Source: node_modules/gl-matrix/esm/vec3.js

  1. import * as glMatrix from "./common.js";
  2. /**
  3.  * 3 Dimensional Vector
  4.  * @module vec3
  5.  */
  7. /**
  8.  * Creates a new, empty vec3
  9.  *
  10.  * @returns {vec3} a new 3D vector
  11.  */
  13. export function create() {
  14.   var out = new glMatrix.ARRAY_TYPE(3);
  16.   if (glMatrix.ARRAY_TYPE != Float32Array) {
  17.     out[0] = 0;
  18.     out[1] = 0;
  19.     out[2] = 0;
  20.   }
  22.   return out;
  23. }
  24. /**
  25.  * Creates a new vec3 initialized with values from an existing vector
  26.  *
  27.  * @param {ReadonlyVec3} a vector to clone
  28.  * @returns {vec3} a new 3D vector
  29.  */
  31. export function clone(a) {
  32.   var out = new glMatrix.ARRAY_TYPE(3);
  33.   out[0] = a[0];
  34.   out[1] = a[1];
  35.   out[2] = a[2];
  36.   return out;
  37. }
  38. /**
  39.  * Calculates the length of a vec3
  40.  *
  41.  * @param {ReadonlyVec3} a vector to calculate length of
  42.  * @returns {Number} length of a
  43.  */
  45. export function length(a) {
  46.   var x = a[0];
  47.   var y = a[1];
  48.   var z = a[2];
  49.   return Math.hypot(x, y, z);
  50. }
  51. /**
  52.  * Creates a new vec3 initialized with the given values
  53.  *
  54.  * @param {Number} x X component
  55.  * @param {Number} y Y component
  56.  * @param {Number} z Z component
  57.  * @returns {vec3} a new 3D vector
  58.  */
  60. export function fromValues(x, y, z) {
  61.   var out = new glMatrix.ARRAY_TYPE(3);
  62.   out[0] = x;
  63.   out[1] = y;
  64.   out[2] = z;
  65.   return out;
  66. }
  67. /**
  68.  * Copy the values from one vec3 to another
  69.  *
  70.  * @param {vec3} out the receiving vector
  71.  * @param {ReadonlyVec3} a the source vector
  72.  * @returns {vec3} out
  73.  */
  75. export function copy(out, a) {
  76.   out[0] = a[0];
  77.   out[1] = a[1];
  78.   out[2] = a[2];
  79.   return out;
  80. }
  81. /**
  82.  * Set the components of a vec3 to the given values
  83.  *
  84.  * @param {vec3} out the receiving vector
  85.  * @param {Number} x X component
  86.  * @param {Number} y Y component
  87.  * @param {Number} z Z component
  88.  * @returns {vec3} out
  89.  */
  91. export function set(out, x, y, z) {
  92.   out[0] = x;
  93.   out[1] = y;
  94.   out[2] = z;
  95.   return out;
  96. }
  97. /**
  98.  * Adds two vec3's
  99.  *
  100.  * @param {vec3} out the receiving vector
  101.  * @param {ReadonlyVec3} a the first operand
  102.  * @param {ReadonlyVec3} b the second operand
  103.  * @returns {vec3} out
  104.  */
  106. export function add(out, a, b) {
  107.   out[0] = a[0] + b[0];
  108.   out[1] = a[1] + b[1];
  109.   out[2] = a[2] + b[2];
  110.   return out;
  111. }
  112. /**
  113.  * Subtracts vector b from vector a
  114.  *
  115.  * @param {vec3} out the receiving vector
  116.  * @param {ReadonlyVec3} a the first operand
  117.  * @param {ReadonlyVec3} b the second operand
  118.  * @returns {vec3} out
  119.  */
  121. export function subtract(out, a, b) {
  122.   out[0] = a[0] - b[0];
  123.   out[1] = a[1] - b[1];
  124.   out[2] = a[2] - b[2];
  125.   return out;
  126. }
  127. /**
  128.  * Multiplies two vec3's
  129.  *
  130.  * @param {vec3} out the receiving vector
  131.  * @param {ReadonlyVec3} a the first operand
  132.  * @param {ReadonlyVec3} b the second operand
  133.  * @returns {vec3} out
  134.  */
  136. export function multiply(out, a, b) {
  137.   out[0] = a[0] * b[0];
  138.   out[1] = a[1] * b[1];
  139.   out[2] = a[2] * b[2];
  140.   return out;
  141. }
  142. /**
  143.  * Divides two vec3's
  144.  *
  145.  * @param {vec3} out the receiving vector
  146.  * @param {ReadonlyVec3} a the first operand
  147.  * @param {ReadonlyVec3} b the second operand
  148.  * @returns {vec3} out
  149.  */
  151. export function divide(out, a, b) {
  152.   out[0] = a[0] / b[0];
  153.   out[1] = a[1] / b[1];
  154.   out[2] = a[2] / b[2];
  155.   return out;
  156. }
  157. /**
  158.  * Math.ceil the components of a vec3
  159.  *
  160.  * @param {vec3} out the receiving vector
  161.  * @param {ReadonlyVec3} a vector to ceil
  162.  * @returns {vec3} out
  163.  */
  165. export function ceil(out, a) {
  166.   out[0] = Math.ceil(a[0]);
  167.   out[1] = Math.ceil(a[1]);
  168.   out[2] = Math.ceil(a[2]);
  169.   return out;
  170. }
  171. /**
  172.  * Math.floor the components of a vec3
  173.  *
  174.  * @param {vec3} out the receiving vector
  175.  * @param {ReadonlyVec3} a vector to floor
  176.  * @returns {vec3} out
  177.  */
  179. export function floor(out, a) {
  180.   out[0] = Math.floor(a[0]);
  181.   out[1] = Math.floor(a[1]);
  182.   out[2] = Math.floor(a[2]);
  183.   return out;
  184. }
  185. /**
  186.  * Returns the minimum of two vec3's
  187.  *
  188.  * @param {vec3} out the receiving vector
  189.  * @param {ReadonlyVec3} a the first operand
  190.  * @param {ReadonlyVec3} b the second operand
  191.  * @returns {vec3} out
  192.  */
  194. export function min(out, a, b) {
  195.   out[0] = Math.min(a[0], b[0]);
  196.   out[1] = Math.min(a[1], b[1]);
  197.   out[2] = Math.min(a[2], b[2]);
  198.   return out;
  199. }
  200. /**
  201.  * Returns the maximum of two vec3's
  202.  *
  203.  * @param {vec3} out the receiving vector
  204.  * @param {ReadonlyVec3} a the first operand
  205.  * @param {ReadonlyVec3} b the second operand
  206.  * @returns {vec3} out
  207.  */
  209. export function max(out, a, b) {
  210.   out[0] = Math.max(a[0], b[0]);
  211.   out[1] = Math.max(a[1], b[1]);
  212.   out[2] = Math.max(a[2], b[2]);
  213.   return out;
  214. }
  215. /**
  216.  * Math.round the components of a vec3
  217.  *
  218.  * @param {vec3} out the receiving vector
  219.  * @param {ReadonlyVec3} a vector to round
  220.  * @returns {vec3} out
  221.  */
  223. export function round(out, a) {
  224.   out[0] = Math.round(a[0]);
  225.   out[1] = Math.round(a[1]);
  226.   out[2] = Math.round(a[2]);
  227.   return out;
  228. }
  229. /**
  230.  * Scales a vec3 by a scalar number
  231.  *
  232.  * @param {vec3} out the receiving vector
  233.  * @param {ReadonlyVec3} a the vector to scale
  234.  * @param {Number} b amount to scale the vector by
  235.  * @returns {vec3} out
  236.  */
  238. export function scale(out, a, b) {
  239.   out[0] = a[0] * b;
  240.   out[1] = a[1] * b;
  241.   out[2] = a[2] * b;
  242.   return out;
  243. }
  244. /**
  245.  * Adds two vec3's after scaling the second operand by a scalar value
  246.  *
  247.  * @param {vec3} out the receiving vector
  248.  * @param {ReadonlyVec3} a the first operand
  249.  * @param {ReadonlyVec3} b the second operand
  250.  * @param {Number} scale the amount to scale b by before adding
  251.  * @returns {vec3} out
  252.  */
  254. export function scaleAndAdd(out, a, b, scale) {
  255.   out[0] = a[0] + b[0] * scale;
  256.   out[1] = a[1] + b[1] * scale;
  257.   out[2] = a[2] + b[2] * scale;
  258.   return out;
  259. }
  260. /**
  261.  * Calculates the euclidian distance between two vec3's
  262.  *
  263.  * @param {ReadonlyVec3} a the first operand
  264.  * @param {ReadonlyVec3} b the second operand
  265.  * @returns {Number} distance between a and b
  266.  */
  268. export function distance(a, b) {
  269.   var x = b[0] - a[0];
  270.   var y = b[1] - a[1];
  271.   var z = b[2] - a[2];
  272.   return Math.hypot(x, y, z);
  273. }
  274. /**
  275.  * Calculates the squared euclidian distance between two vec3's
  276.  *
  277.  * @param {ReadonlyVec3} a the first operand
  278.  * @param {ReadonlyVec3} b the second operand
  279.  * @returns {Number} squared distance between a and b
  280.  */
  282. export function squaredDistance(a, b) {
  283.   var x = b[0] - a[0];
  284.   var y = b[1] - a[1];
  285.   var z = b[2] - a[2];
  286.   return x * x + y * y + z * z;
  287. }
  288. /**
  289.  * Calculates the squared length of a vec3
  290.  *
  291.  * @param {ReadonlyVec3} a vector to calculate squared length of
  292.  * @returns {Number} squared length of a
  293.  */
  295. export function squaredLength(a) {
  296.   var x = a[0];
  297.   var y = a[1];
  298.   var z = a[2];
  299.   return x * x + y * y + z * z;
  300. }
  301. /**
  302.  * Negates the components of a vec3
  303.  *
  304.  * @param {vec3} out the receiving vector
  305.  * @param {ReadonlyVec3} a vector to negate
  306.  * @returns {vec3} out
  307.  */
  309. export function negate(out, a) {
  310.   out[0] = -a[0];
  311.   out[1] = -a[1];
  312.   out[2] = -a[2];
  313.   return out;
  314. }
  315. /**
  316.  * Returns the inverse of the components of a vec3
  317.  *
  318.  * @param {vec3} out the receiving vector
  319.  * @param {ReadonlyVec3} a vector to invert
  320.  * @returns {vec3} out
  321.  */
  323. export function inverse(out, a) {
  324.   out[0] = 1.0 / a[0];
  325.   out[1] = 1.0 / a[1];
  326.   out[2] = 1.0 / a[2];
  327.   return out;
  328. }
  329. /**
  330.  * Normalize a vec3
  331.  *
  332.  * @param {vec3} out the receiving vector
  333.  * @param {ReadonlyVec3} a vector to normalize
  334.  * @returns {vec3} out
  335.  */
  337. export function normalize(out, a) {
  338.   var x = a[0];
  339.   var y = a[1];
  340.   var z = a[2];
  341.   var len = x * x + y * y + z * z;
  343.   if (len > 0) {
  344.     //TODO: evaluate use of glm_invsqrt here?
  345.     len = 1 / Math.sqrt(len);
  346.   }
  348.   out[0] = a[0] * len;
  349.   out[1] = a[1] * len;
  350.   out[2] = a[2] * len;
  351.   return out;
  352. }
  353. /**
  354.  * Calculates the dot product of two vec3's
  355.  *
  356.  * @param {ReadonlyVec3} a the first operand
  357.  * @param {ReadonlyVec3} b the second operand
  358.  * @returns {Number} dot product of a and b
  359.  */
  361. export function dot(a, b) {
  362.   return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
  363. }
  364. /**
  365.  * Computes the cross product of two vec3's
  366.  *
  367.  * @param {vec3} out the receiving vector
  368.  * @param {ReadonlyVec3} a the first operand
  369.  * @param {ReadonlyVec3} b the second operand
  370.  * @returns {vec3} out
  371.  */
  373. export function cross(out, a, b) {
  374.   var ax = a[0],
  375.       ay = a[1],
  376.       az = a[2];
  377.   var bx = b[0],
  378.       by = b[1],
  379.       bz = b[2];
  380.   out[0] = ay * bz - az * by;
  381.   out[1] = az * bx - ax * bz;
  382.   out[2] = ax * by - ay * bx;
  383.   return out;
  384. }
  385. /**
  386.  * Performs a linear interpolation between two vec3's
  387.  *
  388.  * @param {vec3} out the receiving vector
  389.  * @param {ReadonlyVec3} a the first operand
  390.  * @param {ReadonlyVec3} b the second operand
  391.  * @param {Number} t interpolation amount, in the range [0-1], between the two inputs
  392.  * @returns {vec3} out
  393.  */
  395. export function lerp(out, a, b, t) {
  396.   var ax = a[0];
  397.   var ay = a[1];
  398.   var az = a[2];
  399.   out[0] = ax + t * (b[0] - ax);
  400.   out[1] = ay + t * (b[1] - ay);
  401.   out[2] = az + t * (b[2] - az);
  402.   return out;
  403. }
  404. /**
  405.  * Performs a hermite interpolation with two control points
  406.  *
  407.  * @param {vec3} out the receiving vector
  408.  * @param {ReadonlyVec3} a the first operand
  409.  * @param {ReadonlyVec3} b the second operand
  410.  * @param {ReadonlyVec3} c the third operand
  411.  * @param {ReadonlyVec3} d the fourth operand
  412.  * @param {Number} t interpolation amount, in the range [0-1], between the two inputs
  413.  * @returns {vec3} out
  414.  */
  416. export function hermite(out, a, b, c, d, t) {
  417.   var factorTimes2 = t * t;
  418.   var factor1 = factorTimes2 * (2 * t - 3) + 1;
  419.   var factor2 = factorTimes2 * (t - 2) + t;
  420.   var factor3 = factorTimes2 * (t - 1);
  421.   var factor4 = factorTimes2 * (3 - 2 * t);
  422.   out[0] = a[0] * factor1 + b[0] * factor2 + c[0] * factor3 + d[0] * factor4;
  423.   out[1] = a[1] * factor1 + b[1] * factor2 + c[1] * factor3 + d[1] * factor4;
  424.   out[2] = a[2] * factor1 + b[2] * factor2 + c[2] * factor3 + d[2] * factor4;
  425.   return out;
  426. }
  427. /**
  428.  * Performs a bezier interpolation with two control points
  429.  *
  430.  * @param {vec3} out the receiving vector
  431.  * @param {ReadonlyVec3} a the first operand
  432.  * @param {ReadonlyVec3} b the second operand
  433.  * @param {ReadonlyVec3} c the third operand
  434.  * @param {ReadonlyVec3} d the fourth operand
  435.  * @param {Number} t interpolation amount, in the range [0-1], between the two inputs
  436.  * @returns {vec3} out
  437.  */
  439. export function bezier(out, a, b, c, d, t) {
  440.   var inverseFactor = 1 - t;
  441.   var inverseFactorTimesTwo = inverseFactor * inverseFactor;
  442.   var factorTimes2 = t * t;
  443.   var factor1 = inverseFactorTimesTwo * inverseFactor;
  444.   var factor2 = 3 * t * inverseFactorTimesTwo;
  445.   var factor3 = 3 * factorTimes2 * inverseFactor;
  446.   var factor4 = factorTimes2 * t;
  447.   out[0] = a[0] * factor1 + b[0] * factor2 + c[0] * factor3 + d[0] * factor4;
  448.   out[1] = a[1] * factor1 + b[1] * factor2 + c[1] * factor3 + d[1] * factor4;
  449.   out[2] = a[2] * factor1 + b[2] * factor2 + c[2] * factor3 + d[2] * factor4;
  450.   return out;
  451. }
  452. /**
  453.  * Generates a random vector with the given scale
  454.  *
  455.  * @param {vec3} out the receiving vector
  456.  * @param {Number} [scale] Length of the resulting vector. If ommitted, a unit vector will be returned
  457.  * @returns {vec3} out
  458.  */
  460. export function random(out, scale) {
  461.   scale = scale || 1.0;
  462.   var r = glMatrix.RANDOM() * 2.0 * Math.PI;
  463.   var z = glMatrix.RANDOM() * 2.0 - 1.0;
  464.   var zScale = Math.sqrt(1.0 - z * z) * scale;
  465.   out[0] = Math.cos(r) * zScale;
  466.   out[1] = Math.sin(r) * zScale;
  467.   out[2] = z * scale;
  468.   return out;
  469. }
  470. /**
  471.  * Transforms the vec3 with a mat4.
  472.  * 4th vector component is implicitly '1'
  473.  *
  474.  * @param {vec3} out the receiving vector
  475.  * @param {ReadonlyVec3} a the vector to transform
  476.  * @param {ReadonlyMat4} m matrix to transform with
  477.  * @returns {vec3} out
  478.  */
  480. export function transformMat4(out, a, m) {
  481.   var x = a[0],
  482.       y = a[1],
  483.       z = a[2];
  484.   var w = m[3] * x + m[7] * y + m[11] * z + m[15];
  485.   w = w || 1.0;
  486.   out[0] = (m[0] * x + m[4] * y + m[8] * z + m[12]) / w;
  487.   out[1] = (m[1] * x + m[5] * y + m[9] * z + m[13]) / w;
  488.   out[2] = (m[2] * x + m[6] * y + m[10] * z + m[14]) / w;
  489.   return out;
  490. }
  491. /**
  492.  * Transforms the vec3 with a mat3.
  493.  *
  494.  * @param {vec3} out the receiving vector
  495.  * @param {ReadonlyVec3} a the vector to transform
  496.  * @param {ReadonlyMat3} m the 3x3 matrix to transform with
  497.  * @returns {vec3} out
  498.  */
  500. export function transformMat3(out, a, m) {
  501.   var x = a[0],
  502.       y = a[1],
  503.       z = a[2];
  504.   out[0] = x * m[0] + y * m[3] + z * m[6];
  505.   out[1] = x * m[1] + y * m[4] + z * m[7];
  506.   out[2] = x * m[2] + y * m[5] + z * m[8];
  507.   return out;
  508. }
  509. /**
  510.  * Transforms the vec3 with a quat
  511.  * Can also be used for dual quaternions. (Multiply it with the real part)
  512.  *
  513.  * @param {vec3} out the receiving vector
  514.  * @param {ReadonlyVec3} a the vector to transform
  515.  * @param {ReadonlyQuat} q quaternion to transform with
  516.  * @returns {vec3} out
  517.  */
  519. export function transformQuat(out, a, q) {
  520.   // benchmarks: https://jsperf.com/quaternion-transform-vec3-implementations-fixed
  521.   var qx = q[0],
  522.       qy = q[1],
  523.       qz = q[2],
  524.       qw = q[3];
  525.   var x = a[0],
  526.       y = a[1],
  527.       z = a[2]; // var qvec = [qx, qy, qz];
  528.   // var uv = vec3.cross([], qvec, a);
  530.   var uvx = qy * z - qz * y,
  531.       uvy = qz * x - qx * z,
  532.       uvz = qx * y - qy * x; // var uuv = vec3.cross([], qvec, uv);
  534.   var uuvx = qy * uvz - qz * uvy,
  535.       uuvy = qz * uvx - qx * uvz,
  536.       uuvz = qx * uvy - qy * uvx; // vec3.scale(uv, uv, 2 * w);
  538.   var w2 = qw * 2;
  539.   uvx *= w2;
  540.   uvy *= w2;
  541.   uvz *= w2; // vec3.scale(uuv, uuv, 2);
  543.   uuvx *= 2;
  544.   uuvy *= 2;
  545.   uuvz *= 2; // return vec3.add(out, a, vec3.add(out, uv, uuv));
  547.   out[0] = x + uvx + uuvx;
  548.   out[1] = y + uvy + uuvy;
  549.   out[2] = z + uvz + uuvz;
  550.   return out;
  551. }
  552. /**
  553.  * Rotate a 3D vector around the x-axis
  554.  * @param {vec3} out The receiving vec3
  555.  * @param {ReadonlyVec3} a The vec3 point to rotate
  556.  * @param {ReadonlyVec3} b The origin of the rotation
  557.  * @param {Number} rad The angle of rotation in radians
  558.  * @returns {vec3} out
  559.  */
  561. export function rotateX(out, a, b, rad) {
  562.   var p = [],
  563.       r = []; //Translate point to the origin
  565.   p[0] = a[0] - b[0];
  566.   p[1] = a[1] - b[1];
  567.   p[2] = a[2] - b[2]; //perform rotation
  569.   r[0] = p[0];
  570.   r[1] = p[1] * Math.cos(rad) - p[2] * Math.sin(rad);
  571.   r[2] = p[1] * Math.sin(rad) + p[2] * Math.cos(rad); //translate to correct position
  573.   out[0] = r[0] + b[0];
  574.   out[1] = r[1] + b[1];
  575.   out[2] = r[2] + b[2];
  576.   return out;
  577. }
  578. /**
  579.  * Rotate a 3D vector around the y-axis
  580.  * @param {vec3} out The receiving vec3
  581.  * @param {ReadonlyVec3} a The vec3 point to rotate
  582.  * @param {ReadonlyVec3} b The origin of the rotation
  583.  * @param {Number} rad The angle of rotation in radians
  584.  * @returns {vec3} out
  585.  */
  587. export function rotateY(out, a, b, rad) {
  588.   var p = [],
  589.       r = []; //Translate point to the origin
  591.   p[0] = a[0] - b[0];
  592.   p[1] = a[1] - b[1];
  593.   p[2] = a[2] - b[2]; //perform rotation
  595.   r[0] = p[2] * Math.sin(rad) + p[0] * Math.cos(rad);
  596.   r[1] = p[1];
  597.   r[2] = p[2] * Math.cos(rad) - p[0] * Math.sin(rad); //translate to correct position
  599.   out[0] = r[0] + b[0];
  600.   out[1] = r[1] + b[1];
  601.   out[2] = r[2] + b[2];
  602.   return out;
  603. }
  604. /**
  605.  * Rotate a 3D vector around the z-axis
  606.  * @param {vec3} out The receiving vec3
  607.  * @param {ReadonlyVec3} a The vec3 point to rotate
  608.  * @param {ReadonlyVec3} b The origin of the rotation
  609.  * @param {Number} rad The angle of rotation in radians
  610.  * @returns {vec3} out
  611.  */
  613. export function rotateZ(out, a, b, rad) {
  614.   var p = [],
  615.       r = []; //Translate point to the origin
  617.   p[0] = a[0] - b[0];
  618.   p[1] = a[1] - b[1];
  619.   p[2] = a[2] - b[2]; //perform rotation
  621.   r[0] = p[0] * Math.cos(rad) - p[1] * Math.sin(rad);
  622.   r[1] = p[0] * Math.sin(rad) + p[1] * Math.cos(rad);
  623.   r[2] = p[2]; //translate to correct position
  625.   out[0] = r[0] + b[0];
  626.   out[1] = r[1] + b[1];
  627.   out[2] = r[2] + b[2];
  628.   return out;
  629. }
  630. /**
  631.  * Get the angle between two 3D vectors
  632.  * @param {ReadonlyVec3} a The first operand
  633.  * @param {ReadonlyVec3} b The second operand
  634.  * @returns {Number} The angle in radians
  635.  */
  637. export function angle(a, b) {
  638.   var ax = a[0],
  639.       ay = a[1],
  640.       az = a[2],
  641.       bx = b[0],
  642.       by = b[1],
  643.       bz = b[2],
  644.       mag1 = Math.sqrt(ax * ax + ay * ay + az * az),
  645.       mag2 = Math.sqrt(bx * bx + by * by + bz * bz),
  646.       mag = mag1 * mag2,
  647.       cosine = mag && dot(a, b) / mag;
  648.   return Math.acos(Math.min(Math.max(cosine, -1), 1));
  649. }
  650. /**
  651.  * Set the components of a vec3 to zero
  652.  *
  653.  * @param {vec3} out the receiving vector
  654.  * @returns {vec3} out
  655.  */
  657. export function zero(out) {
  658.   out[0] = 0.0;
  659.   out[1] = 0.0;
  660.   out[2] = 0.0;
  661.   return out;
  662. }
  663. /**
  664.  * Returns a string representation of a vector
  665.  *
  666.  * @param {ReadonlyVec3} a vector to represent as a string
  667.  * @returns {String} string representation of the vector
  668.  */
  670. export function str(a) {
  671.   return "vec3(" + a[0] + ", " + a[1] + ", " + a[2] + ")";
  672. }
  673. /**
  674.  * Returns whether or not the vectors have exactly the same elements in the same position (when compared with ===)
  675.  *
  676.  * @param {ReadonlyVec3} a The first vector.
  677.  * @param {ReadonlyVec3} b The second vector.
  678.  * @returns {Boolean} True if the vectors are equal, false otherwise.
  679.  */
  681. export function exactEquals(a, b) {
  682.   return a[0] === b[0] && a[1] === b[1] && a[2] === b[2];
  683. }
  684. /**
  685.  * Returns whether or not the vectors have approximately the same elements in the same position.
  686.  *
  687.  * @param {ReadonlyVec3} a The first vector.
  688.  * @param {ReadonlyVec3} b The second vector.
  689.  * @returns {Boolean} True if the vectors are equal, false otherwise.
  690.  */
  692. export function equals(a, b) {
  693.   var a0 = a[0],
  694.       a1 = a[1],
  695.       a2 = a[2];
  696.   var b0 = b[0],
  697.       b1 = b[1],
  698.       b2 = b[2];
  699.   return Math.abs(a0 - b0) <= glMatrix.EPSILON * Math.max(1.0, Math.abs(a0), Math.abs(b0)) && Math.abs(a1 - b1) <= glMatrix.EPSILON * Math.max(1.0, Math.abs(a1), Math.abs(b1)) && Math.abs(a2 - b2) <= glMatrix.EPSILON * Math.max(1.0, Math.abs(a2), Math.abs(b2));
  700. }
  701. /**
  702.  * Alias for {@link vec3.subtract}
  703.  * @function
  704.  */
  706. export var sub = subtract;
  707. /**
  708.  * Alias for {@link vec3.multiply}
  709.  * @function
  710.  */
  712. export var mul = multiply;
  713. /**
  714.  * Alias for {@link vec3.divide}
  715.  * @function
  716.  */
  718. export var div = divide;
  719. /**
  720.  * Alias for {@link vec3.distance}
  721.  * @function
  722.  */
  724. export var dist = distance;
  725. /**
  726.  * Alias for {@link vec3.squaredDistance}
  727.  * @function
  728.  */
  730. export var sqrDist = squaredDistance;
  731. /**
  732.  * Alias for {@link vec3.length}
  733.  * @function
  734.  */
  736. export var len = length;
  737. /**
  738.  * Alias for {@link vec3.squaredLength}
  739.  * @function
  740.  */
  742. export var sqrLen = squaredLength;
  743. /**
  744.  * Perform some operation over an array of vec3s.
  745.  *
  746.  * @param {Array} a the array of vectors to iterate over
  747.  * @param {Number} stride Number of elements between the start of each vec3. If 0 assumes tightly packed
  748.  * @param {Number} offset Number of elements to skip at the beginning of the array
  749.  * @param {Number} count Number of vec3s to iterate over. If 0 iterates over entire array
  750.  * @param {Function} fn Function to call for each vector in the array
  751.  * @param {Object} [arg] additional argument to pass to fn
  752.  * @returns {Array} a
  753.  * @function
  754.  */
  756. export var forEach = function () {
  757.   var vec = create();
  758.   return function (a, stride, offset, count, fn, arg) {
  759.     var i, l;
  761.     if (!stride) {
  762.       stride = 3;
  763.     }
  765.     if (!offset) {
  766.       offset = 0;
  767.     }
  769.     if (count) {
  770.       l = Math.min(count * stride + offset, a.length);
  771.     } else {
  772.       l = a.length;
  773.     }
  775.     for (i = offset; i < l; i += stride) {
  776.       vec[0] = a[i];
  777.       vec[1] = a[i + 1];
  778.       vec[2] = a[i + 2];
  779.       fn(vec, vec, arg);
  780.       a[i] = vec[0];
  781.       a[i + 1] = vec[1];
  782.       a[i + 2] = vec[2];
  783.     }
  785.     return a;
  786.   };
  787. }();