Method rotate4x4

src/math/Matrices/Matrix.js:1000–1061

* Rotate the Matrix around a specified axis by a given angle. * * This method applies a rotation transformation to the matrix, modifying its orientation * in 3D space. The rotation is performed around the provided axis, which can be defined * as a `p5.Vector` or an array of numbers repre

(a, x, y, z)

   * }
   */
  rotate4x4(a, x, y, z) {
    if (x instanceof Vector) {
      // x is a vector, extract the components from it.
      y = x.y;
      z = x.z;
      x = x.x; //must be last
    } else if (x instanceof Array) {
      // x is an array, extract the components from it.
      y = x[1];
      z = x[2];
      x = x[0]; //must be last
    }

    const len = Math.sqrt(x * x + y * y + z * z);
    x *= 1 / len;
    y *= 1 / len;
    z *= 1 / len;

    const a00 = this.matrix[0];
    const a01 = this.matrix[1];
    const a02 = this.matrix[2];
    const a03 = this.matrix[3];
    const a10 = this.matrix[4];
    const a11 = this.matrix[5];
    const a12 = this.matrix[6];
    const a13 = this.matrix[7];
    const a20 = this.matrix[8];
    const a21 = this.matrix[9];
    const a22 = this.matrix[10];
    const a23 = this.matrix[11];

    //sin,cos, and tan of respective angle
    const sA = Math.sin(a);
    const cA = Math.cos(a);
    const tA = 1 - cA;
    // Construct the elements of the rotation matrix
    const b00 = x * x * tA + cA;
    const b01 = y * x * tA + z * sA;
    const b02 = z * x * tA - y * sA;
    const b10 = x * y * tA - z * sA;
    const b11 = y * y * tA + cA;
    const b12 = z * y * tA + x * sA;
    const b20 = x * z * tA + y * sA;
    const b21 = y * z * tA - x * sA;
    const b22 = z * z * tA + cA;

    // rotation-specific matrix multiplication
    this.matrix[0] = a00 * b00 + a10 * b01 + a20 * b02;
    this.matrix[1] = a01 * b00 + a11 * b01 + a21 * b02;
    this.matrix[2] = a02 * b00 + a12 * b01 + a22 * b02;
    this.matrix[3] = a03 * b00 + a13 * b01 + a23 * b02;
    this.matrix[4] = a00 * b10 + a10 * b11 + a20 * b12;
    this.matrix[5] = a01 * b10 + a11 * b11 + a21 * b12;
    this.matrix[6] = a02 * b10 + a12 * b11 + a22 * b12;
    this.matrix[7] = a03 * b10 + a13 * b11 + a23 * b12;
    this.matrix[8] = a00 * b20 + a10 * b21 + a20 * b22;
    this.matrix[9] = a01 * b20 + a11 * b21 + a21 * b22;
    this.matrix[10] = a02 * b20 + a12 * b21 + a22 * b22;