libmeep-lam4-dev 1.1.1-10 / usr / include / meep / vec.hpp

// -*- C++ -*-
/* Copyright (C) 2005-2009 Massachusetts Institute of Technology
%
%  This program is free software; you can redistribute it and/or modify
%  it under the terms of the GNU General Public License as published by
%  the Free Software Foundation; either version 2, or (at your option)
%  any later version.
%
%  This program is distributed in the hope that it will be useful,
%  but WITHOUT ANY WARRANTY; without even the implied warranty of
%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%  GNU General Public License for more details.
%
%  You should have received a copy of the GNU General Public License
%  along with this program; if not, write to the Free Software Foundation,
%  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#ifndef MEEP_VEC_H
#define MEEP_VEC_H

#include <complex>

using namespace std;

namespace meep {

const int NUM_FIELD_COMPONENTS = 20;
const int NUM_FIELD_TYPES = 6;

enum component { Ex=0, Ey, Er, Ep, Ez, Hx, Hy, Hr, Hp, Hz,
                 Dx, Dy, Dr, Dp, Dz, Bx, By, Br, Bp, Bz, Dielectric, Permeability };
#define Centered Dielectric // better name for centered "dielectric" grid
enum derived_component { Sx=100, Sy, Sr, Sp, Sz, EnergyDensity,
			 D_EnergyDensity, H_EnergyDensity };
enum ndim { D1=0, D2, D3, Dcyl };
enum field_type { E_stuff=0, H_stuff=1, D_stuff=2, B_stuff=3, PE_stuff=4, PH_stuff=5 };
enum boundary_side { High=0, Low };
enum direction { X=0,Y,Z,R,P, NO_DIRECTION };
struct signed_direction {
  signed_direction(direction dd=X,bool f=false, complex<double> ph=1.0) {
    d = dd; flipped = f; phase = ph;
  };
  signed_direction(const signed_direction &sd) {
    d = sd.d; flipped = sd.flipped; phase = sd.phase;
  }
  signed_direction operator*(complex<double> ph);
  bool operator==(const signed_direction &sd) const { return (d == sd.d &&
						       flipped == sd.flipped
						       && phase == sd.phase); }
  bool operator!=(const signed_direction &sd) const { return !(*this == sd); }
  direction d;
  bool flipped;
  complex<double> phase;
};

inline int number_of_directions(ndim dim) {
  return (int) (dim + 1 - 2 * (dim == Dcyl));
}

inline direction start_at_direction(ndim dim) {
  return (direction) (((dim == D1) || (dim == Dcyl)) ? 2 : 0);
}

inline direction stop_at_direction(ndim dim) {
  return (direction) (dim + 1 + 2 * (dim == D1));
}

component first_field_component(field_type ft);

#define FOR_FIELD_TYPES(ft) for (field_type ft = E_stuff; \
                                 ft <= PH_stuff; ft = (field_type) (ft+1))
#define FOR_ELECTRIC_COMPONENTS(c) for (component c = Ex; \
                                        c < Hx; c = (component) (c+1))
#define FOR_MAGNETIC_COMPONENTS(c) for (component c = Hz; \
                                        c > Ez; c = (component) (c-1))
#define FOR_B_COMPONENTS(c) for (component c = Bz; \
				 c > Dz; c = (component) (c-1))
#define FOR_H_AND_B(h,b) for (component h=Hx, b=Bx; \
			      h <= Hz; h = (component) (h+1), b = (component) (b+1))
#define FOR_D_COMPONENTS(c) for (component c = Dz; \
                                 c > Hz; c = (component) (c-1))
#define FOR_E_AND_D(e,d) for (component e = Ex, d = Dx; \
                              e <= Ez; e = (component) (e+1), d = (component) (d+1))
#define FOR_E_AND_H(c) for (component c = Ex; c < Dx; c = (component) (c+1))
#define FOR_D_AND_B(c) for (component c = Dx; c < Dielectric; c = (component) (c+1))
#define FOR_FT_COMPONENTS(ft,c) for (component c = first_field_component(ft), loop_cstop = component(first_field_component(ft) + 5); c < loop_cstop; c = component(c+1))
#define FOR_COMPONENTS(c) for (component c = Ex,loop_stop_co=Ey; \
                               c != loop_stop_co; \
                               c = (component)((c+1)%NUM_FIELD_COMPONENTS), \
                               loop_stop_co = Ex)
#define FOR_DIRECTIONS(d) for (direction d = X,loop_stop_di=Y; \
                               d != loop_stop_di; \
                               d = (direction)((d+1)%5), \
                               loop_stop_di = X)
#define FOR_SIDES(s) for (boundary_side s = High, loop_stop_bi=Low; \
			  s != loop_stop_bi; \
			  s = (boundary_side) ((s+1) % 2), \
			  loop_stop_bi = High)

// only loop over directions where we have coordinates
#define LOOP_OVER_DIRECTIONS(dim, d) for (meep::direction d = meep::start_at_direction(dim), \
                                     loop_stop_directi = meep::stop_at_direction(dim); \
                                     d < loop_stop_directi; d = (meep::direction) (d+1))

// loop over all directions in which we might have fields
#define LOOP_OVER_FIELD_DIRECTIONS(dim, d) for (direction d = dim == Dcyl ? Z : X; d < (dim == Dcyl ? NO_DIRECTION : R); d = direction(d+1))

// loop over indices idx from is to ie (inclusive) in gv
#define LOOP_OVER_IVECS(gv, is, ie, idx) \
  for (int loop_is1 = (is).yucky_val(0), \
           loop_is2 = (is).yucky_val(1), \
           loop_is3 = (is).yucky_val(2), \
           loop_n1 = ((ie).yucky_val(0) - loop_is1) / 2 + 1, \
           loop_n2 = ((ie).yucky_val(1) - loop_is2) / 2 + 1, \
           loop_n3 = ((ie).yucky_val(2) - loop_is3) / 2 + 1, \
           loop_d1 = (gv).yucky_direction(0), \
           loop_d2 = (gv).yucky_direction(1), \
           loop_d3 = (gv).yucky_direction(2), \
           loop_s1 = (gv).stride((direction) loop_d1), \
           loop_s2 = (gv).stride((direction) loop_d2), \
           loop_s3 = (gv).stride((direction) loop_d3), \
           idx0 = (is - (gv).little_corner()).yucky_val(0) / 2 * loop_s1 \
                + (is - (gv).little_corner()).yucky_val(1) / 2 * loop_s2 \
                + (is - (gv).little_corner()).yucky_val(2) / 2 * loop_s3,\
           loop_i1 = 0; loop_i1 < loop_n1; loop_i1++) \
    for (int loop_i2 = 0; loop_i2 < loop_n2; loop_i2++) \
      for (int idx = idx0 + loop_i1*loop_s1 + loop_i2*loop_s2, \
           loop_i3 = 0; loop_i3 < loop_n3; loop_i3++, idx+=loop_s3)

#define LOOP_OVER_VOL(gv, c, idx) \
  LOOP_OVER_IVECS(gv, (gv).little_corner() + (gv).iyee_shift(c), (gv).big_corner() + (gv).iyee_shift(c), idx)

#define LOOP_OVER_VOL_OWNED(gv, c, idx) \
  LOOP_OVER_IVECS(gv, (gv).little_owned_corner(c), (gv).big_corner(), idx)

#define LOOP_OVER_VOL_OWNED0(gv, c, idx) \
  LOOP_OVER_IVECS(gv, (gv).little_owned_corner0(c), (gv).big_corner(), idx)

#define LOOP_OVER_VOL_NOTOWNED(gv, c, idx) \
 for (ivec loop_notowned_is((gv).dim,0), loop_notowned_ie((gv).dim,0); \
      loop_notowned_is == zero_ivec((gv).dim);) \
   for (int loop_ibound = 0; (gv).get_boundary_icorners(c, loop_ibound,     \
		  				       &loop_notowned_is,  \
						       &loop_notowned_ie); \
	loop_ibound++) \
     LOOP_OVER_IVECS(gv, loop_notowned_is, loop_notowned_ie, idx)

#define LOOPS_ARE_STRIDE1(gv) ((gv).stride((gv).yucky_direction(2)) == 1)

// The following work identically to the LOOP_* macros above,
// but assume that the inner loop is stride-1: LOOPS_ARE_STRIDE1(gv) *must*
// be true.  These are useful in allowing gcc to auto-vectorize the inner
// loop, since gcc's vectorizer requires the array stride to be known at
// compile time.  Note that stride-1 loops are the most common case in Meep.
// Note that we also specify _Pragma("ivdep"), which is a hint to
// compilers like icc (and hopefully gcc at some point) that the loop
// iterations don't have data dependencies.  This means that you
// should only use these macros where that is true!  (Basically,
// all of this is here to support performance hacks of step_generic.)

// loop over indices idx from is to ie (inclusive) in gv
#define S1LOOP_OVER_IVECS(gv, is, ie, idx) \
  for (int loop_is1 = (is).yucky_val(0), \
           loop_is2 = (is).yucky_val(1), \
           loop_is3 = (is).yucky_val(2), \
           loop_n1 = ((ie).yucky_val(0) - loop_is1) / 2 + 1, \
           loop_n2 = ((ie).yucky_val(1) - loop_is2) / 2 + 1, \
           loop_n3 = ((ie).yucky_val(2) - loop_is3) / 2 + 1, \
           loop_d1 = (gv).yucky_direction(0), \
           loop_d2 = (gv).yucky_direction(1), \
           loop_s1 = (gv).stride((direction) loop_d1), \
           loop_s2 = (gv).stride((direction) loop_d2), \
           loop_s3 = 1, \
           idx0 = (is - (gv).little_corner()).yucky_val(0) / 2 * loop_s1 \
                + (is - (gv).little_corner()).yucky_val(1) / 2 * loop_s2 \
                + (is - (gv).little_corner()).yucky_val(2) / 2 * loop_s3,\
           loop_i1 = 0; loop_i1 < loop_n1; loop_i1++) \
    for (int loop_i2 = 0; loop_i2 < loop_n2; loop_i2++) _Pragma("ivdep") \
      for (int idx = idx0 + loop_i1*loop_s1 + loop_i2*loop_s2, \
           loop_i3 = 0; loop_i3 < loop_n3; loop_i3++, idx++)

#define S1LOOP_OVER_VOL(gv, c, idx) \
  S1LOOP_OVER_IVECS(gv, (gv).little_corner() + (gv).iyee_shift(c), (gv).big_corner() + (gv).iyee_shift(c), idx)

#define S1LOOP_OVER_VOL_OWNED(gv, c, idx) \
  S1LOOP_OVER_IVECS(gv, (gv).little_owned_corner(c), (gv).big_corner(), idx)

#define S1LOOP_OVER_VOL_OWNED0(gv, c, idx) \
  S1LOOP_OVER_IVECS(gv, (gv).little_owned_corner0(c), (gv).big_corner(), idx)

#define S1LOOP_OVER_VOL_NOTOWNED(gv, c, idx) \
 for (ivec loop_notowned_is((gv).dim,0), loop_notowned_ie((gv).dim,0); \
      loop_notowned_is == zero_ivec((gv).dim);) \
   for (int loop_ibound = 0; (gv).get_boundary_icorners(c, loop_ibound,     \
		  				       &loop_notowned_is,  \
						       &loop_notowned_ie); \
	loop_ibound++) \
     S1LOOP_OVER_IVECS(gv, loop_notowned_is, loop_notowned_ie, idx)

#define IVEC_LOOP_AT_BOUNDARY 					\
 ((loop_s1 != 0 && (loop_i1 == 0 || loop_i1 == loop_n1-1)) ||	\
  (loop_s2 != 0 && (loop_i2 == 0 || loop_i2 == loop_n2-1)) ||	\
  (loop_s3 != 0 && (loop_i3 == 0 || loop_i3 == loop_n3-1)))

#define IVEC_LOOP_ILOC(gv, iloc) \
  ivec iloc((gv).dim); \
  iloc.set_direction(direction(loop_d1), loop_is1 + 2*loop_i1); \
  iloc.set_direction(direction(loop_d2), loop_is2 + 2*loop_i2); \
  iloc.set_direction(direction(loop_d3), loop_is3 + 2*loop_i3)

#define IVEC_LOOP_LOC(gv, loc) \
  vec loc((gv).dim); \
  loc.set_direction(direction(loop_d1), (0.5*loop_is1 + loop_i1) * (gv).inva); \
  loc.set_direction(direction(loop_d2), (0.5*loop_is2 + loop_i2) * (gv).inva); \
  loc.set_direction(direction(loop_d3), (0.5*loop_is3 + loop_i3) * (gv).inva)

// integration weight for using LOOP_OVER_IVECS with field::integrate
#define IVEC_LOOP_WEIGHT1x(s0, s1, e0, e1, i, n, dir) ((i > 1 && i < n - 2) ? 1.0 : (i == 0 ? (s0).in_direction(direction(dir)) : (i == 1 ? (s1).in_direction(direction(dir)) : i == n - 1 ? (e0).in_direction(direction(dir)) : (i == n - 2 ? (e1).in_direction(direction(dir)) : 1.0))))
#define IVEC_LOOP_WEIGHT1(s0, s1, e0, e1, k) IVEC_LOOP_WEIGHT1x(s0, s1, e0, e1, loop_i##k,loop_n##k,loop_d##k)
#define IVEC_LOOP_WEIGHT(s0, s1, e0, e1, dV) (IVEC_LOOP_WEIGHT1(s0, s1, e0, e1, 3) * (IVEC_LOOP_WEIGHT1(s0, s1, e0, e1, 2) * ((dV) * IVEC_LOOP_WEIGHT1(s0, s1, e0, e1, 1))))

inline signed_direction flip(signed_direction d) {
  signed_direction d2 = d;
  d2.flipped = !d.flipped;
  return d2;
}

inline bool has_direction(ndim dim, direction d) {
  LOOP_OVER_DIRECTIONS(dim, dd) if (dd == d) return true;
  return false;
}

inline bool has_field_direction(ndim dim, direction d) {
  LOOP_OVER_FIELD_DIRECTIONS(dim, dd) if (dd == d) return true;
  return false;
}

// true if d is polar while dim is cartesian, or vice versa 
inline bool coordinate_mismatch(ndim dim, direction d) {
  return (d != NO_DIRECTION &&
	  ((dim >= D1 && dim <= D3 && d != X && d != Y && d != Z) ||
	   (dim == Dcyl && d != R && d != P && d != Z)));
}

bool is_tm(component c);

extern void abort(const char *, ...); // mympi.cpp

inline bool is_electric(component c) { return c < Hx; }
inline bool is_magnetic(component c) { return c >= Hx && c < Dx; }
inline bool is_D(component c) { return c >= Dx && c < Bx; }
inline bool is_B(component c) { return c >= Bx && c < Dielectric; }
inline bool is_derived(int c) { return c >= Sx; }
inline bool is_poynting(derived_component c) { return c < EnergyDensity; }
inline bool is_energydensity(derived_component c) { return c>=EnergyDensity; }
inline field_type type(component c) {
  if (is_electric(c)) return E_stuff;
  else if (is_magnetic(c)) return H_stuff;
  else if (is_D(c)) return D_stuff;
  else if (is_B(c)) return B_stuff;
  abort("Invalid field in type.\n");
  return E_stuff; // This is never reached.
}
const char *component_name(component c);
const char *component_name(derived_component c);
const char *component_name(int c);
const char *direction_name(direction);
const char *dimension_name(ndim);

inline int component_index(component c) {
  switch (c) {    
  case Ex: case Hx: case Dx: case Bx: return 0;
  case Ey: case Hy: case Dy: case By: return 1;
  case Ez: case Hz: case Dz: case Bz: return 2;
  case Er: case Hr: case Dr: case Br: return 0;
  case Ep: case Hp: case Dp: case Bp: return 1;
  case Dielectric: return -1;
  case Permeability: return -1;
  }
  return -2; // This code is never reached...
}

direction component_direction(int c);
int direction_component(int c, direction d);
inline direction component_direction(component c) {
  switch (c) {    
  case Ex: case Hx: case Dx: case Bx: return X;
  case Ey: case Hy: case Dy: case By: return Y;
  case Ez: case Hz: case Dz: case Bz: return Z;
  case Er: case Hr: case Dr: case Br: return R;
  case Ep: case Hp: case Dp: case Bp: return P;
  case Dielectric: return NO_DIRECTION;
  case Permeability: return NO_DIRECTION;
  }
  return X; // This code is never reached...
}
inline direction component_direction(derived_component c) {
  switch (c) {
  case Sx: return X;
  case Sy: return Y;
  case Sz: return Z;
  case Sr: return R;
  case Sp: return P;
  case EnergyDensity: case D_EnergyDensity: case H_EnergyDensity:
    return NO_DIRECTION;
  }
  return X; // This code is never reached...
}
inline direction component_direction(int c) {
  if (is_derived(c))
    return component_direction(derived_component(c));
  else
    return component_direction(component(c));
}
inline component direction_component(component c, direction d) {
  component start_point;
  if (is_electric(c)) start_point = Ex;
  else if (is_magnetic(c)) start_point = Hx;
  else if (is_D(c)) start_point = Dx;
  else if (is_B(c)) start_point = Bx;
  else if (c == Dielectric && d == NO_DIRECTION) return Dielectric;
  else if (c == Permeability && d == NO_DIRECTION) return Permeability;
  else abort("unknown field component %d", c);
  switch (d) {
  case X: return start_point;
  case Y: return (component) (start_point + 1);
  case Z: return (component) (start_point + 4);
  case R: return (component) (start_point + 2);
  case P: return (component) (start_point + 3);
  case NO_DIRECTION: abort("vector %d component in NO_DIRECTION", c);
  }
  return Ex; // This is never reached.
}
inline derived_component direction_component(derived_component c, direction d) {
  derived_component start_point;
  if (is_poynting(c)) start_point = Sx;
  else if (is_energydensity(c) && d == NO_DIRECTION) return c;
  else abort("unknown field component %d", c);
  switch (d) {
  case X: return start_point;
  case Y: return (derived_component) (start_point + 1);
  case Z: return (derived_component) (start_point + 4);
  case R: return (derived_component) (start_point + 2);
  case P: return (derived_component) (start_point + 3);
  case NO_DIRECTION: abort("vector %d derived_component in NO_DIRECTION", c);
  }
  return Sx; // This is never reached.
}
inline int direction_component(int c, direction d) {
  if (is_derived(c))
    return int(direction_component(derived_component(c), d));
  else
    return int(direction_component(component(c), d));
}

inline component field_type_component(field_type ft, component c) {
  return direction_component(first_field_component(ft),
			     component_direction(c));
}

inline bool coordinate_mismatch(ndim dim, component c) {
  return coordinate_mismatch(dim, component_direction(c));
}
inline bool coordinate_mismatch(ndim dim, derived_component c) {
  return coordinate_mismatch(dim, component_direction(c));
}

// cyclically shift a direction d or a component c by shift
// assumes: shift >= -99, {d, component_direction(c)} != NO_DIRECTION,
//          and has_direction(dim, {d, component_direction(c)})
inline direction cycle_direction(ndim dim, direction d, int shift) {
  int start = dim == Dcyl ? 2 : 0;
  return direction((d - start + shift + 99) % 3 + start);
}
inline component cycle_component(ndim dim, component c, int shift) {
  return direction_component(c, cycle_direction(dim, component_direction(c), shift));
}

class vec;
vec veccyl(double rr, double zz);
vec zero_vec(ndim);

class vec {
 public:
  vec() {};
  vec(ndim di) { dim = di; };
  vec(ndim di, double val) { dim = di; t[0]=t[1]=t[2]=t[3]=t[4]=val; };
  vec(double zz) { dim = D1; t[Z] = zz; };
  vec(double xx, double yy) { dim = D2; t[X] = xx; t[Y] = yy; };
  vec(double xx, double yy, double zz) {
    dim = D3; t[X] = xx; t[Y] = yy; t[Z] = zz; };
  friend vec veccyl(double rr, double zz);
  ~vec() {};

  vec operator+(const vec &a) const {
    vec result = a;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] += t[d];
    return result;
  };

  vec operator+=(const vec &a) {
    LOOP_OVER_DIRECTIONS(dim, d) t[d] += a.t[d];
    return *this;
  };

  vec operator-(const vec &a) const {
    vec result = a;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] = t[d] - result.t[d];
    return result;
  };

  vec operator-(void) const {
    vec result(dim);
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] = -t[d];
    return result;
  };

  vec operator-=(const vec &a) {
    LOOP_OVER_DIRECTIONS(dim, d) t[d] -= a.t[d];
    return *this;
  };

  bool operator!=(const vec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] != a.t[d]) return true;
    return false;
  };

  bool operator==(const vec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] != a.t[d]) return false;
    return true;
  };

  vec round_float(void) const {
    vec result = *this;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] = float(result.t[d]);
    return result;
  }

  vec operator*(double s) const {
    vec result = *this;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] *= s;
    return result;
  };

  vec operator/(double s) const {
    vec result = *this;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] *= (1.0/s);
    return result;
  };

  // I use & as a dot product.
  double operator&(const vec &a) const {
    double result = 0.0;
    LOOP_OVER_DIRECTIONS(dim, d) result += t[d] * a.t[d];
    return result;
  };
  ndim dim;

  double r() const { return t[R]; };
  double x() const { return t[X]; };
  double y() const { return t[Y]; };
  double z() const { return t[Z]; };
  double in_direction(direction d) const { return t[d]; };
  void set_direction(direction d, double val) { t[d] = val; };

  double project_to_boundary(direction, double boundary_loc);
  friend vec zero_vec(ndim);
  friend vec one_vec(ndim);
 private:
  double t[5];
};

inline double abs(const vec &pt) { return sqrt(pt & pt); }

inline vec zero_vec(ndim di) {
  vec pt(di); LOOP_OVER_DIRECTIONS(di, d) pt.set_direction(d, 0.0);
  return pt;
}

inline vec one_vec(ndim di) {
  vec pt(di); LOOP_OVER_DIRECTIONS(di, d) pt.set_direction(d, 1.0);
  return pt;
}

inline vec unit_vec(ndim di, direction d) {
  vec pt(zero_vec(di));
  pt.set_direction(d, 1.0);
  return pt;
}

inline vec clean_vec(const vec &pt, double val_unused = 0.0) {
  vec ptc(pt.dim, val_unused);
  LOOP_OVER_DIRECTIONS(pt.dim, d) ptc.set_direction(d, pt.in_direction(d));
  return ptc;
}

inline vec veccyl(double rr, double zz) {
  vec pt(Dcyl); pt.t[R] = rr; pt.t[Z] = zz; return pt;
}

class ivec;
ivec iveccyl(int xx, int yy);
ivec zero_ivec(ndim);
ivec one_ivec(ndim);

class ivec {
 public:
  ivec() { dim = D2; t[X] = t[Y] = 0; };
  ivec(ndim di) { dim = di; };
  ivec(ndim di, int val) { dim = di; t[0]=t[1]=t[2]=t[3]=t[4]=val; };
  ivec(int zz) { dim = D1; t[Z] = zz; };
  ivec(int xx, int yy) { dim = D2; t[X] = xx; t[Y] = yy; };
  ivec(int xx, int yy, int zz) {
    dim = D3; t[X] = xx; t[Y] = yy; t[Z] = zz; };
  friend ivec iveccyl(int xx, int yy);
  ~ivec() {};

  // Only an idiot (or a macro) would use a yucky function.  Don't be an
  // idiot.
  int yucky_val(int) const;

  ivec operator+(const ivec &a) const {
    ivec result = a;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] += t[d];
    return result;
  };

  ivec operator+=(const ivec &a) {
    LOOP_OVER_DIRECTIONS(dim, d) t[d] += a.t[d];
    return *this;
  };

  ivec operator-(const ivec &a) const {
    ivec result = a;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] = t[d] - result.t[d];
    return result;
  };

  ivec operator-(void) const {
    ivec result(dim);
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] = -t[d];
    return result;
  };

  ivec operator-=(const ivec &a) {
    LOOP_OVER_DIRECTIONS(dim, d) t[d] -= a.t[d];
    return *this;
  };

  bool operator!=(const ivec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] != a.t[d]) return true;
    return false;
  };

  bool operator==(const ivec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] != a.t[d]) return false;
    return true;
  };

  bool operator<=(const ivec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] > a.t[d]) return false;
    return true;
  };

  bool operator>=(const ivec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] < a.t[d]) return false;
    return true;
  };

  bool operator<(const ivec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] >= a.t[d]) return false;
    return true;
  };

  bool operator>(const ivec &a) const {
    LOOP_OVER_DIRECTIONS(dim, d) if (t[d] <= a.t[d]) return false;
    return true;
  };

  ivec operator*(int s) const {
    ivec result = *this;
    LOOP_OVER_DIRECTIONS(dim, d) result.t[d] *= s;
    return result;
  };

  vec operator*(double s) const {
    vec result(dim);
    LOOP_OVER_DIRECTIONS(dim, d) result.set_direction(d, t[d] * s);
    return result;
  };
  ndim dim;

  int r() const { return t[R]; };
  int x() const { return t[X]; };
  int y() const { return t[Y]; };
  int z() const { return t[Z]; };
  int in_direction(direction d) const { return t[d]; };
  void set_direction(direction d, int val) { t[d] = val; };

  ivec round_up_to_even(void) const { 
    ivec result(dim);
    LOOP_OVER_DIRECTIONS(dim, d) 
      result.t[d] = t[d] + (t[d] >= 0 ? t[d] : -t[d]) % 2; 
    return result;
  }

  friend ivec zero_ivec(ndim);
  friend ivec one_ivec(ndim);
 private:
  int t[5];
};

inline ivec zero_ivec(ndim di) {
  ivec pt; pt.dim = di; LOOP_OVER_DIRECTIONS(di, d) pt.set_direction(d, 0);
  return pt;
}

inline ivec one_ivec(ndim di) {
  ivec pt; pt.dim = di; LOOP_OVER_DIRECTIONS(di, d) pt.set_direction(d, 1);
  return pt;
}

inline ivec unit_ivec(ndim di, direction d) {
  ivec pt(zero_ivec(di));
  pt.set_direction(d, 1);
  return pt;
}

inline ivec iveccyl(int rr, int zz) {
  ivec pt(Dcyl); pt.t[R] = rr; pt.t[Z] = zz; return pt;
}

vec max(const vec &vec1, const vec &vec2);
vec min(const vec &vec1, const vec &vec2);
ivec max(const ivec &ivec1, const ivec &ivec2);
ivec min(const ivec &ivec1, const ivec &ivec2);
ivec max_to_all(const ivec &); // in mympi.cpp

class volume {
 public:
  ndim dim;
  volume(ndim di) { dim = di; min_corner.dim = di; max_corner.dim = di; };
  volume(const vec &vec1, const vec &vec2);
  volume(const vec &pt);
  void set_direction_min(direction d, double val) { min_corner.set_direction(d, val); };
  void set_direction_max(direction d, double val) { max_corner.set_direction(d, val); };
  double in_direction_min(direction d) const { return min_corner.in_direction(d); };
  double in_direction_max(direction d) const { return max_corner.in_direction(d); };
  double in_direction(direction d) const { return in_direction_max(d) - in_direction_min(d); }
  double computational_volume() const; 
  double integral_volume() const;
  double full_volume() const;
  vec center() const { return (min_corner + max_corner) * 0.5; }
  double diameter() const;
  bool contains(const vec &h) const;
  bool contains(const volume &a) const;
  volume intersect_with(const volume &a) const;
  volume operator&(const volume &a) const {
    return intersect_with(a);
  };
  volume operator|(const volume &a) const {
    return volume(min(min_corner, a.min_corner),
			    max(max_corner, a.max_corner));
  };
  volume operator+(const vec &a) const {
    return volume(min_corner + a, max_corner + a);
  }
  volume operator+=(const vec &a) {
    min_corner += a; max_corner += a;
    return *this;
  }
  volume operator-(const vec &a) const {
    return volume(min_corner - a, max_corner - a);
  }
  volume operator-=(const vec &a) {
    min_corner -= a; max_corner -= a;
    return *this;
  }
  bool operator==(const volume &a) const {
    return (min_corner == a.min_corner && max_corner == a.max_corner);
  }
  bool operator!=(const volume &a) const { return !(*this == a); };
  volume round_float(void) const {
    return volume(min_corner.round_float(),max_corner.round_float());
  }
  bool intersects(const volume &a) const;
  bool operator&&(const volume &a) const {
    return intersects(a);
  };
  vec get_min_corner() const { return min_corner; };
  vec get_max_corner() const { return max_corner; };
  direction normal_direction() const;
 private:
  vec min_corner, max_corner;
};

class grid_volume;
grid_volume volcyl(double rsize, double zsize, double a);
grid_volume volone(double zsize, double a);
grid_volume vol1d(double zsize, double a);
grid_volume voltwo(double xsize, double ysize, double a);
grid_volume vol2d(double xsize, double ysize, double a);
grid_volume vol3d(double xsize, double ysize, double zsize, double a);

class grid_volume {
 public:
  grid_volume() {};

  ndim dim;
  double a, inva /* = 1/a */;

  void print() const;
  int stride(direction d) const { return the_stride[d]; };
  int num_direction(direction d) const {
    return num[((int) d) % 3];
  };
  // Only an idiot (or a macro) would use a yucky function.  Don't be an
  // idiot.
  int yucky_num(int) const;
  direction yucky_direction(int) const;
  void set_num_direction(direction d, int value);
  int nr() const { return num_direction(R); }
  int nx() const { return num_direction(X); }
  int ny() const { return num_direction(Y); }
  int nz() const { return num_direction(Z); }

  bool has_field(component c) const {
    if (dim == D1) return c == Ex || c == Hy || c == Dx || c == By;
    return (dim == Dcyl)?component_direction(c)>Y:component_direction(c)<R;
  }
  int has_boundary(boundary_side,direction) const;

  vec dr() const;
  vec dx() const;
  vec dy() const;
  vec dz() const;

  int ntot() const { return the_ntot; }
  int nowned_min() const { int n = 1; LOOP_OVER_DIRECTIONS(dim,d) n *= num_direction(d); return n; }
  int nowned(component c) const;
  vec operator[](const ivec &p) const { return p*(0.5*inva); };
  int index(component, const ivec &) const;
  ivec round_vec(const vec &) const;
  void interpolate(component, const vec &, int indices[8], double weights[8]) const;
  void interpolate(component, const vec &, ivec locs[8], double weights[8]) const;

  volume dV(component c, int index) const;
  volume dV(const ivec &, double diameter = 1.0) const;
  bool intersect_with(const grid_volume &vol_in, grid_volume *intersection = NULL, grid_volume *others = NULL, int *num_others = NULL) const;
  double rmin() const;
  double rmax() const;
  double xmin() const;
  double xmax() const;
  double ymin() const;
  double ymax() const;
  double zmin() const;
  double zmax() const;
  vec center() const;
  ivec icenter() const;
  vec loc(component, int index) const;
  vec loc_at_resolution(int index, double res) const;
  int ntot_at_resolution(double res) const;
  ivec iloc(component, int index) const;

  int yee_index(component c) const {
    int idx = 0;
    LOOP_OVER_DIRECTIONS(dim,d)
      idx += (1-iyee_shift(c).in_direction(d))*stride(d);
    return idx;
  }
  vec yee_shift(component) const;
  component eps_component() const;
  void yee2cent_offsets(component c, int &offset1, int &offset2);

  double boundary_location(boundary_side, direction) const;
  ivec big_corner() const;
  ivec little_corner() const { return io; };
  vec corner(boundary_side b) const;

  bool contains(const vec &) const;
  bool contains(const ivec &) const;

  /* differs from little_owned_corner in that it doesn't count
     "ownership" of the r=0 origin for Dcyl, which is updated separately */
  ivec little_owned_corner0(component c) const {
    return ivec(little_corner() + one_ivec(dim)*2 - iyee_shift(c));
  }

  ivec little_owned_corner(component c) const;
  bool owns(const ivec &) const;
  volume surroundings() const;
  volume interior() const;

  bool get_boundary_icorners(component c, int ib, ivec *cs, ivec *ce) const;

  friend grid_volume volcyl(double rsize, double zsize, double a);
  friend grid_volume volone(double zsize, double a);
  friend grid_volume vol1d(double zsize, double a);
  friend grid_volume voltwo(double xsize, double ysize, double a);
  friend grid_volume vol2d(double xsize, double ysize, double a);
  friend grid_volume vol3d(double xsize, double ysize, double zsize, double a);

  grid_volume split(int num, int which) const;
  grid_volume split_by_effort(int num, int which, int Ngv = 0, const grid_volume *v = NULL, double *effort = NULL) const;
  grid_volume split_at_fraction(bool want_high, int numer) const;
  grid_volume halve(direction d) const;
  void pad_self(direction d);
  grid_volume pad(direction d) const;
  grid_volume pad() const {
       grid_volume gv(*this);
       LOOP_OVER_DIRECTIONS(dim,d)
	    gv.pad_self(d);
       return gv;
  }
  ivec iyee_shift(component c) const {
    ivec out = zero_ivec(dim);
    LOOP_OVER_DIRECTIONS(dim,d)
      if (c == Dielectric || c == Permeability || 
          ((is_electric(c) || is_D(c)) && d == component_direction(c)) ||
          ((is_magnetic(c) || is_B(c)) && d != component_direction(c)))
        out.set_direction(d,1);
    return out;
  }

  vec get_origin() const { return origin; }
  void set_origin(const vec &o);
  void set_origin(const ivec &o);
  void shift_origin(const vec &s) { set_origin(origin + s); }
  void shift_origin(const ivec &s) { set_origin(io + s); }
  void shift_origin(direction d, int s) {shift_origin(unit_ivec(dim, d) * s);}
  void set_origin(direction d, int o);
  void center_origin(void) { shift_origin(-icenter()); }
  double origin_in_direction(direction d) const{return origin.in_direction(d);}
  int iorigin_in_direction(direction d) const{return io.in_direction(d);}
  double origin_r() const { return origin.r(); }
  double origin_x() const { return origin.x(); }
  double origin_y() const { return origin.y(); }
  double origin_z() const { return origin.z(); }

 private:
  grid_volume(ndim d, double ta, int na, int nb, int nc);
  ivec io; // integer origin ... always change via set_origin etc.!
  vec origin; // cache of operator[](io), for performance
  void update_ntot();
  void set_strides();
  void num_changed() { update_ntot(); set_strides(); }
  int num[3];
  int the_stride[5];
  int the_ntot;
};

class volume_list;

class symmetry;
symmetry identity();
symmetry rotate4(direction,const grid_volume &);
symmetry rotate2(direction,const grid_volume &);
symmetry mirror(direction,const grid_volume &);
symmetry r_to_minus_r_symmetry(double m);

class symmetry {
 public:
  symmetry();
  symmetry(const symmetry &);
  ~symmetry();
  friend symmetry identity();
  friend symmetry rotate4(direction,const grid_volume &);
  friend symmetry rotate2(direction,const grid_volume &);
  friend symmetry mirror(direction,const grid_volume &);

  signed_direction transform(direction d, int n) const;
  ivec transform(const ivec &, int n) const;
  vec transform(const vec &, int n) const;
  ivec transform_unshifted(const ivec &, int n) const;
  volume transform(const volume &, int n) const;
  component transform(component, int n) const;
  complex<double> phase_shift(component, int n) const;
  derived_component transform(derived_component, int n) const;
  complex<double> phase_shift(derived_component, int n) const;
  int transform(int, int n) const;
  complex<double> phase_shift(int, int n) const;
  int multiplicity() const;
  bool is_primitive(const ivec &) const;

  volume_list *reduce(const volume_list *gl) const;

  symmetry operator+(const symmetry &) const;
  symmetry operator*(complex<double>) const;
  symmetry operator-(const symmetry &b) const { return *this + b * (-1.0); }
  symmetry operator-(void) const { return *this * (-1.0); }
  void operator=(const symmetry &);
  bool operator==(const symmetry &) const;
  bool operator!=(const symmetry &S) const { return !(*this == S); };
 private:
  signed_direction S[5];
  complex<double> ph;
  vec symmetry_point;
  ivec i_symmetry_point;
  int g; // g is the multiplicity of the symmetry.
  symmetry *next;
  friend symmetry r_to_minus_r_symmetry(double m);
};

class volume_list {
public:
  volume_list(const volume &v, int c, complex<double> weight = 1.0, volume_list *next = 0) : v(v), c(c), weight(weight), next(next) {}
  ~volume_list() { delete next; }
  
  volume v;
  int c; // component or derived component associated with v (e.g. for flux)
  complex<double> weight;
  volume_list *next;
};

} /* namespace meep */

#endif /* MEEP_VEC_H */