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Add ol.geom.flat.closestPoint

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Tom Payne
2013-12-07 12:42:21 +01:00
parent 02cee684a7
commit 5d36c2a55e
1 changed files with 33 additions and 0 deletions
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33
src/ol/geom/flatgeom.js
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@@ -5,6 +5,39 @@ goog.require('goog.asserts');
goog.require('goog.vec.Mat4');
/**
* Returns the point on the line segment (x1, y1) to (x2, y2) that is closest to
* the point (x, y).
* @param {number} x X.
* @param {number} y Y.
* @param {number} x1 X1.
* @param {number} y1 Y1.
* @param {number} x2 X2.
* @param {number} y2 Y2.
* @param {Array.<number>} closestPoint Closest point.
*/
ol.geom.flat.closestPoint = function(x, y, x1, y1, x2, y2, closestPoint) {
var dx = x2 - x1;
var dy = y2 - y1;
if (dx === 0 && dy === 0) {
closestPoint[0] = x1;
closestPoint[1] = y1;
} else {
var t = ((x - x1) * dx + (y - y1) * dy) / (dx * dx + dy * dy);
if (t > 1) {
closestPoint[0] = x2;
closestPoint[1] = y2;
} else if (t > 0) {
closestPoint[0] = x1 + dx * t;
closestPoint[1] = y1 + dy * t;
} else {
closestPoint[0] = x1;
closestPoint[1] = y1;
}
}
};
/**
* @param {Array.<number>} flatCoordinates Flat coordinates.
* @param {number} offset Offset.