vec4.ts

/**
 * Copyright (c) 2017-2018 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author David Sehnal <david.sehnal@gmail.com>
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 */

/*
 * This code has been modified from https://github.com/toji/gl-matrix/,
 * copyright (c) 2015, Brandon Jones, Colin MacKenzie IV.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 */

import Quat from './quat';
import Mat4 from './mat4';

interface Vec4 extends Array<number> { [d: number]: number, '@type': 'vec4', length: 4 }

namespace Vec4 {
    export function zero(): Vec4 {
        // force double backing array by 0.1.
        const ret = [0.1, 0, 0, 0];
        ret[0] = 0.0;
        return ret as any;
    }

    export function clone(a: Vec4) {
        const out = zero();
        out[0] = a[0];
        out[1] = a[1];
        out[2] = a[2];
        out[3] = a[3];
        return out;
    }

    export function create(x: number, y: number, z: number, w: number) {
        const out = zero();
        out[0] = x;
        out[1] = y;
        out[2] = z;
        out[3] = w;
        return out;
    }

    export function copy(out: Vec4, a: Vec4) {
        out[0] = a[0];
        out[1] = a[1];
        out[2] = a[2];
        out[3] = a[3];
        return out;
    }

    export function set(out: Vec4, x: number, y: number, z: number, w: number) {
        out[0] = x;
        out[1] = y;
        out[2] = z;
        out[3] = w;
        return out;
    }

    export function add(out: Quat, a: Quat, b: Quat) {
        out[0] = a[0] + b[0];
        out[1] = a[1] + b[1];
        out[2] = a[2] + b[2];
        out[3] = a[3] + b[3];
        return out;
    }

    export function distance(a: Vec4, b: Vec4) {
        const x = b[0] - a[0],
            y = b[1] - a[1],
            z = b[2] - a[2],
            w = b[3] - a[3];
        return Math.sqrt(x * x + y * y + z * z + w * w);
    }

    export function squaredDistance(a: Vec4, b: Vec4) {
        const x = b[0] - a[0],
            y = b[1] - a[1],
            z = b[2] - a[2],
            w = b[3] - a[3];
        return x * x + y * y + z * z + w * w;
    }

    export function norm(a: Vec4) {
        const x = a[0],
            y = a[1],
            z = a[2],
            w = a[3];
        return Math.sqrt(x * x + y * y + z * z + w * w);
    }

    export function squaredNorm(a: Vec4) {
        const x = a[0],
            y = a[1],
            z = a[2],
            w = a[3];
        return x * x + y * y + z * z + w * w;
    }

    export function transform(out: Vec4, a: Vec4, m: Mat4) {
        const x = a[0], y = a[1], z = a[2], w = a[3];
        out[0] = m[0] * x + m[4] * y + m[8] * z + m[12] * w;
        out[1] = m[1] * x + m[5] * y + m[9] * z + m[13] * w;
        out[2] = m[2] * x + m[6] * y + m[10] * z + m[14] * w;
        out[3] = m[3] * x + m[7] * y + m[11] * z + m[15] * w;
        return out;
    }
}

export default Vec4