Extracts a 3x3 matrix from a given matrix and store the result in a FloatArray
a new FloatArray array with 9 elements : the 3x3 matrix extracted from the given matrix
defines the matrix to use
Extracts a 3x3 matrix from a given matrix and store the result in a FloatArray
Returns
a new FloatArray array with 9 elements : the 3x3 matrix extracted from the given matrix