Reference Source

``````import {Curve} from "./Curve.js"
import {math} from "../math/math.js";

/**
* A **QuadraticBezierCurve** is a {@link Curve} along which a 3D position can be animated.
*
* * As shown in the diagram below, a QuadraticBezierCurve is defined by three control points
* * To build a complex path, you can combine an unlimited combination of QuadraticBezierCurves, {@link CubicBezierCurve}s and {@link SplineCurve}s into a {@link Path}.</li>
* <br>
* <br>
* *[Quadratic Bezier Curve from WikiPedia](https://en.wikipedia.org/wiki/B%C3%A9zier_curve)*
*/

/**
* @constructor
* @param {Component} owner Owner component. When destroyed, the owner will destroy this MetallicMaterial as well.
* @param {*} [cfg] Configuration
* @param {String} [cfg.id] Optional ID, unique among all components in the parent {{#crossLink "Scene"}}Scene{{/crossLink}}, generated automatically when omitted.
* @param {Number[]} [cfg.v0=[0,0,0]] The starting point.
* @param {Number[]} [cfg.v1=[0,0,0]] The middle control point.
* @param {Number[]} [cfg.v2=[0,0,0]] The end point.
* @param {Number[]} [cfg.t=0] Current position on this QuadraticBezierCurve, in range between ````0..1````.
*/
constructor(owner, cfg = {}) {
super(owner, cfg);
this.v0 = cfg.v0;
this.v1 = cfg.v1;
this.v2 = cfg.v2;
this.t = cfg.t;
}

/**
* Sets the starting point on this QuadraticBezierCurve.
*
* Default value is ````[0.0, 0.0, 0.0]````.
*
* @param {Number[]} value New starting point.
*/
set v0(value) {
this._v0 = value || math.vec3([0, 0, 0]);
}

/**
* Gets the starting point on this QuadraticBezierCurve.
*
* Default value is ````[0.0, 0.0, 0.0]````.
*
* @returns {Number[]} The starting point.
*/
get v0() {
return this._v0;
}

/**
* Sets the middle control point on this QuadraticBezierCurve.
*
* Default value is ````[0.0, 0.0, 0.0]````.
*
* @param {Number[]} value New middle control point.
*/
set v1(value) {
this._v1 = value || math.vec3([0, 0, 0]);
}

/**
* Gets the middle control point on this QuadraticBezierCurve.
*
* Default value is ````[0.0, 0.0, 0.0]````.
*
* @returns {Number[]} The middle control point.
*/
get v1() {
return this._v1;
}

/**
* Sets the end point on this QuadraticBezierCurve.
*
* Default value is ````[0.0, 0.0, 0.0]````.
*
* @param {Number[]} value The new end point.
*/
set v2(value) {
this._v2 = value || math.vec3([0, 0, 0]);
}

/**
* Gets the end point on this QuadraticBezierCurve.
*
* Default value is ````[0.0, 0.0, 0.0]````.
*
* @returns {Number[]} The end point.
*/
get v2() {
return this._v2;
}

/**
* Sets the progress along this QuadraticBezierCurve.
*
* Automatically clamps to range [0..1].
*
* Default value is ````0````.
*
* @param {Number} value The new progress location.
*/
set t(value) {
value = value || 0;
this._t = value < 0.0 ? 0.0 : (value > 1.0 ? 1.0 : value);
}

/**
* Gets the progress along this QuadraticBezierCurve.
*
* Default value is ````0````.
*
* @returns {Number} The current progress location.
*/
get t() {
return this._t;
}

/**

@property point
@type {Number[]}
*/
get point() {
return this.getPoint(this._t);
}

/**
* Returns the point on this QuadraticBezierCurve at the given position.
*
* @param {Number} t Position to get point at.
* @returns {Number[]} The point.
*/
getPoint(t) {
var vector = math.vec3();
vector[0] = math.b2(t, this._v0[0], this._v1[0], this._v2[0]);
vector[1] = math.b2(t, this._v0[1], this._v1[1], this._v2[1]);
vector[2] = math.b2(t, this._v0[2], this._v1[2], this._v2[2]);
return vector;
}

getJSON() {
return {
v0: this._v0,
v1: this._v1,
v2: this._v2,
t: this._t
};
}
}