Geometry: Added distanceSquaredToSegment() function

lib/OpenLayers/Geometry.js

@@ -445,6 +445,31 @@ OpenLayers.Geometry.segmentsIntersect = function(seg1, seg2, options) {
  *     describes how far between the two segment points the given point is.
  */
 OpenLayers.Geometry.distanceToSegment = function(point, segment) {
+    var result = OpenLayers.Geometry.distanceSquaredToSegment(point, segment);
+    result.distance = Math.sqrt(result.distance);
+    return result;
+};
+
+/**
+ * Function: OpenLayers.Geometry.distanceSquaredToSegment
+ *
+ * Usually the distanceToSegment function should be used. This variant however
+ * can be used for comparisons where the exact distance is not important.
+ *
+ * Parameters:
+ * point - {Object} An object with x and y properties representing the
+ *     point coordinates.
+ * segment - {Object} An object with x1, y1, x2, and y2 properties
+ *     representing endpoint coordinates.
+ *
+ * Returns:
+ * {Object} An object with squared distance, x, and y properties.  The distance
+ *     will be the shortest distance between the input point and segment.
+ *     The x and y properties represent the coordinates along the segment
+ *     where the shortest distance meets the segment. The along attribute
+ *     describes how far between the two segment points the given point is.
+ */
+OpenLayers.Geometry.distanceSquaredToSegment = function(point, segment) {
     var x0 = point.x;
     var y0 = point.y;
     var x1 = segment.x1;
@@ -467,7 +492,7 @@ OpenLayers.Geometry.distanceToSegment = function(point, segment) {
         y = y1 + along * dy;
     }
     return {
-        distance: Math.sqrt(Math.pow(x - x0, 2) + Math.pow(y - y0, 2)),
+        distance: Math.pow(x - x0, 2) + Math.pow(y - y0, 2),
         x: x, y: y,
         along: along
     };