three
Version:
JavaScript 3D library
129 lines (85 loc) • 2.07 kB
JavaScript
import { Vector3 } from '../../math/Vector3.js';
import { Curve } from '../core/Curve.js';
/**
* A curve representing a 3D line segment.
*
* @augments Curve
*/
class LineCurve3 extends Curve {
/**
* Constructs a new line curve.
*
* @param {Vector3} [v1] - The start point.
* @param {Vector3} [v2] - The end point.
*/
constructor( v1 = new Vector3(), v2 = new Vector3() ) {
super();
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isLineCurve3 = true;
this.type = 'LineCurve3';
/**
* The start point.
*
* @type {Vector3}
*/
this.v1 = v1;
/**
* The end point.
*
* @type {Vector2}
*/
this.v2 = v2;
}
/**
* Returns a point on the line.
*
* @param {number} t - A interpolation factor representing a position on the line. Must be in the range `[0,1]`.
* @param {Vector3} [optionalTarget] - The optional target vector the result is written to.
* @return {Vector3} The position on the line.
*/
getPoint( t, optionalTarget = new Vector3() ) {
const point = optionalTarget;
if ( t === 1 ) {
point.copy( this.v2 );
} else {
point.copy( this.v2 ).sub( this.v1 );
point.multiplyScalar( t ).add( this.v1 );
}
return point;
}
// Line curve is linear, so we can overwrite default getPointAt
getPointAt( u, optionalTarget ) {
return this.getPoint( u, optionalTarget );
}
getTangent( t, optionalTarget = new Vector3() ) {
return optionalTarget.subVectors( this.v2, this.v1 ).normalize();
}
getTangentAt( u, optionalTarget ) {
return this.getTangent( u, optionalTarget );
}
copy( source ) {
super.copy( source );
this.v1.copy( source.v1 );
this.v2.copy( source.v2 );
return this;
}
toJSON() {
const data = super.toJSON();
data.v1 = this.v1.toArray();
data.v2 = this.v2.toArray();
return data;
}
fromJSON( json ) {
super.fromJSON( json );
this.v1.fromArray( json.v1 );
this.v2.fromArray( json.v2 );
return this;
}
}
export { LineCurve3 };