-
-
Notifications
You must be signed in to change notification settings - Fork 121
/
zonedetect.c
1260 lines (1069 loc) · 37.6 KB
/
zonedetect.c
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
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (c) 2018, Bertold Van den Bergh ([email protected])
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 OR DISTRIBUTOR 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.
*/
#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#if defined(_MSC_VER) || defined(__MINGW32__)
#include <windows.h>
#elif defined(__APPLE__) || defined(__linux__) || defined(__unix__) || defined(_POSIX_VERSION)
#include <errno.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#endif
#include "zonedetect.h"
enum ZDInternalError {
ZD_OK,
ZD_E_DB_OPEN,
ZD_E_DB_SEEK,
ZD_E_DB_MMAP,
#if defined(_MSC_VER) || defined(__MINGW32__)
ZD_E_DB_MMAP_MSVIEW,
ZD_E_DB_MAP_EXCEPTION,
ZD_E_DB_MUNMAP_MSVIEW,
#endif
ZD_E_DB_MUNMAP,
ZD_E_DB_CLOSE,
ZD_E_PARSE_HEADER
};
struct ZoneDetectOpaque {
#if defined(_MSC_VER) || defined(__MINGW32__)
HANDLE fd;
HANDLE fdMap;
int32_t length;
int32_t padding;
#elif defined(__APPLE__) || defined(__linux__) || defined(__unix__) || defined(_POSIX_VERSION)
int fd;
off_t length;
#else
int length;
#endif
uint8_t closeType;
uint8_t *mapping;
uint8_t tableType;
uint8_t version;
uint8_t precision;
uint8_t numFields;
char *notice;
char **fieldNames;
uint32_t bboxOffset;
uint32_t metadataOffset;
uint32_t dataOffset;
};
static void (*zdErrorHandler)(int, int);
static void zdError(enum ZDInternalError errZD, int errNative)
{
if (zdErrorHandler) zdErrorHandler((int)errZD, errNative);
}
static int32_t ZDFloatToFixedPoint(float input, float scale, unsigned int precision)
{
const float inputScaled = input / scale;
return (int32_t)(inputScaled * (float)(1 << (precision - 1)));
}
static float ZDFixedPointToFloat(int32_t input, float scale, unsigned int precision)
{
const float value = (float)input / (float)(1 << (precision - 1));
return value * scale;
}
static unsigned int ZDDecodeVariableLengthUnsigned(const ZoneDetect *library, uint32_t *index, uint64_t *result)
{
if(*index >= (uint32_t)library->length) {
return 0;
}
uint64_t value = 0;
unsigned int i = 0;
#if defined(_MSC_VER)
__try {
#endif
uint8_t *const buffer = library->mapping + *index;
uint8_t *const bufferEnd = library->mapping + library->length - 1;
unsigned int shift = 0;
while(1) {
value |= ((((uint64_t)buffer[i]) & UINT8_C(0x7F)) << shift);
shift += 7u;
if(!(buffer[i] & UINT8_C(0x80))) {
break;
}
i++;
if(buffer + i > bufferEnd) {
return 0;
}
}
#if defined(_MSC_VER)
} __except(GetExceptionCode() == EXCEPTION_IN_PAGE_ERROR
? EXCEPTION_EXECUTE_HANDLER
: EXCEPTION_CONTINUE_SEARCH) { /* file mapping SEH exception occurred */
zdError(ZD_E_DB_MAP_EXCEPTION, (int)GetLastError());
return 0;
}
#endif
i++;
*result = value;
*index += i;
return i;
}
static unsigned int ZDDecodeVariableLengthUnsignedReverse(const ZoneDetect *library, uint32_t *index, uint64_t *result)
{
uint32_t i = *index;
if(*index >= (uint32_t)library->length) {
return 0;
}
#if defined(_MSC_VER)
__try {
#endif
if(library->mapping[i] & UINT8_C(0x80)) {
return 0;
}
if(!i) {
return 0;
}
i--;
while(library->mapping[i] & UINT8_C(0x80)) {
if(!i) {
return 0;
}
i--;
}
#if defined(_MSC_VER)
} __except(GetExceptionCode() == EXCEPTION_IN_PAGE_ERROR
? EXCEPTION_EXECUTE_HANDLER
: EXCEPTION_CONTINUE_SEARCH) { /* file mapping SEH exception occurred */
zdError(ZD_E_DB_MAP_EXCEPTION, (int)GetLastError());
return 0;
}
#endif
*index = i;
i++;
uint32_t i2 = i;
return ZDDecodeVariableLengthUnsigned(library, &i2, result);
}
static int64_t ZDDecodeUnsignedToSigned(uint64_t value)
{
return (value & 1) ? -(int64_t)(value / 2) : (int64_t)(value / 2);
}
static unsigned int ZDDecodeVariableLengthSigned(const ZoneDetect *library, uint32_t *index, int32_t *result)
{
uint64_t value = 0;
const unsigned int retVal = ZDDecodeVariableLengthUnsigned(library, index, &value);
*result = (int32_t)ZDDecodeUnsignedToSigned(value);
return retVal;
}
static char *ZDParseString(const ZoneDetect *library, uint32_t *index)
{
uint64_t strLength;
if(!ZDDecodeVariableLengthUnsigned(library, index, &strLength)) {
return NULL;
}
uint32_t strOffset = *index;
unsigned int remoteStr = 0;
if(strLength >= 256) {
strOffset = library->metadataOffset + (uint32_t)strLength - 256;
remoteStr = 1;
if(!ZDDecodeVariableLengthUnsigned(library, &strOffset, &strLength)) {
return NULL;
}
if(strLength > 256) {
return NULL;
}
}
char *const str = malloc((size_t)(strLength + 1));
if(str) {
#if defined(_MSC_VER)
__try {
#endif
size_t i;
for(i = 0; i < strLength; i++) {
str[i] = (char)(library->mapping[strOffset + i] ^ UINT8_C(0x80));
}
#if defined(_MSC_VER)
} __except(GetExceptionCode() == EXCEPTION_IN_PAGE_ERROR
? EXCEPTION_EXECUTE_HANDLER
: EXCEPTION_CONTINUE_SEARCH) { /* file mapping SEH exception occurred */
zdError(ZD_E_DB_MAP_EXCEPTION, (int)GetLastError());
return 0;
}
#endif
str[strLength] = 0;
}
if(!remoteStr) {
*index += (uint32_t)strLength;
}
return str;
}
static int ZDParseHeader(ZoneDetect *library)
{
if(library->length < 7) {
return -1;
}
#if defined(_MSC_VER)
__try {
#endif
if(memcmp(library->mapping, "PLB", 3)) {
return -1;
}
library->tableType = library->mapping[3];
library->version = library->mapping[4];
library->precision = library->mapping[5];
library->numFields = library->mapping[6];
#if defined(_MSC_VER)
} __except(GetExceptionCode() == EXCEPTION_IN_PAGE_ERROR
? EXCEPTION_EXECUTE_HANDLER
: EXCEPTION_CONTINUE_SEARCH) { /* file mapping SEH exception occurred */
zdError(ZD_E_DB_MAP_EXCEPTION, (int)GetLastError());
return 0;
}
#endif
if(library->version >= 2) {
return -1;
}
uint32_t index = UINT32_C(7);
library->fieldNames = malloc(library->numFields * sizeof *library->fieldNames);
if (!library->fieldNames) {
return -1;
}
size_t i;
for(i = 0; i < library->numFields; i++) {
library->fieldNames[i] = ZDParseString(library, &index);
}
library->notice = ZDParseString(library, &index);
if(!library->notice) {
return -1;
}
uint64_t tmp;
/* Read section sizes */
/* By memset: library->bboxOffset = 0 */
if(!ZDDecodeVariableLengthUnsigned(library, &index, &tmp)) return -1;
library->metadataOffset = (uint32_t)tmp + library->bboxOffset;
if(!ZDDecodeVariableLengthUnsigned(library, &index, &tmp))return -1;
library->dataOffset = (uint32_t)tmp + library->metadataOffset;
if(!ZDDecodeVariableLengthUnsigned(library, &index, &tmp)) return -1;
/* Add header size to everything */
library->bboxOffset += index;
library->metadataOffset += index;
library->dataOffset += index;
/* Verify file length */
if(tmp + library->dataOffset != (uint32_t)library->length) {
return -2;
}
return 0;
}
static int ZDPointInBox(int32_t xl, int32_t x, int32_t xr, int32_t yl, int32_t y, int32_t yr)
{
if((xl <= x && x <= xr) || (xr <= x && x <= xl)) {
if((yl <= y && y <= yr) || (yr <= y && y <= yl)) {
return 1;
}
}
return 0;
}
static uint32_t ZDUnshuffle(uint64_t w)
{
w &= 0x5555555555555555llu;
w = (w | (w >> 1)) & 0x3333333333333333llu;
w = (w | (w >> 2)) & 0x0F0F0F0F0F0F0F0Fllu;
w = (w | (w >> 4)) & 0x00FF00FF00FF00FFllu;
w = (w | (w >> 8)) & 0x0000FFFF0000FFFFllu;
w = (w | (w >> 16)) & 0x00000000FFFFFFFFllu;
return (uint32_t)w;
}
static void ZDDecodePoint(uint64_t point, int32_t* lat, int32_t* lon)
{
*lat = (int32_t)ZDDecodeUnsignedToSigned(ZDUnshuffle(point));
*lon = (int32_t)ZDDecodeUnsignedToSigned(ZDUnshuffle(point >> 1));
}
struct Reader {
const ZoneDetect *library;
uint32_t polygonIndex;
uint64_t numVertices;
uint8_t done, first;
uint32_t referenceStart, referenceEnd;
int32_t referenceDirection;
int32_t pointLat, pointLon;
int32_t firstLat, firstLon;
};
static void ZDReaderInit(struct Reader *reader, const ZoneDetect *library, uint32_t polygonIndex)
{
memset(reader, 0, sizeof(*reader));
reader->library = library;
reader->polygonIndex = polygonIndex;
reader->first = 1;
}
static int ZDReaderGetPoint(struct Reader *reader, int32_t *pointLat, int32_t *pointLon)
{
int32_t diffLat = 0, diffLon = 0;
readNewPoint:
if(reader->done > 1) {
return 0;
}
if(reader->first && reader->library->version == 0) {
if(!ZDDecodeVariableLengthUnsigned(reader->library, &reader->polygonIndex, &reader->numVertices)) return -1;
if(!reader->numVertices) return -1;
}
uint8_t referenceDone = 0;
if(reader->library->version == 1) {
uint64_t point = 0;
if(!reader->referenceDirection) {
if(!ZDDecodeVariableLengthUnsigned(reader->library, &reader->polygonIndex, &point)) return -1;
} else {
if(reader->referenceDirection > 0) {
/* Read reference forward */
if(!ZDDecodeVariableLengthUnsigned(reader->library, &reader->referenceStart, &point)) return -1;
if(reader->referenceStart >= reader->referenceEnd) {
referenceDone = 1;
}
} else if(reader->referenceDirection < 0) {
/* Read reference backwards */
if(!ZDDecodeVariableLengthUnsignedReverse(reader->library, &reader->referenceStart, &point)) return -1;
if(reader->referenceStart <= reader->referenceEnd) {
referenceDone = 1;
}
}
}
if(!point) {
/* This is a special marker, it is not allowed in reference mode */
if(reader->referenceDirection) {
return -1;
}
uint64_t value;
if(!ZDDecodeVariableLengthUnsigned(reader->library, &reader->polygonIndex, &value)) return -1;
if(value == 0) {
reader->done = 2;
} else if(value == 1) {
int32_t diff;
int64_t start;
if(!ZDDecodeVariableLengthUnsigned(reader->library, &reader->polygonIndex, (uint64_t*)&start)) return -1;
if(!ZDDecodeVariableLengthSigned(reader->library, &reader->polygonIndex, &diff)) return -1;
reader->referenceStart = reader->library->dataOffset+(uint32_t)start;
reader->referenceEnd = reader->library->dataOffset+(uint32_t)(start + diff);
reader->referenceDirection = diff;
if(diff < 0) {
reader->referenceStart--;
reader->referenceEnd--;
}
goto readNewPoint;
}
} else {
ZDDecodePoint(point, &diffLat, &diffLon);
if(reader->referenceDirection < 0) {
diffLat = -diffLat;
diffLon = -diffLon;
}
}
}
if(reader->library->version == 0) {
if(!ZDDecodeVariableLengthSigned(reader->library, &reader->polygonIndex, &diffLat)) return -1;
if(!ZDDecodeVariableLengthSigned(reader->library, &reader->polygonIndex, &diffLon)) return -1;
}
if(!reader->done) {
reader->pointLat += diffLat;
reader->pointLon += diffLon;
if(reader->first) {
reader->firstLat = reader->pointLat;
reader->firstLon = reader->pointLon;
}
} else {
/* Close the polygon (the closing point is not encoded) */
reader->pointLat = reader->firstLat;
reader->pointLon = reader->firstLon;
reader->done = 2;
}
reader->first = 0;
if(reader->library->version == 0) {
reader->numVertices--;
if(!reader->numVertices) {
reader->done = 1;
}
if(!diffLat && !diffLon) {
goto readNewPoint;
}
}
if(referenceDone) {
reader->referenceDirection = 0;
}
if(pointLat) {
*pointLat = reader->pointLat;
}
if(pointLon) {
*pointLon = reader->pointLon;
}
return 1;
}
static int ZDFindPolygon(const ZoneDetect *library, uint32_t wantedId, uint32_t* metadataIndexPtr, uint32_t* polygonIndexPtr)
{
uint32_t polygonId = 0;
uint32_t bboxIndex = library->bboxOffset;
uint32_t metadataIndex = 0, polygonIndex = 0;
while(bboxIndex < library->metadataOffset) {
uint64_t polygonIndexDelta;
int32_t metadataIndexDelta;
int32_t tmp;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &tmp)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &tmp)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &tmp)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &tmp)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &metadataIndexDelta)) break;
if(!ZDDecodeVariableLengthUnsigned(library, &bboxIndex, &polygonIndexDelta)) break;
metadataIndex += (uint32_t)metadataIndexDelta;
polygonIndex += (uint32_t)polygonIndexDelta;
if(polygonId == wantedId) {
if(metadataIndexPtr) {
metadataIndex += library->metadataOffset;
*metadataIndexPtr = metadataIndex;
}
if(polygonIndexPtr) {
polygonIndex += library->dataOffset;
*polygonIndexPtr = polygonIndex;
}
return 1;
}
polygonId ++;
}
return 0;
}
static int32_t* ZDPolygonToListInternal(const ZoneDetect *library, uint32_t polygonIndex, size_t* length)
{
struct Reader reader;
ZDReaderInit(&reader, library, polygonIndex);
size_t listLength = 2 * 100;
size_t listIndex = 0;
int32_t* list = malloc(sizeof(int32_t) * listLength);
if(!list) {
goto fail;
}
while(1) {
int32_t pointLat, pointLon;
int result = ZDReaderGetPoint(&reader, &pointLat, &pointLon);
if(result < 0) {
goto fail;
} else if(result == 0) {
break;
}
if(listIndex >= listLength) {
listLength *= 2;
if(listLength >= 1048576) {
goto fail;
}
list = realloc(list, sizeof(int32_t) * listLength);
if(!list) {
goto fail;
}
}
list[listIndex++] = pointLat;
list[listIndex++] = pointLon;
}
if(length) {
*length = listIndex;
}
return list;
fail:
if(list) {
free(list);
}
return NULL;
}
float* ZDPolygonToList(const ZoneDetect *library, uint32_t polygonId, size_t* lengthPtr)
{
uint32_t polygonIndex;
int32_t* data = NULL;
float* flData = NULL;
if(!ZDFindPolygon(library, polygonId, NULL, &polygonIndex)) {
goto fail;
}
size_t length = 0;
data = ZDPolygonToListInternal(library, polygonIndex, &length);
if(!data) {
goto fail;
}
flData = malloc(sizeof(float) * length);
if(!flData) {
goto fail;
}
size_t i;
for(i = 0; i<length; i+= 2) {
int32_t lat = data[i];
int32_t lon = data[i+1];
flData[i] = ZDFixedPointToFloat(lat, 90, library->precision);
flData[i+1] = ZDFixedPointToFloat(lon, 180, library->precision);
}
if(lengthPtr) {
*lengthPtr = length;
}
return flData;
fail:
if(data) {
free(data);
}
if(flData) {
free(flData);
}
return NULL;
}
static ZDLookupResult ZDPointInPolygon(const ZoneDetect *library, uint32_t polygonIndex, int32_t latFixedPoint, int32_t lonFixedPoint, uint64_t *distanceSqrMin)
{
int32_t pointLat, pointLon, prevLat = 0, prevLon = 0;
int prevQuadrant = 0, winding = 0;
uint8_t first = 1;
struct Reader reader;
ZDReaderInit(&reader, library, polygonIndex);
while(1) {
int result = ZDReaderGetPoint(&reader, &pointLat, &pointLon);
if(result < 0) {
return ZD_LOOKUP_PARSE_ERROR;
} else if(result == 0) {
break;
}
/* Check if point is ON the border */
if(pointLat == latFixedPoint && pointLon == lonFixedPoint) {
if(distanceSqrMin) *distanceSqrMin = 0;
return ZD_LOOKUP_ON_BORDER_VERTEX;
}
/* Find quadrant */
int quadrant;
if(pointLat >= latFixedPoint) {
if(pointLon >= lonFixedPoint) {
quadrant = 0;
} else {
quadrant = 1;
}
} else {
if(pointLon >= lonFixedPoint) {
quadrant = 3;
} else {
quadrant = 2;
}
}
if(!first) {
int windingNeedCompare = 0, lineIsStraight = 0;
float a = 0, b = 0;
/* Calculate winding number */
if(quadrant == prevQuadrant) {
/* Do nothing */
} else if(quadrant == (prevQuadrant + 1) % 4) {
winding ++;
} else if((quadrant + 1) % 4 == prevQuadrant) {
winding --;
} else {
windingNeedCompare = 1;
}
/* Avoid horizontal and vertical lines */
if((pointLon == prevLon || pointLat == prevLat)) {
lineIsStraight = 1;
}
/* Calculate the parameters of y=ax+b if needed */
if(!lineIsStraight && (distanceSqrMin || windingNeedCompare)) {
a = ((float)pointLat - (float)prevLat) / ((float)pointLon - (float)prevLon);
b = (float)pointLat - a * (float)pointLon;
}
int onStraight = ZDPointInBox(pointLat, latFixedPoint, prevLat, pointLon, lonFixedPoint, prevLon);
if(lineIsStraight && (onStraight || windingNeedCompare)) {
if(distanceSqrMin) *distanceSqrMin = 0;
return ZD_LOOKUP_ON_BORDER_SEGMENT;
}
/* Jumped two quadrants. */
if(windingNeedCompare) {
/* Check if the target is on the border */
const int32_t intersectLon = (int32_t)(((float)latFixedPoint - b) / a);
if(intersectLon >= lonFixedPoint-1 && intersectLon <= lonFixedPoint+1) {
if(distanceSqrMin) *distanceSqrMin = 0;
return ZD_LOOKUP_ON_BORDER_SEGMENT;
}
/* Ok, it's not. In which direction did we go round the target? */
const int sign = (intersectLon < lonFixedPoint) ? 2 : -2;
if(quadrant == 2 || quadrant == 3) {
winding += sign;
} else {
winding -= sign;
}
}
/* Calculate closest point on line (if needed) */
if(distanceSqrMin) {
float closestLon, closestLat;
if(!lineIsStraight) {
closestLon = ((float)lonFixedPoint + a * (float)latFixedPoint - a * b) / (a * a + 1);
closestLat = (a * ((float)lonFixedPoint + a * (float)latFixedPoint) + b) / (a * a + 1);
} else {
if(pointLon == prevLon) {
closestLon = (float)pointLon;
closestLat = (float)latFixedPoint;
} else {
closestLon = (float)lonFixedPoint;
closestLat = (float)pointLat;
}
}
const int closestInBox = ZDPointInBox(pointLon, (int32_t)closestLon, prevLon, pointLat, (int32_t)closestLat, prevLat);
int64_t diffLat, diffLon;
if(closestInBox) {
/* Calculate squared distance to segment. */
diffLat = (int64_t)(closestLat - (float)latFixedPoint);
diffLon = (int64_t)(closestLon - (float)lonFixedPoint);
} else {
/*
* Calculate squared distance to vertices
* It is enough to check the current point since the polygon is closed.
*/
diffLat = (int64_t)(pointLat - latFixedPoint);
diffLon = (int64_t)(pointLon - lonFixedPoint);
}
/* Note: lon has half scale */
uint64_t distanceSqr = (uint64_t)(diffLat * diffLat) + (uint64_t)(diffLon * diffLon) * 4;
if(distanceSqr < *distanceSqrMin) *distanceSqrMin = distanceSqr;
}
}
prevQuadrant = quadrant;
prevLat = pointLat;
prevLon = pointLon;
first = 0;
};
if(winding == -4) {
return ZD_LOOKUP_IN_ZONE;
} else if(winding == 4) {
return ZD_LOOKUP_IN_EXCLUDED_ZONE;
} else if(winding == 0) {
return ZD_LOOKUP_NOT_IN_ZONE;
}
/* Should not happen */
if(distanceSqrMin) *distanceSqrMin = 0;
return ZD_LOOKUP_ON_BORDER_SEGMENT;
}
void ZDCloseDatabase(ZoneDetect *library)
{
if(library) {
if(library->fieldNames) {
size_t i;
for(i = 0; i < (size_t)library->numFields; i++) {
if(library->fieldNames[i]) {
free(library->fieldNames[i]);
}
}
free(library->fieldNames);
}
if(library->notice) {
free(library->notice);
}
if(library->closeType == 0) {
#if defined(_MSC_VER) || defined(__MINGW32__)
if(library->mapping && !UnmapViewOfFile(library->mapping)) zdError(ZD_E_DB_MUNMAP_MSVIEW, (int)GetLastError());
if(library->fdMap && !CloseHandle(library->fdMap)) zdError(ZD_E_DB_MUNMAP, (int)GetLastError());
if(library->fd && !CloseHandle(library->fd)) zdError(ZD_E_DB_CLOSE, (int)GetLastError());
#elif defined(__APPLE__) || defined(__linux__) || defined(__unix__) || defined(_POSIX_VERSION)
if(library->mapping && munmap(library->mapping, (size_t)(library->length))) zdError(ZD_E_DB_MUNMAP, 0);
if(library->fd >= 0 && close(library->fd)) zdError(ZD_E_DB_CLOSE, 0);
#endif
}
free(library);
}
}
ZoneDetect *ZDOpenDatabaseFromMemory(void* buffer, size_t length)
{
ZoneDetect *const library = malloc(sizeof *library);
if(library) {
memset(library, 0, sizeof(*library));
library->closeType = 1;
library->length = (long int)length;
if(library->length <= 0) {
#if defined(_MSC_VER) || defined(__MINGW32__) || defined(__APPLE__) || defined(__linux__) || defined(__unix__) || defined(_POSIX_VERSION)
zdError(ZD_E_DB_SEEK, errno);
#else
zdError(ZD_E_DB_SEEK, 0);
#endif
goto fail;
}
library->mapping = buffer;
/* Parse the header */
if(ZDParseHeader(library)) {
zdError(ZD_E_PARSE_HEADER, 0);
goto fail;
}
}
return library;
fail:
ZDCloseDatabase(library);
return NULL;
}
ZoneDetect *ZDOpenDatabase(const char *path)
{
ZoneDetect *const library = malloc(sizeof *library);
if(library) {
memset(library, 0, sizeof(*library));
#if defined(_MSC_VER) || defined(__MINGW32__)
library->fd = CreateFile(path, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (library->fd == INVALID_HANDLE_VALUE) {
zdError(ZD_E_DB_OPEN, (int)GetLastError());
goto fail;
}
const DWORD fsize = GetFileSize(library->fd, NULL);
if (fsize == INVALID_FILE_SIZE) {
zdError(ZD_E_DB_SEEK, (int)GetLastError());
goto fail;
}
library->length = (int32_t)fsize;
library->fdMap = CreateFileMappingA(library->fd, NULL, PAGE_READONLY, 0, 0, NULL);
if (!library->fdMap) {
zdError(ZD_E_DB_MMAP, (int)GetLastError());
goto fail;
}
library->mapping = MapViewOfFile(library->fdMap, FILE_MAP_READ, 0, 0, 0);
if (!library->mapping) {
zdError(ZD_E_DB_MMAP_MSVIEW, (int)GetLastError());
goto fail;
}
#elif defined(__APPLE__) || defined(__linux__) || defined(__unix__) || defined(_POSIX_VERSION)
library->fd = open(path, O_RDONLY | O_CLOEXEC);
if(library->fd < 0) {
zdError(ZD_E_DB_OPEN, errno);
goto fail;
}
library->length = lseek(library->fd, 0, SEEK_END);
if(library->length <= 0 || library->length > 50331648) {
zdError(ZD_E_DB_SEEK, errno);
goto fail;
}
lseek(library->fd, 0, SEEK_SET);
library->mapping = mmap(NULL, (size_t)library->length, PROT_READ, MAP_PRIVATE | MAP_FILE, library->fd, 0);
if(library->mapping == MAP_FAILED) {
zdError(ZD_E_DB_MMAP, errno);
goto fail;
}
#endif
/* Parse the header */
if(ZDParseHeader(library)) {
zdError(ZD_E_PARSE_HEADER, 0);
goto fail;
}
}
return library;
fail:
ZDCloseDatabase(library);
return NULL;
}
ZoneDetectResult *ZDLookup(const ZoneDetect *library, float lat, float lon, float *safezone)
{
const int32_t latFixedPoint = ZDFloatToFixedPoint(lat, 90, library->precision);
const int32_t lonFixedPoint = ZDFloatToFixedPoint(lon, 180, library->precision);
size_t numResults = 0;
uint64_t distanceSqrMin = (uint64_t)-1;
/* Iterate over all polygons */
uint32_t bboxIndex = library->bboxOffset;
uint32_t metadataIndex = 0;
uint32_t polygonIndex = 0;
ZoneDetectResult *results = malloc(sizeof *results);
if(!results) {
return NULL;
}
uint32_t polygonId = 0;
while(bboxIndex < library->metadataOffset) {
int32_t minLat, minLon, maxLat, maxLon, metadataIndexDelta;
uint64_t polygonIndexDelta;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &minLat)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &minLon)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &maxLat)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &maxLon)) break;
if(!ZDDecodeVariableLengthSigned(library, &bboxIndex, &metadataIndexDelta)) break;
if(!ZDDecodeVariableLengthUnsigned(library, &bboxIndex, &polygonIndexDelta)) break;
metadataIndex += (uint32_t)metadataIndexDelta;
polygonIndex += (uint32_t)polygonIndexDelta;
if(latFixedPoint >= minLat) {
if(latFixedPoint <= maxLat &&
lonFixedPoint >= minLon &&
lonFixedPoint <= maxLon) {
const ZDLookupResult lookupResult = ZDPointInPolygon(library, library->dataOffset + polygonIndex, latFixedPoint, lonFixedPoint, (safezone) ? &distanceSqrMin : NULL);
if(lookupResult == ZD_LOOKUP_PARSE_ERROR) {
break;
} else if(lookupResult != ZD_LOOKUP_NOT_IN_ZONE) {
ZoneDetectResult *const newResults = realloc(results, sizeof *newResults * (numResults + 2));
if(newResults) {
results = newResults;
results[numResults].polygonId = polygonId;
results[numResults].metaId = metadataIndex;
results[numResults].numFields = library->numFields;
results[numResults].fieldNames = library->fieldNames;
results[numResults].lookupResult = lookupResult;
numResults++;
} else {
break;
}
}
}
} else {
/* The data is sorted along minLat */
break;
}
polygonId++;
}
/* Clean up results */
size_t i;
for(i = 0; i < numResults; i++) {
int insideSum = 0;
ZDLookupResult overrideResult = ZD_LOOKUP_IGNORE;
size_t j;
for(j = i; j < numResults; j++) {
if(results[i].metaId == results[j].metaId) {
ZDLookupResult tmpResult = results[j].lookupResult;
results[j].lookupResult = ZD_LOOKUP_IGNORE;
/* This is the same result. Is it an exclusion zone? */
if(tmpResult == ZD_LOOKUP_IN_ZONE) {
insideSum++;
} else if(tmpResult == ZD_LOOKUP_IN_EXCLUDED_ZONE) {
insideSum--;
} else {
/* If on the bodrder then the final result is on the border */
overrideResult = tmpResult;