From 87d6208403e9ec36114abee9ebe4c3323bd74ab2 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Mon, 4 Mar 2013 10:25:20 +0100
Subject: [PATCH] Add international feet to projection units

---
 src/ol/projection.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/ol/projection.js b/src/ol/projection.js
index 91d00d3fd5..a70ac2a8bd 100644
--- a/src/ol/projection.js
+++ b/src/ol/projection.js
@@ -28,6 +28,7 @@ ol.HAVE_PROJ4JS = ol.ENABLE_PROJ4JS && typeof Proj4js == 'object';
  */
 ol.ProjectionUnits = {
   DEGREES: 'degrees',
+  FEET: 'ft',
   METERS: 'm'
 };
 
@@ -168,7 +169,13 @@ ol.Proj4jsProjection_.prototype.getPointResolution =
     var height = ol.sphere.NORMAL.haversineDistance(
         new ol.Coordinate(vertices[4], vertices[5]),
         new ol.Coordinate(vertices[6], vertices[7]));
-    return (width + height) / 2;
+    var pointResolution = (width + height) / 2;
+    if (this.getUnits() == ol.ProjectionUnits.FEET) {
+      // The radius of the normal sphere is defined in meters, so we must
+      // convert back to feet.
+      pointResolution /= 0.3048;
+    }
+    return pointResolution;
   }
 };