Matrix.isIdentity

mat2 m2 = mat2( 1.0f );
assert( m2.isIdentity );
assert( m2.data == mat2( 1 ).data );

m2 = mat2.identity;
assert( m2.data == [[ 1.0f, 0.0f ],
                    [ 0.0f, 1.0f ]] );

mat3 m3 = mat3.identity;
assert( m3.isIdentity );
assert( m3.data == mat3( 1.0f ).data );

mat4 m4 = mat4( 2.0f );
assert( m4.data == mat4( 2.0f ).data );

m4 = mat4.identity;
assert( m4.isIdentity );
assert( m4.data == [[ 1.0f, 0.0f, 0.0f, 0.0f ],
                    [ 0.0f, 1.0f, 0.0f, 0.0f ],
                    [ 0.0f, 0.0f, 1.0f, 0.0f ],
                    [ 0.0f, 0.0f, 0.0f, 1.0f ]] );
assert( m4.data == m4.identity.data );