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Geometry: Added distanceSquaredToSegment() function

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This commit is contained in:
Tobias Bieniek
2013-03-23 16:56:32 +01:00
parent 04d3c6ce53
commit 29976ba98a
1 changed files with 26 additions and 1 deletions
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27
lib/OpenLayers/Geometry.js
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@@ -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
};