From 449131a516f38e4816905c7db433e92287e20e08 Mon Sep 17 00:00:00 2001
From: Marc Jansen <jansen@terrestris.de>
Date: Fri, 9 Oct 2015 23:04:00 +0200
Subject: [PATCH] Use MDN polyfill for Math.cosh

This commit replaces the current implementation of ol.math.cosh with the
reference implementation of the Mozilla developer network. This method
only has one call to the Math.exp-function compared to two in the original
implementation.

See also: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Math/cosh
---
 src/ol/math.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/ol/math.js b/src/ol/math.js
index c0244bda01..22e5c0fca2 100644
--- a/src/ol/math.js
+++ b/src/ol/math.js
@@ -21,7 +21,8 @@ ol.math.clamp = function(value, min, max) {
  * @return {number} Hyperbolic cosine of x.
  */
 ol.math.cosh = function(x) {
-  return (Math.exp(x) + Math.exp(-x)) / 2;
+  var y = Math.exp(x);
+  return (y + 1 / y) / 2;
 };