Files
openlayers/src/ol/rotationconstraint.js

40 lines
867 B
JavaScript

goog.provide('ol.RotationConstraint');
goog.provide('ol.RotationConstraintType');
/**
* @typedef {function((number|undefined), number): (number|undefined)}
*/
ol.RotationConstraintType;
/**
* @param {number|undefined} rotation Rotation.
* @param {number} delta Delta.
* @return {number|undefined} Rotation.
*/
ol.RotationConstraint.none = function(rotation, delta) {
if (goog.isDef(rotation)) {
return rotation + delta;
} else {
return undefined;
}
};
/**
* @param {number} n N.
* @return {ol.RotationConstraintType} Rotation constraint.
*/
ol.RotationConstraint.createSnapToN = function(n) {
var theta = 2 * Math.PI / n;
return function(rotation, delta) {
if (goog.isDef(rotation)) {
rotation = Math.floor((rotation + delta) / theta + 0.5) * theta;
return rotation;
} else {
return undefined;
}
};
};