qpms/qpms/lattices.h

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/*! \file lattices.h
* \brief Lattice point generators and lattice vector analysis / transformation.
*
*/
#ifndef LATTICES_H
#define LATTICES_H
#include <math.h>
#include <stdbool.h>
#include <assert.h>
#include <stddef.h>
#include <stdlib.h>
#ifndef M_SQRT3
#define M_SQRT3 1.7320508075688772935274463415058724
#endif
#ifndef M_SQRT3_2
#define M_SQRT3_2 (M_SQRT3/2)
#endif
#ifndef M_1_SQRT3
#define M_1_SQRT3 0.57735026918962576450914878050195746
#endif
/* IMPORTANT TODO
* ==============
*
* The current content of this part (and the implementation) is extremely ugly.
* When I have some time, I have to rewrite this in the style of lattices2d.py
*
*/
typedef enum LatticeDimensionality {
LAT1D = 1,
LAT2D = 2,
LAT3D = 4,
SPACE1D = 8,
SPACE2D = 16,
SPACE3D = 32,
LAT_1D_IN_3D = 33,
LAT_2D_IN_3D = 34,
LAT_3D_IN_3D = 40,
// special coordinate arrangements (indicating possible optimisations)
LAT_ZONLY = 64,
LAT_XYONLY = 128,
LAT_1D_IN_3D_ZONLY = 97, // LAT1D | SPACE3D | 64
LAT_2D_IN_3D_XYONLY = 162 // LAT2D | SPACE3D | 128
} LatticeDimensionality;
inline static bool LatticeDimensionality_checkflags(
LatticeDimensionality a, LatticeDimensionality flags_a_has_to_contain) {
return ((a & flags_a_has_to_contain) == flags_a_has_to_contain);
}
// fuck, I already had had suitable type
#include "vectors.h"
typedef cart2_t point2d;
static inline point2d point2d_fromxy(const double x, const double y) {
point2d p;
p.x = x;
p.y = y;
return p;
}
/// Lattice basis reduction.
/** This is currenty a bit naïve implementation of
* Lenstra-Lenstra-Lovász algorithm.
*
* The reduction happens in-place, i.e. the basis vectors in \a b are
* replaced with the reduced basis.
*/
int qpms_reduce_lattice_basis(double *b, ///< Array of dimension [bsize][ndim].
const size_t bsize, ///< Number of the basis vectors (dimensionality of the lattice).
const size_t ndim, ///< Dimension of the space into which the lattice is embedded.
/// Lovász condition parameter \f$ \delta \f$.
/** Polynomial time complexity guaranteed for \f$\delta \in (1/4,1)\f$.
*/
double delta
);
/// Generic lattice point generator type.
/**
* A bit of OOP-in-C brainfuck here.
*
* The basic principle of operation is following:
* Instead of a list (array) of points, an initialized PGen object
* is passed to a function that does something over a set of points.
* Each time PGen-type object is "called" (more specifically, one of
* the "methods" specified in the PGenClassInfo structure in @ref c,
* it returns PGenReturnData
* which contains a point in given coordinates (depending on the generator
* class) and some metadata.
*
* After the last generated point, the generator frees all internal memory
* and returns PGenSphReturnData with PGEN_NOTDONE flag unset (the rest
* shall be considered invalid data).
* The caller can also decide not to use the rest and end getting the points
* even when the PGEN_NOTDONE was set in the last returned data.
* In such case, the caller shall call PGen_destroy() manually.
*
* Methods
* -------
*
* The standard wrapper "methods" to generate a single point in a given
* coordinate system are
*
* * PGen_next_z(),
* * PGen_next_cart2(),
* * PGen_next_cart3(),
* * PGen_next_pol(),
* * PGen_next_sph().
*
* Memory management policy
* ------------------------
*
* The basic PGen structure shall be allocated on stack (it's only two pointers),
* everything internal goes on heap.
*/
typedef struct PGen {
/// Pointer to the "class" metadata defining the behaviour of the generator.
const struct PGenClassInfo * /*const*/ c;
/// Pointer to internal state data; shall be NULL if invalid (destroyed);
void *stateData;
} PGen;
typedef enum PGenPointFlags {
/** The most important flag: when this is not set, the
* interation ended other data returned should be
* considered nonsense and at this point, the generator
* should have de-allocated all internal memory.
*/
PGEN_NOTDONE = 2,
/** Set if the r-coordinate is not different than in the
* previous generated point (so radial parts of the
* calculation have to be redone).
* Optional.
*/
PGEN_OLD_R = 1,
/** Set if the r-coordinate has not changed between the
* first and the last point generated in the current
* call.
* Only for the bulk generator methods.
* Optional.
*/
PGEN_SINGLE_R = 16,
PGEN_AT_Z = 4, ///< Set if the point(s) lie(s) at the z-axis (theta is either 0 or M_PI).
PGEN_AT_XY = 8, ///< Set if the point(s) lie(s) in the xy-plane (theta is M_PI2).
PGEN_METHOD_UNAVAILABLE = 2048, ///< Set if no suitable method exists (no point generated).
PGEN_DONE = 0, ///< Convenience identifier, not an actual flag.
PGEN_COORDS_CART1 = QPMS_COORDS_CART1,
PGEN_COORDS_CART2 = QPMS_COORDS_CART2,
PGEN_COORDS_CART3 = QPMS_COORDS_CART3,
PGEN_COORDS_POL = QPMS_COORDS_POL,
PGEN_COORDS_SPH = QPMS_COORDS_SPH,
PGEN_COORDS_BITRANGE = QPMS_COORDS_BITRANGE,
} PGenPointFlags;
/// Metadata generated by the fetch*() methods from PGenClassInfo
typedef struct PGenReturnDataBulk {
/// Flags describing the returned data.
PGenPointFlags flags;
size_t generated; ///< Number of points really generated
} PGenReturnDataBulk;
/// Generic PGen return type that might contain point represented in any of the supported coordinate systems.
typedef struct PGenReturnData {
PGenPointFlags flags; ///< Metadata, must contain valid coordinate system defining flags.
anycoord_point_t point; ///< Generated point in a coordinate system defined by flags.
} PGenReturnData;
/// PGen single-point return data type (1D).
typedef struct PGenZReturnData {
PGenPointFlags flags; ///< Medatata.
double point_z; ///< Generated point on a real axis.
} PGenZReturnData;
/// PGen single-point return data type (2D, polar coordinates).
typedef struct PGenPolReturnData {
PGenPointFlags flags; ///< Metadata.
pol_t point_pol; ///< Generated point in polar coordinates.
} PGenPolReturnData;
/// PGen single-point return data type (3D, spherical coordinates).
typedef struct PGenSphReturnData {
PGenPointFlags flags; ///< Metadata.
sph_t point_sph; ///< Generated point in spherical coordinates.
} PGenSphReturnData;
/// PGen single-point return data type (2D, cartesian coordinates).
typedef struct PGenCart2ReturnData {
PGenPointFlags flags; ///< Metadata.
cart2_t point_cart2; ///< Generated point in cartesian coordinates.
} PGenCart2ReturnData;
/// PGen single-point return data type (3D, cartesian coordinates).
typedef struct PGenCart3ReturnData {
PGenPointFlags flags; ///< Metadata.
cart3_t point_cart3; ///< Generated point in cartesian coordinates.
} PGenCart3ReturnData;
// convenience constants for use in the extractor implementations
static const PGenZReturnData PGenZDoneVal = {PGEN_DONE, 0};
static const PGenPolReturnData PGenPolDoneVal = {PGEN_DONE, {0,0}};
static const PGenSphReturnData PGenSphDoneVal = {PGEN_DONE, {0,0,0}};
static const PGenCart2ReturnData PGenCart2DoneVal = {PGEN_DONE, {0,0}};
static const PGenCart3ReturnData PGenCart3DoneVal = {PGEN_DONE, {0,0,0}};
/// PGen class metadata.
/**
* This structure determines the behaviour of the PGen
* instance pointing to it.
*
* For generating a single point, use the next() method.
* For generating up to N points in a single call, use the
* fetch() method.
*
* It is strongly recommended that at least the native-coordinate
* fetch method and the native-coordinate next method are implemented.
*
* Usually, each generator uses internally one "native" coordinate
* system (in lattice generators, this will typically be nD
* cartesian coordinates) in which the next() method gives its result.
*
* One does not have to explicitly implement every single method.
*
* TODO doc about the default transformations etc.
*/
typedef struct PGenClassInfo { // static PGenSph info
char * const name; // mainly for debugging purposes
int dimensionality; // lower-dimensional can be converted to higher-D, not vice versa; bit redundant with the following, whatever.
/// Info about the generator native coordinate system.
PGenPointFlags native_point_flags;
/// Generate a single point in the native coordinates.
PGenReturnData (*next)(struct PGen *);
/// Generate a single 1D point.
PGenZReturnData (*next_z)(struct PGen *);
/// Generate a single 2D point in polar coordinates.
PGenPolReturnData (*next_pol)(struct PGen *);
/// Generate a single 3D point in spherical coordinates.
PGenSphReturnData (*next_sph)(struct PGen *);
/// Generate a single 2D point in cartesian coordinates.
PGenCart2ReturnData (*next_cart2)(struct PGen *);
/// Generate a single 3D point in cartesian coordinates.
PGenCart3ReturnData (*next_cart3)(struct PGen *);
/// Generate up to \a n points in the native coordinates.
PGenReturnDataBulk (*fetch)(struct PGen *, size_t, anycoord_point_t *);
/// Generate up to \a n 1D points.
PGenReturnDataBulk (*fetch_z)(struct PGen *, size_t, double *);
/// Generate up to \a n 2D points in polar coordinates.
PGenReturnDataBulk (*fetch_pol)(struct PGen *, size_t, pol_t *);
/// Generate up to \a n 3D points in spherical coordinates.
PGenReturnDataBulk (*fetch_sph)(struct PGen *, size_t, sph_t *);
/// Generate up to \a n 2D points in cartesian coordinates.
PGenReturnDataBulk (*fetch_cart2)(struct PGen *, size_t, cart2_t *);
/// Generate up to \a n 3D points in cartesian coordinates.
PGenReturnDataBulk (*fetch_cart3)(struct PGen *, size_t, cart3_t *);
/// Destructor.
/** To be called by next() at iteration end, or by the caller
* if ending the generation prematurely
*/
void (*destructor)(struct PGen *);
} PGenClassInfo;
/// Generate a point with any of the next-methods.
static inline PGenReturnData PGen_next_nf(struct PGen *g) {
if (g->c->next)
return g->c->next(g);
else {
PGenReturnData r;
if (g->c->next_z) {
PGenZReturnData res = g->c->next_z(g);
r.flags = res.flags;
r.point.z = res.point_z;
} else if (g->c->next_pol) {
PGenPolReturnData res = g->c->next_pol(g);
r.flags = res.flags;
r.point.pol = res.point_pol;
} else if (g->c->next_cart2) {
PGenCart2ReturnData res = g->c->next_cart2(g);
r.flags = res.flags;
r.point.cart2 = res.point_cart2;
} else if (g->c->next_sph) {
PGenSphReturnData res = g->c->next_sph(g);
r.flags = res.flags;
r.point.sph = res.point_sph;
} else if (g->c->next_cart3) {
PGenCart3ReturnData res = g->c->next_cart3(g);
r.flags = res.flags;
r.point.cart3 = res.point_cart3;
} else
r.flags = PGEN_METHOD_UNAVAILABLE;
return r;
}
}
/// Generate multiple points with PGen in any coordinate system.
// Ultimate ugliness
static inline PGenReturnDataBulk PGen_fetch_any(struct PGen *g, size_t nmemb,
anycoord_point_t *target) {
if (g->c->fetch)
return g->c->fetch(g, nmemb, target);
else if (g->c->fetch_cart3) {
cart3_t *t2 = (cart3_t*) ((char *) target
+ nmemb * (sizeof(anycoord_point_t)-sizeof(cart3_t)));
PGenReturnDataBulk res = g->c->fetch_cart3(g, nmemb, t2);
for (size_t i = 0; i < nmemb; ++i)
target[i].cart3 = t2[i];
return res;
} else if (g->c->fetch_sph) {
sph_t *t2 = (sph_t*) ((char *) target
+ nmemb * (sizeof(anycoord_point_t)-sizeof(sph_t)));
PGenReturnDataBulk res = g->c->fetch_sph(g, nmemb, t2);
for (size_t i = 0; i < nmemb; ++i)
target[i].sph = t2[i];
return res;
} else if (g->c->fetch_cart2) {
cart2_t *t2 = (cart2_t*) ((char *) target
+ nmemb * (sizeof(anycoord_point_t)-sizeof(cart2_t)));
PGenReturnDataBulk res = g->c->fetch_cart2(g, nmemb, t2);
for (size_t i = 0; i < nmemb; ++i)
target[i].cart2 = t2[i];
return res;
} else if (g->c->fetch_pol) {
pol_t *t2 = (pol_t*) ((char *) target
+ nmemb * (sizeof(anycoord_point_t)-sizeof(pol_t)));
PGenReturnDataBulk res = g->c->fetch_pol(g, nmemb, t2);
for (size_t i = 0; i < nmemb; ++i)
target[i].pol = t2[i];
return res;
} else if (g->c->fetch_z) {
double *t2 = (double*) ((char *) target
+ nmemb * (sizeof(anycoord_point_t)-sizeof(double)));
PGenReturnDataBulk res = g->c->fetch_z(g, nmemb, t2);
for (size_t i = 0; i < nmemb; ++i)
target[i].z = t2[i];
return res;
} else {
// This is ridiculously inefficient
PGenReturnDataBulk res = {PGEN_NOTDONE, 0};
for (res.generated = 0; res.generated < nmemb;
++res.generated) {
PGenReturnData res1 = PGen_next_nf(g);
QPMS_ENSURE(!(res1.flags & PGEN_METHOD_UNAVAILABLE),
"No method found to generate points. The PGenClassInfo"
" %s is apparently broken.", g->c->name);
if (res1.flags & PGEN_NOTDONE) {
target[res.generated] = res1.point;
// The coordinate system generated by next() must be consistent:
assert(!res.generated || ((res1.flags & PGEN_COORDS_BITRANGE) == (res.flags & PGEN_COORDS_BITRANGE)));
res.flags |= res1.flags & PGEN_COORDS_BITRANGE;
} else {
res.flags &= ~PGEN_NOTDONE;
break;
}
}
// Do not guarantee anything for; low priority TODO
res.flags &= ~(PGEN_OLD_R & PGEN_SINGLE_R);
return res;
}
}
/// Generate a point with any of the next-methods or fetch-methods.
static inline PGenReturnData PGen_next(struct PGen *g) {
PGenReturnData res = PGen_next_nf(g);
if (!(res.flags & PGEN_METHOD_UNAVAILABLE))
return res;
else { // Slow if implementation is stupid, but short!
PGenReturnDataBulk resb = PGen_fetch_any(g, 1, &res.point);
if (resb.generated)
// the | PGEN_NOTDONE may not be needed, but my brain melted
res.flags = resb.flags | PGEN_NOTDONE;
else
res.flags = PGEN_DONE;
return res;
}
}
/// Generate multiple points in spherical coordinates.
static inline PGenReturnDataBulk PGen_fetch_sph(struct PGen *g,
size_t nmemb, sph_t *target) {
if (g->c->fetch_sph)
return g->c->fetch_sph(g, nmemb, target);
else {
anycoord_point_t *tmp;
QPMS_CRASHING_MALLOC(tmp, sizeof(anycoord_point_t) * nmemb);
PGenReturnDataBulk res = PGen_fetch_any(g, nmemb, tmp);
anycoord_arr2something(target, QPMS_COORDS_SPH,
tmp, res.flags, res.generated);
free(tmp);
res.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_SPH;
return res;
}
}
/// Generate multiple points in 3D cartesian coordinates.
static inline PGenReturnDataBulk PGen_fetch_cart3(struct PGen *g,
size_t nmemb, cart3_t *target) {
if (g->c->fetch_cart3)
return g->c->fetch_cart3(g, nmemb, target);
else {
anycoord_point_t *tmp;
QPMS_CRASHING_MALLOC(tmp, sizeof(anycoord_point_t) * nmemb);
PGenReturnDataBulk res = PGen_fetch_any(g, nmemb, tmp);
anycoord_arr2something(target, QPMS_COORDS_CART3,
tmp, res.flags, res.generated);
free(tmp);
res.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_CART3;
return res;
}
}
/// Generate multiple points in polar coordinates.
static inline PGenReturnDataBulk PGen_fetch_pol(struct PGen *g,
size_t nmemb, pol_t *target) {
if (g->c->fetch_pol)
return g->c->fetch_pol(g, nmemb, target);
else {
anycoord_point_t *tmp;
QPMS_CRASHING_MALLOC(tmp, sizeof(anycoord_point_t) * nmemb);
PGenReturnDataBulk res = PGen_fetch_any(g, nmemb, tmp);
anycoord_arr2something(target, QPMS_COORDS_POL,
tmp, res.flags, res.generated);
free(tmp);
res.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_POL;
return res;
}
}
/// Generate multiple points in 2D cartesian coordinates.
static inline PGenReturnDataBulk PGen_fetch_cart2(struct PGen *g,
size_t nmemb, cart2_t *target) {
if (g->c->fetch_cart2)
return g->c->fetch_cart2(g, nmemb, target);
else {
anycoord_point_t *tmp;
QPMS_CRASHING_MALLOC(tmp, sizeof(anycoord_point_t) * nmemb);
PGenReturnDataBulk res = PGen_fetch_any(g, nmemb, tmp);
anycoord_arr2something(target, QPMS_COORDS_CART2,
tmp, res.flags, res.generated);
free(tmp);
res.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_CART2;
return res;
}
}
/// Generate multiple points in 1D cartesian coordinates.
static inline PGenReturnDataBulk PGen_fetch_z(struct PGen *g,
size_t nmemb, double *target) {
if (g->c->fetch_z)
return g->c->fetch_z(g, nmemb, target);
else {
anycoord_point_t *tmp;
QPMS_CRASHING_MALLOC(tmp, sizeof(anycoord_point_t) * nmemb);
PGenReturnDataBulk res = PGen_fetch_any(g, nmemb, tmp);
anycoord_arr2something(target, QPMS_COORDS_CART1,
tmp, res.flags, res.generated);
free(tmp);
res.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_CART1;
return res;
}
}
/// Deallocate and invalidate a PGen point generator.
static inline void PGen_destroy(PGen *g) {
g->c->destructor(g);
assert(g->stateData == NULL); // this should be done by the destructor
}
/// Generate a point in a 1D real space.
static inline PGenZReturnData PGen_next_z(PGen *g) {
if (g->c->next_z)
return g->c->next_z(g);
else { // Super-slow generic fallback.
PGenReturnData res = PGen_next(g);
if (res.flags & PGEN_NOTDONE) {
PGenZReturnData r;
r.point_z = anycoord2cart1(res.point, res.flags);
r.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_CART1;
return r;
} else
return PGenZDoneVal;
}
}
/// Generate a point in a 3D real space (spherical coordinates).
static inline PGenSphReturnData PGen_next_sph(PGen *g) {
if (g->c->next_sph)
return g->c->next_sph(g);
else { // Super-slow generic fallback.
PGenReturnData res = PGen_next(g);
if (res.flags & PGEN_NOTDONE) {
PGenSphReturnData r;
r.point_sph = anycoord2sph(res.point, res.flags);
r.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_SPH;
return r;
} else
return PGenSphDoneVal;
}
}
/// Generate a point in a 2D real space (polar coordinates).
static inline PGenPolReturnData PGen_next_pol(PGen *g) {
if (g->c->next_pol)
return g->c->next_pol(g);
else { // Super-slow generic fallback.
PGenReturnData res = PGen_next(g);
if (res.flags & PGEN_NOTDONE) {
PGenPolReturnData r;
r.point_pol = anycoord2pol(res.point, res.flags);
r.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_POL;
return r;
} else
return PGenPolDoneVal;
}
}
/// Generate a point in a 3D real space (cartesian coordinates).
static inline PGenCart3ReturnData PGen_next_cart3(PGen *g) {
if (g->c->next_cart3)
return g->c->next_cart3(g);
else { // Super-slow generic fallback.
PGenReturnData res = PGen_next(g);
if (res.flags & PGEN_NOTDONE) {
PGenCart3ReturnData r;
r.point_cart3 = anycoord2cart3(res.point, res.flags);
r.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_CART3;
return r;
} else
return PGenCart3DoneVal;
}
}
/// Generate a point in a 2D real space (cartesian coordinates).
static inline PGenCart2ReturnData PGen_next_cart2(PGen *g) {
if (g->c->next_cart2)
return g->c->next_cart2(g);
else { // Super-slow generic fallback.
PGenReturnData res = PGen_next(g);
if (res.flags & PGEN_NOTDONE) {
PGenCart2ReturnData r;
r.point_cart2 = anycoord2cart2(res.point, res.flags);
r.flags = (res.flags & ~QPMS_COORDS_BITRANGE)
| QPMS_COORDS_CART2;
return r;
} else
return PGenCart2DoneVal;
}
}
#if 0
/// Generate up to \a n points.
static inline PGenReturnDataBulk PGen_fetch(PGen *g, size_t n, anycoord_point_t *arr){
if (g->c->fetch)
return g->c->fetch(g, n, arr);
else abort();
}
#endif
static inline bool PGenSph_notDone(PGenSphReturnData data) {
return data.flags & PGEN_NOTDONE ? true : false;
}
static inline bool PGenCart3_notDone(PGenCart3ReturnData data) {
return data.flags & PGEN_NOTDONE ? true : false;
}
/// Standard PGen spherical coordinates -> 3d cartesian convertor.
static inline PGenCart3ReturnData PGenReturnDataConv_sph_cart3(PGenSphReturnData sphdata){
PGenCart3ReturnData c3data;
c3data.flags = sphdata.flags;
c3data.point_cart3 = sph2cart(sphdata.point_sph);
return c3data;
}
/// Standard PGen 3d cartesian -> spherical coordinates convertor.
static inline PGenSphReturnData PGenReturnDataConv_cart3_sph(PGenCart3ReturnData c){
PGenSphReturnData s;
s.flags = c.flags;
s.point_sph = cart2sph(c.point_cart3);
return s;
}
/*
* Some basic lattice generators implementing the abstract interface above (implemented in latticegens.c).
*/
/// 2D point generator that simply iterates over an existing array of Point2d.
extern const PGenClassInfo PGen_FromPoint2DArray; // TODO Do I even need this to be declared here?
/// PGen_FromPoint2DArray constructor.
PGen PGen_FromPoints2DArray_new(const point2d *points, size_t len);
/// 1D equidistant point generator.
extern const PGenClassInfo PGen_1D;
typedef enum PGen_1D_incrementDirection{
//PGEN_1D_POSITIVE_INC, // not implemented
//PGEN_1D_NEGATIVE_INC, // not implemented
PGEN_1D_INC_FROM_ORIGIN,
PGEN_1D_INC_TOWARDS_ORIGIN
} PGen_1D_incrementDirection;
/// PGen_1D point generator constructor.
PGen PGen_1D_new_minMaxR(double period, ///< Distance between points.
double offset, ///< Lattice offset from zero.
double minR, ///< Lower bound of |z| of the generated points.
bool inc_minR, ///< Include also |z| == minR (if applicable).
double maxR, ///< Upper bound of |z| of the generated points.
bool inc_maxR, ///< Include also |z| == maxR if applicable.
PGen_1D_incrementDirection incdir ///< Order of generated points.
);
extern const PGenClassInfo PGen_xyWeb;
PGen PGen_xyWeb_new(cart2_t b1, cart2_t b2, double rtol, cart2_t offset,
double minR, bool inc_minR, double maxR, bool inc_maxR);
/// Returns a number larger or equal than the number of all the points generated by a PGen_xyWeb.
size_t PGen_xyWeb_sizecap(cart2_t b1, cart2_t b2, double rtol, cart2_t offset,
double minR, bool inc_minR, double maxR, bool inc_maxR);
/*
* THE NICE PART (adaptation of lattices2d.py)
* ===========================================
*
* all the functions are prefixed with l2d_
* convention for argument order: inputs, *outputs, add. params
*/
#define BASIS_RTOL 1e-13
// Bravais lattice types
typedef enum {
OBLIQUE = 1,
RECTANGULAR = 2,
SQUARE = 4,
RHOMBIC = 5,
EQUILATERAL_TRIANGULAR = 3,
RIGHT_ISOSCELES=SQUARE,
PARALLELOGRAMMIC=OBLIQUE,
CENTERED_RHOMBIC=RECTANGULAR,
RIGHT_TRIANGULAR=RECTANGULAR,
CENTERED_RECTANGULAR=RHOMBIC,
ISOSCELE_TRIANGULAR=RHOMBIC,
RIGHT_ISOSCELE_TRIANGULAR=SQUARE,
HEXAGONAL=EQUILATERAL_TRIANGULAR
} LatticeType2;
#if 0
// Wallpaper groups
typedef enum {
TODO
} SpaceGroup2;
#endif
// Just for detecting the right angles (needed for generators).
typedef enum {
NOT_ORTHOGONAL = 0,
ORTHOGONAL_01 = 1,
ORTHOGONAL_12 = 2,
ORTHOGONAL_02 = 4
} LatticeFlags;
/*
* Lagrange-Gauss reduction of a 2D basis.
* The output shall satisfy |out1| <= |out2| <= |out2 - out1|
*/
void l2d_reduceBasis(cart2_t in1, cart2_t in2, cart2_t *out1, cart2_t *out2);
// This one uses LLL reduction.
void l3d_reduceBasis(const cart3_t in[3], cart3_t out[3]);
/*
* This gives the "ordered shortest triple" of base vectors (each pair from the triple
* is a base) and there may not be obtuse angle between o1, o2 and between o2, o3
*/
void l2d_shortestBase3(cart2_t i1, cart2_t i2, cart2_t *o1, cart2_t *o2, cart2_t *o3);
/*
* TODO doc
* return value is 4 or 6.
*/
int l2d_shortestBase46(cart2_t i1, cart2_t i2, cart2_t *o1, cart2_t *o2, cart2_t *o3, cart2_t *o4, cart2_t *o5, cart2_t *o6, double rtol);
// variant
int l2d_shortestBase46_arr(cart2_t i1, cart2_t i2, cart2_t *oarr, double rtol);
// Determines whether angle between inputs is obtuse
bool l2d_is_obtuse_r(cart2_t i1, cart2_t i2, double rtol);
bool l2d_is_obtuse(cart2_t i1, cart2_t i2);
/*
* Given two basis vectors, returns 2D Bravais lattice type.
*/
LatticeType2 l2d_classifyLattice(cart2_t b1, cart2_t b2, double rtol);
// Detects right angles.
LatticeFlags l2d_detectRightAngles(cart2_t b1, cart2_t b2, double rtol);
LatticeFlags l3d_detectRightAngles(const cart3_t basis[3], double rtol);
// Other functions in lattices2d.py: TODO?
// range2D()
// generateLattice()
// generateLatticeDisk()
// cutWS()
// filledWS()
// change_basis()
/*
* Given basis vectors, returns the corners of the Wigner-Seits unit cell (W1, W2, -W1, W2)
* for rectangular and square lattice or (w1, w2, w3, -w1, -w2, -w3) otherwise.
*/
int l2d_cellCornersWS(cart2_t i1, cart2_t i2, cart2_t *o1, cart2_t *o2, cart2_t *o3, cart2_t *o4, cart2_t *o5, cart2_t *o6, double rtol);
// variant
int l2d_cellCornersWS_arr(cart2_t i1, cart2_t i2, cart2_t *oarr, double rtol);
// Reciprocal bases; returns 0 on success, possibly a non-zero if b1 and b2 are parallel
int l2d_reciprocalBasis1(cart2_t b1, cart2_t b2, cart2_t *rb1, cart2_t *rb2);
int l2d_reciprocalBasis2pi(cart2_t b1, cart2_t b2, cart2_t *rb1, cart2_t *rb2);
double l2d_unitcell_area(cart2_t b1, cart2_t b2);
// returns the radius of inscribed circle of a hexagon (or rectangle/square if applicable) created by the shortest base triple
double l2d_hexWebInCircleRadius(cart2_t b1, cart2_t b2);
/*
* THE MORE OR LESS OK PART
* ========================
*/
/*
* General set of points ordered by the r-coordinate.
* Typically, this will include all lattice inside a certain circle.
* This structure is internally used by the "lattice generators" below.
* It does not have its memory management of its own, as it is handled
* by the "generators". For everything except the generators,
* this structure shall be read-only.
*/
typedef struct {
size_t nrs; // number of different radii
double *rs; // the radii; of length nrs (largest contained radius == rs[nrs-1])
point2d *base;
ptrdiff_t *r_offsets; // of length nrs+1 (using relative offsets due to possible realloc's)
// the jth point of i-th radius is base[r_offsets[i]+j] or using the inline below..
/* // redundand (therefore removed) members
* point2d *points; // redundant as it is the same as points_at_r[0]
* size_t npoints; // redundant as it is the same as points_at_r[nrs]-points_at_r[0]
*/
} points2d_rordered_t;
// sorts arbitrary points and creates points2d_rordered_t
points2d_rordered_t *points2d_rordered_frompoints(const point2d *orig_base,
size_t nmemb, double rtol, double atol);
// returns a copy but shifted by a constant (actually in a stupid way, but whatever)
points2d_rordered_t *points2d_rordered_shift(const points2d_rordered_t *orig,
point2d shift, double rtol, double atol);
// returns a copy but scaled by a factor
points2d_rordered_t *points2d_rordered_scale(const points2d_rordered_t *orig,
double factor);
/* The destructor: use only for results of
* - points2D_rordered_frompoints,
* - points2d_rordered_shift,
* - points2d_rordered_scale.
*/
void points2d_rordered_free(points2d_rordered_t *);
static inline point2d points2d_rordered_get_point(const points2d_rordered_t *ps, int r_order, int i) {
assert(i >= 0);
assert(r_order < ps->nrs);
assert(i < (ps->r_offsets[r_order+1] - ps->r_offsets[r_order]));
return ps->base[ps->r_offsets[r_order] + i];
}
static inline double points2d_rordered_get_r(const points2d_rordered_t *ps, int r_order) {
assert(r_order < ps->nrs);
return ps->rs[r_order];
}
ptrdiff_t points2d_rordered_locate_r(const points2d_rordered_t *, double r);
// returns a "view" (does not copy any of the arrays)
// -- DO NOT FREE orig BEFORE THE END OF SCOPE OF THE RESULT
points2d_rordered_t points2d_rordered_annulus(const points2d_rordered_t *orig, double minr, bool minr_inc,
double maxr, bool maxr_inc);
#if 0
/// Gives the frequency of \a n-th empty lattice mode at a given wave vector \a k.
double qpms_emptylattice2_mode_nth(
cart2_t b1_rec, ///< First reciprocal lattice base vector
cart2_t b2_rec, ///< Second reciprocal lattice base vector
double rtol, ///< Relative tolerance to detect right angles
cart2_t k, ///< The wave vector
double wave_speed, ///< Wave speed in a given medium (i.e. vacuum speed / refractive index).
size_t N ///< Index of the mode (note that degenerate modes are counted multiple times).
);
/// Gives the first `maxindex` frequencies of empty lattice modes at a given wave vector \a k.
void qpms_emptylattice2_modes_maxindex(
double target_freqs[], ///< Target array of size maxindex.
cart2_t b1_rec, ///< First reciprocal lattice base vector
cart2_t b2_rec, ///< Second reciprocal lattice base vector
double rtol, ///< Relative tolerance to detect right angles
cart2_t k, ///< The wave vector
double wave_speed, ///< Wave speed in a given medium (i.e. vacuum speed / refractive index).
size_t maxindex ///< Number of the frequencies generated.
);
#endif
/// Gives the frequencies of empty lattice modes at a given wave vector \a k up to \a maxfreq and one more.
/**
* The frequencies are saved to a newly allocated array *target_freqs (to be deallocated
* using free() by the caller).
*
* \returns Number of found mode frequencies lower or equal than \a maxfreq plus one.
*/
size_t qpms_emptylattice2_modes_maxfreq(
double **target_freqs,
cart2_t b1_rec, ///< First reciprocal lattice base vector
cart2_t b2_rec, ///< Second reciprocal lattice base vector
double rtol, ///< Relative tolerance to detect right angles
cart2_t k, ///< The wave vector
double wave_speed, ///< Wave speed in a given medium (i.e. vacuum speed / refractive index).
double maxfreq ///< The maximum frequency.
);
/// Gives the frequencies of two empty lattice modes nearest to \a omega at a given wave vector \a k.
void qpms_emptylattice2_modes_nearest(
double target[2], ///< Target array with lower ([0]) and upper ([1]) frequency.
cart2_t b1_rec, ///< First reciprocal lattice base vector
cart2_t b2_rec, ///< Second reciprocal lattice base vector
double rtol, ///< Relative tolerance to detect right angles
cart2_t k, ///< The wave vector
double wave_speed, ///< Wave speed in a given medium (i.e. vacuum speed / refractive index).
double omega ///< The frequency around which the frequencies are searched.
);
/*
* THE UGLY PART
* =============
*/
/*
* EQUILATERAL TRIANGULAR LATTICE
*/
typedef enum {
TRIANGULAR_VERTICAL, // there is a lattice base vector parallel to the y-axis
TRIANGULAR_HORIZONTAL // there is a lattice base vector parallel to the x-axis
} TriangularLatticeOrientation;
static inline TriangularLatticeOrientation reverseTriangularLatticeOrientation(TriangularLatticeOrientation o){
switch(o) {
case TRIANGULAR_VERTICAL:
return TRIANGULAR_HORIZONTAL;
break;
case TRIANGULAR_HORIZONTAL:
return TRIANGULAR_VERTICAL;
break;
default:
abort();
}
abort();
}
// implementation data structures; not needed in the header file
typedef struct triangular_lattice_gen_privstuff_t triangular_lattice_gen_privstuff_t;
typedef struct {
// public:
points2d_rordered_t ps;
TriangularLatticeOrientation orientation;
double a; // lattice vector length
// not sure if needed:
bool includes_origin;
// Denotes an offset of the "origin" point; meaning step hexshift * a / sqrt(2) upwards
// or leftwards for the horizontal or vertical orientations, respectively.
int hexshift;
// private:
triangular_lattice_gen_privstuff_t *priv;
} triangular_lattice_gen_t;
triangular_lattice_gen_t *triangular_lattice_gen_init(double a, TriangularLatticeOrientation ori, bool include_origin,
int halfoffset);
const points2d_rordered_t * triangular_lattice_gen_getpoints(const triangular_lattice_gen_t *g);
int triangular_lattice_gen_extend_to_r(triangular_lattice_gen_t *g, double r);
int triangular_lattice_gen_extend_to_steps(triangular_lattice_gen_t *g, int maxsteps);
void triangular_lattice_gen_free(triangular_lattice_gen_t *g);
/*
* HONEYCOMB LATTICE
*/
typedef struct {
// public:
points2d_rordered_t ps;
TriangularLatticeOrientation orientation;
double a;
double h;
// private:
triangular_lattice_gen_t *tg;
} honeycomb_lattice_gen_t;
honeycomb_lattice_gen_t *honeycomb_lattice_gen_init_h(double h, TriangularLatticeOrientation ori);
honeycomb_lattice_gen_t *honeycomb_lattice_gen_init_a(double a, TriangularLatticeOrientation ori);
int honeycomb_lattice_gen_extend_to_steps(honeycomb_lattice_gen_t *g, int maxsteps);
int honeycomb_lattice_gen_extend_to_r(honeycomb_lattice_gen_t *g, double r);
void honeycomb_lattice_gen_free(honeycomb_lattice_gen_t *g);
#endif // LATTICES_H