From 43e95e89f32e7db6e04b01fe75a9dd38469ec6ff Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Tue, 14 Feb 2023 13:50:43 +0300
Subject: [PATCH] Add cubic hermite spline to geom

---
 libs/geom/include/psemek/geom/hermite.hpp | 26 +++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 libs/geom/include/psemek/geom/hermite.hpp

diff --git a/libs/geom/include/psemek/geom/hermite.hpp b/libs/geom/include/psemek/geom/hermite.hpp
new file mode 100644
index 00000000..c4de2694
--- /dev/null
+++ b/libs/geom/include/psemek/geom/hermite.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+namespace psemek::geom
+{
+
+	template <typename T>
+	struct cubic_hermite
+	{
+		T a[3];
+
+		cubic_hermite() = default;
+		cubic_hermite(T p0, T m0, T p1, T m1)
+		{
+			a[0] = p0;
+			a[1] = m0;
+			a[2] = - 3 * p0 - 2 * m0 + 3 * p1 - m1;
+			a[3] = 2 * p0 + m0 - 2 * p1 + m1;
+		}
+
+		T operator() (T t) const
+		{
+			return a[0] + t * (a[1] + t * (a[2] + t * a[3]));
+		}
+	};
+
+}