Rzutowanie 3d na 2d (rzut izometryczny)

Vector2.js

/** Class representing a 2D vector. (X, Y)*/
export default class Vector2 {
    constructor(X = 0, Y = 0) {
        this.X = X
        this.Y = Y
    }

    /** Returns new Vector2 rotated by given angle (in radians) and any point.
     * @param {Number} rad Angle of rotation given in radians.
     * @param {Vector2} vector2 Point against which rotation is performed.
     * @returns {Vector2}
     */
    rotate(rad, vector2 = new Vector2(0, 0)) {
        const x = this.X - vector2.X
        const y = this.Y - vector2.Y
        const sin = Math.sin(rad)
        const cos = Math.cos(rad)

        return new Vector2(
            x * cos - y * sin + vector2.X,
            x * sin + y * cos + vector2.Y
        )
    }

    /** Returns new Vector2 created with sum of this vector and specified vector.
     * @param {Vector2} vector
     * @returns {Vector2}
     */
    translate(vector) {
        return new Vector2(this.X + vector.X, this.Y + vector.Y)
    }
}

Vector3.js

import Vector2 from './Vector2'
const SIN27 = Math.sin(27)
const COS27 = Math.cos(27)

/** Class representing a 3D vector. (X, Y, Z)*/
export default class Vector3 {
    constructor(X = 0, Y = 0, Z = 0) {
        this.X = X
        this.Y = Y
        this.Z = Z
    }

    /** Returns new Vector2 created from the isometric projection of this vector.
     * @returns {Vector2}
     */
    toVector2() {
        const {X, Y, Z} = this
        return new Vector2(
            (Y - X) * SIN27,
            -((Y + X) * COS27 + Z)
        )
    }

    /** Returns new Vector3 rotated by given angle (in radians) and any point.
     * @param {Number} rad Angle of rotation given in radians.
     * @param {Vector2|Vector3} vector Point against which rotation is performed.
     * @returns {Vector3}
     */
    rotate(rad, vector = new Vector3(0, 0)) {
        const x = this.X - vector.X
        const y = this.Y - vector.Y
        const sin = Math.sin(rad)
        const cos = Math.cos(rad)

        return new Vector3(
            x * cos - y * sin + vector.X,
            x * sin + y * cos + vector.Y,
            this.Z
        )
    }

    /** Returns new Vector3 created with sum of this vector and specified vector.
     * @param {Vector3} vector
     * @returns {Vector3}
     */
    translate(vector) {
        return new Vector3(this.X + vector.X, this.Y + vector.Y, this.Z + vector.Z)
    }

    /** Returns new Vector3 created by multiplying vector by n.
     * @param {Number} n
     * @returns {Vector3}
     */
    scale(n) {
        return new Vector3(this.X * n, this.Y * n, this.Z * n)
    }
}