From 639f8650d4402bf924c7dadc5bf67411b48b1228 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Fri, 16 Oct 2020 07:37:22 +0300
Subject: [PATCH] Support constructing a matrix by rows/columns

---
 libs/geom/include/psemek/geom/matrix.hpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/libs/geom/include/psemek/geom/matrix.hpp b/libs/geom/include/psemek/geom/matrix.hpp
index 0d2a6d4b..83606b4a 100644
--- a/libs/geom/include/psemek/geom/matrix.hpp
+++ b/libs/geom/include/psemek/geom/matrix.hpp
@@ -235,4 +235,28 @@ namespace psemek::geom
 		return r;
 	}
 
+	template <typename T, std::size_t N, typename ... Rows>
+	auto by_rows(vector<T, N> const & v, Rows const & ... rows)
+	{
+		vector<T, N> m[] = {v, rows...};
+
+		matrix<T, sizeof...(Rows) + 1, N> result;
+		for (std::size_t i = 0; i < result.rows; ++i)
+			for (std::size_t j = 0; j < result.columns; ++j)
+				result[i][j] = m[i][j];
+		return result;
+	}
+
+	template <typename T, std::size_t N, typename ... Columns>
+	auto by_columns(vector<T, N> const & v, Columns const & ... columns)
+	{
+		vector<T, N> m[] = {v, columns...};
+
+		matrix<T, N, sizeof...(Columns) + 1> result;
+		for (std::size_t i = 0; i < result.rows; ++i)
+			for (std::size_t j = 0; j < result.columns; ++j)
+				result[i][j] = m[j][i];
+		return result;
+	}
+
 }