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openlayers

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Build tools and sources for developing OpenLayers based mapping applications

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