three
Version:
JavaScript 3D library
146 lines (112 loc) • 2.83 kB
JavaScript
import { Curve } from '../core/Curve.js';
import { CubicBezier } from '../core/Interpolations.js';
import { Vector2 } from '../../math/Vector2.js';
/**
* A curve representing a 2D Cubic Bezier curve.
*
* ```js
* const curve = new THREE.CubicBezierCurve(
* new THREE.Vector2( - 0, 0 ),
* new THREE.Vector2( - 5, 15 ),
* new THREE.Vector2( 20, 15 ),
* new THREE.Vector2( 10, 0 )
* );
*
* const points = curve.getPoints( 50 );
* const geometry = new THREE.BufferGeometry().setFromPoints( points );
*
* const material = new THREE.LineBasicMaterial( { color: 0xff0000 } );
*
* // Create the final object to add to the scene
* const curveObject = new THREE.Line( geometry, material );
* ```
*
* @augments Curve
*/
class CubicBezierCurve extends Curve {
/**
* Constructs a new Cubic Bezier curve.
*
* @param {Vector2} [v0] - The start point.
* @param {Vector2} [v1] - The first control point.
* @param {Vector2} [v2] - The second control point.
* @param {Vector2} [v3] - The end point.
*/
constructor( v0 = new Vector2(), v1 = new Vector2(), v2 = new Vector2(), v3 = new Vector2() ) {
super();
/**
* This flag can be used for type testing.
*
* @type {boolean}
* @readonly
* @default true
*/
this.isCubicBezierCurve = true;
this.type = 'CubicBezierCurve';
/**
* The start point.
*
* @type {Vector2}
*/
this.v0 = v0;
/**
* The first control point.
*
* @type {Vector2}
*/
this.v1 = v1;
/**
* The second control point.
*
* @type {Vector2}
*/
this.v2 = v2;
/**
* The end point.
*
* @type {Vector2}
*/
this.v3 = v3;
}
/**
* Returns a point on the curve.
*
* @param {number} t - A interpolation factor representing a position on the curve. Must be in the range `[0,1]`.
* @param {Vector2} [optionalTarget] - The optional target vector the result is written to.
* @return {Vector2} The position on the curve.
*/
getPoint( t, optionalTarget = new Vector2() ) {
const point = optionalTarget;
const v0 = this.v0, v1 = this.v1, v2 = this.v2, v3 = this.v3;
point.set(
CubicBezier( t, v0.x, v1.x, v2.x, v3.x ),
CubicBezier( t, v0.y, v1.y, v2.y, v3.y )
);
return point;
}
copy( source ) {
super.copy( source );
this.v0.copy( source.v0 );
this.v1.copy( source.v1 );
this.v2.copy( source.v2 );
this.v3.copy( source.v3 );
return this;
}
toJSON() {
const data = super.toJSON();
data.v0 = this.v0.toArray();
data.v1 = this.v1.toArray();
data.v2 = this.v2.toArray();
data.v3 = this.v3.toArray();
return data;
}
fromJSON( json ) {
super.fromJSON( json );
this.v0.fromArray( json.v0 );
this.v1.fromArray( json.v1 );
this.v2.fromArray( json.v2 );
this.v3.fromArray( json.v3 );
return this;
}
}
export { CubicBezierCurve };