three
Version:
JavaScript 3D library
210 lines (155 loc) • 4.82 kB
JavaScript
import { Vector3 } from './Vector3.js';
import { clamp } from './MathUtils.js';
const _startP = /*@__PURE__*/ new Vector3();
const _startEnd = /*@__PURE__*/ new Vector3();
/**
* An analytical line segment in 3D space represented by a start and end point.
*/
class Line3 {
/**
* Constructs a new line segment.
*
* @param {Vector3} [start=(0,0,0)] - Start of the line segment.
* @param {Vector3} [end=(0,0,0)] - End of the line segment.
*/
constructor( start = new Vector3(), end = new Vector3() ) {
/**
* Start of the line segment.
*
* @type {Vector3}
*/
this.start = start;
/**
* End of the line segment.
*
* @type {Vector3}
*/
this.end = end;
}
/**
* Sets the start and end values by copying the given vectors.
*
* @param {Vector3} start - The start point.
* @param {Vector3} end - The end point.
* @return {Line3} A reference to this line segment.
*/
set( start, end ) {
this.start.copy( start );
this.end.copy( end );
return this;
}
/**
* Copies the values of the given line segment to this instance.
*
* @param {Line3} line - The line segment to copy.
* @return {Line3} A reference to this line segment.
*/
copy( line ) {
this.start.copy( line.start );
this.end.copy( line.end );
return this;
}
/**
* Returns the center of the line segment.
*
* @param {Vector3} target - The target vector that is used to store the method's result.
* @return {Vector3} The center point.
*/
getCenter( target ) {
return target.addVectors( this.start, this.end ).multiplyScalar( 0.5 );
}
/**
* Returns the delta vector of the line segment's start and end point.
*
* @param {Vector3} target - The target vector that is used to store the method's result.
* @return {Vector3} The delta vector.
*/
delta( target ) {
return target.subVectors( this.end, this.start );
}
/**
* Returns the squared Euclidean distance between the line' start and end point.
*
* @return {number} The squared Euclidean distance.
*/
distanceSq() {
return this.start.distanceToSquared( this.end );
}
/**
* Returns the Euclidean distance between the line' start and end point.
*
* @return {number} The Euclidean distance.
*/
distance() {
return this.start.distanceTo( this.end );
}
/**
* Returns a vector at a certain position along the line segment.
*
* @param {number} t - A value between `[0,1]` to represent a position along the line segment.
* @param {Vector3} target - The target vector that is used to store the method's result.
* @return {Vector3} The delta vector.
*/
at( t, target ) {
return this.delta( target ).multiplyScalar( t ).add( this.start );
}
/**
* Returns a point parameter based on the closest point as projected on the line segment.
*
* @param {Vector3} point - The point for which to return a point parameter.
* @param {boolean} clampToLine - Whether to clamp the result to the range `[0,1]` or not.
* @return {number} The point parameter.
*/
closestPointToPointParameter( point, clampToLine ) {
_startP.subVectors( point, this.start );
_startEnd.subVectors( this.end, this.start );
const startEnd2 = _startEnd.dot( _startEnd );
const startEnd_startP = _startEnd.dot( _startP );
let t = startEnd_startP / startEnd2;
if ( clampToLine ) {
t = clamp( t, 0, 1 );
}
return t;
}
/**
* Returns the closets point on the line for a given point.
*
* @param {Vector3} point - The point to compute the closest point on the line for.
* @param {boolean} clampToLine - Whether to clamp the result to the range `[0,1]` or not.
* @param {Vector3} target - The target vector that is used to store the method's result.
* @return {Vector3} The closest point on the line.
*/
closestPointToPoint( point, clampToLine, target ) {
const t = this.closestPointToPointParameter( point, clampToLine );
return this.delta( target ).multiplyScalar( t ).add( this.start );
}
/**
* Applies a 4x4 transformation matrix to this line segment.
*
* @param {Matrix4} matrix - The transformation matrix.
* @return {Line3} A reference to this line segment.
*/
applyMatrix4( matrix ) {
this.start.applyMatrix4( matrix );
this.end.applyMatrix4( matrix );
return this;
}
/**
* Returns `true` if this line segment is equal with the given one.
*
* @param {Line3} line - The line segment to test for equality.
* @return {boolean} Whether this line segment is equal with the given one.
*/
equals( line ) {
return line.start.equals( this.start ) && line.end.equals( this.end );
}
/**
* Returns a new line segment with copied values from this instance.
*
* @return {Line3} A clone of this instance.
*/
clone() {
return new this.constructor().copy( this );
}
}
export { Line3 };