/*global define*/
define([
'../Core/buildModuleUrl',
'../Core/Cartesian3',
'../Core/defaultValue',
'../Core/defined',
'../Core/defineProperties',
'../Core/destroyObject',
'../Core/Ellipsoid',
'../Core/IauOrientationAxes',
'../Core/Matrix3',
'../Core/Matrix4',
'../Core/Simon1994PlanetaryPositions',
'../Core/Transforms',
'./EllipsoidPrimitive',
'./Material'
], function(
buildModuleUrl,
Cartesian3,
defaultValue,
defined,
defineProperties,
destroyObject,
Ellipsoid,
IauOrientationAxes,
Matrix3,
Matrix4,
Simon1994PlanetaryPositions,
Transforms,
EllipsoidPrimitive,
Material) {
"use strict";
/**
* Draws the Moon in 3D.
* @alias Moon
* @constructor
*
* @param {Object} [options] Object with the following properties:
* @param {Boolean} [options.show=true] Determines whether the moon will be rendered.
* @param {String} [options.textureUrl=buildModuleUrl('Assets/Textures/moonSmall.jpg')] The moon texture.
* @param {Ellipsoid} [options.ellipsoid=Ellipsoid.MOON] The moon ellipsoid.
* @param {Boolean} [options.onlySunLighting=true] Use the sun as the only light source.
*
* @see Scene#moon
*
* @example
* scene.moon = new Cesium.Moon();
*/
var Moon = function(options) {
options = defaultValue(options, defaultValue.EMPTY_OBJECT);
var url = options.textureUrl;
if (!defined(url)) {
url = buildModuleUrl('Assets/Textures/moonSmall.jpg');
}
/**
* Determines if the moon will be shown.
*
* @type {Boolean}
* @default true
*/
this.show = defaultValue(options.show, true);
/**
* The moon texture.
* @type {String}
* @default buildModuleUrl('Assets/Textures/moonSmall.jpg')
*/
this.textureUrl = url;
this._ellipsoid = defaultValue(options.ellipsoid, Ellipsoid.MOON);
/**
* Use the sun as the only light source.
* @type {Boolean}
* @default true
*/
this.onlySunLighting = defaultValue(options.onlySunLighting, true);
this._ellipsoidPrimitive = new EllipsoidPrimitive({
radii : this.ellipsoid.radii,
material : Material.fromType(Material.ImageType),
_owner : this
});
this._ellipsoidPrimitive.material.translucent = false;
this._axes = new IauOrientationAxes();
};
defineProperties(Moon.prototype, {
/**
* Get the ellipsoid that defines the shape of the moon.
*
* @memberof Moon.prototype
*
* @type {Ellipsoid}
* @readonly
*
* @default {@link Ellipsoid.MOON}
*/
ellipsoid : {
get : function() {
return this._ellipsoid;
}
}
});
var icrfToFixed = new Matrix3();
var rotationScratch = new Matrix3();
var translationScratch = new Cartesian3();
/**
* @private
*/
Moon.prototype.update = function(context, frameState, commandList) {
if (!this.show) {
return;
}
var ellipsoidPrimitive = this._ellipsoidPrimitive;
ellipsoidPrimitive.material.uniforms.image = this.textureUrl;
ellipsoidPrimitive.onlySunLighting = this.onlySunLighting;
var date = frameState.time;
if (!defined(Transforms.computeIcrfToFixedMatrix(date, icrfToFixed))) {
Transforms.computeTemeToPseudoFixedMatrix(date, icrfToFixed);
}
var rotation = this._axes.evaluate(date, rotationScratch);
Matrix3.transpose(rotation, rotation);
Matrix3.multiply(icrfToFixed, rotation, rotation);
var translation = Simon1994PlanetaryPositions.computeMoonPositionInEarthInertialFrame(date, translationScratch);
Matrix3.multiplyByVector(icrfToFixed, translation, translation);
Matrix4.fromRotationTranslation(rotation, translation, ellipsoidPrimitive.modelMatrix);
ellipsoidPrimitive.update(context, frameState, commandList);
};
/**
* Returns true if this object was destroyed; otherwise, false.
*
* If this object was destroyed, it should not be used; calling any function other than
* isDestroyed
will result in a {@link DeveloperError} exception.
*
* @returns {Boolean} true
if this object was destroyed; otherwise, false
.
*
* @see Moon#destroy
*/
Moon.prototype.isDestroyed = function() {
return false;
};
/**
* Destroys the WebGL resources held by this object. Destroying an object allows for deterministic
* release of WebGL resources, instead of relying on the garbage collector to destroy this object.
*
* Once an object is destroyed, it should not be used; calling any function other than
* isDestroyed
will result in a {@link DeveloperError} exception. Therefore,
* assign the return value (undefined
) to the object as done in the example.
*
* @returns {undefined}
*
* @exception {DeveloperError} This object was destroyed, i.e., destroy() was called.
*
* @see Moon#isDestroyed
*
* @example
* moon = moon && moon.destroy();
*/
Moon.prototype.destroy = function() {
this._ellipsoidPrimitive = this._ellipsoidPrimitive && this._ellipsoidPrimitive.destroy();
return destroyObject(this);
};
return Moon;
});