71 lines
2.2 KiB
JavaScript
71 lines
2.2 KiB
JavaScript
/**
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* @module ol/ResolutionConstraint
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*/
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import _ol_array_ from './array.js';
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import _ol_math_ from './math.js';
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var _ol_ResolutionConstraint_ = {};
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/**
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* @param {Array.<number>} resolutions Resolutions.
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* @return {ol.ResolutionConstraintType} Zoom function.
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*/
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_ol_ResolutionConstraint_.createSnapToResolutions = function(resolutions) {
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return (
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/**
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* @param {number|undefined} resolution Resolution.
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* @param {number} delta Delta.
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* @param {number} direction Direction.
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* @return {number|undefined} Resolution.
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*/
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function(resolution, delta, direction) {
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if (resolution !== undefined) {
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var z =
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_ol_array_.linearFindNearest(resolutions, resolution, direction);
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z = _ol_math_.clamp(z + delta, 0, resolutions.length - 1);
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var index = Math.floor(z);
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if (z != index && index < resolutions.length - 1) {
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var power = resolutions[index] / resolutions[index + 1];
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return resolutions[index] / Math.pow(power, z - index);
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} else {
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return resolutions[index];
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}
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} else {
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return undefined;
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}
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}
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);
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};
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/**
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* @param {number} power Power.
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* @param {number} maxResolution Maximum resolution.
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* @param {number=} opt_maxLevel Maximum level.
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* @return {ol.ResolutionConstraintType} Zoom function.
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*/
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_ol_ResolutionConstraint_.createSnapToPower = function(power, maxResolution, opt_maxLevel) {
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return (
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/**
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* @param {number|undefined} resolution Resolution.
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* @param {number} delta Delta.
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* @param {number} direction Direction.
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* @return {number|undefined} Resolution.
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*/
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function(resolution, delta, direction) {
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if (resolution !== undefined) {
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var offset = -direction / 2 + 0.5;
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var oldLevel = Math.floor(
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Math.log(maxResolution / resolution) / Math.log(power) + offset);
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var newLevel = Math.max(oldLevel + delta, 0);
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if (opt_maxLevel !== undefined) {
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newLevel = Math.min(newLevel, opt_maxLevel);
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}
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return maxResolution / Math.pow(power, newLevel);
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} else {
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return undefined;
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}
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});
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};
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export default _ol_ResolutionConstraint_;
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