container_prd.hh

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// Voro++, a 3D cell-based Voronoi library
//
// Author   : Chris H. Rycroft (LBL / UC Berkeley)
// Email    : chr@alum.mit.edu
// Date     : August 30th 2011

/** \file container_prd.hh
 * \brief Header file for the container_periodic_base and related classes. */

#ifndef VOROPP_CONTAINER_PRD_HH
#define VOROPP_CONTAINER_PRD_HH

#include <cstdio>
#include <vector>

#include "config.hh"
#include "common.hh"
#include "v_base.hh"
#include "cell.hh"
#include "c_loops.hh"
#include "v_compute.hh"
#include "unitcell.hh"
#include "rad_option.hh"

namespace voro {

/** \brief Class for representing a particle system in a 3D periodic
 * non-orthogonal periodic domain.
 *
 * This class represents a particle system in a three-dimensional
 * non-orthogonal periodic domain. The domain is defined by three periodicity
 * vectors (bx,0,0), (bxy,by,0), and (bxz,byz,bz) that represent a
 * parallelepiped. Internally, the class stores particles in the box 0<x<bx,
 * 0<y<by, 0<z<bz, and constructs periodic images of particles that displaced
 * by the three periodicity vectors when they are necessary for the
 * computation. The internal memory structure for this class is significantly
 * different from the container_base class in order to handle the dynamic
 * construction of these periodic images.
 *
 * The class is derived from the unitcell class, which encapsulates information
 * about the domain geometry, and the voro_base class, which encapsulates
 * information about the underlying computational grid. */
class container_periodic_base : public unitcell, public voro_base {
        public:
                /** The lower y index (inclusive) of the primary domain within
                 * the block structure. */
                int ey;
                /** The lower z index (inclusive) of the primary domain within
                 * the block structure. */
                int ez;
                /** The upper y index (exclusive) of the primary domain within
                 * the block structure. */
                int wy;
                /** The upper z index (exclusive) of the primary domain within
                 * the block structure. */
                int wz;
                /** The total size of the block structure (including images) in
                 * the y direction. */
                int oy;
                /** The total size of the block structure (including images) in
                 * the z direction. */
                int oz;
                /** The total number of blocks. */
                int oxyz;
                /** This array holds the numerical IDs of each particle in each
                 * computational box. */
                int **id;
                /** A two dimensional array holding particle positions. For the
                 * derived container_poly class, this also holds particle
                 * radii. */
                double **p;
                /** This array holds the number of particles within each
                 * computational box of the container. */
                int *co;
                /** This array holds the maximum amount of particle memory for
                 * each computational box of the container. If the number of
                 * particles in a particular box ever approaches this limit,
                 * more is allocated using the add_particle_memory() function.
                 */
                int *mem;
                /** An array holding information about periodic image
                 * construction at a given location. */
                char *img;
                /** The initial amount of memory to allocate for particles
                 * for each block. */
                const int init_mem;
                /** The amount of memory in the array structure for each
                 * particle. This is set to 3 when the basic class is
                 * initialized, so that the array holds (x,y,z) positions. If
                 * the container class is initialized as part of the derived
                 * class container_poly, then this is set to 4, to also hold
                 * the particle radii. */
                const int ps;
                container_periodic_base(double bx_,double bxy_,double by_,double bxz_,double byz_,double bz_,
                                int nx_,int ny_,int nz_,int init_mem_,int ps);
                ~container_periodic_base();
                /** Prints all particles in the container, including those that
                 * have been constructed in image blocks. */
                inline void print_all_particles() {
                        int ijk,q;
                        for(ijk=0;ijk<oxyz;ijk++) for(q=0;q<co[ijk];q++)
                                printf("%d %g %g %g\n",id[ijk][q],p[ijk][ps*q],p[ijk][ps*q+1],p[ijk][ps*q+2]);
                }
                void region_count();
                /** Initializes the Voronoi cell prior to a compute_cell
                 * operation for a specific particle being carried out by a
                 * voro_compute class. The cell is initialized to be the
                 * pre-computed unit Voronoi cell based on planes formed by
                 * periodic images of the particle.
                 * \param[in,out] c a reference to a voronoicell object.
                 * \param[in] ijk the block that the particle is within.
                 * \param[in] q the index of the particle within its block.
                 * \param[in] (ci,cj,ck) the coordinates of the block in the
                 *                       container coordinate system.
                 * \param[out] (i,j,k) the coordinates of the test block
                 *                     relative to the voro_compute
                 *                     coordinate system.
                 * \param[out] (x,y,z) the position of the particle.
                 * \param[out] disp a block displacement used internally by the
                 *                  compute_cell routine.
                 * \return False if the plane cuts applied by walls completely
                 * removed the cell, true otherwise. */
                template<class v_cell>
                inline bool initialize_voronoicell(v_cell &c,int ijk,int q,int ci,int cj,int ck,int &i,int &j,int &k,double &x,double &y,double &z,int &disp) {
                        c=unit_voro;
                        double *pp=p[ijk]+ps*q;
                        x=*(pp++);y=*(pp++);z=*pp;
                        i=nx;j=ey;k=ez;
                        return true;
                }
                /** Initializes parameters for a find_voronoi_cell call within
                 * the voro_compute template.
                 * \param[in] (ci,cj,ck) the coordinates of the test block in
                 *                       the container coordinate system.
                 * \param[in] ijk the index of the test block
                 * \param[out] (i,j,k) the coordinates of the test block
                 *                     relative to the voro_compute
                 *                     coordinate system.
                 * \param[out] disp a block displacement used internally by the
                 *                  find_voronoi_cell routine (but not needed
                 *                  in this instance.) */
                inline void initialize_search(int ci,int cj,int ck,int ijk,int &i,int &j,int &k,int &disp) {
                        i=nx;j=ey;k=ez;
                }
                /** Returns the position of a particle currently being computed
                 * relative to the computational block that it is within. It is
                 * used to select the optimal worklist entry to use.
                 * \param[in] (x,y,z) the position of the particle.
                 * \param[in] (ci,cj,ck) the block that the particle is within.
                 * \param[out] (fx,fy,fz) the position relative to the block.
                 */
                inline void frac_pos(double x,double y,double z,double ci,double cj,double ck,double &fx,double &fy,double &fz) {
                        fx=x-boxx*ci;
                        fy=y-boxy*(cj-ey);
                        fz=z-boxz*(ck-ez);
                }
                /** Calculates the index of block in the container structure
                 * corresponding to given coordinates.
                 * \param[in] (ci,cj,ck) the coordinates of the original block
                 *                       in the current computation, relative
                 *                       to the container coordinate system.
                 * \param[in] (ei,ej,ek) the displacement of the current block
                 *                       from the original block.
                 * \param[in,out] (qx,qy,qz) the periodic displacement that
                 *                           must be added to the particles
                 *                           within the computed block.
                 * \param[in] disp a block displacement used internally by the
                 *                  find_voronoi_cell and compute_cell routines
                 *                  (but not needed in this instance.)
                 * \return The block index. */
                inline int region_index(int ci,int cj,int ck,int ei,int ej,int ek,double &qx,double &qy,double &qz,int &disp) {
                        int qi=ci+(ei-nx),qj=cj+(ej-ey),qk=ck+(ek-ez);
                        int iv(step_div(qi,nx));if(iv!=0) {qx=iv*bx;qi-=nx*iv;} else qx=0;
                        create_periodic_image(qi,qj,qk);
                        return qi+nx*(qj+oy*qk);
                }
                void create_all_images();
                void check_compartmentalized();
        protected:
                void add_particle_memory(int i);
                void put_locate_block(int &ijk,double &x,double &y,double &z);
                void put_locate_block(int &ijk,double &x,double &y,double &z,int &ai,int &aj,int &ak);
                /** Creates particles within an image block by copying them
                 * from the primary domain and shifting them. If the given
                 * block is aligned with the primary domain in the z-direction,
                 * the routine calls the simpler create_side_image routine
                 * where the image block may comprise of particles from up to
                 * two primary blocks. Otherwise is calls the more complex
                 * create_vertical_image where the image block may comprise of
                 * particles from up to four primary blocks.
                 * \param[in] (di,dj,dk) the coordinates of the image block to
                 *                       create. */
                inline void create_periodic_image(int di,int dj,int dk) {
                        if(di<0||di>=nx||dj<0||dj>=oy||dk<0||dk>=oz)
                                voro_fatal_error("Constructing periodic image for nonexistent point",VOROPP_INTERNAL_ERROR);
                        if(dk>=ez&&dk<wz) {
                                if(dj<ey||dj>=wy) create_side_image(di,dj,dk);
                        } else create_vertical_image(di,dj,dk);
                }
                void create_side_image(int di,int dj,int dk);
                void create_vertical_image(int di,int dj,int dk);
                void put_image(int reg,int fijk,int l,double dx,double dy,double dz);
                inline void remap(int &ai,int &aj,int &ak,int &ci,int &cj,int &ck,double &x,double &y,double &z,int &ijk);
};

/** \brief Extension of the container_periodic_base class for computing regular
 * Voronoi tessellations.
 *
 * This class is an extension of the container_periodic_base that has routines
 * specifically for computing the regular Voronoi tessellation with no
 * dependence on particle radii. */
class container_periodic : public container_periodic_base, public radius_mono {
        public:
                container_periodic(double bx_,double bxy_,double by_,double bxz_,double byz_,double bz_,
                                int nx_,int ny_,int nz_,int init_mem_);
                void clear();
                void put(int n,double x,double y,double z);
                void put(int n,double x,double y,double z,int &ai,int &aj,int &ak);
                void put(particle_order &vo,int n,double x,double y,double z);
                void import(FILE *fp=stdin);
                void import(particle_order &vo,FILE *fp=stdin);
                /** Imports a list of particles from an open file stream into
                 * the container. Entries of four numbers (Particle ID, x
                 * position, y position, z position) are searched for. If the
                 * file cannot be successfully read, then the routine causes a
                 * fatal error.
                 * \param[in] filename the name of the file to open and read
                 *                     from. */
                inline void import(const char* filename) {
                        FILE *fp=safe_fopen(filename,"r");
                        import(fp);
                        fclose(fp);
                }
                /** Imports a list of particles from an open file stream into
                 * the container. Entries of four numbers (Particle ID, x
                 * position, y position, z position) are searched for. In
                 * addition, the order in which particles are read is saved
                 * into an ordering class. If the file cannot be successfully
                 * read, then the routine causes a fatal error.
                 * \param[in,out] vo the ordering class to use.
                 * \param[in] filename the name of the file to open and read
                 *                     from. */
                inline void import(particle_order &vo,const char* filename) {
                        FILE *fp=safe_fopen(filename,"r");
                        import(vo,fp);
                        fclose(fp);
                }
                void compute_all_cells();
                double sum_cell_volumes();
                /** Dumps particle IDs and positions to a file.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_particles(c_loop &vl,FILE *fp) {
                        double *pp;
                        if(vl.start()) do {
                                pp=p[vl.ijk]+3*vl.q;
                                fprintf(fp,"%d %g %g %g\n",id[vl.ijk][vl.q],*pp,pp[1],pp[2]);
                        } while(vl.inc());
                }
                /** Dumps all of the particle IDs and positions to a file.
                 * \param[in] fp a file handle to write to. */
                inline void draw_particles(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_particles(vl,fp);
                }
                /** Dumps all of the particle IDs and positions to a file.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_particles(const char *filename) {
                        FILE *fp=safe_fopen(filename,"w");
                        draw_particles(fp);
                        fclose(fp);
                }
                /** Dumps particle positions in POV-Ray format.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_particles_pov(c_loop &vl,FILE *fp) {
                        double *pp;
                        if(vl.start()) do {
                                pp=p[vl.ijk]+3*vl.q;
                                fprintf(fp,"// id %d\nsphere{<%g,%g,%g>,s}\n",
                                                id[vl.ijk][vl.q],*pp,pp[1],pp[2]);
                        } while(vl.inc());
                }
                /** Dumps all particle positions in POV-Ray format.
                 * \param[in] fp a file handle to write to. */
                inline void draw_particles_pov(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_particles_pov(vl,fp);
                }
                /** Dumps all particle positions in POV-Ray format.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_particles_pov(const char *filename) {
                        FILE *fp=safe_fopen(filename,"w");
                        draw_particles_pov(fp);
                        fclose(fp);
                }
                /** Computes Voronoi cells and saves the output in gnuplot
                 * format.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_cells_gnuplot(c_loop &vl,FILE *fp) {
                        voronoicell c;double *pp;
                        if(vl.start()) do if(compute_cell(c,vl)) {
                                pp=p[vl.ijk]+ps*vl.q;
                                c.draw_gnuplot(*pp,pp[1],pp[2],fp);
                        } while(vl.inc());
                }
                /** Computes all Voronoi cells and saves the output in gnuplot
                 * format.
                 * \param[in] fp a file handle to write to. */
                inline void draw_cells_gnuplot(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_cells_gnuplot(vl,fp);
                }
                /** Compute all Voronoi cells and saves the output in gnuplot
                 * format.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_cells_gnuplot(const char *filename) {
                        FILE *fp=safe_fopen(filename,"w");
                        draw_cells_gnuplot(fp);
                        fclose(fp);
                }
                /** Computes Voronoi cells and saves the output in POV-Ray
                 * format.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_cells_pov(c_loop &vl,FILE *fp) {
                        voronoicell c;double *pp;
                        if(vl.start()) do if(compute_cell(c,vl)) {
                                fprintf(fp,"// cell %d\n",id[vl.ijk][vl.q]);
                                pp=p[vl.ijk]+ps*vl.q;
                                c.draw_pov(*pp,pp[1],pp[2],fp);
                        } while(vl.inc());
                }
                /** Computes all Voronoi cells and saves the output in POV-Ray
                 * format.
                 * \param[in] fp a file handle to write to. */
                inline void draw_cells_pov(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_cells_pov(vl,fp);
                }
                /** Computes all Voronoi cells and saves the output in POV-Ray
                 * format.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_cells_pov(const char *filename) {
                        FILE *fp=safe_fopen(filename,"w");
                        draw_cells_pov(fp);
                        fclose(fp);
                }
                /** Computes the Voronoi cells and saves customized information
                 * about them.
                 * \param[in] vl the loop class to use.
                 * \param[in] format the custom output string to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void print_custom(c_loop &vl,const char *format,FILE *fp) {
                        int ijk,q;double *pp;
                        if(contains_neighbor(format)) {
                                voronoicell_neighbor c;
                                if(vl.start()) do if(compute_cell(c,vl)) {
                                        ijk=vl.ijk;q=vl.q;pp=p[ijk]+ps*q;
                                        c.output_custom(format,id[ijk][q],*pp,pp[1],pp[2],default_radius,fp);
                                } while(vl.inc());
                        } else {
                                voronoicell c;
                                if(vl.start()) do if(compute_cell(c,vl)) {
                                        ijk=vl.ijk;q=vl.q;pp=p[ijk]+ps*q;
                                        c.output_custom(format,id[ijk][q],*pp,pp[1],pp[2],default_radius,fp);
                                } while(vl.inc());
                        }
                }
                void print_custom(const char *format,FILE *fp=stdout);
                void print_custom(const char *format,const char *filename);
                bool find_voronoi_cell(double x,double y,double z,double &rx,double &ry,double &rz,int &pid);
                /** Computes the Voronoi cell for a particle currently being
                 * referenced by a loop class.
                 * \param[out] c a Voronoi cell class in which to store the
                 *               computed cell.
                 * \param[in] vl the loop class to use.
                 * \return True if the cell was computed. If the cell cannot be
                 * computed because it was removed entirely for some reason,
                 * then the routine returns false. */
                template<class v_cell,class c_loop>
                inline bool compute_cell(v_cell &c,c_loop &vl) {
                        return vc.compute_cell(c,vl.ijk,vl.q,vl.i,vl.j,vl.k);
                }
                /** Computes the Voronoi cell for given particle.
                 * \param[out] c a Voronoi cell class in which to store the
                 *               computed cell.
                 * \param[in] ijk the block that the particle is within.
                 * \param[in] q the index of the particle within the block.
                 * \return True if the cell was computed. If the cell cannot be
                 * computed because it was removed entirely for some reason,
                 * then the routine returns false. */
                template<class v_cell>
                inline bool compute_cell(v_cell &c,int ijk,int q) {
                        int k(ijk/(nx*oy)),ijkt(ijk-(nx*oy)*k),j(ijkt/nx),i(ijkt-j*nx);
                        return vc.compute_cell(c,ijk,q,i,j,k);
                }
                /** Computes the Voronoi cell for a ghost particle at a given
                 * location.
                 * \param[out] c a Voronoi cell class in which to store the
                 *               computed cell.
                 * \param[in] (x,y,z) the location of the ghost particle.
                 * \return True if the cell was computed. If the cell cannot be
                 * computed, if it is removed entirely by a wall or boundary
                 * condition, then the routine returns false. */
                template<class v_cell>
                inline bool compute_ghost_cell(v_cell &c,double x,double y,double z) {
                        int ijk;
                        put_locate_block(ijk,x,y,z);
                        double *pp=p[ijk]+3*co[ijk]++;
                        *(pp++)=x;*(pp++)=y;*(pp++)=z;
                        bool q=compute_cell(c,ijk,co[ijk]-1);
                        co[ijk]--;
                        return q;
                }               
        private:
                voro_compute<container_periodic> vc;
                friend class voro_compute<container_periodic>;
};

/** \brief Extension of the container_periodic_base class for computing radical
 * Voronoi tessellations.
 *
 * This class is an extension of container_periodic_base that has routines
 * specifically for computing the radical Voronoi tessellation that depends
 * on the particle radii. */
class container_periodic_poly : public container_periodic_base, public radius_poly {
        public:
                container_periodic_poly(double bx_,double bxy_,double by_,double bxz_,double byz_,double bz_,
                                int nx_,int ny_,int nz_,int init_mem_);
                void clear();
                void put(int n,double x,double y,double z,double r);
                void put(int n,double x,double y,double z,double r,int &ai,int &aj,int &ak);
                void put(particle_order &vo,int n,double x,double y,double z,double r);
                void import(FILE *fp=stdin);
                void import(particle_order &vo,FILE *fp=stdin);
                /** Imports a list of particles from an open file stream into
                 * the container_poly class. Entries of five numbers (Particle
                 * ID, x position, y position, z position, radius) are searched
                 * for. If the file cannot be successfully read, then the
                 * routine causes a fatal error.
                 * \param[in] filename the name of the file to open and read
                 *                     from. */
                inline void import(const char* filename) {
                        FILE *fp=safe_fopen(filename,"r");
                        import(fp);
                        fclose(fp);
                }
                /** Imports a list of particles from an open file stream into
                 * the container_poly class. Entries of five numbers (Particle
                 * ID, x position, y position, z position, radius) are searched
                 * for. In addition, the order in which particles are read is
                 * saved into an ordering class. If the file cannot be
                 * successfully read, then the routine causes a fatal error.
                 * \param[in,out] vo the ordering class to use.
                 * \param[in] filename the name of the file to open and read
                 *                     from. */
                inline void import(particle_order &vo,const char* filename) {
                        FILE *fp=safe_fopen(filename,"r");
                        import(vo,fp);
                        fclose(fp);
                }
                void compute_all_cells();
                double sum_cell_volumes();
                /** Dumps particle IDs, positions and radii to a file.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_particles(c_loop &vl,FILE *fp) {
                        double *pp;
                        if(vl.start()) do {
                                pp=p[vl.ijk]+4*vl.q;
                                fprintf(fp,"%d %g %g %g %g\n",id[vl.ijk][vl.q],*pp,pp[1],pp[2],pp[3]);
                        } while(vl.inc());
                }
                /** Dumps all of the particle IDs, positions and radii to a
                 * file.
                 * \param[in] fp a file handle to write to. */
                inline void draw_particles(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_particles(vl,fp);
                }
                /** Dumps all of the particle IDs, positions and radii to a
                 * file.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_particles(const char *filename) {
                        FILE *fp=safe_fopen(filename,"w");
                        draw_particles(fp);
                        fclose(fp);
                }
                /** Dumps particle positions in POV-Ray format.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_particles_pov(c_loop &vl,FILE *fp) {
                        double *pp;
                        if(vl.start()) do {
                                pp=p[vl.ijk]+4*vl.q;
                                fprintf(fp,"// id %d\nsphere{<%g,%g,%g>,%g}\n",
                                                id[vl.ijk][vl.q],*pp,pp[1],pp[2],pp[3]);
                        } while(vl.inc());
                }
                /** Dumps all the particle positions in POV-Ray format.
                 * \param[in] fp a file handle to write to. */
                inline void draw_particles_pov(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_particles_pov(vl,fp);
                }
                /** Dumps all the particle positions in POV-Ray format.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_particles_pov(const char *filename) {
                        FILE *fp(safe_fopen(filename,"w"));
                        draw_particles_pov(fp);
                        fclose(fp);
                }
                /** Computes Voronoi cells and saves the output in gnuplot
                 * format.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_cells_gnuplot(c_loop &vl,FILE *fp) {
                        voronoicell c;double *pp;
                        if(vl.start()) do if(compute_cell(c,vl)) {
                                pp=p[vl.ijk]+ps*vl.q;
                                c.draw_gnuplot(*pp,pp[1],pp[2],fp);
                        } while(vl.inc());
                }
                /** Compute all Voronoi cells and saves the output in gnuplot
                 * format.
                 * \param[in] fp a file handle to write to. */
                inline void draw_cells_gnuplot(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_cells_gnuplot(vl,fp);
                }
                /** Compute all Voronoi cells and saves the output in gnuplot
                 * format.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_cells_gnuplot(const char *filename) {
                        FILE *fp(safe_fopen(filename,"w"));
                        draw_cells_gnuplot(fp);
                        fclose(fp);
                }
                /** Computes Voronoi cells and saves the output in POV-Ray
                 * format.
                 * \param[in] vl the loop class to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void draw_cells_pov(c_loop &vl,FILE *fp) {
                        voronoicell c;double *pp;
                        if(vl.start()) do if(compute_cell(c,vl)) {
                                fprintf(fp,"// cell %d\n",id[vl.ijk][vl.q]);
                                pp=p[vl.ijk]+ps*vl.q;
                                c.draw_pov(*pp,pp[1],pp[2],fp);
                        } while(vl.inc());
                }
                /** Computes all Voronoi cells and saves the output in POV-Ray
                 * format.
                 * \param[in] fp a file handle to write to. */
                inline void draw_cells_pov(FILE *fp=stdout) {
                        c_loop_all_periodic vl(*this);
                        draw_cells_pov(vl,fp);
                }
                /** Computes all Voronoi cells and saves the output in POV-Ray
                 * format.
                 * \param[in] filename the name of the file to write to. */
                inline void draw_cells_pov(const char *filename) {
                        FILE *fp(safe_fopen(filename,"w"));
                        draw_cells_pov(fp);
                        fclose(fp);
                }
                /** Computes the Voronoi cells and saves customized information
                 * about them.
                 * \param[in] vl the loop class to use.
                 * \param[in] format the custom output string to use.
                 * \param[in] fp a file handle to write to. */
                template<class c_loop>
                void print_custom(c_loop &vl,const char *format,FILE *fp) {
                        int ijk,q;double *pp;
                        if(contains_neighbor(format)) {
                                voronoicell_neighbor c;
                                if(vl.start()) do if(compute_cell(c,vl)) {
                                        ijk=vl.ijk;q=vl.q;pp=p[ijk]+ps*q;
                                        c.output_custom(format,id[ijk][q],*pp,pp[1],pp[2],pp[3],fp);
                                } while(vl.inc());
                        } else {
                                voronoicell c;
                                if(vl.start()) do if(compute_cell(c,vl)) {
                                        ijk=vl.ijk;q=vl.q;pp=p[ijk]+ps*q;
                                        c.output_custom(format,id[ijk][q],*pp,pp[1],pp[2],pp[3],fp);
                                } while(vl.inc());
                        }
                }
                /** Computes the Voronoi cell for a particle currently being
                 * referenced by a loop class.
                 * \param[out] c a Voronoi cell class in which to store the
                 *               computed cell.
                 * \param[in] vl the loop class to use.
                 * \return True if the cell was computed. If the cell cannot be
                 * computed because it was removed entirely for some reason,
                 * then the routine returns false. */
                template<class v_cell,class c_loop>
                inline bool compute_cell(v_cell &c,c_loop &vl) {
                        return vc.compute_cell(c,vl.ijk,vl.q,vl.i,vl.j,vl.k);
                }
                /** Computes the Voronoi cell for given particle.
                 * \param[out] c a Voronoi cell class in which to store the
                 *               computed cell.
                 * \param[in] ijk the block that the particle is within.
                 * \param[in] q the index of the particle within the block.
                 * \return True if the cell was computed. If the cell cannot be
                 * computed because it was removed entirely for some reason,
                 * then the routine returns false. */
                template<class v_cell>
                inline bool compute_cell(v_cell &c,int ijk,int q) {
                        int k(ijk/(nx*oy)),ijkt(ijk-(nx*oy)*k),j(ijkt/nx),i(ijkt-j*nx);
                        return vc.compute_cell(c,ijk,q,i,j,k);
                }
                /** Computes the Voronoi cell for a ghost particle at a given
                 * location.
                 * \param[out] c a Voronoi cell class in which to store the
                 *               computed cell.
                 * \param[in] (x,y,z) the location of the ghost particle.
                 * \param[in] r the radius of the ghost particle.
                 * \return True if the cell was computed. If the cell cannot be
                 * computed, if it is removed entirely by a wall or boundary
                 * condition, then the routine returns false. */
                template<class v_cell>
                inline bool compute_ghost_cell(v_cell &c,double x,double y,double z,double r) {
                        int ijk;
                        put_locate_block(ijk,x,y,z);
                        double *pp=p[ijk]+4*co[ijk]++,tm=max_radius;
                        *(pp++)=x;*(pp++)=y;*(pp++)=z;*pp=r;
                        if(r>max_radius) max_radius=r;
                        bool q=compute_cell(c,ijk,co[ijk]-1);
                        co[ijk]--;max_radius=tm;
                        return q;
                }
                void print_custom(const char *format,FILE *fp=stdout);
                void print_custom(const char *format,const char *filename);
                bool find_voronoi_cell(double x,double y,double z,double &rx,double &ry,double &rz,int &pid);
        private:
                voro_compute<container_periodic_poly> vc;
                friend class voro_compute<container_periodic_poly>;
};

}

#endif