method rotateZ

Source

void rotateZ(num angle) {

  var cos = math.cos(angle);
  var sin = math.sin(angle);
  var m00 = this.m00;
  var m10 = this.m10;
  var m20 = this.m20;
  var m30 = this.m30;
  var m01 = this.m01;
  var m11 = this.m11;
  var m21 = this.m21;
  var m31 = this.m31;

  _data[00] = m00 * cos + m01 * sin;
  _data[01] = m10 * cos + m11 * sin;
  _data[02] = m20 * cos + m21 * sin;
  _data[03] = m30 * cos + m31 * sin;
  _data[04] = m01 * cos - m00 * sin;
  _data[05] = m11 * cos - m10 * sin;
  _data[06] = m21 * cos - m20 * sin;
  _data[07] = m31 * cos - m30 * sin;
}