PostGIS 3.7.0dev-r@@SVN_REVISION@@
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◆ create_multipolygon()

static SHPObject * create_multipolygon ( SHPDUMPERSTATE state,
LWMPOLY lwmultipolygon 
)
static

Definition at line 265 of file pgsql2shp-core.c.

266{
267 SHPObject *obj;
268 POINT4D p4d;
269 uint32_t i, j, k;
270
271 double *xpts, *ypts, *zpts, *mpts;
272
273 int *shpparts, shppointtotal = 0, shppoint = 0, shpringtotal = 0, shpring = 0;
274
275 /* NOTE: Multipolygons are stored in shapefiles as Polygon* shapes with multiple outer rings */
276
277 /* First count through each ring of each polygon so we now know much memory is required */
278 for (i = 0; i < lwmultipolygon->ngeoms; i++)
279 {
280 for (j = 0; j < lwmultipolygon->geoms[i]->nrings; j++)
281 {
282 shpringtotal++;
283 shppointtotal += lwmultipolygon->geoms[i]->rings[j]->npoints;
284 }
285 }
286
287 /* Allocate storage for ring pointers */
288 shpparts = malloc(sizeof(int) * shpringtotal);
289
290 /* Allocate storage for points */
291 xpts = malloc(sizeof(double) * shppointtotal);
292 ypts = malloc(sizeof(double) * shppointtotal);
293 zpts = malloc(sizeof(double) * shppointtotal);
294 mpts = malloc(sizeof(double) * shppointtotal);
295
296 LWDEBUGF(4, "Total number of rings: %d Total number of points: %d", shpringtotal, shppointtotal);
297
298 /* Iterate through each ring of each polygon in turn */
299 for (i = 0; i < lwmultipolygon->ngeoms; i++)
300 {
301 for (j = 0; j < lwmultipolygon->geoms[i]->nrings; j++)
302 {
303 /* For each ring, store the integer coordinate offset for the start of each ring */
304 shpparts[shpring] = shppoint;
305
306 LWDEBUGF(4, "Ring offset: %d", shpring);
307
308 for (k = 0; k < lwmultipolygon->geoms[i]->rings[j]->npoints; k++)
309 {
310 p4d = getPoint4d(lwmultipolygon->geoms[i]->rings[j], k);
311
312 xpts[shppoint] = p4d.x;
313 ypts[shppoint] = p4d.y;
314 zpts[shppoint] = p4d.z;
315 mpts[shppoint] = p4d.m;
316
317 LWDEBUGF(4, "MultiPolygon %d Polygon Ring %d - Point: %g %g %g %g", i, j, xpts[shppoint], ypts[shppoint], zpts[shppoint], mpts[shppoint]);
318
319 /* Increment the point counter */
320 shppoint++;
321 }
322
323 /*
324 * First ring should be clockwise,
325 * other rings should be counter-clockwise
326 */
327 if ( j == 0 )
328 {
329 if ( ! is_clockwise(lwmultipolygon->geoms[i]->rings[j]->npoints,
330 &xpts[shpparts[shpring]], &ypts[shpparts[shpring]], NULL) )
331 {
332 LWDEBUG(4, "Outer ring not clockwise, forcing clockwise\n");
333
334 reverse_points(lwmultipolygon->geoms[i]->rings[j]->npoints,
335 &xpts[shpparts[shpring]], &ypts[shpparts[shpring]],
336 &zpts[shpparts[shpring]], &mpts[shpparts[shpring]]);
337 }
338 }
339 else
340 {
341 if ( is_clockwise(lwmultipolygon->geoms[i]->rings[j]->npoints,
342 &xpts[shpparts[shpring]], &ypts[shpparts[shpring]], NULL) )
343 {
344 LWDEBUGF(4, "Inner ring %d not counter-clockwise, forcing counter-clockwise\n", i);
345
346 reverse_points(lwmultipolygon->geoms[i]->rings[j]->npoints,
347 &xpts[shpparts[shpring]], &ypts[shpparts[shpring]],
348 &zpts[shpparts[shpring]], &mpts[shpparts[shpring]]);
349 }
350 }
351
352 /* Increment the ring counter */
353 shpring++;
354 }
355 }
356
357 obj = SHPCreateObject(state->outshptype, -1, shpringtotal, shpparts, NULL, shppointtotal, xpts, ypts, zpts, mpts);
358
359 free(xpts);
360 free(ypts);
361 free(zpts);
362 free(mpts);
363 free(shpparts);
364
365 return obj;
366}
POINT4D getPoint4d(const POINTARRAY *pa, uint32_t n)
Definition lwgeom_api.c:107
#define LWDEBUG(level, msg)
Definition lwgeom_log.h:101
#define LWDEBUGF(level, msg,...)
Definition lwgeom_log.h:106
void * malloc(YYSIZE_T)
void free(void *)
static int reverse_points(int num_points, double *x, double *y, double *z, double *m)
static int is_clockwise(int num_points, double *x, double *y, double *z)
SHPObject SHPAPI_CALL1 * SHPCreateObject(int nSHPType, int nShapeId, int nParts, const int *panPartStart, const int *panPartType, int nVertices, const double *padfX, const double *padfY, const double *padfZ, const double *padfM);SHPObject SHPAPI_CALL1(*) SHPCreateSimpleObject(int nSHPType, int nVertices, const double *padfX, const double *padfY, const double *padfZ
uint32_t ngeoms
Definition liblwgeom.h:566
LWPOLY ** geoms
Definition liblwgeom.h:561
POINTARRAY ** rings
Definition liblwgeom.h:519
uint32_t nrings
Definition liblwgeom.h:524
double m
Definition liblwgeom.h:414
double x
Definition liblwgeom.h:414
double z
Definition liblwgeom.h:414
double y
Definition liblwgeom.h:414
uint32_t npoints
Definition liblwgeom.h:427

References free(), LWMPOLY::geoms, getPoint4d(), is_clockwise(), LWDEBUG, LWDEBUGF, POINT4D::m, malloc(), LWMPOLY::ngeoms, POINTARRAY::npoints, LWPOLY::nrings, shp_dumper_state::outshptype, reverse_points(), LWPOLY::rings, SHPCreateObject(), POINT4D::x, POINT4D::y, and POINT4D::z.

Referenced by ShpLoaderGenerateShapeRow().

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