/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator 

   Original Version:
   http://lammps.sandia.gov, Sandia National Laboratories
   Steve Plimpton, sjplimp@sandia.gov 

   See the README file in the top-level LAMMPS directory. 

   ----------------------------------------------------------------------- 

   USER-CUDA Package and associated modifications:
   https://sourceforge.net/projects/lammpscuda/ 

   Christian Trott, christian.trott@tu-ilmenau.de
   Lars Winterfeld, lars.winterfeld@tu-ilmenau.de
   Theoretical Physics II, University of Technology Ilmenau, Germany 

   See the README file in the USER-CUDA directory. 

   This software is distributed under the GNU General Public License.
------------------------------------------------------------------------- */

static inline __device__ void check_distance(X_FLOAT &xtmp,X_FLOAT &ytmp,X_FLOAT &ztmp,int &i,int groupbit)
{
  if(_dist_check)
  {
  	
  	X_FLOAT d=X_F(0.0);
  	if(i<_nlocal)
  	{
  	  X_FLOAT tmp=xtmp-_xhold[i];
  	  d=tmp*tmp;
  	  tmp=ytmp-_xhold[i+_maxhold];
  	  d+=tmp*tmp;
  	  tmp=ztmp-_xhold[i+2*_maxhold];
  	  d+=tmp*tmp;
  
  	  d=((_mask[i] & groupbit))?d:X_F(0.0);
  	}
  	if(not __all(d<=_triggerneighsq)) 
  		_reneigh_flag[0]=1;
  }
}

__global__ void FixNHCuda_nh_v_press_Kernel(int groupbit, F_FLOAT3 factor,int p_triclinic,F_FLOAT3 factor2)
{
	int i=(blockIdx.x*gridDim.y+blockIdx.y)*blockDim.x+threadIdx.x;
	if(i < _nlocal && _mask[i] & groupbit)
	{
		V_FLOAT* my_v = _v + i;
		V_FLOAT vx=my_v[0];
		V_FLOAT vy=my_v[_nmax];
		V_FLOAT vz=my_v[2*_nmax];
		vx*=factor.x;
		vy*=factor.y;
		vz*=factor.z;
		if(p_triclinic) {
			vx += vy*factor2.z + vz*factor2.y;
			vy += vz*factor2.x;
		}
		vx*=factor.x;
		vy*=factor.y;
		vz*=factor.z;
		my_v[0]       = vx;  
		my_v[_nmax]   = vy;  
		my_v[2*_nmax] = vz; 
	}
	
}

__global__ void FixNHCuda_nh_v_temp_Kernel(int groupbit, F_FLOAT factor_eta)
{
	int i=(blockIdx.x*gridDim.y+blockIdx.y)*blockDim.x+threadIdx.x;
	if(i < _nlocal && _mask[i] & groupbit)
	{
		V_FLOAT* my_v = _v + i;
		my_v[0]*=factor_eta;
		my_v[_nmax]*=factor_eta;
		my_v[2*_nmax]*=factor_eta;
	}
	
}

__global__ void FixNHCuda_nh_v_press_and_nve_v_NoBias_Kernel(int groupbit, F_FLOAT3 factor,int p_triclinic,F_FLOAT3 factor2)
{
	int i=(blockIdx.x*gridDim.y+blockIdx.y)*blockDim.x+threadIdx.x;
	if(i < _nlocal && _mask[i] & groupbit)
	{
		F_FLOAT* my_f = _f + i;
		V_FLOAT* my_v = _v + i;
		
		V_FLOAT 		dtfm = _dtf;
		if(_rmass_flag) dtfm*= V_F(1.0) / _rmass[i];
		else 			dtfm*= V_F(1.0) / _mass[_type[i]];
		
		V_FLOAT vx=my_v[0];
		V_FLOAT vy=my_v[_nmax];
		V_FLOAT vz=my_v[2*_nmax];
		vx*=factor.x;
		vy*=factor.y;
		vz*=factor.z;
		if(p_triclinic) {
			vx += vy*factor2.z + vz*factor2.y;
			vy += vz*factor2.x;
		}
		vx*=factor.x;
		vy*=factor.y;
		vz*=factor.z;
		my_v[0]       = vx + dtfm * my_f[0];  
		my_v[_nmax]   = vy + dtfm * my_f[_nmax];  
		my_v[2*_nmax] = vz + dtfm * my_f[_nmax*2]; 
	}
	
}

__global__ void FixNHCuda_nve_v_Kernel(int groupbit)
{
	
	int i=(blockIdx.x*gridDim.y+blockIdx.y)*blockDim.x+threadIdx.x;
	if(i < _nlocal && _mask[i] & groupbit)
	{
		F_FLOAT* my_f = _f + i;
		V_FLOAT* my_v = _v + i;

		V_FLOAT 		dtfm = _dtf;
		if(_rmass_flag) dtfm*=V_F(1.0) / _rmass[i];
		else 			dtfm*=V_F(1.0) / _mass[_type[i]];

		*my_v = (*my_v + dtfm*(*my_f)); my_f += _nmax; my_v += _nmax;
		*my_v = (*my_v + dtfm*(*my_f)); my_f += _nmax; my_v += _nmax;
		*my_v = (*my_v + dtfm*(*my_f));
	}
}

__global__ void FixNHCuda_nve_x_Kernel(int groupbit)
{
	X_FLOAT xtmp,ytmp,ztmp;
		
	int i=(blockIdx.x*gridDim.y+blockIdx.y)*blockDim.x+threadIdx.x;
	if(i < _nlocal && _mask[i] & groupbit)
	{
		V_FLOAT* my_v = _v + i;
		X_FLOAT* my_x = _x + i;
		
		xtmp = *my_x += _dtv * *my_v;  my_v += _nmax; my_x += _nmax;
		ytmp = *my_x += _dtv * *my_v;  my_v += _nmax; my_x += _nmax;
		ztmp = *my_x += _dtv * *my_v;
	}
	check_distance(xtmp,ytmp,ztmp,i,groupbit);
}


__global__ void FixNHCuda_nve_v_and_nh_v_press_NoBias_Kernel(int groupbit, F_FLOAT3 factor,int p_triclinic,F_FLOAT3 factor2)
{
	
	int i=(blockIdx.x*gridDim.y+blockIdx.y)*blockDim.x+threadIdx.x;
	if(i < _nlocal && _mask[i] & groupbit)
	{
		F_FLOAT* my_f = _f + i;
		V_FLOAT* my_v = _v + i;

		V_FLOAT 		dtfm = _dtf;
		if(_rmass_flag) dtfm*=V_F(1.0) / _rmass[i];
		else 			dtfm*=V_F(1.0) / _mass[_type[i]];

		V_FLOAT vx = my_v[0] + dtfm*my_f[0];
		V_FLOAT vy = my_v[_nmax] + dtfm*my_f[_nmax];
		V_FLOAT vz = my_v[2*_nmax] + dtfm*my_f[2*_nmax];
		
		vx*=factor.x;
		vy*=factor.y;
		vz*=factor.z;
		if(p_triclinic) {
			vx += vy*factor2.z + vz*factor2.y;
			vy += vz*factor2.x;
		}		
		vx*=factor.x;
		vy*=factor.y;
		vz*=factor.z;
		my_v[0]       = vx;  
		my_v[_nmax]   = vy;  
		my_v[2*_nmax] = vz; 
		
	}
}

