add first LIGGGHTS test

apps/cpu/LiggghtsApp/LiggghtsApp.cpp

@@ -5,6 +5,10 @@
 #include "VirtualFluids.h"
 
 #include "lammps.h"
+#include "input.h"
+#include "atom.h"
+#include "modify.h"
+#include "fix_lb_coupling_onetoone.h"
 
 using namespace std;
 
@@ -347,8 +351,61 @@ int main(int argc, char *argv[])
 
     // create LAMMPS instance
     lmp = new LAMMPS_NS::LAMMPS(lmpargc, (char **)lmpargv, MPI_COMM_WORLD);
-    // output numerical version string
-    //std::cout << "LAMMPS version ID: " << lmp->num_ver << std::endl;
+    lmp->input->file("in.chute_wear");
+    //lmp->input->one("run 1");
+    
+    //# Try extracting a global value
+    //    print("")
+    //    print("Attempting to get the number of atoms in simulation")
+    //    numAtoms = lmp.extract_global("natoms", 0)
+    //    print("natoms =", numAtoms)
+
+    //    # Try extracting atom's positions
+    //    print("")
+    //    print("Attempting to get the atom's positions")
+    //    pos = lmp.extract_atom("x",3)
+    //    for k in range(0,numAtoms):
+    //        print("Pos[%i] = [%f, %f, %f]" % (k, pos[k][0], pos[k][1], pos[k][2]))
+
+    LAMMPS_NS::FixLbCouplingOnetoone 
+        *couplingFix 
+        = dynamic_cast<LAMMPS_NS::FixLbCouplingOnetoone*>
+        (lmp->modify->find_fix_style("couple/lb/onetoone",0));
+
+    cout << "test1\n";
+    
+    //double **t_liggghts = couplingFix->get_torque_ptr();
+    cout << "test2\n";
+
+    lmp->input->one("run 9 upto");
+
+    for (int step = 0; step < 3; step++)
+    {
+        
+
+        int numAtoms = lmp->atom->natoms;
+
+        //double** pos = (double**)lmp->atom->extract("x");
+        double** pos = lmp->atom->x;
+        
+        //double* forceX = lmp->atom->fx;
+
+        for (int i = 0; i < numAtoms; i++)
+        {
+            double **f_liggghts = couplingFix->get_force_ptr();
+            double** force = lmp->atom->f;
+            cout << "Pos[" << i << "] = [" << pos[i][0] << ", " << pos[i][1] << ", " << pos[i][2] << "]\n";
+            cout << "Force[" << i << "] = [" << f_liggghts[i][0] << ", " << f_liggghts[i][1] << ", " << f_liggghts[i][2] << "]\n";
+            f_liggghts[i][2] += 500;
+            cout << "Force[" << i << "] = [" << force[i][0] << ", " << force[i][1] << ", " << force[i][2] << "]\n";
+        }
+
+        couplingFix->comm_force_torque();
+
+        lmp->input->one("run 10");
+       
+    }
+
     // delete LAMMPS instance
     delete lmp;