1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
|
/*
This file is part of ``kdtree'', a library for working with kd-trees.
Copyright (C) 2007-2011 John Tsiombikas <nuclear@member.fsf.org>
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
OF SUCH DAMAGE.
*/
/* single nearest neighbor search written by Tamas Nepusz <tamas@cs.rhul.ac.uk> */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "kdtree.h"
#if defined(WIN32) || defined(__WIN32__)
#include <malloc.h>
#endif
#ifdef USE_LIST_NODE_ALLOCATOR
#ifndef NO_PTHREADS
#include <pthread.h>
#else
#ifndef I_WANT_THREAD_BUGS
#error "You are compiling with the fast list node allocator, with pthreads disabled! This WILL break if used from multiple threads."
#endif /* I want thread bugs */
#endif /* pthread support */
#endif /* use list node allocator */
struct kdhyperrect {
int dim;
double *min, *max; /* minimum/maximum coords */
};
struct kdnode {
double *pos;
int dir;
void *data;
struct kdnode *left, *right; /* negative/positive side */
};
struct res_node {
struct kdnode *item;
double dist_sq;
struct res_node *next;
};
struct kdtree {
int dim;
struct kdnode *root;
struct kdhyperrect *rect;
void (*destr)(void*);
};
struct kdres {
struct kdtree *tree;
struct res_node *rlist, *riter;
int size;
};
#define SQ(x) ((x) * (x))
static void clear_rec(struct kdnode *node, void (*destr)(void*));
static int insert_rec(struct kdnode **node, const double *pos, void *data, int dir, int dim);
static int rlist_insert(struct res_node *list, struct kdnode *item, double dist_sq);
static void clear_results(struct kdres *set);
static struct kdhyperrect* hyperrect_create(int dim, const double *min, const double *max);
static void hyperrect_free(struct kdhyperrect *rect);
static struct kdhyperrect* hyperrect_duplicate(const struct kdhyperrect *rect);
static void hyperrect_extend(struct kdhyperrect *rect, const double *pos);
static double hyperrect_dist_sq(struct kdhyperrect *rect, const double *pos);
#ifdef USE_LIST_NODE_ALLOCATOR
static struct res_node *alloc_resnode(void);
static void free_resnode(struct res_node*);
#else
#define alloc_resnode() malloc(sizeof(struct res_node))
#define free_resnode(n) free(n)
#endif
struct kdtree *kd_create(int k)
{
struct kdtree *tree;
if(!(tree = malloc(sizeof *tree))) {
return 0;
}
tree->dim = k;
tree->root = 0;
tree->destr = 0;
tree->rect = 0;
return tree;
}
void kd_free(struct kdtree *tree)
{
if(tree) {
kd_clear(tree);
free(tree);
}
}
static void clear_rec(struct kdnode *node, void (*destr)(void*))
{
if(!node) return;
clear_rec(node->left, destr);
clear_rec(node->right, destr);
if(destr) {
destr(node->data);
}
free(node->pos);
free(node);
}
void kd_clear(struct kdtree *tree)
{
clear_rec(tree->root, tree->destr);
tree->root = 0;
if (tree->rect) {
hyperrect_free(tree->rect);
tree->rect = 0;
}
}
void kd_data_destructor(struct kdtree *tree, void (*destr)(void*))
{
tree->destr = destr;
}
static int insert_rec(struct kdnode **nptr, const double *pos, void *data, int dir, int dim)
{
int new_dir;
struct kdnode *node;
if(!*nptr) {
if(!(node = malloc(sizeof *node))) {
return -1;
}
if(!(node->pos = malloc(dim * sizeof *node->pos))) {
free(node);
return -1;
}
memcpy(node->pos, pos, dim * sizeof *node->pos);
node->data = data;
node->dir = dir;
node->left = node->right = 0;
*nptr = node;
return 0;
}
node = *nptr;
new_dir = (node->dir + 1) % dim;
if(pos[node->dir] < node->pos[node->dir]) {
return insert_rec(&(*nptr)->left, pos, data, new_dir, dim);
}
return insert_rec(&(*nptr)->right, pos, data, new_dir, dim);
}
int kd_insert(struct kdtree *tree, const double *pos, void *data)
{
if (insert_rec(&tree->root, pos, data, 0, tree->dim)) {
return -1;
}
if (tree->rect == 0) {
tree->rect = hyperrect_create(tree->dim, pos, pos);
} else {
hyperrect_extend(tree->rect, pos);
}
return 0;
}
int kd_insertf(struct kdtree *tree, const float *pos, void *data)
{
static double sbuf[16];
double *bptr, *buf = 0;
int res, dim = tree->dim;
if(dim > 16) {
#ifndef NO_ALLOCA
if(dim <= 256)
bptr = buf = alloca(dim * sizeof *bptr);
else
#endif
if(!(bptr = buf = malloc(dim * sizeof *bptr))) {
return -1;
}
} else {
bptr = buf = sbuf;
}
while(dim-- > 0) {
*bptr++ = *pos++;
}
res = kd_insert(tree, buf, data);
#ifndef NO_ALLOCA
if(tree->dim > 256)
#else
if(tree->dim > 16)
#endif
free(buf);
return res;
}
int kd_insert3(struct kdtree *tree, double x, double y, double z, void *data)
{
double buf[3];
buf[0] = x;
buf[1] = y;
buf[2] = z;
return kd_insert(tree, buf, data);
}
int kd_insert3f(struct kdtree *tree, float x, float y, float z, void *data)
{
double buf[3];
buf[0] = x;
buf[1] = y;
buf[2] = z;
return kd_insert(tree, buf, data);
}
static int find_nearest(struct kdnode *node, const double *pos, double range, struct res_node *list, int ordered, int dim)
{
double dist_sq, dx;
int i, ret, added_res = 0;
if(!node) return 0;
dist_sq = 0;
for(i=0; i<dim; i++) {
dist_sq += SQ(node->pos[i] - pos[i]);
}
if(dist_sq <= SQ(range)) {
if(rlist_insert(list, node, ordered ? dist_sq : -1.0) == -1) {
return -1;
}
added_res = 1;
}
dx = pos[node->dir] - node->pos[node->dir];
ret = find_nearest(dx <= 0.0 ? node->left : node->right, pos, range, list, ordered, dim);
if(ret >= 0 && fabs(dx) < range) {
added_res += ret;
ret = find_nearest(dx <= 0.0 ? node->right : node->left, pos, range, list, ordered, dim);
}
if(ret == -1) {
return -1;
}
added_res += ret;
return added_res;
}
#if 0
static int find_nearest_n(struct kdnode *node, const double *pos, double range, int num, struct rheap *heap, int dim)
{
double dist_sq, dx;
int i, ret, added_res = 0;
if(!node) return 0;
/* if the photon is close enough, add it to the result heap */
dist_sq = 0;
for(i=0; i<dim; i++) {
dist_sq += SQ(node->pos[i] - pos[i]);
}
if(dist_sq <= range_sq) {
if(heap->size >= num) {
/* get furthest element */
struct res_node *maxelem = rheap_get_max(heap);
/* and check if the new one is closer than that */
if(maxelem->dist_sq > dist_sq) {
rheap_remove_max(heap);
if(rheap_insert(heap, node, dist_sq) == -1) {
return -1;
}
added_res = 1;
range_sq = dist_sq;
}
} else {
if(rheap_insert(heap, node, dist_sq) == -1) {
return =1;
}
added_res = 1;
}
}
/* find signed distance from the splitting plane */
dx = pos[node->dir] - node->pos[node->dir];
ret = find_nearest_n(dx <= 0.0 ? node->left : node->right, pos, range, num, heap, dim);
if(ret >= 0 && fabs(dx) < range) {
added_res += ret;
ret = find_nearest_n(dx <= 0.0 ? node->right : node->left, pos, range, num, heap, dim);
}
}
#endif
static void kd_nearest_i(struct kdnode *node, const double *pos, struct kdnode **result, double *result_dist_sq, struct kdhyperrect* rect)
{
int dir = node->dir;
int i;
double dummy, dist_sq;
struct kdnode *nearer_subtree, *farther_subtree;
double *nearer_hyperrect_coord, *farther_hyperrect_coord;
/* Decide whether to go left or right in the tree */
dummy = pos[dir] - node->pos[dir];
if (dummy <= 0) {
nearer_subtree = node->left;
farther_subtree = node->right;
nearer_hyperrect_coord = rect->max + dir;
farther_hyperrect_coord = rect->min + dir;
} else {
nearer_subtree = node->right;
farther_subtree = node->left;
nearer_hyperrect_coord = rect->min + dir;
farther_hyperrect_coord = rect->max + dir;
}
if (nearer_subtree) {
/* Slice the hyperrect to get the hyperrect of the nearer subtree */
dummy = *nearer_hyperrect_coord;
*nearer_hyperrect_coord = node->pos[dir];
/* Recurse down into nearer subtree */
kd_nearest_i(nearer_subtree, pos, result, result_dist_sq, rect);
/* Undo the slice */
*nearer_hyperrect_coord = dummy;
}
/* Check the distance of the point at the current node, compare it
* with our best so far */
dist_sq = 0;
for(i=0; i < rect->dim; i++) {
dist_sq += SQ(node->pos[i] - pos[i]);
}
if (dist_sq < *result_dist_sq) {
*result = node;
*result_dist_sq = dist_sq;
}
if (farther_subtree) {
/* Get the hyperrect of the farther subtree */
dummy = *farther_hyperrect_coord;
*farther_hyperrect_coord = node->pos[dir];
/* Check if we have to recurse down by calculating the closest
* point of the hyperrect and see if it's closer than our
* minimum distance in result_dist_sq. */
if (hyperrect_dist_sq(rect, pos) < *result_dist_sq) {
/* Recurse down into farther subtree */
kd_nearest_i(farther_subtree, pos, result, result_dist_sq, rect);
}
/* Undo the slice on the hyperrect */
*farther_hyperrect_coord = dummy;
}
}
struct kdres *kd_nearest(struct kdtree *kd, const double *pos)
{
struct kdhyperrect *rect;
struct kdnode *result;
struct kdres *rset;
double dist_sq;
int i;
if (!kd) return 0;
if (!kd->rect) return 0;
/* Allocate result set */
if(!(rset = malloc(sizeof *rset))) {
return 0;
}
if(!(rset->rlist = alloc_resnode())) {
free(rset);
return 0;
}
rset->rlist->next = 0;
rset->tree = kd;
/* Duplicate the bounding hyperrectangle, we will work on the copy */
if (!(rect = hyperrect_duplicate(kd->rect))) {
kd_res_free(rset);
return 0;
}
/* Our first guesstimate is the root node */
result = kd->root;
dist_sq = 0;
for (i = 0; i < kd->dim; i++)
dist_sq += SQ(result->pos[i] - pos[i]);
/* Search for the nearest neighbour recursively */
kd_nearest_i(kd->root, pos, &result, &dist_sq, rect);
/* Free the copy of the hyperrect */
hyperrect_free(rect);
/* Store the result */
if (result) {
if (rlist_insert(rset->rlist, result, -1.0) == -1) {
kd_res_free(rset);
return 0;
}
rset->size = 1;
kd_res_rewind(rset);
return rset;
} else {
kd_res_free(rset);
return 0;
}
}
struct kdres *kd_nearestf(struct kdtree *tree, const float *pos)
{
static double sbuf[16];
double *bptr, *buf = 0;
int dim = tree->dim;
struct kdres *res;
if(dim > 16) {
#ifndef NO_ALLOCA
if(dim <= 256)
bptr = buf = alloca(dim * sizeof *bptr);
else
#endif
if(!(bptr = buf = malloc(dim * sizeof *bptr))) {
return 0;
}
} else {
bptr = buf = sbuf;
}
while(dim-- > 0) {
*bptr++ = *pos++;
}
res = kd_nearest(tree, buf);
#ifndef NO_ALLOCA
if(tree->dim > 256)
#else
if(tree->dim > 16)
#endif
free(buf);
return res;
}
struct kdres *kd_nearest3(struct kdtree *tree, double x, double y, double z)
{
double pos[3];
pos[0] = x;
pos[1] = y;
pos[2] = z;
return kd_nearest(tree, pos);
}
struct kdres *kd_nearest3f(struct kdtree *tree, float x, float y, float z)
{
double pos[3];
pos[0] = x;
pos[1] = y;
pos[2] = z;
return kd_nearest(tree, pos);
}
/* ---- nearest N search ---- */
/*
static kdres *kd_nearest_n(struct kdtree *kd, const double *pos, int num)
{
int ret;
struct kdres *rset;
if(!(rset = malloc(sizeof *rset))) {
return 0;
}
if(!(rset->rlist = alloc_resnode())) {
free(rset);
return 0;
}
rset->rlist->next = 0;
rset->tree = kd;
if((ret = find_nearest_n(kd->root, pos, range, num, rset->rlist, kd->dim)) == -1) {
kd_res_free(rset);
return 0;
}
rset->size = ret;
kd_res_rewind(rset);
return rset;
}*/
struct kdres *kd_nearest_range(struct kdtree *kd, const double *pos, double range)
{
int ret;
struct kdres *rset;
if(!(rset = malloc(sizeof *rset))) {
return 0;
}
if(!(rset->rlist = alloc_resnode())) {
free(rset);
return 0;
}
rset->rlist->next = 0;
rset->tree = kd;
if((ret = find_nearest(kd->root, pos, range, rset->rlist, 0, kd->dim)) == -1) {
kd_res_free(rset);
return 0;
}
rset->size = ret;
kd_res_rewind(rset);
return rset;
}
struct kdres *kd_nearest_rangef(struct kdtree *kd, const float *pos, float range)
{
static double sbuf[16];
double *bptr, *buf = 0;
int dim = kd->dim;
struct kdres *res;
if(dim > 16) {
#ifndef NO_ALLOCA
if(dim <= 256)
bptr = buf = alloca(dim * sizeof *bptr);
else
#endif
if(!(bptr = buf = malloc(dim * sizeof *bptr))) {
return 0;
}
} else {
bptr = buf = sbuf;
}
while(dim-- > 0) {
*bptr++ = *pos++;
}
res = kd_nearest_range(kd, buf, range);
#ifndef NO_ALLOCA
if(kd->dim > 256)
#else
if(kd->dim > 16)
#endif
free(buf);
return res;
}
struct kdres *kd_nearest_range3(struct kdtree *tree, double x, double y, double z, double range)
{
double buf[3];
buf[0] = x;
buf[1] = y;
buf[2] = z;
return kd_nearest_range(tree, buf, range);
}
struct kdres *kd_nearest_range3f(struct kdtree *tree, float x, float y, float z, float range)
{
double buf[3];
buf[0] = x;
buf[1] = y;
buf[2] = z;
return kd_nearest_range(tree, buf, range);
}
void kd_res_free(struct kdres *rset)
{
clear_results(rset);
free_resnode(rset->rlist);
free(rset);
}
int kd_res_size(struct kdres *set)
{
return (set->size);
}
void kd_res_rewind(struct kdres *rset)
{
rset->riter = rset->rlist->next;
}
int kd_res_end(struct kdres *rset)
{
return rset->riter == 0;
}
int kd_res_next(struct kdres *rset)
{
rset->riter = rset->riter->next;
return rset->riter != 0;
}
void *kd_res_item(struct kdres *rset, double *pos)
{
if(rset->riter) {
if(pos) {
memcpy(pos, rset->riter->item->pos, rset->tree->dim * sizeof *pos);
}
return rset->riter->item->data;
}
return 0;
}
void *kd_res_itemf(struct kdres *rset, float *pos)
{
if(rset->riter) {
if(pos) {
int i;
for(i=0; i<rset->tree->dim; i++) {
pos[i] = rset->riter->item->pos[i];
}
}
return rset->riter->item->data;
}
return 0;
}
void *kd_res_item3(struct kdres *rset, double *x, double *y, double *z)
{
if(rset->riter) {
if(*x) *x = rset->riter->item->pos[0];
if(*y) *y = rset->riter->item->pos[1];
if(*z) *z = rset->riter->item->pos[2];
}
return 0;
}
void *kd_res_item3f(struct kdres *rset, float *x, float *y, float *z)
{
if(rset->riter) {
if(*x) *x = rset->riter->item->pos[0];
if(*y) *y = rset->riter->item->pos[1];
if(*z) *z = rset->riter->item->pos[2];
}
return 0;
}
void *kd_res_item_data(struct kdres *set)
{
return kd_res_item(set, 0);
}
/* ---- hyperrectangle helpers ---- */
static struct kdhyperrect* hyperrect_create(int dim, const double *min, const double *max)
{
size_t size = dim * sizeof(double);
struct kdhyperrect* rect = 0;
if (!(rect = malloc(sizeof(struct kdhyperrect)))) {
return 0;
}
rect->dim = dim;
if (!(rect->min = malloc(size))) {
free(rect);
return 0;
}
if (!(rect->max = malloc(size))) {
free(rect->min);
free(rect);
return 0;
}
memcpy(rect->min, min, size);
memcpy(rect->max, max, size);
return rect;
}
static void hyperrect_free(struct kdhyperrect *rect)
{
free(rect->min);
free(rect->max);
free(rect);
}
static struct kdhyperrect* hyperrect_duplicate(const struct kdhyperrect *rect)
{
return hyperrect_create(rect->dim, rect->min, rect->max);
}
static void hyperrect_extend(struct kdhyperrect *rect, const double *pos)
{
int i;
for (i=0; i < rect->dim; i++) {
if (pos[i] < rect->min[i]) {
rect->min[i] = pos[i];
}
if (pos[i] > rect->max[i]) {
rect->max[i] = pos[i];
}
}
}
static double hyperrect_dist_sq(struct kdhyperrect *rect, const double *pos)
{
int i;
double result = 0;
for (i=0; i < rect->dim; i++) {
if (pos[i] < rect->min[i]) {
result += SQ(rect->min[i] - pos[i]);
} else if (pos[i] > rect->max[i]) {
result += SQ(rect->max[i] - pos[i]);
}
}
return result;
}
/* ---- static helpers ---- */
#ifdef USE_LIST_NODE_ALLOCATOR
/* special list node allocators. */
static struct res_node *free_nodes;
#ifndef NO_PTHREADS
static pthread_mutex_t alloc_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif
static struct res_node *alloc_resnode(void)
{
struct res_node *node;
#ifndef NO_PTHREADS
pthread_mutex_lock(&alloc_mutex);
#endif
if(!free_nodes) {
node = malloc(sizeof *node);
} else {
node = free_nodes;
free_nodes = free_nodes->next;
node->next = 0;
}
#ifndef NO_PTHREADS
pthread_mutex_unlock(&alloc_mutex);
#endif
return node;
}
static void free_resnode(struct res_node *node)
{
#ifndef NO_PTHREADS
pthread_mutex_lock(&alloc_mutex);
#endif
node->next = free_nodes;
free_nodes = node;
#ifndef NO_PTHREADS
pthread_mutex_unlock(&alloc_mutex);
#endif
}
#endif /* list node allocator or not */
/* inserts the item. if dist_sq is >= 0, then do an ordered insert */
/* TODO make the ordering code use heapsort */
static int rlist_insert(struct res_node *list, struct kdnode *item, double dist_sq)
{
struct res_node *rnode;
if(!(rnode = alloc_resnode())) {
return -1;
}
rnode->item = item;
rnode->dist_sq = dist_sq;
if(dist_sq >= 0.0) {
while(list->next && list->next->dist_sq < dist_sq) {
list = list->next;
}
}
rnode->next = list->next;
list->next = rnode;
return 0;
}
static void clear_results(struct kdres *rset)
{
struct res_node *tmp, *node = rset->rlist->next;
while(node) {
tmp = node;
node = node->next;
free_resnode(tmp);
}
rset->rlist->next = 0;
}
|