public void applyMatrix(float n00, float n01, float n02,
                            float n10, float n11, float n12) {
      ctm.apply(n00, n01, n02,
                n10, n11, n12);
//
//      float r00 = m00*n00 + m01*n10;
//      float r01 = m00*n01 + m01*n11;
//      float r02 = m00*n02 + m01*n12 + m02;
//
//      float r10 = m10*n00 + m11*n10;
//      float r11 = m10*n01 + m11*n11;
//      float r12 = m10*n02 + m11*n12 + m12;
//
//      m00 = r00; m01 = r01; m02 = r02;
//      m10 = r10; m11 = r11; m12 = r12;
    }