@jscad/modeling/src/maths/mat4/mirror.js

Constructive Solid Geometry (CSG) Library for JSCAD

/*
 * m the mat4 by the dimensions in the given vec3
 * create an affine matrix for mirroring into an arbitrary plane:
 *
 * @param {mat4} out - the receiving matrix
 * @param {vec3} vector - the vec3 to mirror the matrix by
 * @param {mat4} matrix - the matrix to mirror
 * @returns {mat4} out
 */
const mirror = (out, vector, matrix) => {
  const x = vector[0]
  const y = vector[1]
  const z = vector[2]

  out[0] = matrix[0] * x
  out[1] = matrix[1] * x
  out[2] = matrix[2] * x
  out[3] = matrix[3] * x
  out[4] = matrix[4] * y
  out[5] = matrix[5] * y
  out[6] = matrix[6] * y
  out[7] = matrix[7] * y
  out[8] = matrix[8] * z
  out[9] = matrix[9] * z
  out[10] = matrix[10] * z
  out[11] = matrix[11] * z
  out[12] = matrix[12]
  out[13] = matrix[13]
  out[14] = matrix[14]
  out[15] = matrix[15]
  return out
}

module.exports = mirror