trunk/src/c_loops.cc

   1 // Voro++, a 3D cell-based Voronoi library
   2 //
   3 // Author   : Chris H. Rycroft (LBL / UC Berkeley)
   4 // Email    : chr@alum.mit.edu
   5 // Date     : August 30th 2011
   6
   7 /** \file c_loops.cc
   8  * \brief Function implementations for the loop classes. */
   9
  10 #include "c_loops.hh"
  11
  12 namespace voro {
  13
  14 /** Initializes a c_loop_subset object to scan over all particles within a
  15  * given sphere.
  16  * \param[in] (vx,vy,vz) the position vector of the center of the sphere.
  17  * \param[in] r the radius of the sphere.
  18  * \param[in] bounds_test whether to do detailed bounds checking. If this is
  19  *                        false then the class will loop over all particles in
  20  *                        blocks that overlap the given sphere. If it is true,
  21  *                        the particle will only loop over the particles which
  22  *                        actually lie within the sphere.
  23  * \return True if there is any valid point to loop over, false otherwise. */
  24 void c_loop_subset::setup_sphere(double vx,double vy,double vz,double r,bool bounds_test) {
  25         if(bounds_test) {mode=sphere;v0=vx;v1=vy;v2=vz;v3=r*r;} else mode=no_check;
  26         ai=step_int((vx-ax-r)*xsp);
  27         bi=step_int((vx-ax+r)*xsp);
  28         aj=step_int((vy-ay-r)*ysp);
  29         bj=step_int((vy-ay+r)*ysp);
  30         ak=step_int((vz-az-r)*zsp);
  31         bk=step_int((vz-az+r)*zsp);
  32         setup_common();
  33 }
  34
  35 /** Initializes the class to loop over all particles in a rectangular subgrid
  36  * of blocks.
  37  * \param[in] (ai_,bi_) the subgrid range in the x-direction, inclusive of both
  38  *                      ends.
  39  * \param[in] (aj_,bj_) the subgrid range in the y-direction, inclusive of both
  40  *                      ends.
  41  * \param[in] (ak_,bk_) the subgrid range in the z-direction, inclusive of both
  42  *                      ends.
  43  * \return True if there is any valid point to loop over, false otherwise. */
  44 void c_loop_subset::setup_intbox(int ai_,int bi_,int aj_,int bj_,int ak_,int bk_) {
  45         ai=ai_;bi=bi_;aj=aj_;bj=bj_;ak=ak_;bk=bk_;
  46         mode=no_check;
  47         setup_common();
  48 }
  49
  50 /** Sets up all of the common constants used for the loop.
  51  * \return True if there is any valid point to loop over, false otherwise. */
  52 void c_loop_subset::setup_common() {
  53         if(!xperiodic) {
  54                 if(ai<0) {ai=0;if(bi<0) bi=0;}
  55                 if(bi>=nx) {bi=nx-1;if(ai>=nx) ai=nx-1;}
  56         }
  57         if(!yperiodic) {
  58                 if(aj<0) {aj=0;if(bj<0) bj=0;}
  59                 if(bj>=ny) {bj=ny-1;if(aj>=ny) aj=ny-1;}
  60         }
  61         if(!zperiodic) {
  62                 if(ak<0) {ak=0;if(bk<0) bk=0;}
  63                 if(bk>=nz) {bk=nz-1;if(ak>=nz) ak=nz-1;}
  64         }
  65         ci=ai;cj=aj;ck=ak;
  66         di=i=step_mod(ci,nx);apx=px=step_div(ci,nx)*sx;
  67         dj=j=step_mod(cj,ny);apy=py=step_div(cj,ny)*sy;
  68         dk=k=step_mod(ck,nz);apz=pz=step_div(ck,nz)*sz;
  69         inc1=di-step_mod(bi,nx);
  70         inc2=nx*(ny+dj-step_mod(bj,ny))+inc1;
  71         inc1+=nx;
  72         ijk=di+nx*(dj+ny*dk);
  73         q=0;
  74 }
  75
  76 /** Starts the loop by finding the first particle within the container to
  77  * consider.
  78  * \return True if there is any particle to consider, false otherwise. */
  79 bool c_loop_subset::start() {
  80         while(co[ijk]==0) {if(!next_block()) return false;}
  81         while(mode!=no_check&&out_of_bounds()) {
  82                 q++;
  83                 while(q>=co[ijk]) {q=0;if(!next_block()) return false;}
  84         }
  85         return true;
  86 }
  87
  88 /** Initializes the class to loop over all particles in a rectangular box.
  89  * \param[in] (xmin,xmax) the minimum and maximum x coordinates of the box.
  90  * \param[in] (ymin,ymax) the minimum and maximum y coordinates of the box.
  91  * \param[in] (zmin,zmax) the minimum and maximum z coordinates of the box.
  92  * \param[in] bounds_test whether to do detailed bounds checking. If this is
  93  *                        false then the class will loop over all particles in
  94  *                        blocks that overlap the given box. If it is true, the
  95  *                        particle will only loop over the particles which
  96  *                        actually lie within the box.
  97  * \return True if there is any valid point to loop over, false otherwise. */
  98 void c_loop_subset::setup_box(double xmin,double xmax,double ymin,double ymax,double zmin,double zmax,bool bounds_test) {
  99         if(bounds_test) {mode=box;v0=xmin;v1=xmax;v2=ymin;v3=ymax;v4=zmin;v5=zmax;} else mode=no_check;
 100         ai=step_int((xmin-ax)*xsp);
 101         bi=step_int((xmax-ax)*xsp);
 102         aj=step_int((ymin-ay)*ysp);
 103         bj=step_int((ymax-ay)*ysp);
 104         ak=step_int((zmin-az)*zsp);
 105         bk=step_int((zmax-az)*zsp);
 106         setup_common();
 107 }
 108
 109 /** Computes whether the current point is out of bounds, relative to the
 110  * current loop setup.
 111  * \return True if the point is out of bounds, false otherwise. */
 112 bool c_loop_subset::out_of_bounds() {
 113         double *pp=p[ijk]+ps*q;
 114         if(mode==sphere) {
 115                 double fx(*pp+px-v0),fy(pp[1]+py-v1),fz(pp[2]+pz-v2);
 116                 return fx*fx+fy*fy+fz*fz>v3;
 117         } else {
 118                 double f(*pp+px);if(f<v0||f>v1) return true;
 119                 f=pp[1]+py;if(f<v2||f>v3) return true;
 120                 f=pp[2]+pz;return f<v4||f>v5;
 121         }
 122 }
 123
 124 /** Returns the next block to be tested in a loop, and updates the periodicity
 125  * vector if necessary. */
 126 bool c_loop_subset::next_block() {
 127         if(i<bi) {
 128                 i++;
 129                 if(ci<nx-1) {ci++;ijk++;} else {ci=0;ijk+=1-nx;px+=sx;}
 130                 return true;
 131         } else if(j<bj) {
 132                 i=ai;ci=di;px=apx;j++;
 133                 if(cj<ny-1) {cj++;ijk+=inc1;} else {cj=0;ijk+=inc1-nxy;py+=sy;}
 134                 return true;
 135         } else if(k<bk) {
 136                 i=ai;ci=di;j=aj;cj=dj;px=apx;py=apy;k++;
 137                 if(ck<nz-1) {ck++;ijk+=inc2;} else {ck=0;ijk+=inc2-nxyz;pz+=sz;}
 138                 return true;
 139         } else return false;
 140 }
 141
 142 /** Extends the memory available for storing the ordering. */
 143 void particle_order::add_ordering_memory() {
 144         int *no=new int[size<<2],*nop=no,*opp=o;
 145         while(opp<op) *(nop++)=*(opp++);
 146         delete [] o;
 147         size<<=1;o=no;op=nop;
 148 }
 149
 150 }