setRotationZ method
Turns the matrix into a rotation of radians
around Z
Implementation
void setRotationZ(double radians) {
final c = math.cos(radians);
final s = math.sin(radians);
_m3storage[0] = c;
_m3storage[1] = s;
_m3storage[2] = 0.0;
_m3storage[3] = -s;
_m3storage[4] = c;
_m3storage[5] = 0.0;
_m3storage[6] = 0.0;
_m3storage[7] = 0.0;
_m3storage[8] = 1.0;
}