copy method
Copies all values from the given matrix to this matrix.
Implementation
Matrix3 copy(Matrix3 m ) {
final e = elements;
final me = m.elements;
e[ 0 ] = me[ 0 ]; e[ 1 ] = me[ 1 ]; e[ 2 ] = me[ 2 ];
e[ 3 ] = me[ 3 ]; e[ 4 ] = me[ 4 ]; e[ 5 ] = me[ 5 ];
e[ 6 ] = me[ 6 ]; e[ 7 ] = me[ 7 ]; e[ 8 ] = me[ 8 ];
return this;
}