source: trunk/liblwgeom/ptarray.c

Last change on this file was 17821, checked in by Raul Marin, 5 years ago

Speed up ST_Simplify

Closes #4510
Closes ​https://github.com/postgis/postgis/pull/480
  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 47.2 KB
Line 
1/**********************************************************************
2 *
3 * PostGIS - Spatial Types for PostgreSQL
4 * http://postgis.net
5 *
6 * PostGIS is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * PostGIS is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with PostGIS. If not, see <http://www.gnu.org/licenses/>.
18 *
19 **********************************************************************
20 *
21 * Copyright (C) 2012 Sandro Santilli <strk@kbt.io>
22 * Copyright (C) 2001-2006 Refractions Research Inc.
23 *
24 **********************************************************************/
25
26
27#include <stdio.h>
28#include <string.h>
29#include <stdlib.h>
30
31#include "../postgis_config.h"
32/*#define POSTGIS_DEBUG_LEVEL 4*/
33#include "liblwgeom_internal.h"
34#include "lwgeom_log.h"
35
36int
37ptarray_has_z(const POINTARRAY *pa)
38{
39 if ( ! pa ) return LW_FALSE;
40 return FLAGS_GET_Z(pa->flags);
41}
42
43int
44ptarray_has_m(const POINTARRAY *pa)
45{
46 if ( ! pa ) return LW_FALSE;
47 return FLAGS_GET_M(pa->flags);
48}
49
50POINTARRAY*
51ptarray_construct(char hasz, char hasm, uint32_t npoints)
52{
53 POINTARRAY *pa = ptarray_construct_empty(hasz, hasm, npoints);
54 pa->npoints = npoints;
55 return pa;
56}
57
58POINTARRAY*
59ptarray_construct_empty(char hasz, char hasm, uint32_t maxpoints)
60{
61 POINTARRAY *pa = lwalloc(sizeof(POINTARRAY));
62 pa->serialized_pointlist = NULL;
63
64 /* Set our dimensionality info on the bitmap */
65 pa->flags = lwflags(hasz, hasm, 0);
66
67 /* We will be allocating a bit of room */
68 pa->npoints = 0;
69 pa->maxpoints = maxpoints;
70
71 /* Allocate the coordinate array */
72 if ( maxpoints > 0 )
73 pa->serialized_pointlist = lwalloc(maxpoints * ptarray_point_size(pa));
74 else
75 pa->serialized_pointlist = NULL;
76
77 return pa;
78}
79
80/*
81* Add a point into a pointarray. Only adds as many dimensions as the
82* pointarray supports.
83*/
84int
85ptarray_insert_point(POINTARRAY *pa, const POINT4D *p, uint32_t where)
86{
87 if (!pa || !p)
88 return LW_FAILURE;
89 size_t point_size = ptarray_point_size(pa);
90 LWDEBUGF(5,"pa = %p; p = %p; where = %d", pa, p, where);
91 LWDEBUGF(5,"pa->npoints = %d; pa->maxpoints = %d", pa->npoints, pa->maxpoints);
92
93 if ( FLAGS_GET_READONLY(pa->flags) )
94 {
95 lwerror("ptarray_insert_point: called on read-only point array");
96 return LW_FAILURE;
97 }
98
99 /* Error on invalid offset value */
100 if ( where > pa->npoints )
101 {
102 lwerror("ptarray_insert_point: offset out of range (%d)", where);
103 return LW_FAILURE;
104 }
105
106 /* If we have no storage, let's allocate some */
107 if( pa->maxpoints == 0 || ! pa->serialized_pointlist )
108 {
109 pa->maxpoints = 32;
110 pa->npoints = 0;
111 pa->serialized_pointlist = lwalloc(ptarray_point_size(pa) * pa->maxpoints);
112 }
113
114 /* Error out if we have a bad situation */
115 if ( pa->npoints > pa->maxpoints )
116 {
117 lwerror("npoints (%d) is greater than maxpoints (%d)", pa->npoints, pa->maxpoints);
118 return LW_FAILURE;
119 }
120
121 /* Check if we have enough storage, add more if necessary */
122 if( pa->npoints == pa->maxpoints )
123 {
124 pa->maxpoints *= 2;
125 pa->serialized_pointlist = lwrealloc(pa->serialized_pointlist, ptarray_point_size(pa) * pa->maxpoints);
126 }
127
128 /* Make space to insert the new point */
129 if( where < pa->npoints )
130 {
131 size_t copy_size = point_size * (pa->npoints - where);
132 memmove(getPoint_internal(pa, where+1), getPoint_internal(pa, where), copy_size);
133 LWDEBUGF(5,"copying %d bytes to start vertex %d from start vertex %d", copy_size, where+1, where);
134 }
135
136 /* We have one more point */
137 ++pa->npoints;
138
139 /* Copy the new point into the gap */
140 ptarray_set_point4d(pa, where, p);
141 LWDEBUGF(5,"copying new point to start vertex %d", point_size, where);
142
143 return LW_SUCCESS;
144}
145
146int
147ptarray_append_point(POINTARRAY *pa, const POINT4D *pt, int repeated_points)
148{
149 /* Check for pathology */
150 if( ! pa || ! pt )
151 {
152 lwerror("ptarray_append_point: null input");
153 return LW_FAILURE;
154 }
155
156 /* Check for duplicate end point */
157 if ( repeated_points == LW_FALSE && pa->npoints > 0 )
158 {
159 POINT4D tmp;
160 getPoint4d_p(pa, pa->npoints-1, &tmp);
161 LWDEBUGF(4,"checking for duplicate end point (pt = POINT(%g %g) pa->npoints-q = POINT(%g %g))",pt->x,pt->y,tmp.x,tmp.y);
162
163 /* Return LW_SUCCESS and do nothing else if previous point in list is equal to this one */
164 if ( (pt->x == tmp.x) && (pt->y == tmp.y) &&
165 (FLAGS_GET_Z(pa->flags) ? pt->z == tmp.z : 1) &&
166 (FLAGS_GET_M(pa->flags) ? pt->m == tmp.m : 1) )
167 {
168 return LW_SUCCESS;
169 }
170 }
171
172 /* Append is just a special case of insert */
173 return ptarray_insert_point(pa, pt, pa->npoints);
174}
175
176int
177ptarray_append_ptarray(POINTARRAY *pa1, POINTARRAY *pa2, double gap_tolerance)
178{
179 unsigned int poff = 0;
180 unsigned int npoints;
181 unsigned int ncap;
182 unsigned int ptsize;
183
184 /* Check for pathology */
185 if( ! pa1 || ! pa2 )
186 {
187 lwerror("ptarray_append_ptarray: null input");
188 return LW_FAILURE;
189 }
190
191 npoints = pa2->npoints;
192
193 if ( ! npoints ) return LW_SUCCESS; /* nothing more to do */
194
195 if( FLAGS_GET_READONLY(pa1->flags) )
196 {
197 lwerror("ptarray_append_ptarray: target pointarray is read-only");
198 return LW_FAILURE;
199 }
200
201 if( FLAGS_GET_ZM(pa1->flags) != FLAGS_GET_ZM(pa2->flags) )
202 {
203 lwerror("ptarray_append_ptarray: appending mixed dimensionality is not allowed");
204 return LW_FAILURE;
205 }
206
207 ptsize = ptarray_point_size(pa1);
208
209 /* Check for duplicate end point */
210 if ( pa1->npoints )
211 {
212 POINT2D tmp1, tmp2;
213 getPoint2d_p(pa1, pa1->npoints-1, &tmp1);
214 getPoint2d_p(pa2, 0, &tmp2);
215
216 /* If the end point and start point are the same, then don't copy start point */
217 if (p2d_same(&tmp1, &tmp2)) {
218 poff = 1;
219 --npoints;
220 }
221 else if ( gap_tolerance == 0 || ( gap_tolerance > 0 &&
222 distance2d_pt_pt(&tmp1, &tmp2) > gap_tolerance ) )
223 {
224 lwerror("Second line start point too far from first line end point");
225 return LW_FAILURE;
226 }
227 }
228
229 /* Check if we need extra space */
230 ncap = pa1->npoints + npoints;
231 if ( pa1->maxpoints < ncap )
232 {
233 pa1->maxpoints = ncap > pa1->maxpoints*2 ?
234 ncap : pa1->maxpoints*2;
235 pa1->serialized_pointlist = lwrealloc(pa1->serialized_pointlist, ptsize * pa1->maxpoints);
236 }
237
238 memcpy(getPoint_internal(pa1, pa1->npoints),
239 getPoint_internal(pa2, poff), ptsize * npoints);
240
241 pa1->npoints = ncap;
242
243 return LW_SUCCESS;
244}
245
246/*
247* Add a point into a pointarray. Only adds as many dimensions as the
248* pointarray supports.
249*/
250int
251ptarray_remove_point(POINTARRAY *pa, uint32_t where)
252{
253 /* Check for pathology */
254 if( ! pa )
255 {
256 lwerror("ptarray_remove_point: null input");
257 return LW_FAILURE;
258 }
259
260 /* Error on invalid offset value */
261 if ( where >= pa->npoints )
262 {
263 lwerror("ptarray_remove_point: offset out of range (%d)", where);
264 return LW_FAILURE;
265 }
266
267 /* If the point is any but the last, we need to copy the data back one point */
268 if (where < pa->npoints - 1)
269 memmove(getPoint_internal(pa, where),
270 getPoint_internal(pa, where + 1),
271 ptarray_point_size(pa) * (pa->npoints - where - 1));
272
273 /* We have one less point */
274 pa->npoints--;
275
276 return LW_SUCCESS;
277}
278
279/**
280* Build a new #POINTARRAY, but on top of someone else's ordinate array.
281* Flag as read-only, so that ptarray_free() does not free the serialized_ptlist
282*/
283POINTARRAY* ptarray_construct_reference_data(char hasz, char hasm, uint32_t npoints, uint8_t *ptlist)
284{
285 POINTARRAY *pa = lwalloc(sizeof(POINTARRAY));
286 LWDEBUGF(5, "hasz = %d, hasm = %d, npoints = %d, ptlist = %p", hasz, hasm, npoints, ptlist);
287 pa->flags = lwflags(hasz, hasm, 0);
288 FLAGS_SET_READONLY(pa->flags, 1); /* We don't own this memory, so we can't alter or free it. */
289 pa->npoints = npoints;
290 pa->maxpoints = npoints;
291 pa->serialized_pointlist = ptlist;
292 return pa;
293}
294
295
296POINTARRAY*
297ptarray_construct_copy_data(char hasz, char hasm, uint32_t npoints, const uint8_t *ptlist)
298{
299 POINTARRAY *pa = lwalloc(sizeof(POINTARRAY));
300
301 pa->flags = lwflags(hasz, hasm, 0);
302 pa->npoints = npoints;
303 pa->maxpoints = npoints;
304
305 if ( npoints > 0 )
306 {
307 pa->serialized_pointlist = lwalloc(ptarray_point_size(pa) * npoints);
308 memcpy(pa->serialized_pointlist, ptlist, ptarray_point_size(pa) * npoints);
309 }
310 else
311 {
312 pa->serialized_pointlist = NULL;
313 }
314
315 return pa;
316}
317
318void
319ptarray_free(POINTARRAY *pa)
320{
321 if (pa)
322 {
323 if (pa->serialized_pointlist && (!FLAGS_GET_READONLY(pa->flags)))
324 lwfree(pa->serialized_pointlist);
325 lwfree(pa);
326 }
327}
328
329
330void
331ptarray_reverse_in_place(POINTARRAY *pa)
332{
333 if (!pa->npoints)
334 return;
335 uint32_t i;
336 uint32_t last = pa->npoints - 1;
337 uint32_t mid = pa->npoints / 2;
338
339 double *d = (double*)(pa->serialized_pointlist);
340 int j;
341 int ndims = FLAGS_NDIMS(pa->flags);
342 for (i = 0; i < mid; i++)
343 {
344 for (j = 0; j < ndims; j++)
345 {
346 double buf;
347 buf = d[i*ndims+j];
348 d[i*ndims+j] = d[(last-i)*ndims+j];
349 d[(last-i)*ndims+j] = buf;
350 }
351 }
352 return;
353}
354
355
356/**
357 * Reverse X and Y axis on a given POINTARRAY
358 */
359POINTARRAY*
360ptarray_flip_coordinates(POINTARRAY *pa)
361{
362 uint32_t i;
363 double d;
364 POINT4D p;
365
366 for (i=0 ; i < pa->npoints ; i++)
367 {
368 getPoint4d_p(pa, i, &p);
369 d = p.y;
370 p.y = p.x;
371 p.x = d;
372 ptarray_set_point4d(pa, i, &p);
373 }
374
375 return pa;
376}
377
378void
379ptarray_swap_ordinates(POINTARRAY *pa, LWORD o1, LWORD o2)
380{
381 uint32_t i;
382 double d, *dp1, *dp2;
383 POINT4D p;
384
385 dp1 = ((double*)&p)+(unsigned)o1;
386 dp2 = ((double*)&p)+(unsigned)o2;
387 for (i=0 ; i < pa->npoints ; i++)
388 {
389 getPoint4d_p(pa, i, &p);
390 d = *dp2;
391 *dp2 = *dp1;
392 *dp1 = d;
393 ptarray_set_point4d(pa, i, &p);
394 }
395}
396
397/**
398 * @brief Returns a modified #POINTARRAY so that no segment is
399 * longer than the given distance (computed using 2d).
400 *
401 * Every input point is kept.
402 * Z and M values for added points (if needed) are set proportionally.
403 */
404POINTARRAY *
405ptarray_segmentize2d(const POINTARRAY *ipa, double dist)
406{
407 double segdist;
408 POINT4D p1, p2;
409 POINT4D pbuf;
410 POINTARRAY *opa;
411 uint32_t i, j, nseg;
412 int hasz = FLAGS_GET_Z(ipa->flags);
413 int hasm = FLAGS_GET_M(ipa->flags);
414
415 pbuf.x = pbuf.y = pbuf.z = pbuf.m = 0;
416
417 /* Initial storage */
418 opa = ptarray_construct_empty(hasz, hasm, ipa->npoints);
419
420 /* Add first point */
421 getPoint4d_p(ipa, 0, &p1);
422 ptarray_append_point(opa, &p1, LW_FALSE);
423
424 /* Loop on all other input points */
425 for (i = 1; i < ipa->npoints; i++)
426 {
427 /*
428 * We use these pointers to avoid
429 * "strict-aliasing rules break" warning raised
430 * by gcc (3.3 and up).
431 *
432 * It looks that casting a variable address (also
433 * referred to as "type-punned pointer")
434 * breaks those "strict" rules.
435 */
436 POINT4D *p1ptr=&p1, *p2ptr=&p2;
437 double segments;
438
439 getPoint4d_p(ipa, i, &p2);
440
441 segdist = distance2d_pt_pt((POINT2D *)p1ptr, (POINT2D *)p2ptr);
442 /* Split input segment into shorter even chunks */
443 segments = ceil(segdist / dist);
444
445 /* Uses INT32_MAX instead of UINT32_MAX to be safe that it fits */
446 if (segments >= INT32_MAX)
447 {
448 lwnotice("%s:%d - %s: Too many segments required (%e)",
449 __FILE__, __LINE__,__func__, segments);
450 ptarray_free(opa);
451 return NULL;
452 }
453 nseg = segments;
454
455 for (j = 1; j < nseg; j++)
456 {
457 pbuf.x = p1.x + (p2.x - p1.x) * j / nseg;
458 pbuf.y = p1.y + (p2.y - p1.y) * j / nseg;
459 if (hasz)
460 pbuf.z = p1.z + (p2.z - p1.z) * j / nseg;
461 if (hasm)
462 pbuf.m = p1.m + (p2.m - p1.m) * j / nseg;
463 ptarray_append_point(opa, &pbuf, LW_FALSE);
464 LW_ON_INTERRUPT(ptarray_free(opa); return NULL);
465 }
466
467 ptarray_append_point(opa, &p2, (ipa->npoints == 2) ? LW_TRUE : LW_FALSE);
468 p1 = p2;
469 LW_ON_INTERRUPT(ptarray_free(opa); return NULL);
470 }
471
472 return opa;
473}
474
475char
476ptarray_same(const POINTARRAY *pa1, const POINTARRAY *pa2)
477{
478 uint32_t i;
479 size_t ptsize;
480
481 if ( FLAGS_GET_ZM(pa1->flags) != FLAGS_GET_ZM(pa2->flags) ) return LW_FALSE;
482 LWDEBUG(5,"dimensions are the same");
483
484 if ( pa1->npoints != pa2->npoints ) return LW_FALSE;
485 LWDEBUG(5,"npoints are the same");
486
487 ptsize = ptarray_point_size(pa1);
488 LWDEBUGF(5, "ptsize = %d", ptsize);
489
490 for (i=0; i<pa1->npoints; i++)
491 {
492 if ( memcmp(getPoint_internal(pa1, i), getPoint_internal(pa2, i), ptsize) )
493 return LW_FALSE;
494 LWDEBUGF(5,"point #%d is the same",i);
495 }
496
497 return LW_TRUE;
498}
499
500POINTARRAY *
501ptarray_addPoint(const POINTARRAY *pa, uint8_t *p, size_t pdims, uint32_t where)
502{
503 POINTARRAY *ret;
504 POINT4D pbuf;
505 size_t ptsize = ptarray_point_size(pa);
506
507 LWDEBUGF(3, "pa %x p %x size %d where %d",
508 pa, p, pdims, where);
509
510 if ( pdims < 2 || pdims > 4 )
511 {
512 lwerror("ptarray_addPoint: point dimension out of range (%d)",
513 pdims);
514 return NULL;
515 }
516
517 if ( where > pa->npoints )
518 {
519 lwerror("ptarray_addPoint: offset out of range (%d)",
520 where);
521 return NULL;
522 }
523
524 LWDEBUG(3, "called with a %dD point");
525
526 pbuf.x = pbuf.y = pbuf.z = pbuf.m = 0.0;
527 memcpy((uint8_t *)&pbuf, p, pdims*sizeof(double));
528
529 LWDEBUG(3, "initialized point buffer");
530
531 ret = ptarray_construct(FLAGS_GET_Z(pa->flags),
532 FLAGS_GET_M(pa->flags), pa->npoints+1);
533
534
535 if ( where )
536 {
537 memcpy(getPoint_internal(ret, 0), getPoint_internal(pa, 0), ptsize*where);
538 }
539
540 memcpy(getPoint_internal(ret, where), (uint8_t *)&pbuf, ptsize);
541
542 if ( where+1 != ret->npoints )
543 {
544 memcpy(getPoint_internal(ret, where+1),
545 getPoint_internal(pa, where),
546 ptsize*(pa->npoints-where));
547 }
548
549 return ret;
550}
551
552POINTARRAY *
553ptarray_removePoint(POINTARRAY *pa, uint32_t which)
554{
555 POINTARRAY *ret;
556 size_t ptsize = ptarray_point_size(pa);
557
558 LWDEBUGF(3, "pa %x which %d", pa, which);
559
560#if PARANOIA_LEVEL > 0
561 if ( which > pa->npoints-1 )
562 {
563 lwerror("%s [%d] offset (%d) out of range (%d..%d)", __FILE__, __LINE__,
564 which, 0, pa->npoints-1);
565 return NULL;
566 }
567
568 if ( pa->npoints < 3 )
569 {
570 lwerror("%s [%d] can't remove a point from a 2-vertex POINTARRAY", __FILE__, __LINE__);
571 return NULL;
572 }
573#endif
574
575 ret = ptarray_construct(FLAGS_GET_Z(pa->flags),
576 FLAGS_GET_M(pa->flags), pa->npoints-1);
577
578 /* copy initial part */
579 if ( which )
580 {
581 memcpy(getPoint_internal(ret, 0), getPoint_internal(pa, 0), ptsize*which);
582 }
583
584 /* copy final part */
585 if ( which < pa->npoints-1 )
586 {
587 memcpy(getPoint_internal(ret, which), getPoint_internal(pa, which+1),
588 ptsize*(pa->npoints-which-1));
589 }
590
591 return ret;
592}
593
594POINTARRAY *
595ptarray_merge(POINTARRAY *pa1, POINTARRAY *pa2)
596{
597 POINTARRAY *pa;
598 size_t ptsize = ptarray_point_size(pa1);
599
600 if (FLAGS_GET_ZM(pa1->flags) != FLAGS_GET_ZM(pa2->flags))
601 lwerror("ptarray_cat: Mixed dimension");
602
603 pa = ptarray_construct( FLAGS_GET_Z(pa1->flags),
604 FLAGS_GET_M(pa1->flags),
605 pa1->npoints + pa2->npoints);
606
607 memcpy( getPoint_internal(pa, 0),
608 getPoint_internal(pa1, 0),
609 ptsize*(pa1->npoints));
610
611 memcpy( getPoint_internal(pa, pa1->npoints),
612 getPoint_internal(pa2, 0),
613 ptsize*(pa2->npoints));
614
615 ptarray_free(pa1);
616 ptarray_free(pa2);
617
618 return pa;
619}
620
621
622/**
623 * @brief Deep clone a pointarray (also clones serialized pointlist)
624 */
625POINTARRAY *
626ptarray_clone_deep(const POINTARRAY *in)
627{
628 POINTARRAY *out = lwalloc(sizeof(POINTARRAY));
629
630 LWDEBUG(3, "ptarray_clone_deep called.");
631
632 out->flags = in->flags;
633 out->npoints = in->npoints;
634 out->maxpoints = in->npoints;
635
636 FLAGS_SET_READONLY(out->flags, 0);
637
638 if (!in->npoints)
639 {
640 // Avoid calling lwalloc of 0 bytes
641 out->serialized_pointlist = NULL;
642 }
643 else
644 {
645 size_t size = in->npoints * ptarray_point_size(in);
646 out->serialized_pointlist = lwalloc(size);
647 memcpy(out->serialized_pointlist, in->serialized_pointlist, size);
648 }
649
650 return out;
651}
652
653/**
654 * @brief Clone a POINTARRAY object. Serialized pointlist is not copied.
655 */
656POINTARRAY *
657ptarray_clone(const POINTARRAY *in)
658{
659 POINTARRAY *out = lwalloc(sizeof(POINTARRAY));
660
661 LWDEBUG(3, "ptarray_clone called.");
662
663 out->flags = in->flags;
664 out->npoints = in->npoints;
665 out->maxpoints = in->maxpoints;
666
667 FLAGS_SET_READONLY(out->flags, 1);
668
669 out->serialized_pointlist = in->serialized_pointlist;
670
671 return out;
672}
673
674/**
675* Check for ring closure using whatever dimensionality is declared on the
676* pointarray.
677*/
678int
679ptarray_is_closed(const POINTARRAY *in)
680{
681 if (!in)
682 {
683 lwerror("ptarray_is_closed: called with null point array");
684 return 0;
685 }
686 if (in->npoints <= 1 ) return in->npoints; /* single-point are closed, empty not closed */
687
688 return 0 == memcmp(getPoint_internal(in, 0), getPoint_internal(in, in->npoints-1), ptarray_point_size(in));
689}
690
691
692int
693ptarray_is_closed_2d(const POINTARRAY *in)
694{
695 if (!in)
696 {
697 lwerror("ptarray_is_closed_2d: called with null point array");
698 return 0;
699 }
700 if (in->npoints <= 1 ) return in->npoints; /* single-point are closed, empty not closed */
701
702 return 0 == memcmp(getPoint_internal(in, 0), getPoint_internal(in, in->npoints-1), sizeof(POINT2D) );
703}
704
705int
706ptarray_is_closed_3d(const POINTARRAY *in)
707{
708 if (!in)
709 {
710 lwerror("ptarray_is_closed_3d: called with null point array");
711 return 0;
712 }
713 if (in->npoints <= 1 ) return in->npoints; /* single-point are closed, empty not closed */
714
715 return 0 == memcmp(getPoint_internal(in, 0), getPoint_internal(in, in->npoints-1), sizeof(POINT3D) );
716}
717
718int
719ptarray_is_closed_z(const POINTARRAY *in)
720{
721 if ( FLAGS_GET_Z(in->flags) )
722 return ptarray_is_closed_3d(in);
723 else
724 return ptarray_is_closed_2d(in);
725}
726
727/**
728* Return 1 if the point is inside the POINTARRAY, -1 if it is outside,
729* and 0 if it is on the boundary.
730*/
731int
732ptarray_contains_point(const POINTARRAY *pa, const POINT2D *pt)
733{
734 return ptarray_contains_point_partial(pa, pt, LW_TRUE, NULL);
735}
736
737int
738ptarray_contains_point_partial(const POINTARRAY *pa, const POINT2D *pt, int check_closed, int *winding_number)
739{
740 int wn = 0;
741 uint32_t i;
742 double side;
743 const POINT2D *seg1;
744 const POINT2D *seg2;
745 double ymin, ymax;
746
747 seg1 = getPoint2d_cp(pa, 0);
748 seg2 = getPoint2d_cp(pa, pa->npoints-1);
749 if ( check_closed && ! p2d_same(seg1, seg2) )
750 lwerror("ptarray_contains_point called on unclosed ring");
751
752 for ( i=1; i < pa->npoints; i++ )
753 {
754 seg2 = getPoint2d_cp(pa, i);
755
756 /* Zero length segments are ignored. */
757 if ( seg1->x == seg2->x && seg1->y == seg2->y )
758 {
759 seg1 = seg2;
760 continue;
761 }
762
763 ymin = FP_MIN(seg1->y, seg2->y);
764 ymax = FP_MAX(seg1->y, seg2->y);
765
766 /* Only test segments in our vertical range */
767 if ( pt->y > ymax || pt->y < ymin )
768 {
769 seg1 = seg2;
770 continue;
771 }
772
773 side = lw_segment_side(seg1, seg2, pt);
774
775 /*
776 * A point on the boundary of a ring is not contained.
777 * WAS: if (fabs(side) < 1e-12), see #852
778 */
779 if ( (side == 0) && lw_pt_in_seg(pt, seg1, seg2) )
780 {
781 return LW_BOUNDARY;
782 }
783
784 /*
785 * If the point is to the left of the line, and it's rising,
786 * then the line is to the right of the point and
787 * circling counter-clockwise, so increment.
788 */
789 if ( (side < 0) && (seg1->y <= pt->y) && (pt->y < seg2->y) )
790 {
791 wn++;
792 }
793
794 /*
795 * If the point is to the right of the line, and it's falling,
796 * then the line is to the right of the point and circling
797 * clockwise, so decrement.
798 */
799 else if ( (side > 0) && (seg2->y <= pt->y) && (pt->y < seg1->y) )
800 {
801 wn--;
802 }
803
804 seg1 = seg2;
805 }
806
807 /* Sent out the winding number for calls that are building on this as a primitive */
808 if ( winding_number )
809 *winding_number = wn;
810
811 /* Outside */
812 if (wn == 0)
813 {
814 return LW_OUTSIDE;
815 }
816
817 /* Inside */
818 return LW_INSIDE;
819}
820
821/**
822* For POINTARRAYs representing CIRCULARSTRINGS. That is, linked triples
823* with each triple being control points of a circular arc. Such
824* POINTARRAYs have an odd number of vertices.
825*
826* Return 1 if the point is inside the POINTARRAY, -1 if it is outside,
827* and 0 if it is on the boundary.
828*/
829
830int
831ptarrayarc_contains_point(const POINTARRAY *pa, const POINT2D *pt)
832{
833 return ptarrayarc_contains_point_partial(pa, pt, LW_TRUE /* Check closed*/, NULL);
834}
835
836int
837ptarrayarc_contains_point_partial(const POINTARRAY *pa, const POINT2D *pt, int check_closed, int *winding_number)
838{
839 int wn = 0;
840 uint32_t i;
841 int side;
842 const POINT2D *seg1;
843 const POINT2D *seg2;
844 const POINT2D *seg3;
845 GBOX gbox;
846
847 /* Check for not an arc ring (always have odd # of points) */
848 if ( (pa->npoints % 2) == 0 )
849 {
850 lwerror("ptarrayarc_contains_point called with even number of points");
851 return LW_OUTSIDE;
852 }
853
854 /* Check for not an arc ring (always have >= 3 points) */
855 if ( pa->npoints < 3 )
856 {
857 lwerror("ptarrayarc_contains_point called too-short pointarray");
858 return LW_OUTSIDE;
859 }
860
861 /* Check for unclosed case */
862 seg1 = getPoint2d_cp(pa, 0);
863 seg3 = getPoint2d_cp(pa, pa->npoints-1);
864 if ( check_closed && ! p2d_same(seg1, seg3) )
865 {
866 lwerror("ptarrayarc_contains_point called on unclosed ring");
867 return LW_OUTSIDE;
868 }
869 /* OK, it's closed. Is it just one circle? */
870 else if ( p2d_same(seg1, seg3) && pa->npoints == 3 )
871 {
872 double radius, d;
873 POINT2D c;
874 seg2 = getPoint2d_cp(pa, 1);
875
876 /* Wait, it's just a point, so it can't contain anything */
877 if ( lw_arc_is_pt(seg1, seg2, seg3) )
878 return LW_OUTSIDE;
879
880 /* See if the point is within the circle radius */
881 radius = lw_arc_center(seg1, seg2, seg3, &c);
882 d = distance2d_pt_pt(pt, &c);
883 if ( FP_EQUALS(d, radius) )
884 return LW_BOUNDARY; /* Boundary of circle */
885 else if ( d < radius )
886 return LW_INSIDE; /* Inside circle */
887 else
888 return LW_OUTSIDE; /* Outside circle */
889 }
890 else if ( p2d_same(seg1, pt) || p2d_same(seg3, pt) )
891 {
892 return LW_BOUNDARY; /* Boundary case */
893 }
894
895 /* Start on the ring */
896 seg1 = getPoint2d_cp(pa, 0);
897 for ( i=1; i < pa->npoints; i += 2 )
898 {
899 seg2 = getPoint2d_cp(pa, i);
900 seg3 = getPoint2d_cp(pa, i+1);
901
902 /* Catch an easy boundary case */
903 if( p2d_same(seg3, pt) )
904 return LW_BOUNDARY;
905
906 /* Skip arcs that have no size */
907 if ( lw_arc_is_pt(seg1, seg2, seg3) )
908 {
909 seg1 = seg3;
910 continue;
911 }
912
913 /* Only test segments in our vertical range */
914 lw_arc_calculate_gbox_cartesian_2d(seg1, seg2, seg3, &gbox);
915 if ( pt->y > gbox.ymax || pt->y < gbox.ymin )
916 {
917 seg1 = seg3;
918 continue;
919 }
920
921 /* Outside of horizontal range, and not between end points we also skip */
922 if ( (pt->x > gbox.xmax || pt->x < gbox.xmin) &&
923 (pt->y > FP_MAX(seg1->y, seg3->y) || pt->y < FP_MIN(seg1->y, seg3->y)) )
924 {
925 seg1 = seg3;
926 continue;
927 }
928
929 side = lw_arc_side(seg1, seg2, seg3, pt);
930
931 /* On the boundary */
932 if ( (side == 0) && lw_pt_in_arc(pt, seg1, seg2, seg3) )
933 {
934 return LW_BOUNDARY;
935 }
936
937 /* Going "up"! Point to left of arc. */
938 if ( side < 0 && (seg1->y <= pt->y) && (pt->y < seg3->y) )
939 {
940 wn++;
941 }
942
943 /* Going "down"! */
944 if ( side > 0 && (seg2->y <= pt->y) && (pt->y < seg1->y) )
945 {
946 wn--;
947 }
948
949 /* Inside the arc! */
950 if ( pt->x <= gbox.xmax && pt->x >= gbox.xmin )
951 {
952 POINT2D C;
953 double radius = lw_arc_center(seg1, seg2, seg3, &C);
954 double d = distance2d_pt_pt(pt, &C);
955
956 /* On the boundary! */
957 if ( d == radius )
958 return LW_BOUNDARY;
959
960 /* Within the arc! */
961 if ( d < radius )
962 {
963 /* Left side, increment winding number */
964 if ( side < 0 )
965 wn++;
966 /* Right side, decrement winding number */
967 if ( side > 0 )
968 wn--;
969 }
970 }
971
972 seg1 = seg3;
973 }
974
975 /* Sent out the winding number for calls that are building on this as a primitive */
976 if ( winding_number )
977 *winding_number = wn;
978
979 /* Outside */
980 if (wn == 0)
981 {
982 return LW_OUTSIDE;
983 }
984
985 /* Inside */
986 return LW_INSIDE;
987}
988
989/**
990* Returns the area in cartesian units. Area is negative if ring is oriented CCW,
991* positive if it is oriented CW and zero if the ring is degenerate or flat.
992* http://en.wikipedia.org/wiki/Shoelace_formula
993*/
994double
995ptarray_signed_area(const POINTARRAY *pa)
996{
997 const POINT2D *P1;
998 const POINT2D *P2;
999 const POINT2D *P3;
1000 double sum = 0.0;
1001 double x0, x, y1, y2;
1002 uint32_t i;
1003
1004 if (! pa || pa->npoints < 3 )
1005 return 0.0;
1006
1007 P1 = getPoint2d_cp(pa, 0);
1008 P2 = getPoint2d_cp(pa, 1);
1009 x0 = P1->x;
1010 for ( i = 2; i < pa->npoints; i++ )
1011 {
1012 P3 = getPoint2d_cp(pa, i);
1013 x = P2->x - x0;
1014 y1 = P3->y;
1015 y2 = P1->y;
1016 sum += x * (y2-y1);
1017
1018 /* Move forwards! */
1019 P1 = P2;
1020 P2 = P3;
1021 }
1022 return sum / 2.0;
1023}
1024
1025int
1026ptarray_isccw(const POINTARRAY *pa)
1027{
1028 double area = 0;
1029 area = ptarray_signed_area(pa);
1030 if ( area > 0 ) return LW_FALSE;
1031 else return LW_TRUE;
1032}
1033
1034POINTARRAY*
1035ptarray_force_dims(const POINTARRAY *pa, int hasz, int hasm)
1036{
1037 /* TODO handle zero-length point arrays */
1038 uint32_t i;
1039 int in_hasz = FLAGS_GET_Z(pa->flags);
1040 int in_hasm = FLAGS_GET_M(pa->flags);
1041 POINT4D pt;
1042 POINTARRAY *pa_out = ptarray_construct_empty(hasz, hasm, pa->npoints);
1043
1044 for( i = 0; i < pa->npoints; i++ )
1045 {
1046 getPoint4d_p(pa, i, &pt);
1047 if( hasz && ! in_hasz )
1048 pt.z = 0.0;
1049 if( hasm && ! in_hasm )
1050 pt.m = 0.0;
1051 ptarray_append_point(pa_out, &pt, LW_TRUE);
1052 }
1053
1054 return pa_out;
1055}
1056
1057POINTARRAY *
1058ptarray_substring(POINTARRAY *ipa, double from, double to, double tolerance)
1059{
1060 POINTARRAY *dpa;
1061 POINT4D pt;
1062 POINT4D p1, p2;
1063 POINT4D *p1ptr=&p1; /* don't break strict-aliasing rule */
1064 POINT4D *p2ptr=&p2;
1065 int nsegs, i;
1066 double length, slength, tlength;
1067 int state = 0; /* 0=before, 1=inside */
1068
1069 /*
1070 * Create a dynamic pointarray with an initial capacity
1071 * equal to full copy of input points
1072 */
1073 dpa = ptarray_construct_empty(FLAGS_GET_Z(ipa->flags), FLAGS_GET_M(ipa->flags), ipa->npoints);
1074
1075 /* Compute total line length */
1076 length = ptarray_length_2d(ipa);
1077
1078
1079 LWDEBUGF(3, "Total length: %g", length);
1080
1081
1082 /* Get 'from' and 'to' lengths */
1083 from = length*from;
1084 to = length*to;
1085
1086
1087 LWDEBUGF(3, "From/To: %g/%g", from, to);
1088
1089
1090 tlength = 0;
1091 getPoint4d_p(ipa, 0, &p1);
1092 nsegs = ipa->npoints - 1;
1093 for ( i = 0; i < nsegs; i++ )
1094 {
1095 double dseg;
1096
1097 getPoint4d_p(ipa, i+1, &p2);
1098
1099
1100 LWDEBUGF(3 ,"Segment %d: (%g,%g,%g,%g)-(%g,%g,%g,%g)",
1101 i, p1.x, p1.y, p1.z, p1.m, p2.x, p2.y, p2.z, p2.m);
1102
1103
1104 /* Find the length of this segment */
1105 slength = distance2d_pt_pt((POINT2D *)p1ptr, (POINT2D *)p2ptr);
1106
1107 /*
1108 * We are before requested start.
1109 */
1110 if ( state == 0 ) /* before */
1111 {
1112
1113 LWDEBUG(3, " Before start");
1114
1115 if ( fabs ( from - ( tlength + slength ) ) <= tolerance )
1116 {
1117
1118 LWDEBUG(3, " Second point is our start");
1119
1120 /*
1121 * Second point is our start
1122 */
1123 ptarray_append_point(dpa, &p2, LW_FALSE);
1124 state=1; /* we're inside now */
1125 goto END;
1126 }
1127
1128 else if ( fabs(from - tlength) <= tolerance )
1129 {
1130
1131 LWDEBUG(3, " First point is our start");
1132
1133 /*
1134 * First point is our start
1135 */
1136 ptarray_append_point(dpa, &p1, LW_FALSE);
1137
1138 /*
1139 * We're inside now, but will check
1140 * 'to' point as well
1141 */
1142 state=1;
1143 }
1144
1145 /*
1146 * Didn't reach the 'from' point,
1147 * nothing to do
1148 */
1149 else if ( from > tlength + slength ) goto END;
1150
1151 else /* tlength < from < tlength+slength */
1152 {
1153
1154 LWDEBUG(3, " Seg contains first point");
1155
1156 /*
1157 * Our start is between first and
1158 * second point
1159 */
1160 dseg = (from - tlength) / slength;
1161
1162 interpolate_point4d(&p1, &p2, &pt, dseg);
1163
1164 ptarray_append_point(dpa, &pt, LW_FALSE);
1165
1166 /*
1167 * We're inside now, but will check
1168 * 'to' point as well
1169 */
1170 state=1;
1171 }
1172 }
1173
1174 if ( state == 1 ) /* inside */
1175 {
1176
1177 LWDEBUG(3, " Inside");
1178
1179 /*
1180 * 'to' point is our second point.
1181 */
1182 if ( fabs(to - ( tlength + slength ) ) <= tolerance )
1183 {
1184
1185 LWDEBUG(3, " Second point is our end");
1186
1187 ptarray_append_point(dpa, &p2, LW_FALSE);
1188 break; /* substring complete */
1189 }
1190
1191 /*
1192 * 'to' point is our first point.
1193 * (should only happen if 'to' is 0)
1194 */
1195 else if ( fabs(to - tlength) <= tolerance )
1196 {
1197
1198 LWDEBUG(3, " First point is our end");
1199
1200 ptarray_append_point(dpa, &p1, LW_FALSE);
1201
1202 break; /* substring complete */
1203 }
1204
1205 /*
1206 * Didn't reach the 'end' point,
1207 * just copy second point
1208 */
1209 else if ( to > tlength + slength )
1210 {
1211 ptarray_append_point(dpa, &p2, LW_FALSE);
1212 goto END;
1213 }
1214
1215 /*
1216 * 'to' point falls on this segment
1217 * Interpolate and break.
1218 */
1219 else if ( to < tlength + slength )
1220 {
1221
1222 LWDEBUG(3, " Seg contains our end");
1223
1224 dseg = (to - tlength) / slength;
1225 interpolate_point4d(&p1, &p2, &pt, dseg);
1226
1227 ptarray_append_point(dpa, &pt, LW_FALSE);
1228
1229 break;
1230 }
1231
1232 else
1233 {
1234 LWDEBUG(3, "Unhandled case");
1235 }
1236 }
1237
1238
1239END:
1240
1241 tlength += slength;
1242 memcpy(&p1, &p2, sizeof(POINT4D));
1243 }
1244
1245 LWDEBUGF(3, "Out of loop, ptarray has %d points", dpa->npoints);
1246
1247 return dpa;
1248}
1249
1250/*
1251 * Write into the *ret argument coordinates of the closes point on
1252 * the given segment to the reference input point.
1253 */
1254void
1255closest_point_on_segment(const POINT4D *p, const POINT4D *A, const POINT4D *B, POINT4D *ret)
1256{
1257 double r;
1258
1259 if ( FP_EQUALS(A->x, B->x) && FP_EQUALS(A->y, B->y) )
1260 {
1261 *ret = *A;
1262 return;
1263 }
1264
1265 /*
1266 * We use comp.graphics.algorithms Frequently Asked Questions method
1267 *
1268 * (1) AC dot AB
1269 * r = ----------
1270 * ||AB||^2
1271 * r has the following meaning:
1272 * r=0 P = A
1273 * r=1 P = B
1274 * r<0 P is on the backward extension of AB
1275 * r>1 P is on the forward extension of AB
1276 * 0<r<1 P is interior to AB
1277 *
1278 */
1279 r = ( (p->x-A->x) * (B->x-A->x) + (p->y-A->y) * (B->y-A->y) )/( (B->x-A->x)*(B->x-A->x) +(B->y-A->y)*(B->y-A->y) );
1280
1281 if (r<0)
1282 {
1283 *ret = *A;
1284 return;
1285 }
1286 if (r>1)
1287 {
1288 *ret = *B;
1289 return;
1290 }
1291
1292 ret->x = A->x + ( (B->x - A->x) * r );
1293 ret->y = A->y + ( (B->y - A->y) * r );
1294 ret->z = A->z + ( (B->z - A->z) * r );
1295 ret->m = A->m + ( (B->m - A->m) * r );
1296}
1297
1298/*
1299 * Given a point, returns the location of closest point on pointarray
1300 * and, optionally, it's actual distance from the point array.
1301 */
1302double
1303ptarray_locate_point(const POINTARRAY *pa, const POINT4D *p4d, double *mindistout, POINT4D *proj4d)
1304{
1305 double mindist=DBL_MAX;
1306 double tlen, plen;
1307 uint32_t t, seg=0;
1308 POINT4D start4d, end4d, projtmp;
1309 POINT2D proj, p;
1310 const POINT2D *start = NULL, *end = NULL;
1311
1312 /* Initialize our 2D copy of the input parameter */
1313 p.x = p4d->x;
1314 p.y = p4d->y;
1315
1316 if ( ! proj4d ) proj4d = &projtmp;
1317
1318 /* Check for special cases (length 0 and 1) */
1319 if ( pa->npoints <= 1 )
1320 {
1321 if ( pa->npoints == 1 )
1322 {
1323 getPoint4d_p(pa, 0, proj4d);
1324 if ( mindistout )
1325 *mindistout = distance2d_pt_pt(&p, getPoint2d_cp(pa, 0));
1326 }
1327 return 0.0;
1328 }
1329
1330 start = getPoint2d_cp(pa, 0);
1331 /* Loop through pointarray looking for nearest segment */
1332 for (t=1; t<pa->npoints; t++)
1333 {
1334 double dist_sqr;
1335 end = getPoint2d_cp(pa, t);
1336 dist_sqr = distance2d_sqr_pt_seg(&p, start, end);
1337
1338 if (dist_sqr < mindist)
1339 {
1340 mindist = dist_sqr;
1341 seg=t-1;
1342 if ( mindist == 0 )
1343 {
1344 LWDEBUG(3, "Breaking on mindist=0");
1345 break;
1346 }
1347 }
1348
1349 start = end;
1350 }
1351 mindist = sqrt(mindist);
1352
1353 if ( mindistout ) *mindistout = mindist;
1354
1355 LWDEBUGF(3, "Closest segment: %d", seg);
1356 LWDEBUGF(3, "mindist: %g", mindist);
1357
1358 /*
1359 * We need to project the
1360 * point on the closest segment.
1361 */
1362 getPoint4d_p(pa, seg, &start4d);
1363 getPoint4d_p(pa, seg+1, &end4d);
1364 closest_point_on_segment(p4d, &start4d, &end4d, proj4d);
1365
1366 /* Copy 4D values into 2D holder */
1367 proj.x = proj4d->x;
1368 proj.y = proj4d->y;
1369
1370 LWDEBUGF(3, "Closest segment:%d, npoints:%d", seg, pa->npoints);
1371
1372 /* For robustness, force 1 when closest point == endpoint */
1373 if ( (seg >= (pa->npoints-2)) && p2d_same(&proj, end) )
1374 {
1375 return 1.0;
1376 }
1377
1378 LWDEBUGF(3, "Closest point on segment: %g,%g", proj.x, proj.y);
1379
1380 tlen = ptarray_length_2d(pa);
1381
1382 LWDEBUGF(3, "tlen %g", tlen);
1383
1384 /* Location of any point on a zero-length line is 0 */
1385 /* See http://trac.osgeo.org/postgis/ticket/1772#comment:2 */
1386 if ( tlen == 0 ) return 0;
1387
1388 plen=0;
1389 start = getPoint2d_cp(pa, 0);
1390 for (t=0; t<seg; t++, start=end)
1391 {
1392 end = getPoint2d_cp(pa, t+1);
1393 plen += distance2d_pt_pt(start, end);
1394
1395 LWDEBUGF(4, "Segment %d made plen %g", t, plen);
1396 }
1397
1398 plen+=distance2d_pt_pt(&proj, start);
1399
1400 LWDEBUGF(3, "plen %g, tlen %g", plen, tlen);
1401
1402 return plen/tlen;
1403}
1404
1405/**
1406 * @brief Longitude shift for a pointarray.
1407 * Y remains the same
1408 * X is converted:
1409 * from -180..180 to 0..360
1410 * from 0..360 to -180..180
1411 * X < 0 becomes X + 360
1412 * X > 180 becomes X - 360
1413 */
1414void
1415ptarray_longitude_shift(POINTARRAY *pa)
1416{
1417 uint32_t i;
1418 double x;
1419
1420 for (i=0; i<pa->npoints; i++)
1421 {
1422 memcpy(&x, getPoint_internal(pa, i), sizeof(double));
1423 if ( x < 0 ) x+= 360;
1424 else if ( x > 180 ) x -= 360;
1425 memcpy(getPoint_internal(pa, i), &x, sizeof(double));
1426 }
1427}
1428
1429
1430/*
1431 * Returns a POINTARRAY with consecutive equal points
1432 * removed. Equality test on all dimensions of input.
1433 *
1434 * Always returns a newly allocated object.
1435 */
1436static POINTARRAY *
1437ptarray_remove_repeated_points_minpoints(const POINTARRAY *in, double tolerance, int minpoints)
1438{
1439 POINTARRAY *out = ptarray_clone_deep(in);
1440 ptarray_remove_repeated_points_in_place(out, tolerance, minpoints);
1441 return out;
1442}
1443
1444POINTARRAY *
1445ptarray_remove_repeated_points(const POINTARRAY *in, double tolerance)
1446{
1447 return ptarray_remove_repeated_points_minpoints(in, tolerance, 2);
1448}
1449
1450
1451void
1452ptarray_remove_repeated_points_in_place(POINTARRAY *pa, double tolerance, uint32_t min_points)
1453{
1454 uint32_t i;
1455 double tolsq = tolerance * tolerance;
1456 const POINT2D *last = NULL;
1457 const POINT2D *pt;
1458 uint32_t n_points = pa->npoints;
1459 uint32_t n_points_out = 1;
1460 size_t pt_size = ptarray_point_size(pa);
1461
1462 double dsq = FLT_MAX;
1463
1464 /* No-op on short inputs */
1465 if ( n_points <= min_points ) return;
1466
1467 last = getPoint2d_cp(pa, 0);
1468 void *p_to = ((char *)last) + pt_size;
1469 for (i = 1; i < n_points; i++)
1470 {
1471 int last_point = (i == n_points - 1);
1472
1473 /* Look straight into the abyss */
1474 pt = getPoint2d_cp(pa, i);
1475
1476 /* Don't drop points if we are running short of points */
1477 if (n_points + n_points_out > min_points + i)
1478 {
1479 if (tolerance > 0.0)
1480 {
1481 /* Only drop points that are within our tolerance */
1482 dsq = distance2d_sqr_pt_pt(last, pt);
1483 /* Allow any point but the last one to be dropped */
1484 if (!last_point && dsq <= tolsq)
1485 {
1486 continue;
1487 }
1488 }
1489 else
1490 {
1491 /* At tolerance zero, only skip exact dupes */
1492 if (memcmp((char*)pt, (char*)last, pt_size) == 0)
1493 continue;
1494 }
1495
1496 /* Got to last point, and it's not very different from */
1497 /* the point that preceded it. We want to keep the last */
1498 /* point, not the second-to-last one, so we pull our write */
1499 /* index back one value */
1500 if (last_point && n_points_out > 1 && tolerance > 0.0 && dsq <= tolsq)
1501 {
1502 n_points_out--;
1503 p_to -= pt_size;
1504 }
1505 }
1506
1507 /* Compact all remaining values to front of array */
1508 memcpy(p_to, pt, pt_size);
1509 n_points_out++;
1510 p_to += pt_size;
1511 last = pt;
1512 }
1513 /* Adjust array length */
1514 pa->npoints = n_points_out;
1515 return;
1516}
1517
1518/* Out of the points in pa [itfist .. itlast], finds the one that's farthest away from
1519 * the segment determined by pts[itfist] and pts[itlast].
1520 * Returns itfirst if no point was found futher away than max_distance_sqr
1521 */
1522static uint32_t
1523ptarray_dp_findsplit_in_place(const POINTARRAY *pts, uint32_t it_first, uint32_t it_last, double max_distance_sqr)
1524{
1525 uint32_t split = it_first;
1526 if ((it_first - it_last) < 2)
1527 return it_first;
1528
1529 const POINT2D *A = getPoint2d_cp(pts, it_first);
1530 const POINT2D *B = getPoint2d_cp(pts, it_last);
1531
1532 if (distance2d_sqr_pt_pt(A, B) < DBL_EPSILON)
1533 {
1534 /* If p1 == p2, we can just calculate the distance from each point to A */
1535 for (uint32_t itk = it_first + 1; itk < it_last; itk++)
1536 {
1537 const POINT2D *pk = getPoint2d_cp(pts, itk);
1538 double distance_sqr = distance2d_sqr_pt_pt(pk, A);
1539 if (distance_sqr > max_distance_sqr)
1540 {
1541 split = itk;
1542 max_distance_sqr = distance_sqr;
1543 }
1544 }
1545 return split;
1546 }
1547
1548 /* This is based on distance2d_sqr_pt_seg, but heavily inlined here to avoid recalculations */
1549 double ba_x = (B->x - A->x);
1550 double ba_y = (B->y - A->y);
1551 double ab_length_sqr = (ba_x * ba_x + ba_y * ba_y);
1552 /* To avoid the division by ab_length_sqr in the 3rd path, we normalize here
1553 * and multiply in the first two paths [(dot_ac_ab < 0) and (> ab_length_sqr)] */
1554 max_distance_sqr *= ab_length_sqr;
1555 for (uint32_t itk = it_first + 1; itk < it_last; itk++)
1556 {
1557 const POINT2D *C = getPoint2d_cp(pts, itk);
1558 double distance_sqr;
1559 double ca_x = (C->x - A->x);
1560 double ca_y = (C->y - A->y);
1561 double dot_ac_ab = (ca_x * ba_x + ca_y * ba_y);
1562
1563 if (dot_ac_ab <= 0.0)
1564 {
1565 distance_sqr = distance2d_sqr_pt_pt(C, A) * ab_length_sqr;
1566 }
1567 else if (dot_ac_ab >= ab_length_sqr)
1568 {
1569 distance_sqr = distance2d_sqr_pt_pt(C, B) * ab_length_sqr;
1570 }
1571 else
1572 {
1573 double s_numerator = ca_x * ba_y - ca_y * ba_x;
1574 distance_sqr = s_numerator * s_numerator; /* Missing division by ab_length_sqr on purpose */
1575 }
1576
1577 if (distance_sqr > max_distance_sqr)
1578 {
1579 split = itk;
1580 max_distance_sqr = distance_sqr;
1581 }
1582 }
1583 return split;
1584}
1585
1586void
1587ptarray_simplify_in_place(POINTARRAY *pa, double tolerance, uint32_t minpts)
1588{
1589 /* Do not try to simplify really short things */
1590 if (pa->npoints < 3 || pa->npoints <= minpts)
1591 return;
1592
1593 /* We use this array to keep track of the points we are keeping, so
1594 * we store just TRUE / FALSE in their position */
1595 uint8_t *kept_points = lwalloc(sizeof(uint8_t) * pa->npoints);
1596 memset(kept_points, LW_FALSE, sizeof(uint8_t) * pa->npoints);
1597 kept_points[0] = LW_TRUE;
1598 kept_points[pa->npoints - 1] = LW_TRUE;
1599 uint32_t keptn = 2;
1600
1601 /* We use this array as a stack to store the iterators that we are going to need
1602 * in the following steps.
1603 * This is ~10% faster than iterating over @kept_points looking for them
1604 */
1605 uint32_t *iterator_stack = lwalloc(sizeof(uint32_t) * pa->npoints);
1606 iterator_stack[0] = 0;
1607 uint32_t iterator_stack_size = 1;
1608
1609 uint32_t it_first = 0;
1610 uint32_t it_last = pa->npoints - 1;
1611
1612 const double tolerance_sqr = tolerance * tolerance;
1613 /* For the first @minpts points we ignore the tolerance */
1614 double it_tol = keptn >= minpts ? tolerance_sqr : -1.0;
1615
1616 while (iterator_stack_size)
1617 {
1618 uint32_t split = ptarray_dp_findsplit_in_place(pa, it_first, it_last, it_tol);
1619 if (split == it_first)
1620 {
1621 it_first = it_last;
1622 it_last = iterator_stack[--iterator_stack_size];
1623 }
1624 else
1625 {
1626 kept_points[split] = LW_TRUE;
1627 keptn++;
1628
1629 iterator_stack[iterator_stack_size++] = it_last;
1630 it_last = split;
1631 it_tol = keptn >= minpts ? tolerance_sqr : -1.0;
1632 }
1633 }
1634
1635 const size_t pt_size = ptarray_point_size(pa);
1636 /* The first point is already in place, so we don't need to copy it */
1637 size_t kept_it = 1;
1638 if (keptn == 2)
1639 {
1640 /* If there are 2 points remaining, it has to be first and last as
1641 * we added those at the start */
1642 memcpy(pa->serialized_pointlist + pt_size * kept_it,
1643 pa->serialized_pointlist + pt_size * (pa->npoints - 1),
1644 pt_size);
1645 }
1646 else
1647 {
1648 for (uint32_t i = 1; i < pa->npoints; i++)
1649 {
1650 if (kept_points[i])
1651 {
1652 memcpy(pa->serialized_pointlist + pt_size * kept_it,
1653 pa->serialized_pointlist + pt_size * i,
1654 pt_size);
1655 kept_it++;
1656 }
1657 }
1658 }
1659 pa->npoints = keptn;
1660
1661 lwfree(kept_points);
1662 lwfree(iterator_stack);
1663}
1664
1665/************************************************************************/
1666
1667/**
1668* Find the 2d length of the given #POINTARRAY, using circular
1669* arc interpolation between each coordinate triple.
1670* Length(A1, A2, A3, A4, A5) = Length(A1, A2, A3)+Length(A3, A4, A5)
1671*/
1672double
1673ptarray_arc_length_2d(const POINTARRAY *pts)
1674{
1675 double dist = 0.0;
1676 uint32_t i;
1677 const POINT2D *a1;
1678 const POINT2D *a2;
1679 const POINT2D *a3;
1680
1681 if ( pts->npoints % 2 != 1 )
1682 lwerror("arc point array with even number of points");
1683
1684 a1 = getPoint2d_cp(pts, 0);
1685
1686 for ( i=2; i < pts->npoints; i += 2 )
1687 {
1688 a2 = getPoint2d_cp(pts, i-1);
1689 a3 = getPoint2d_cp(pts, i);
1690 dist += lw_arc_length(a1, a2, a3);
1691 a1 = a3;
1692 }
1693 return dist;
1694}
1695
1696/**
1697* Find the 2d length of the given #POINTARRAY (even if it's 3d)
1698*/
1699double
1700ptarray_length_2d(const POINTARRAY *pts)
1701{
1702 double dist = 0.0;
1703 uint32_t i;
1704 const POINT2D *frm;
1705 const POINT2D *to;
1706
1707 if ( pts->npoints < 2 ) return 0.0;
1708
1709 frm = getPoint2d_cp(pts, 0);
1710
1711 for ( i=1; i < pts->npoints; i++ )
1712 {
1713 to = getPoint2d_cp(pts, i);
1714
1715 dist += sqrt( ((frm->x - to->x)*(frm->x - to->x)) +
1716 ((frm->y - to->y)*(frm->y - to->y)) );
1717
1718 frm = to;
1719 }
1720 return dist;
1721}
1722
1723/**
1724* Find the 3d/2d length of the given #POINTARRAY
1725* (depending on its dimensionality)
1726*/
1727double
1728ptarray_length(const POINTARRAY *pts)
1729{
1730 double dist = 0.0;
1731 uint32_t i;
1732 POINT3DZ frm;
1733 POINT3DZ to;
1734
1735 if ( pts->npoints < 2 ) return 0.0;
1736
1737 /* compute 2d length if 3d is not available */
1738 if ( ! FLAGS_GET_Z(pts->flags) ) return ptarray_length_2d(pts);
1739
1740 getPoint3dz_p(pts, 0, &frm);
1741 for ( i=1; i < pts->npoints; i++ )
1742 {
1743 getPoint3dz_p(pts, i, &to);
1744 dist += sqrt( ((frm.x - to.x)*(frm.x - to.x)) +
1745 ((frm.y - to.y)*(frm.y - to.y)) +
1746 ((frm.z - to.z)*(frm.z - to.z)) );
1747 frm = to;
1748 }
1749 return dist;
1750}
1751
1752
1753
1754/**
1755 * Affine transform a pointarray.
1756 */
1757void
1758ptarray_affine(POINTARRAY *pa, const AFFINE *a)
1759{
1760 uint32_t i;
1761 double x,y,z;
1762 POINT4D p4d;
1763
1764 LWDEBUG(2, "lwgeom_affine_ptarray start");
1765
1766 if ( FLAGS_GET_Z(pa->flags) )
1767 {
1768 LWDEBUG(3, " has z");
1769
1770 for (i=0; i<pa->npoints; i++)
1771 {
1772 getPoint4d_p(pa, i, &p4d);
1773 x = p4d.x;
1774 y = p4d.y;
1775 z = p4d.z;
1776 p4d.x = a->afac * x + a->bfac * y + a->cfac * z + a->xoff;
1777 p4d.y = a->dfac * x + a->efac * y + a->ffac * z + a->yoff;
1778 p4d.z = a->gfac * x + a->hfac * y + a->ifac * z + a->zoff;
1779 ptarray_set_point4d(pa, i, &p4d);
1780
1781 LWDEBUGF(3, " POINT %g %g %g => %g %g %g", x, y, z, p4d.x, p4d.y, p4d.z);
1782 }
1783 }
1784 else
1785 {
1786 LWDEBUG(3, " doesn't have z");
1787
1788 for (i=0; i<pa->npoints; i++)
1789 {
1790 getPoint4d_p(pa, i, &p4d);
1791 x = p4d.x;
1792 y = p4d.y;
1793 p4d.x = a->afac * x + a->bfac * y + a->xoff;
1794 p4d.y = a->dfac * x + a->efac * y + a->yoff;
1795 ptarray_set_point4d(pa, i, &p4d);
1796
1797 LWDEBUGF(3, " POINT %g %g => %g %g", x, y, p4d.x, p4d.y);
1798 }
1799 }
1800
1801 LWDEBUG(3, "lwgeom_affine_ptarray end");
1802
1803}
1804
1805/**
1806* WARNING, make sure you send in only 16-member double arrays
1807* or obviously things will go pear-shaped fast.
1808*/
1809#if 0
1810static int gluInvertMatrix(const double *m, double *invOut)
1811{
1812 double inv[16], det;
1813 int i;
1814
1815 inv[0] = m[5] * m[10] * m[15] -
1816 m[5] * m[11] * m[14] -
1817 m[9] * m[6] * m[15] +
1818 m[9] * m[7] * m[14] +
1819 m[13] * m[6] * m[11] -
1820 m[13] * m[7] * m[10];
1821
1822 inv[4] = -m[4] * m[10] * m[15] +
1823 m[4] * m[11] * m[14] +
1824 m[8] * m[6] * m[15] -
1825 m[8] * m[7] * m[14] -
1826 m[12] * m[6] * m[11] +
1827 m[12] * m[7] * m[10];
1828
1829 inv[8] = m[4] * m[9] * m[15] -
1830 m[4] * m[11] * m[13] -
1831 m[8] * m[5] * m[15] +
1832 m[8] * m[7] * m[13] +
1833 m[12] * m[5] * m[11] -
1834 m[12] * m[7] * m[9];
1835
1836 inv[12] = -m[4] * m[9] * m[14] +
1837 m[4] * m[10] * m[13] +
1838 m[8] * m[5] * m[14] -
1839 m[8] * m[6] * m[13] -
1840 m[12] * m[5] * m[10] +
1841 m[12] * m[6] * m[9];
1842
1843 inv[1] = -m[1] * m[10] * m[15] +
1844 m[1] * m[11] * m[14] +
1845 m[9] * m[2] * m[15] -
1846 m[9] * m[3] * m[14] -
1847 m[13] * m[2] * m[11] +
1848 m[13] * m[3] * m[10];
1849
1850 inv[5] = m[0] * m[10] * m[15] -
1851 m[0] * m[11] * m[14] -
1852 m[8] * m[2] * m[15] +
1853 m[8] * m[3] * m[14] +
1854 m[12] * m[2] * m[11] -
1855 m[12] * m[3] * m[10];
1856
1857 inv[9] = -m[0] * m[9] * m[15] +
1858 m[0] * m[11] * m[13] +
1859 m[8] * m[1] * m[15] -
1860 m[8] * m[3] * m[13] -
1861 m[12] * m[1] * m[11] +
1862 m[12] * m[3] * m[9];
1863
1864 inv[13] = m[0] * m[9] * m[14] -
1865 m[0] * m[10] * m[13] -
1866 m[8] * m[1] * m[14] +
1867 m[8] * m[2] * m[13] +
1868 m[12] * m[1] * m[10] -
1869 m[12] * m[2] * m[9];
1870
1871 inv[2] = m[1] * m[6] * m[15] -
1872 m[1] * m[7] * m[14] -
1873 m[5] * m[2] * m[15] +
1874 m[5] * m[3] * m[14] +
1875 m[13] * m[2] * m[7] -
1876 m[13] * m[3] * m[6];
1877
1878 inv[6] = -m[0] * m[6] * m[15] +
1879 m[0] * m[7] * m[14] +
1880 m[4] * m[2] * m[15] -
1881 m[4] * m[3] * m[14] -
1882 m[12] * m[2] * m[7] +
1883 m[12] * m[3] * m[6];
1884
1885 inv[10] = m[0] * m[5] * m[15] -
1886 m[0] * m[7] * m[13] -
1887 m[4] * m[1] * m[15] +
1888 m[4] * m[3] * m[13] +
1889 m[12] * m[1] * m[7] -
1890 m[12] * m[3] * m[5];
1891
1892 inv[14] = -m[0] * m[5] * m[14] +
1893 m[0] * m[6] * m[13] +
1894 m[4] * m[1] * m[14] -
1895 m[4] * m[2] * m[13] -
1896 m[12] * m[1] * m[6] +
1897 m[12] * m[2] * m[5];
1898
1899 inv[3] = -m[1] * m[6] * m[11] +
1900 m[1] * m[7] * m[10] +
1901 m[5] * m[2] * m[11] -
1902 m[5] * m[3] * m[10] -
1903 m[9] * m[2] * m[7] +
1904 m[9] * m[3] * m[6];
1905
1906 inv[7] = m[0] * m[6] * m[11] -
1907 m[0] * m[7] * m[10] -
1908 m[4] * m[2] * m[11] +
1909 m[4] * m[3] * m[10] +
1910 m[8] * m[2] * m[7] -
1911 m[8] * m[3] * m[6];
1912
1913 inv[11] = -m[0] * m[5] * m[11] +
1914 m[0] * m[7] * m[9] +
1915 m[4] * m[1] * m[11] -
1916 m[4] * m[3] * m[9] -
1917 m[8] * m[1] * m[7] +
1918 m[8] * m[3] * m[5];
1919
1920 inv[15] = m[0] * m[5] * m[10] -
1921 m[0] * m[6] * m[9] -
1922 m[4] * m[1] * m[10] +
1923 m[4] * m[2] * m[9] +
1924 m[8] * m[1] * m[6] -
1925 m[8] * m[2] * m[5];
1926
1927 det = m[0] * inv[0] + m[1] * inv[4] + m[2] * inv[8] + m[3] * inv[12];
1928
1929 if (det == 0)
1930 return LW_FALSE;
1931
1932 det = 1.0 / det;
1933
1934 for (i = 0; i < 16; i++)
1935 invOut[i] = inv[i] * det;
1936
1937 return LW_TRUE;
1938}
1939#endif
1940
1941/**
1942 * Scale a pointarray.
1943 */
1944void
1945ptarray_scale(POINTARRAY *pa, const POINT4D *fact)
1946{
1947 uint32_t i;
1948 POINT4D p4d;
1949 LWDEBUG(3, "ptarray_scale start");
1950 for (i=0; i<pa->npoints; i++)
1951 {
1952 getPoint4d_p(pa, i, &p4d);
1953 p4d.x *= fact->x;
1954 p4d.y *= fact->y;
1955 p4d.z *= fact->z;
1956 p4d.m *= fact->m;
1957 ptarray_set_point4d(pa, i, &p4d);
1958 }
1959 LWDEBUG(3, "ptarray_scale end");
1960}
1961
1962int
1963ptarray_startpoint(const POINTARRAY *pa, POINT4D *pt)
1964{
1965 return getPoint4d_p(pa, 0, pt);
1966}
1967
1968
1969/*
1970 * Stick an array of points to the given gridspec.
1971 * Return "gridded" points in *outpts and their number in *outptsn.
1972 *
1973 * Two consecutive points falling on the same grid cell are collapsed
1974 * into one single point.
1975 *
1976 */
1977void
1978ptarray_grid_in_place(POINTARRAY *pa, const gridspec *grid)
1979{
1980 uint32_t i, j = 0;
1981 POINT4D *p, *p_out = NULL;
1982 int ndims = FLAGS_NDIMS(pa->flags);
1983 int has_z = FLAGS_GET_Z(pa->flags);
1984 int has_m = FLAGS_GET_M(pa->flags);
1985
1986 LWDEBUGF(2, "%s called on %p", __func__, pa);
1987
1988 for (i = 0; i < pa->npoints; i++)
1989 {
1990 /* Look straight into the abyss */
1991 p = (POINT4D*)(getPoint_internal(pa, i));
1992
1993 if (grid->xsize > 0)
1994 {
1995 p->x = rint((p->x - grid->ipx)/grid->xsize) * grid->xsize + grid->ipx;
1996 }
1997
1998 if (grid->ysize > 0)
1999 {
2000 p->y = rint((p->y - grid->ipy)/grid->ysize) * grid->ysize + grid->ipy;
2001 }
2002
2003 /* Read and round this point */
2004 /* Z is always in third position */
2005 if (has_z)
2006 {
2007 if (grid->zsize > 0)
2008 p->z = rint((p->z - grid->ipz)/grid->zsize) * grid->zsize + grid->ipz;
2009 }
2010 /* M might be in 3rd or 4th position */
2011 if (has_m)
2012 {
2013 /* In POINT M, M is in 3rd position */
2014 if (grid->msize > 0 && !has_z)
2015 p->z = rint((p->z - grid->ipm)/grid->msize) * grid->msize + grid->ipm;
2016 /* In POINT ZM, M is in 4th position */
2017 if (grid->msize > 0 && has_z)
2018 p->m = rint((p->m - grid->ipm)/grid->msize) * grid->msize + grid->ipm;
2019 }
2020
2021 /* Skip duplicates */
2022 if ( p_out && FP_EQUALS(p_out->x, p->x) && FP_EQUALS(p_out->y, p->y)
2023 && (ndims > 2 ? FP_EQUALS(p_out->z, p->z) : 1)
2024 && (ndims > 3 ? FP_EQUALS(p_out->m, p->m) : 1) )
2025 {
2026 continue;
2027 }
2028
2029 /* Write rounded values into the next available point */
2030 p_out = (POINT4D*)(getPoint_internal(pa, j++));
2031 p_out->x = p->x;
2032 p_out->y = p->y;
2033 if (ndims > 2)
2034 p_out->z = p->z;
2035 if (ndims > 3)
2036 p_out->m = p->m;
2037 }
2038
2039 /* Update output ptarray length */
2040 pa->npoints = j;
2041 return;
2042}
2043
2044
2045int
2046ptarray_npoints_in_rect(const POINTARRAY *pa, const GBOX *gbox)
2047{
2048 const POINT2D *pt;
2049 int n = 0;
2050 uint32_t i;
2051 for ( i = 0; i < pa->npoints; i++ )
2052 {
2053 pt = getPoint2d_cp(pa, i);
2054 if ( gbox_contains_point2d(gbox, pt) )
2055 n++;
2056 }
2057 return n;
2058}
2059
2060
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