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 1/2] 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;
   }
 };
 

From b9a9e84c1bc86a15a87aec75bc6c5de72c18bbd2 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Mon, 4 Mar 2013 10:26:06 +0100
Subject: [PATCH 2/2] Handle projections in feet in scale line control

---
 src/ol/control/scalelinecontrol.js | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/ol/control/scalelinecontrol.js b/src/ol/control/scalelinecontrol.js
index a2144e502c..02fb5bcf26 100644
--- a/src/ol/control/scalelinecontrol.js
+++ b/src/ol/control/scalelinecontrol.js
@@ -168,11 +168,13 @@ ol.control.ScaleLine.prototype.updateElement_ = function(frameState) {
     this.toEPSG4326_ = null;
     cosLatitude = Math.cos(goog.math.toRadians(center.y));
     pointResolution *= Math.PI * cosLatitude * ol.sphere.NORMAL.radius / 180;
+    projectionUnits = ol.ProjectionUnits.METERS;
 
-  } else if (projectionUnits == ol.ProjectionUnits.METERS &&
+  } else if ((projectionUnits == ol.ProjectionUnits.FEET ||
+      projectionUnits == ol.ProjectionUnits.METERS) &&
       this.units_ == ol.control.ScaleLineUnits.DEGREES) {
 
-    // Convert pointResolution from meters to degrees
+    // Convert pointResolution from meters or feet to degrees
     if (goog.isNull(this.toEPSG4326_)) {
       this.toEPSG4326_ = ol.projection.getTransform(
           projection, ol.projection.getFromCode('EPSG:4326'));
@@ -180,20 +182,26 @@ ol.control.ScaleLine.prototype.updateElement_ = function(frameState) {
     var vertex = [center.x, center.y];
     vertex = this.toEPSG4326_(vertex, vertex, 2);
     cosLatitude = Math.cos(goog.math.toRadians(vertex[1]));
-    pointResolution *= 180 / (Math.PI * cosLatitude * ol.sphere.NORMAL.radius);
+    var radius = ol.sphere.NORMAL.radius;
+    if (projectionUnits == ol.ProjectionUnits.FEET) {
+      radius /= 0.3048;
+    }
+    pointResolution *= 180 / (Math.PI * cosLatitude * radius);
+    projectionUnits = ol.ProjectionUnits.DEGREES;
 
   } else {
 
     this.toEPSG4326_ = null;
-    goog.asserts.assert(
-        ((this.units_ == ol.control.ScaleLineUnits.METRIC ||
-          this.units_ == ol.control.ScaleLineUnits.IMPERIAL) &&
-         projectionUnits == ol.ProjectionUnits.METERS) ||
-        (this.units_ == ol.control.ScaleLineUnits.DEGREES &&
-         projectionUnits == ol.ProjectionUnits.DEGREES));
 
   }
 
+  goog.asserts.assert(
+      ((this.units_ == ol.control.ScaleLineUnits.METRIC ||
+        this.units_ == ol.control.ScaleLineUnits.IMPERIAL) &&
+       projectionUnits == ol.ProjectionUnits.METERS) ||
+      (this.units_ == ol.control.ScaleLineUnits.DEGREES &&
+       projectionUnits == ol.ProjectionUnits.DEGREES));
+
   var nominalCount = this.minWidth_ * pointResolution;
   var suffix = '';
   if (this.units_ == ol.control.ScaleLineUnits.DEGREES) {