Add a file for general geometric mesh utilities

libs/geom/include/psemek/geom/mesh.hpp

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <psemek/geom/box.hpp>
+#include <psemek/geom/simplex.hpp>
+
+#include <vector>
+#include <cstdint>
+
+namespace psemek::geom
+{
+
+	template <typename T, std::size_t N>
+	std::vector<point<T, N>> vertices(box<T, N> const & b)
+	{
+		std::vector<point<T, N>> result;
+
+		for (std::size_t mask = 0; mask < (1 << N); ++mask)
+		{
+			point<T, N> p;
+			for (std::size_t i = 0; i < N; ++i)
+			{
+				p[i] = (mask & (1 << i)) ? b[i].max : b[i].min;
+			}
+			result.push_back(p);
+		}
+
+		return result;
+	}
+
+	template <typename Index = std::uint32_t, typename T, std::size_t N>
+	std::vector<simplex<Index, 1>> edges(box<T, N> const &)
+	{
+		static_assert(N > 0); // who knows?..
+
+		std::vector<simplex<Index, 1>> result;
+
+		for (std::size_t i = 0; i < N; ++i)
+		{
+			for (std::size_t mask = 0; mask < (1 << (N - 1)); ++mask)
+			{
+				auto const lo = mask & ((1 << i) - 1);
+				auto const hi = mask ^ lo;
+
+				auto const idx0 = lo | (hi << 1);
+				auto const idx1 = idx0 | (1 << i);
+
+				result.push_back({static_cast<Index>(idx0), static_cast<Index>(idx1)});
+			}
+		}
+
+		return result;
+	}
+
+}