spookonomics/library/mathhelpers.js

import * as THREE from 'three'

export function getForwardVector(object3d) {
    const up = object3d.up.clone()
    const forwardVector = new THREE.Vector3(0,0,0)
    forwardVector.setFromMatrixColumn(object3d.matrix, 0)
    forwardVector.crossVectors(up.multiplyScalar(-1), forwardVector)
    return forwardVector.normalize()
}

export function getRightVector(object3d) {
    const up = object3d.up.clone()
    const rightVector = new THREE.Vector3(0,0,0)
    rightVector.setFromMatrixColumn(object3d.matrix, 0)
    rightVector.crossVectors(up.multiplyScalar(-1), rightVector)
    rightVector.crossVectors(object3d.up, rightVector)
    return rightVector.normalize()
}

export function drawDebugLine(game, startPoint, endPoint, color = 0xff0000, delay = 0) {
    const points = []
    points.push(startPoint)
    points.push(endPoint)
    const geometry = new THREE.BufferGeometry().setFromPoints( points );
    const material = new THREE.LineBasicMaterial( { color } );
    const line = new THREE.Line( geometry, material )
    game.scene.add(line)

    if(delay > 0) {
        setTimeout(() => {
            game.scene.remove(line)
        }, delay)
    }
}