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Shifted triangular lattices 

Former-commit-id: 5d37f291890930d0b3ed6cbcec16ec6eba6077c6
This commit is contained in:
Marek Nečada 2018-08-25 01:13:27 +03:00
parent 74dc487732
commit 91523005fb
2 changed files with 68 additions and 15 deletions
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10
qpms/lattices.h
View File

@ -6,6 +6,7 @@
#include <stddef.h>
#define M_SQRT3 1.7320508075688772935274463415058724
#define M_SQRT3_2 (M_SQRT3/2)
#define M_1_SQRT3 0.57735026918962576450914878050195746
// fuck, I already had had suitable type
@ -73,16 +74,21 @@ typedef struct {
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);
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);

73
qpms/lattices2d.c
View File

@ -132,6 +132,16 @@ static inline int trilat_r2_coord(const intcoord2_t c) {
return trilat_r2_ij(c.i, c.j);
}
// version with offset (n.b. this is includes a factor of 3)
static inline int trilat_3r2_ijs(const int i, const int j, const int s) {
return 3*(sqi(i) + sqi(j) + i*j + j*s) + sqi(s);
}
static inline int trilat_3r2_coord_s(const intcoord2_t c, const int s) {
return trilat_3r2_ijs(c.i, c.j, s);
}
// Classify points into sextants (variant [a] above)
static int trilat_sextant_ij_a(const int i, const int j) {
@ -282,20 +292,50 @@ static int trilatgen_ensure_ps_points_capacity(triangular_lattice_gen_t *g, int
}
static int trilat_cmp_intcoord2_by_r2(const void *p1, const void *p2) {
// CHECK the sign is right
return trilat_r2_coord(*(const intcoord2_t *)p1) - trilat_r2_coord(*(const intcoord2_t *)p2);
}
static int trilat_cmp_intcoord2_by_3r2_plus1s(const void *p1, const void *p2) {
return trilat_3r2_coord_s(*(const intcoord2_t *)p1, +1) - trilat_3r2_coord_s(*(const intcoord2_t *)p2, +1);
}
static int trilat_cmp_intcoord2_by_3r2_minus1s(const void *p1, const void *p2) {
return trilat_3r2_coord_s(*(const intcoord2_t *)p1, -1) - trilat_3r2_coord_s(*(const intcoord2_t *)p2, -1);
}
static int trilat_cmp_intcoord2_by_3r2(const void *p1, const void *p2, void *sarg) {
return trilat_3r2_coord_s(*(const intcoord2_t *)p1, *(int *)sarg) - trilat_3r2_coord_s(*(const intcoord2_t *)p2, *(int *)sarg);
}
static void trilatgen_sort_pointlist(triangular_lattice_gen_t *g) {
trilatgen_pointlist_linearise(g);
triangular_lattice_gen_privstuff_t *p = g->priv;
qsort(p->pointlist_base + p->pointlist_beg, p->pointlist_n, sizeof(intcoord2_t), trilat_cmp_intcoord2_by_r2);
int (*compar)(const void *, const void *);
switch (g->hexshift) {
case 0:
compar = trilat_cmp_intcoord2_by_r2;
break;
case -1:
compar = trilat_cmp_intcoord2_by_3r2_minus1s;
break;
case 1:
compar = trilat_cmp_intcoord2_by_3r2_plus1s;
break;
default:
abort();
}
qsort(p->pointlist_base + p->pointlist_beg, p->pointlist_n, sizeof(intcoord2_t), compar);
}
triangular_lattice_gen_t * triangular_lattice_gen_init(double a, TriangularLatticeOrientation ori, bool include_origin)
triangular_lattice_gen_t * triangular_lattice_gen_init(double a, TriangularLatticeOrientation ori, bool include_origin,
int hexshift)
{
triangular_lattice_gen_t *g = malloc(sizeof(triangular_lattice_gen_t));
g->a = a;
g->hexshift = ((hexshift % 3)+3)%3; // reduce to the set {-1, 0, 1}
if (2 == g->hexshift)
g->hexshift = -1;
g->orientation = ori;
g->includes_origin = include_origin;
g->ps.nrs = 0;
@ -332,11 +372,14 @@ int triangular_lattice_gen_extend_to_steps(triangular_lattice_gen_t * g, int max
return 0;
// TODO FIXME: check for maximum possible maxsteps (not sure what it is)
int err;
err = trilatgen_ensure_pointlist_capacity(g, maxsteps);
err = trilatgen_ensure_pointlist_capacity(g, maxsteps
+ abs(g->hexshift) /*FIXME this is quite brainless addition, probably not even needed.*/);
if(err) return err;
err = trilatgen_ensure_ps_rs_capacity(g, maxsteps);
err = trilatgen_ensure_ps_rs_capacity(g, maxsteps
+ abs(g->hexshift) /*FIXME this is quite brainless addition, probably not even needed.*/);
if(err) return err;
err = trilatgen_ensure_ps_points_capacity(g, maxsteps);
err = trilatgen_ensure_ps_points_capacity(g, maxsteps
+ abs(g->hexshift) /*FIXME this is quite brainless addition, probably not even needed.*/);
if(err) return err;
if(g->includes_origin && g->priv->maxs < 0) // Add origin if not there yet
@ -361,27 +404,31 @@ int triangular_lattice_gen_extend_to_steps(triangular_lattice_gen_t * g, int max
//ted je potřeba vytahat potřebný počet bodů z fronty a naflákat je do ps.
// FIXME pohlídat si kapacitu datových typů
int maxr2i = sqi(maxsteps) * 3 / 4;
//int maxr2i = sqi(maxsteps) * 3 / 4;
int maxr2i3 = sqi(maxsteps) * 9 / 4 + sqi(g->hexshift) - abs(3*maxsteps*g->hexshift);
while (g->priv->pointlist_n > 0) { // This condition should probably be always true anyways.
intcoord2_t coord = trilatgen_pointlist_first(g);
int r2i_cur = trilat_r2_coord(coord);
if(r2i_cur > maxr2i)
//int r2i_cur = trilat_r2_coord(coord);
//if(r2i_cur > maxr2i)
int r2i3_cur = trilat_3r2_coord_s(coord, g->hexshift);
if(r2i3_cur > maxr2i3)
break;
g->ps.rs[g->ps.nrs] = sqrt(r2i_cur) * g->a;
g->ps.rs[g->ps.nrs] = sqrt(/*r2i_cur*/ r2i3_cur/3.) * g->a;
g->ps.r_offsets[g->ps.nrs+1] = g->ps.r_offsets[g->ps.nrs]; // the difference is the number of points on the circle
while(1) {
coord = trilatgen_pointlist_first(g);
if(r2i_cur != trilat_r2_coord(coord))
//if(r2i_cur != trilat_r2_coord(coord))
if (r2i3_cur != trilat_3r2_coord_s(coord, g->hexshift))
break;
else {
trilatgen_pointlist_deletefirst(g);
point2d thepoint;
switch (g->orientation) {
case TRIANGULAR_HORIZONTAL:
thepoint = point2d_fromxy((coord.i+.5*coord.j)*g->a, (M_SQRT3_2*coord.j)*g->a);
thepoint = point2d_fromxy((coord.i+.5*coord.j)*g->a, (M_SQRT3_2*coord.j + g->hexshift*M_1_SQRT3)*g->a);
break;
case TRIANGULAR_VERTICAL:
thepoint = point2d_fromxy((-M_SQRT3_2*coord.j)*g->a, (coord.i+.5*coord.j)*g->a);
thepoint = point2d_fromxy(-(M_SQRT3_2*coord.j + g->hexshift*M_1_SQRT3)*g->a, (coord.i+.5*coord.j)*g->a);
break;
default:
abort();