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/*
Vector3 wraps a vector of length 3, often used as a position in 3D space.
Taken from https://github.com/googlevr/webvr-polyfill/blob/master/src/math-util.js which took it from Three.js
*/
export default class Vector3 {
constructor(x=0, y=0, z=0){
this.x = x
this.y = y
this.z = z
}
set(x, y, z){
this.x = x
this.y = y
this.z = z
return this
}
copy(v){
this.x = v.x
this.y = v.y
this.z = v.z
return this
}
toArray(){
return [this.x, this.y, this.z]
}
length(){
return Math.sqrt(this.x * this.x + this.y * this.y + this.z * this.z)
}
add(x, y, z){
this.x += x
this.y += y
this.z += z
}
normalize(){
var scalar = this.length()
if (scalar !== 0){
this.multiplyScalar(1 / scalar)
} else {
this.x = 0
this.y = 0
this.z = 0
}
return this
}
multiplyScalar(scalar){
this.x *= scalar
this.y *= scalar
this.z *= scalar
}
applyQuaternion(q){
const x = this.x
const y = this.y
const z = this.z
const qx = q.x
const qy = q.y
const qz = q.z
const qw = q.w
// calculate quat * vector
const ix = qw * x + qy * z - qz * y
const iy = qw * y + qz * x - qx * z
const iz = qw * z + qx * y - qy * x
const iw = - qx * x - qy * y - qz * z
// calculate result * inverse quat
this.x = ix * qw + iw * - qx + iy * - qz - iz * - qy
this.y = iy * qw + iw * - qy + iz * - qx - ix * - qz
this.z = iz * qw + iw * - qz + ix * - qy - iy * - qx
return this
}
applyMatrix4(matrix){
const x = this.x
const y = this.y
const z = this.z
const w = 1 / (matrix[3] * x + matrix[7] * y + matrix[11] * z + matrix[15])
this.x = (matrix[0] * x + matrix[4] * y + matrix[8] * z + matrix[12]) * w
this.y = (matrix[1] * x + matrix[5] * y + matrix[9] * z + matrix[13]) * w
this.z = (matrix[2] * x + matrix[6] * y + matrix[10] * z + matrix[14]) * w
return this
}
dot(v){
return this.x * v.x + this.y * v.y + this.z * v.z
}
crossVectors(a, b){
const ax = a.x, ay = a.y, az = a.z
const bx = b.x, by = b.y, bz = b.z
this.x = ay * bz - az * by
this.y = az * bx - ax * bz
this.z = ax * by - ay * bx
return this
}
}