From 8c6e5287b557dbd5e58d19c170c7e76e606ca92c Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Sun, 24 Nov 2013 14:15:41 +0100
Subject: [PATCH] Add ol.extent.getIntersectionArea

---
 src/ol/extent.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/ol/extent.js b/src/ol/extent.js
index ee5761541a..3a00a840c9 100644
--- a/src/ol/extent.js
+++ b/src/ol/extent.js
@@ -409,6 +409,20 @@ ol.extent.getHeight = function(extent) {
 };
 
 
+/**
+ * @param {ol.Extent} extent1 Extent 1.
+ * @param {ol.Extent} extent2 Extent 2.
+ * @return {number} Intersection area.
+ */
+ol.extent.getIntersectionArea = function(extent1, extent2) {
+  var minX = Math.max(extent1[0], extent2[0]);
+  var minY = Math.max(extent1[1], extent2[1]);
+  var maxX = Math.min(extent1[2], extent2[2]);
+  var maxY = Math.min(extent1[3], extent2[3]);
+  return Math.max(0, maxX - minX) * Math.max(0, maxY - minY);
+};
+
+
 /**
  * @param {ol.Extent} extent Extent.
  * @return {ol.Size} Size.