From 4f3bd984d2dadf2bee667805cf7cb222a9875f69 Mon Sep 17 00:00:00 2001
From: Ahmet Inan <inan@aicodix.de>
Date: Fri, 17 Jan 2020 15:06:48 +0100
Subject: [PATCH] added simpler eval interface for uniform splines

---
 spline.hh | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/spline.hh b/spline.hh
index 341152e..aeb86e5 100644
--- a/spline.hh
+++ b/spline.hh
@@ -113,6 +113,18 @@ struct CubicHermiteSpline
 		:
 			h00(t) * y[n-2] + h10(t) * central(y+n-2) + h01(t) * y[n-1] + h11(t) * left(y+n-1);
 	}
+	static OTYPE eval(const OTYPE *y, ITYPE x, int n, ITYPE x0 = 0, ITYPE dx = 1)
+	{
+		ITYPE tx = (x - x0) / dx;
+		int k = tx;
+		ITYPE t = tx - ITYPE(k);
+		return k < 0 ?
+			eval(y, tx, 0, n)
+		: k < n-1 ?
+			eval(y, t, k, n)
+		:
+			eval(y, tx-ITYPE(n-2), n-2, n);
+	}
 };
 
 }