add support for calling Particles3D::initialize without gravity

src/gravity/grav3D.cpp

@@ -16,39 +16,38 @@
 
 Grav3D::Grav3D(void) {}
 
-void Grav3D::Initialize(Real x_min, Real y_min, Real z_min, Real x_max, Real y_max, Real z_max, Real Lx, Real Ly,
-                        Real Lz, int nx, int ny, int nz, int nx_real, int ny_real, int nz_real, Real dx_real,
-                        Real dy_real, Real dz_real, int n_ghost_pot_offset, struct Parameters *P)
+void Grav3D::Initialize(const SpatialDomainProps& spatial_props, Real Lx, Real Ly, Real Lz,
+                        int n_ghost_pot_offset, Parameters *P)
 {
   // Set Box Size
   Lbox_x = Lx;
   Lbox_y = Ly;
   Lbox_z = Lz;
 
   // Set Box Left boundary positions
-  xMin = x_min;
-  yMin = y_min;
-  zMin = z_min;
+  xMin = spatial_props.xMin;
+  yMin = spatial_props.yMin;
+  zMin = spatial_props.zMin;
 
   // Set Box Right boundary positions
-  xMax = x_max;
-  yMax = y_max;
-  zMax = z_max;
+  xMax = spatial_props.xMax;
+  yMax = spatial_props.yMax;
+  zMax = spatial_props.zMax;
 
   // Set uniform ( dx, dy, dz )
-  dx = dx_real;
-  dy = dy_real;
-  dz = dz_real;
+  dx = spatial_props.dx;
+  dy = spatial_props.dy;
+  dz = spatial_props.dz;
 
   // Set Box Total number of cells
-  nx_total = nx;
-  ny_total = ny;
-  nz_total = nz;
+  nx_total = spatial_props.nx_total;
+  ny_total = spatial_props.ny_total;
+  nz_total = spatial_props.nz_total;
 
   // Set Box local domain number of cells
-  nx_local = nx_real;
-  ny_local = ny_real;
-  nz_local = nz_real;
+  nx_local = spatial_props.nx_local;
+  ny_local = spatial_props.ny_local;
+  nz_local = spatial_props.nz_local;
 
   // Local n_cells without ghost cells
   n_cells = nx_local * ny_local * nz_local;

src/gravity/grav3D.h

@@ -4,6 +4,7 @@
 #include <stdio.h>
 
 #include "../global/global.h"
+#include "../grid/spatial_domain_props.h"
 
 #ifdef SOR
   #include "../gravity/potential_SOR_3D.h"
@@ -191,9 +192,8 @@ class Grav3D
 
   /*! \fn void Initialize(int nx_in, int ny_in, int nz_in)
    *  \brief Initialize the grid. */
-  void Initialize(Real x_min, Real y_min, Real z_min, Real x_max, Real y_max, Real z_max, Real Lx, Real Ly, Real Lz,
-                  int nx_total, int ny_total, int nz_total, int nx_real, int ny_real, int nz_real, Real dx_real,
-                  Real dy_real, Real dz_real, int n_ghost_pot_offset, struct Parameters *P);
+  void Initialize(const SpatialDomainProps& spatial_props, Real Lx, Real Ly, Real Lz,
+                  int n_ghost_pot_offset, struct Parameters *P);
 
   void AllocateMemory_CPU(void);
   void Initialize_values_CPU();

src/gravity/gravity_functions.cpp

@@ -358,9 +358,8 @@ static void printDiff(const Real *p, const Real *q, const int nx, const int ny,
 void Grid3D::Initialize_Gravity(struct Parameters *P)
 {
   chprintf("\nInitializing Gravity... \n");
-  Grav.Initialize(H.xblocal, H.yblocal, H.zblocal, H.xblocal_max, H.yblocal_max, H.zblocal_max, H.xdglobal, H.ydglobal,
-                  H.zdglobal, P->nx, P->ny, P->nz, H.nx_real, H.ny_real, H.nz_real, H.dx, H.dy, H.dz,
-                  H.n_ghost_potential_offset, P);
+  SpatialDomainProps spatial_props = SpatialDomainProps::From_Grid3D(*this, P);
+  Grav.Initialize(spatial_props, H.xdglobal, H.ydglobal, H.zdglobal, H.n_ghost_potential_offset, P);
   chprintf("Gravity Successfully Initialized. \n\n");
 
   if (P->bc_potential_type == 1) {

src/grid/spatial_domain_props.cpp

@@ -0,0 +1,64 @@
+#include "../grid/spatial_domain_props.h"
+#include "../gravity/grav3D.h"
+#include "../grid/grid3D.h"
+
+SpatialDomainProps SpatialDomainProps::From_Grav3D(Grav3D& grav)
+{
+  SpatialDomainProps out;
+
+  out.nx_local = grav.nx_local;
+  out.ny_local = grav.ny_local;
+  out.nz_local = grav.nz_local;
+
+  out.nx_total = grav.nx_total;
+  out.ny_total = grav.ny_total;
+  out.nz_total = grav.nz_total;
+
+  out.dx = grav.dx;
+  out.dy = grav.dy;
+  out.dz = grav.dz;
+
+  // Left boundaries of the local domain
+  out.xMin = grav.xMin;
+  out.yMin = grav.yMin;
+  out.zMin = grav.zMin;
+
+  // Right boundaries of the local domain
+  out.xMax = grav.xMax;
+  out.yMax = grav.yMax;
+  out.zMax = grav.zMax;
+
+  return out;
+}
+
+SpatialDomainProps SpatialDomainProps::From_Grid3D(Grid3D& grid, struct Parameters * P)
+{
+
+  SpatialDomainProps out;
+
+  // Set Box Left boundary positions
+  out.xMin = grid.H.xblocal; // x_min
+  out.yMin = grid.H.yblocal; // y_min
+  out.zMin = grid.H.zblocal; // z_min
+
+  // Set Box Right boundary positions
+  out.xMax = grid.H.xblocal_max; //x_max;
+  out.yMax = grid.H.yblocal_max; //y_max;
+  out.zMax = grid.H.zblocal_max; //z_max;
+
+  // Set uniform ( dx, dy, dz )
+  out.dx = grid.H.dx; // dx_real;
+  out.dy = grid.H.dy; // dy_real;
+  out.dz = grid.H.dz; // dz_real;
+
+  // Set Box Total number of cells
+  out.nx_total = P->nx; // nx;
+  out.ny_total = P->ny; // ny;
+  out.nz_total = P->nz; // nz;
+
+  // Set Box local domain number of cells
+  out.nx_local = grid.H.nx_real; // nx_real;
+  out.ny_local = grid.H.ny_real; // ny_real;
+  out.nz_local = grid.H.nz_real; // nz_real;
+  return out;
+};

src/grid/spatial_domain_props.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "../global/global.h"
+
+class Grav3D;
+class Grid3D;
+struct Parameters;
+
+/* This is a collection of 15 quantities that appear in 3 other locations throughout the codebase.
+ *
+ * The struct primarily exists to simplify the process of copying these values from one place to
+ * another. (But it may make sense to refactor other parts of the code in terms of this object)
+ */
+struct SpatialDomainProps {
+    // number of cells in the local domain
+    int nx_local, ny_local, nz_local;
+
+    // total number of cells in the entire (global) domain
+    int nx_total, ny_total, nz_total;
+
+    // Left boundaries of the local domain
+    Real xMin, yMin, zMin;
+
+    // Right boundaries of the local domain
+    Real xMax, yMax, zMax;
+
+    // cell widths
+    Real dx, dy, dz;
+
+    static SpatialDomainProps From_Grav3D(Grav3D&);
+    static SpatialDomainProps From_Grid3D(Grid3D&, Parameters* P);
+};

src/particles/particles_3D.cpp

@@ -29,7 +29,13 @@ void Grid3D::Initialize_Particles(struct Parameters *P)
 {
   chprintf("\nInitializing Particles...\n");
 
-  Particles.Initialize(P, Grav, H.xbound, H.ybound, H.zbound, H.xdglobal, H.ydglobal, H.zdglobal);
+#ifdef GRAVITY
+  SpatialDomainProps spatial_props = SpatialDomainProps::From_Grav3D(Grav);
+#else
+  SpatialDomainProps spatial_props = SpatialDomainProps::From_Grid3D(*this, P);
+#endif
+
+  Particles.Initialize(P, spatial_props, H.xbound, H.ybound, H.zbound, H.xdglobal, H.ydglobal, H.zdglobal);
 
   #if defined(PARTICLES_GPU) && defined(GRAVITY_GPU)
   // Set the GPU array for the particles potential equal to the Gravity GPU
@@ -47,7 +53,7 @@ void Grid3D::Initialize_Particles(struct Parameters *P)
   chprintf("Particles Initialized Successfully. \n\n");
 }
 
-void Particles3D::Initialize(struct Parameters *P, Grav3D &Grav, Real xbound, Real ybound, Real zbound, Real xdglobal,
+void Particles3D::Initialize(struct Parameters *P, const SpatialDomainProps& spatial_props, Real xbound, Real ybound, Real zbound, Real xdglobal,
                              Real ydglobal, Real zdglobal)
 {
   // Initialize local and total number of particles to 0
@@ -108,27 +114,27 @@ void Particles3D::Initialize(struct Parameters *P, Grav3D &Grav, Real xbound, Re
 
   // Initialize Grid Values
   // Local and total number of cells
-  G.nx_local = Grav.nx_local;
-  G.ny_local = Grav.ny_local;
-  G.nz_local = Grav.nz_local;
-  G.nx_total = Grav.nx_total;
-  G.ny_total = Grav.ny_total;
-  G.nz_total = Grav.nz_total;
+  G.nx_local = spatial_props.nx_local;
+  G.ny_local = spatial_props.ny_local;
+  G.nz_local = spatial_props.nz_local;
+  G.nx_total = spatial_props.nx_total;
+  G.ny_total = spatial_props.ny_total;
+  G.nz_total = spatial_props.nz_total;
 
   // Uniform (dx, dy, dz)
-  G.dx = Grav.dx;
-  G.dy = Grav.dy;
-  G.dz = Grav.dz;
+  G.dx = spatial_props.dx;
+  G.dy = spatial_props.dy;
+  G.dz = spatial_props.dz;
 
   // Left boundaries of the local domain
-  G.xMin = Grav.xMin;
-  G.yMin = Grav.yMin;
-  G.zMin = Grav.zMin;
+  G.xMin = spatial_props.xMin;
+  G.yMin = spatial_props.yMin;
+  G.zMin = spatial_props.zMin;
 
   // Right boundaries of the local domain
-  G.xMax = Grav.xMax;
-  G.yMax = Grav.yMax;
-  G.zMax = Grav.zMax;
+  G.xMax = spatial_props.xMax;
+  G.yMax = spatial_props.yMax;
+  G.zMax = spatial_props.zMax;
 
   // Left boundaries of the global domain
   G.domainMin_x = xbound;
@@ -176,8 +182,16 @@ void Particles3D::Initialize(struct Parameters *P, Grav3D &Grav, Real xbound, Re
     #endif
 
   G.size_blocks_array = 1024 * 128;
-  G.n_cells_potential = (G.nx_local + 2 * N_GHOST_POTENTIAL) * (G.ny_local + 2 * N_GHOST_POTENTIAL) *
-                        (G.nz_local + 2 * N_GHOST_POTENTIAL);
+  {
+    #ifdef N_GHOST_POTENTIAL
+    int n_ghost_pot = N_GHOST_POTENTIAL;
+    #else
+    int n_ghost_pot = 0;
+    #endif
+
+    G.n_cells_potential = (G.nx_local + 2 * n_ghost_pot) * (G.ny_local + 2 * n_ghost_pot) *
+                          (G.nz_local + 2 * n_ghost_pot);
+  }
 
     #ifdef SINGLE_PARTICLE_MASS
   mass_dev = NULL;  // This array won't be used

src/particles/particles_3D.h

@@ -14,6 +14,7 @@
 
     #include "../global/global.h"
     #include "../gravity/grav3D.h"
+    #include "../grid/spatial_domain_props.h"
 
     #ifdef PARTICLES_GPU
       #define TPB_PARTICLES 1024
@@ -218,7 +219,7 @@ class Particles3D
 
   Particles3D(void);
 
-  void Initialize(struct Parameters *P, Grav3D &Grav, Real xbound, Real ybound, Real zbound, Real xdglobal,
+  void Initialize(struct Parameters *P, const SpatialDomainProps& spatial_props, Real xbound, Real ybound, Real zbound, Real xdglobal,
                   Real ydglobal, Real zdglobal);
 
   void Allocate_Particles_Grid_Field_Real(Real **array_dev, int size);