//1
+		{3,1,7},//2
+		{4,2,8},//3
+		{0,3,9},//4
+		{14,10,0},//5
+		{10,11,1},//6
+		{11,12,2},//7
+		{12,13,3},//8
+		{13,14,4},//9
+		{6,5,15},//10
+		{7,6,16},//11
+		{8,7,17},//12
+		{9,8,18},//13
+		{5,9,19},//14
+		{19,16,10},//15
+		{15,17,11},//16
+		{16,18,12},//17
+		{17,19,13},//18
+		{18,15,14} //19
+	};
+};
+}
+
+template<uint64_t SubD>
+class ico_addr {
+private:
+	std::array<uint8_t, SubD+1u> vals_;
+public:
+	template<uint64_t Div = 1u>
+	ico_addr<Div> slice() const {
+		return {};
+	}
+};
+
+template<typename T, uint64_t D>
+class ico_triangle {
+private:
+	std::array<ico_triangle<T,D-1u>> subdivs_;
+public:
+};
+
+template<typename T>
+class ico_triangle<T,0u> final {
+private:
+	T val_;
+public:
+};
+
+template<typename T, uint64_t SubD>
+class icosahedron final {
+private:
+	std::array<ico_triangle<T,SubD>,20u> surfaces_;
+public:
+};
+}