three
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JavaScript 3D library
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JavaScript
import { Float32BufferAttribute } from '../core/BufferAttribute.js';
import { BufferGeometry } from '../core/BufferGeometry.js';
import { Object3D } from '../core/Object3D.js';
import { CylinderGeometry } from '../geometries/CylinderGeometry.js';
import { MeshBasicMaterial } from '../materials/MeshBasicMaterial.js';
import { LineBasicMaterial } from '../materials/LineBasicMaterial.js';
import { Mesh } from '../objects/Mesh.js';
import { Line } from '../objects/Line.js';
import { Vector3 } from '../math/Vector3.js';
const _axis = /*@__PURE__*/ new Vector3();
let _lineGeometry, _coneGeometry;
/**
* An 3D arrow object for visualizing directions.
*
* ```js
* const dir = new THREE.Vector3( 1, 2, 0 );
*
* //normalize the direction vector (convert to vector of length 1)
* dir.normalize();
*
* const origin = new THREE.Vector3( 0, 0, 0 );
* const length = 1;
* const hex = 0xffff00;
*
* const arrowHelper = new THREE.ArrowHelper( dir, origin, length, hex );
* scene.add( arrowHelper );
* ```
*
* @augments Object3D
*/
class ArrowHelper extends Object3D {
/**
* Constructs a new arrow helper.
*
* @param {Vector3} [dir=(0, 0, 1)] - The (normalized) direction vector.
* @param {Vector3} [origin=(0, 0, 0)] - Point at which the arrow starts.
* @param {number} [length=1] - Length of the arrow in world units.
* @param {(number|Color|string)} [color=0xffff00] - Color of the arrow.
* @param {number} [headLength=length*0.2] - The length of the head of the arrow.
* @param {number} [headWidth=headLength*0.2] - The width of the head of the arrow.
*/
constructor( dir = new Vector3( 0, 0, 1 ), origin = new Vector3( 0, 0, 0 ), length = 1, color = 0xffff00, headLength = length * 0.2, headWidth = headLength * 0.2 ) {
super();
this.type = 'ArrowHelper';
if ( _lineGeometry === undefined ) {
_lineGeometry = new BufferGeometry();
_lineGeometry.setAttribute( 'position', new Float32BufferAttribute( [ 0, 0, 0, 0, 1, 0 ], 3 ) );
_coneGeometry = new CylinderGeometry( 0, 0.5, 1, 5, 1 );
_coneGeometry.translate( 0, - 0.5, 0 );
}
this.position.copy( origin );
/**
* The line part of the arrow helper.
*
* @type {Line}
*/
this.line = new Line( _lineGeometry, new LineBasicMaterial( { color: color, toneMapped: false } ) );
this.line.matrixAutoUpdate = false;
this.add( this.line );
/**
* The cone part of the arrow helper.
*
* @type {Mesh}
*/
this.cone = new Mesh( _coneGeometry, new MeshBasicMaterial( { color: color, toneMapped: false } ) );
this.cone.matrixAutoUpdate = false;
this.add( this.cone );
this.setDirection( dir );
this.setLength( length, headLength, headWidth );
}
/**
* Sets the direction of the helper.
*
* @param {Vector3} dir - The normalized direction vector.
*/
setDirection( dir ) {
// dir is assumed to be normalized
if ( dir.y > 0.99999 ) {
this.quaternion.set( 0, 0, 0, 1 );
} else if ( dir.y < - 0.99999 ) {
this.quaternion.set( 1, 0, 0, 0 );
} else {
_axis.set( dir.z, 0, - dir.x ).normalize();
const radians = Math.acos( dir.y );
this.quaternion.setFromAxisAngle( _axis, radians );
}
}
/**
* Sets the length of the helper.
*
* @param {number} length - Length of the arrow in world units.
* @param {number} [headLength=length*0.2] - The length of the head of the arrow.
* @param {number} [headWidth=headLength*0.2] - The width of the head of the arrow.
*/
setLength( length, headLength = length * 0.2, headWidth = headLength * 0.2 ) {
this.line.scale.set( 1, Math.max( 0.0001, length - headLength ), 1 ); // see #17458
this.line.updateMatrix();
this.cone.scale.set( headWidth, headLength, headWidth );
this.cone.position.y = length;
this.cone.updateMatrix();
}
/**
* Sets the color of the helper.
*
* @param {number|Color|string} color - The color to set.
*/
setColor( color ) {
this.line.material.color.set( color );
this.cone.material.color.set( color );
}
copy( source ) {
super.copy( source, false );
this.line.copy( source.line );
this.cone.copy( source.cone );
return this;
}
/**
* Frees the GPU-related resources allocated by this instance. Call this
* method whenever this instance is no longer used in your app.
*/
dispose() {
this.line.geometry.dispose();
this.line.material.dispose();
this.cone.geometry.dispose();
this.cone.material.dispose();
}
}
export { ArrowHelper };