mMatrix* Math::matrixMatrixMultiplication(mMatrix *M1, mMatrix *M2){
        mMatrix *result = new mMatrix(M1->rows,M2->columns);

        //Do the multiplication
        for (int i = 0; i < M1->rows; i++) { //the result is M1_RowsxM2_Columns
            for (int j = 0; j < M2->columns; j++) { //the result is M1_Rows x M2_Columns
                for (int k = 0; k < M2->rows; k++) { //for each column in M1 / row in M2
                    result->theMatrix[i][j]+=M1->theMatrix[i][k]*M2->theMatrix[k][j];
                }
            }
        }

        return result;
    }

fabio bento library