From ec86b0c0aa4aed4c1148cc01b8c05cbb3a0a32d8 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Wed, 1 Dec 2021 21:22:00 +0300
Subject: [PATCH] Add geom::signed_distance

---
 libs/geom/include/psemek/geom/distance.hpp | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/libs/geom/include/psemek/geom/distance.hpp b/libs/geom/include/psemek/geom/distance.hpp
index eb33f94e..c5d9c5a4 100644
--- a/libs/geom/include/psemek/geom/distance.hpp
+++ b/libs/geom/include/psemek/geom/distance.hpp
@@ -5,6 +5,7 @@
 #include <psemek/geom/math.hpp>
 #include <psemek/geom/simplex.hpp>
 #include <psemek/geom/gauss.hpp>
+#include <psemek/geom/contains.hpp>
 
 namespace psemek::geom
 {
@@ -17,6 +18,12 @@ namespace psemek::geom
 		return std::min(std::abs(x - i.min), std::abs(x - i.max));
 	}
 
+	template <typename T>
+	T signed_distance(T const & x, interval<T> const & i)
+	{
+		return std::max(i.min - x, x - i.max);
+	}
+
 	template <typename T, std::size_t N>
 	T distance(point<T, N> const & p, box<T, N> const & b)
 	{
@@ -31,6 +38,18 @@ namespace psemek::geom
 		return std::sqrt(s);
 	}
 
+	template <typename T, std::size_t N>
+	T signed_distance(point<T, N> const & p, box<T, N> const & b)
+	{
+		if (!contains(b, p))
+			return distance(p, b);
+
+		T s = limits<T>::min();
+		for (std::size_t i = 0; i < N; ++i)
+			s = std::max(s, signed_distance(p[i], b[i]));
+		return s;
+	}
+
 	template <typename T, std::size_t N>
 	T distance(point<T, N> const & p, segment<point<T, N>> const & s)
 	{