@thewtex/vtk.js-esm/vendor/gl-matrix/esm/vec4.js

Visualization Toolkit for the Web

import { A as ARRAY_TYPE } from './common.js';

/**
 * 4 Dimensional Vector
 * @module vec4
 */

/**
 * Creates a new, empty vec4
 *
 * @returns {vec4} a new 4D vector
 */

function create() {
  var out = new ARRAY_TYPE(4);

  if (ARRAY_TYPE != Float32Array) {
    out[0] = 0;
    out[1] = 0;
    out[2] = 0;
    out[3] = 0;
  }

  return out;
}
/**
 * Creates a new vec4 initialized with the given values
 *
 * @param {Number} x X component
 * @param {Number} y Y component
 * @param {Number} z Z component
 * @param {Number} w W component
 * @returns {vec4} a new 4D vector
 */

function fromValues(x, y, z, w) {
  var out = new ARRAY_TYPE(4);
  out[0] = x;
  out[1] = y;
  out[2] = z;
  out[3] = w;
  return out;
}
/**
 * Normalize a vec4
 *
 * @param {vec4} out the receiving vector
 * @param {ReadonlyVec4} a vector to normalize
 * @returns {vec4} out
 */

function normalize(out, a) {
  var x = a[0];
  var y = a[1];
  var z = a[2];
  var w = a[3];
  var len = x * x + y * y + z * z + w * w;

  if (len > 0) {
    len = 1 / Math.sqrt(len);
  }

  out[0] = x * len;
  out[1] = y * len;
  out[2] = z * len;
  out[3] = w * len;
  return out;
}
/**
 * Transforms the vec4 with a mat4.
 *
 * @param {vec4} out the receiving vector
 * @param {ReadonlyVec4} a the vector to transform
 * @param {ReadonlyMat4} m matrix to transform with
 * @returns {vec4} out
 */

function transformMat4(out, a, m) {
  var 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;
}
/**
 * Perform some operation over an array of vec4s.
 *
 * @param {Array} a the array of vectors to iterate over
 * @param {Number} stride Number of elements between the start of each vec4. If 0 assumes tightly packed
 * @param {Number} offset Number of elements to skip at the beginning of the array
 * @param {Number} count Number of vec4s to iterate over. If 0 iterates over entire array
 * @param {Function} fn Function to call for each vector in the array
 * @param {Object} [arg] additional argument to pass to fn
 * @returns {Array} a
 * @function
 */

(function () {
  var vec = create();
  return function (a, stride, offset, count, fn, arg) {
    var i, l;

    if (!stride) {
      stride = 4;
    }

    if (!offset) {
      offset = 0;
    }

    if (count) {
      l = Math.min(count * stride + offset, a.length);
    } else {
      l = a.length;
    }

    for (i = offset; i < l; i += stride) {
      vec[0] = a[i];
      vec[1] = a[i + 1];
      vec[2] = a[i + 2];
      vec[3] = a[i + 3];
      fn(vec, vec, arg);
      a[i] = vec[0];
      a[i + 1] = vec[1];
      a[i + 2] = vec[2];
      a[i + 3] = vec[3];
    }

    return a;
  };
})();

export { fromValues as f, normalize as n, transformMat4 as t };