linear.ts

/*
 * Copyright (c) 2016 - now, David Sehnal, licensed under Apache 2.0, See LICENSE file for more info.
 */

/*
 * 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:
 */

/**
 * Stores a 4x4 matrix in a column major (j * 4 + i indexing) format.
 */
export namespace Matrix4 {
    export function empty(): number[] {
        // force double backing type with the 0.1.
        const ret = [0.1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
        ret[0] = 0;
        return ret;
    }

    export function ofRows(rows: number[][]): number[] {
        let out = empty(), i: number, j: number, r: number[];
        for (i = 0; i < 4; i++) {
            r = rows[i];
            for (j = 0; j < 4; j++) {
                out[4 * j + i] = r[j];
            }
        }
        return out;
    }

    export function invert(out: number[], a: number[]) {
        let a00 = a[0], a01 = a[1], a02 = a[2], a03 = a[3],
            a10 = a[4], a11 = a[5], a12 = a[6], a13 = a[7],
            a20 = a[8], a21 = a[9], a22 = a[10], a23 = a[11],
            a30 = a[12], a31 = a[13], a32 = a[14], a33 = a[15],

            b00 = a00 * a11 - a01 * a10,
            b01 = a00 * a12 - a02 * a10,
            b02 = a00 * a13 - a03 * a10,
            b03 = a01 * a12 - a02 * a11,
            b04 = a01 * a13 - a03 * a11,
            b05 = a02 * a13 - a03 * a12,
            b06 = a20 * a31 - a21 * a30,
            b07 = a20 * a32 - a22 * a30,
            b08 = a20 * a33 - a23 * a30,
            b09 = a21 * a32 - a22 * a31,
            b10 = a21 * a33 - a23 * a31,
            b11 = a22 * a33 - a23 * a32,

            // Calculate the determinant
            det = b00 * b11 - b01 * b10 + b02 * b09 + b03 * b08 - b04 * b07 + b05 * b06;

        if (!det) {
            return null;
        }
        det = 1.0 / det;

        out[0] = (a11 * b11 - a12 * b10 + a13 * b09) * det;
        out[1] = (a02 * b10 - a01 * b11 - a03 * b09) * det;
        out[2] = (a31 * b05 - a32 * b04 + a33 * b03) * det;
        out[3] = (a22 * b04 - a21 * b05 - a23 * b03) * det;
        out[4] = (a12 * b08 - a10 * b11 - a13 * b07) * det;
        out[5] = (a00 * b11 - a02 * b08 + a03 * b07) * det;
        out[6] = (a32 * b02 - a30 * b05 - a33 * b01) * det;
        out[7] = (a20 * b05 - a22 * b02 + a23 * b01) * det;
        out[8] = (a10 * b10 - a11 * b08 + a13 * b06) * det;
        out[9] = (a01 * b08 - a00 * b10 - a03 * b06) * det;
        out[10] = (a30 * b04 - a31 * b02 + a33 * b00) * det;
        out[11] = (a21 * b02 - a20 * b04 - a23 * b00) * det;
        out[12] = (a11 * b07 - a10 * b09 - a12 * b06) * det;
        out[13] = (a00 * b09 - a01 * b07 + a02 * b06) * det;
        out[14] = (a31 * b01 - a30 * b03 - a32 * b00) * det;
        out[15] = (a20 * b03 - a21 * b01 + a22 * b00) * det;

        return out;
    }

    export function mul(out: number[], a: number[], b: number[]) {
        let a00 = a[0], a01 = a[1], a02 = a[2], a03 = a[3],
            a10 = a[4], a11 = a[5], a12 = a[6], a13 = a[7],
            a20 = a[8], a21 = a[9], a22 = a[10], a23 = a[11],
            a30 = a[12], a31 = a[13], a32 = a[14], a33 = a[15];

        // Cache only the current line of the second matrix
        let b0 = b[0], b1 = b[1], b2 = b[2], b3 = b[3];
        out[0] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[1] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[2] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[3] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;

        b0 = b[4]; b1 = b[5]; b2 = b[6]; b3 = b[7];
        out[4] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[5] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[6] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[7] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;

        b0 = b[8]; b1 = b[9]; b2 = b[10]; b3 = b[11];
        out[8] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[9] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[10] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[11] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;

        b0 = b[12]; b1 = b[13]; b2 = b[14]; b3 = b[15];
        out[12] = b0 * a00 + b1 * a10 + b2 * a20 + b3 * a30;
        out[13] = b0 * a01 + b1 * a11 + b2 * a21 + b3 * a31;
        out[14] = b0 * a02 + b1 * a12 + b2 * a22 + b3 * a32;
        out[15] = b0 * a03 + b1 * a13 + b2 * a23 + b3 * a33;
        return out;
    }

    export function transformVector3(out: number[], a: { [i: number]: number }, m: number[]) {
        let x = a[0], y = a[1], z = a[2];
        out[0] = m[0] * x + m[4] * y + m[8] * z + m[12];
        out[1] = m[1] * x + m[5] * y + m[9] * z + m[13];
        out[2] = m[2] * x + m[6] * y + m[10] * z + m[14];
        return out;
    }
}