isZero method
Is this the zero matrix?
Implementation
bool isZero() =>
_m4storage[0] == 0.0 // col 1
&&
_m4storage[1] == 0.0 &&
_m4storage[2] == 0.0 &&
_m4storage[3] == 0.0 &&
_m4storage[4] == 0.0 // col 2
&&
_m4storage[5] == 0.0 &&
_m4storage[6] == 0.0 &&
_m4storage[7] == 0.0 &&
_m4storage[8] == 0.0 // col 3
&&
_m4storage[9] == 0.0 &&
_m4storage[10] == 0.0 &&
_m4storage[11] == 0.0 &&
_m4storage[12] == 0.0 // col 4
&&
_m4storage[13] == 0.0 &&
_m4storage[14] == 0.0 &&
_m4storage[15] == 0.0;