From d7c9b484fe99340ea451bed55a717013840a8217 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Thu, 14 Mar 2024 14:12:23 +0300
Subject: [PATCH] Add cg::irregular_triangular_prism

---
 libs/cg/include/psemek/cg/body/prism.hpp | 51 ++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/libs/cg/include/psemek/cg/body/prism.hpp b/libs/cg/include/psemek/cg/body/prism.hpp
index a89ee758..4766cdf4 100644
--- a/libs/cg/include/psemek/cg/body/prism.hpp
+++ b/libs/cg/include/psemek/cg/body/prism.hpp
@@ -86,4 +86,55 @@ namespace psemek::cg
 		return p.edge_directions;
 	}
 
+	template <typename T>
+	struct irregular_triangular_prism
+	{
+		irregular_triangular_prism() = default;
+		irregular_triangular_prism(geom::triangle<geom::point<T, 3>> const & low_triangle, geom::triangle<geom::point<T, 3>> const & high_triangle);
+
+		std::array<geom::point<T, 3>, 6> vertices;
+		std::array<geom::vector<T, 3>, 9> edge_directions;
+	};
+
+	template <typename T>
+	irregular_triangular_prism<T>::irregular_triangular_prism(geom::triangle<geom::point<T, 3>> const & low_triangle, geom::triangle<geom::point<T, 3>> const & high_triangle)
+	{
+		for (std::size_t i = 0; i < 3; ++i)
+		{
+			vertices[i] = low_triangle[i];
+			vertices[i + 3] = high_triangle[i];
+		}
+
+		for (std::size_t i = 0; i < 3; ++i)
+		{
+			edge_directions[i + 0] = geom::normalized(vertices[(i + 1) % 3] - vertices[i]);
+			edge_directions[i + 3] = geom::normalized(vertices[3 + ((i + 1) % 3)] - vertices[3 + i]);
+			edge_directions[i + 6] = geom::normalized(vertices[i + 3] - vertices[i]);
+		}
+	}
+
+	template <typename T>
+	auto const & vertices(irregular_triangular_prism<T> const & p)
+	{
+		return p.vertices;
+	}
+
+	template <typename T>
+	auto const & edges(irregular_triangular_prism<T> const &)
+	{
+		return edges(triangular_prism<T>{});
+	}
+
+	template <typename T>
+	auto const & faces(irregular_triangular_prism<T> const &)
+	{
+		return faces(triangular_prism<T>{});
+	}
+
+	template <typename T>
+	auto const & edge_directions(irregular_triangular_prism<T> const & p)
+	{
+		return p.edge_directions;
+	}
+
 }