@egjs/view360/src/utils/mathUtil/mat4.js

360 integrated viewing solution from inside-out view to outside-in view. It provides user-friendly service by rotating 360 degrees through various user interaction such as motion sensor and touch.

/**
 * Original Code
 * https://github.com/toji/gl-matrix/blob/v2.3.2/src/gl-matrix/mat4.js
 * 4x4 Matrix util
 * modified by egjs
 */
import glMatrix from "./common.js";

/**
 * @class 4x4 Matrix
 * @name mat4
 */
var mat4 = {};

/**
 * Creates a new identity mat4
 *
 * @returns {mat4} a new 4x4 matrix
 */
mat4.create = function() {
    var out = new glMatrix.ARRAY_TYPE(16);
    out[0] = 1;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
    out[4] = 0;
    out[5] = 1;
    out[6] = 0;
    out[7] = 0;
    out[8] = 0;
    out[9] = 0;
    out[10] = 1;
    out[11] = 0;
    out[12] = 0;
    out[13] = 0;
    out[14] = 0;
    out[15] = 1;
    return out;
};

/**
 * Set a mat4 to the identity matrix
 *
 * @param {mat4} out the receiving matrix
 * @returns {mat4} out
 */
mat4.identity = function(out) {
    out[0] = 1;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
    out[4] = 0;
    out[5] = 1;
    out[6] = 0;
    out[7] = 0;
    out[8] = 0;
    out[9] = 0;
    out[10] = 1;
    out[11] = 0;
    out[12] = 0;
    out[13] = 0;
    out[14] = 0;
    out[15] = 1;
    return out;
};

/**
 * Rotates a matrix by the given angle around the X axis not using SIMD
 *
 * @param {mat4} out the receiving matrix
 * @param {mat4} a the matrix to rotate
 * @param {Number} rad the angle to rotate the matrix by
 * @returns {mat4} out
 */
mat4.rotateX = function (out, a, rad) {
    var s = Math.sin(rad),
        c = Math.cos(rad),
        a10 = a[4],
        a11 = a[5],
        a12 = a[6],
        a13 = a[7],
        a20 = a[8],
        a21 = a[9],
        a22 = a[10],
        a23 = a[11];

    if (a !== out) { // If the source and destination differ, copy the unchanged rows
        out[0]  = a[0];
        out[1]  = a[1];
        out[2]  = a[2];
        out[3]  = a[3];
        out[12] = a[12];
        out[13] = a[13];
        out[14] = a[14];
        out[15] = a[15];
    }

    // Perform axis-specific matrix multiplication
    out[4] = a10 * c + a20 * s;
    out[5] = a11 * c + a21 * s;
    out[6] = a12 * c + a22 * s;
    out[7] = a13 * c + a23 * s;
    out[8] = a20 * c - a10 * s;
    out[9] = a21 * c - a11 * s;
    out[10] = a22 * c - a12 * s;
    out[11] = a23 * c - a13 * s;
    return out;
};

/**
 * Rotates a matrix by the given angle around the Y axis not using SIMD
 *
 * @param {mat4} out the receiving matrix
 * @param {mat4} a the matrix to rotate
 * @param {Number} rad the angle to rotate the matrix by
 * @returns {mat4} out
 */
mat4.rotateY = function (out, a, rad) {
    var s = Math.sin(rad),
        c = Math.cos(rad),
        a00 = a[0],
        a01 = a[1],
        a02 = a[2],
        a03 = a[3],
        a20 = a[8],
        a21 = a[9],
        a22 = a[10],
        a23 = a[11];

    if (a !== out) { // If the source and destination differ, copy the unchanged rows
        out[4]  = a[4];
        out[5]  = a[5];
        out[6]  = a[6];
        out[7]  = a[7];
        out[12] = a[12];
        out[13] = a[13];
        out[14] = a[14];
        out[15] = a[15];
    }

    // Perform axis-specific matrix multiplication
    out[0] = a00 * c - a20 * s;
    out[1] = a01 * c - a21 * s;
    out[2] = a02 * c - a22 * s;
    out[3] = a03 * c - a23 * s;
    out[8] = a00 * s + a20 * c;
    out[9] = a01 * s + a21 * c;
    out[10] = a02 * s + a22 * c;
    out[11] = a03 * s + a23 * c;
    return out;
};

/**
 * Calculates a 4x4 matrix from the given quaternion
 *
 * @param {mat4} out mat4 receiving operation result
 * @param {quat} q Quaternion to create matrix from
 *
 * @returns {mat4} out
 */
mat4.fromQuat = function (out, q) {
    var x = q[0], y = q[1], z = q[2], w = q[3],
        x2 = x + x,
        y2 = y + y,
        z2 = z + z,

        xx = x * x2,
        yx = y * x2,
        yy = y * y2,
        zx = z * x2,
        zy = z * y2,
        zz = z * z2,
        wx = w * x2,
        wy = w * y2,
        wz = w * z2;

    out[0] = 1 - yy - zz;
    out[1] = yx + wz;
    out[2] = zx - wy;
    out[3] = 0;

    out[4] = yx - wz;
    out[5] = 1 - xx - zz;
    out[6] = zy + wx;
    out[7] = 0;

    out[8] = zx + wy;
    out[9] = zy - wx;
    out[10] = 1 - xx - yy;
    out[11] = 0;

    out[12] = 0;
    out[13] = 0;
    out[14] = 0;
    out[15] = 1;

    return out;
};

/**
 * Generates a perspective projection matrix with the given bounds
 *
 * @param {mat4} out mat4 frustum matrix will be written into
 * @param {number} fovy Vertical field of view in radians
 * @param {number} aspect Aspect ratio. typically viewport width/height
 * @param {number} near Near bound of the frustum
 * @param {number} far Far bound of the frustum
 * @returns {mat4} out
 */
mat4.perspective = function (out, fovy, aspect, near, far) {
    var f = 1.0 / Math.tan(fovy / 2),
        nf = 1 / (near - far);
    out[0] = f / aspect;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
    out[4] = 0;
    out[5] = f;
    out[6] = 0;
    out[7] = 0;
    out[8] = 0;
    out[9] = 0;
    out[10] = (far + near) * nf;
    out[11] = -1;
    out[12] = 0;
    out[13] = 0;
    out[14] = (2 * far * near) * nf;
    out[15] = 0;
    return out;
};

export default mat4;