/*
* Copyright 2003-2006, 2009, 2017, United States Government, as represented by the Administrator of the
* National Aeronautics and Space Administration. All rights reserved.
*
* The NASAWorldWind/WebWorldWind platform is licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @exports Level
*/
define([
'../geom/Angle',
'../error/ArgumentError',
'../geom/Location',
'../util/Logger'
],
function (Angle,
ArgumentError,
Location,
Logger) {
"use strict";
/**
* Constructs a Level within a [LevelSet]{@link LevelSet}. Applications typically do not interact with this
* class.
* @alias Level
* @constructor
* @classdesc Represents a level in a tile pyramid.
* @throws {ArgumentError} If either the specified tile delta or parent level set is null or undefined.
*/
var Level = function (levelNumber, tileDelta, parent) {
if (!tileDelta) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "Level", "constructor",
"The specified tile delta is null or undefined"));
}
if (!parent) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "Level", "constructor",
"The specified parent level set is null or undefined"));
}
/**
* The level's ordinal in its parent level set.
* @type {Number}
*/
this.levelNumber = levelNumber;
/**
* The geographic size of tiles within this level.
* @type {Location}
*/
this.tileDelta = tileDelta;
/**
* The level set that this level is a member of.
* @type {LevelSet}
*/
this.parent = parent;
/**
* The size of pixels or elevation cells within this level, in radians per pixel or per cell.
* @type {Number}
*/
this.texelSize = (tileDelta.latitude * Angle.DEGREES_TO_RADIANS) / parent.tileHeight;
/**
* The width in pixels or cells of the resource associated with tiles within this level.
* @type {Number}
*/
this.tileWidth = parent.tileWidth;
/**
* The height in pixels or cells of the resource associated with tiles within this level.
* @type {Number}
*/
this.tileHeight = parent.tileHeight;
/**
* The sector spanned by this level.
* @type {Sector}
*/
this.sector = parent.sector;
};
/**
* Indicates whether this level is the lowest resolution level (level 0) within its parent's level set.
* @returns {Boolean} true If this tile is the lowest resolution in the parent level set,
* otherwise false.
*/
Level.prototype.isFirstLevel = function () {
return this.parent.firstLevel() == this;
};
/**
* Indicates whether this level is the highest resolution level within its parent's level set.
* @returns {Boolean} true If this tile is the highest resolution in the parent level set,
* otherwise false.
*/
Level.prototype.isLastLevel = function () {
return this.parent.lastLevel() == this;
};
/**
* Returns the level whose ordinal occurs immediately before this level's ordinal in the parent level set, or
* null if this is the fist level.
* @returns {Level} The previous level, or null if this is the first level.
*/
Level.prototype.previousLevel = function () {
return this.parent.level(this.levelNumber - 1);
};
/**
* Returns the level whose ordinal occurs immediately after this level's ordinal in the parent level set, or
* null if this is the last level.
* @returns {Level} The next level, or null if this is the last level.
*/
Level.prototype.nextLevel = function () {
return this.parent.level(this.levelNumber + 1);
};
/**
* Compare this level's ordinal to that of a specified level.
* @param {Level} that The level to compare this one to.
* @returns {Number} 0 if the two ordinals are equivalent. -1 if this level's ordinal is less than the specified
* level's ordinal. 1 if this level's ordinal is greater than the specified level's ordinal.
* @throws {ArgumentError} If the specified level is null or undefined.
*/
Level.prototype.compare = function (that) {
if (!that) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "Level", "compare",
"The specified level is null or undefined"));
}
if (this.levelNumber < that.levelNumber)
return -1;
if (this.levelNumber > that.levelNumber)
return 1;
return 0;
};
return Level;
});