PostGIS  2.5.0beta2dev-r@@SVN_REVISION@@

◆ lwpoly_from_gserialized_buffer()

static LWPOLY* lwpoly_from_gserialized_buffer ( uint8_t data_ptr,
uint8_t  g_flags,
size_t *  g_size 
)
static

Definition at line 1311 of file g_serialized.c.

References LWPOLY::bbox, LWPOLY::flags, FLAGS_GET_M, FLAGS_GET_Z, FLAGS_NDIMS, gserialized_get_uint32_t(), lwalloc(), LWDEBUGF, LWPOLY::maxrings, LWPOLY::nrings, POLYGONTYPE, ptarray_construct_reference_data(), LWPOLY::rings, LWPOLY::srid, SRID_UNKNOWN, and LWPOLY::type.

Referenced by lwgeom_from_gserialized_buffer().

1312 {
1313  uint8_t *start_ptr = data_ptr;
1314  LWPOLY *poly;
1315  uint8_t *ordinate_ptr;
1316  uint32_t nrings = 0;
1317  uint32_t i = 0;
1318 
1319  assert(data_ptr);
1320 
1321  poly = (LWPOLY*)lwalloc(sizeof(LWPOLY));
1322  poly->srid = SRID_UNKNOWN; /* Default */
1323  poly->bbox = NULL;
1324  poly->type = POLYGONTYPE;
1325  poly->flags = g_flags;
1326 
1327  data_ptr += 4; /* Skip past the polygontype. */
1328  nrings = gserialized_get_uint32_t(data_ptr); /* Zero => empty geometry */
1329  poly->nrings = nrings;
1330  LWDEBUGF(4, "nrings = %d", nrings);
1331  data_ptr += 4; /* Skip past the nrings. */
1332 
1333  ordinate_ptr = data_ptr; /* Start the ordinate pointer. */
1334  if ( nrings > 0)
1335  {
1336  poly->rings = (POINTARRAY**)lwalloc( sizeof(POINTARRAY*) * nrings );
1337  poly->maxrings = nrings;
1338  ordinate_ptr += nrings * 4; /* Move past all the npoints values. */
1339  if ( nrings % 2 ) /* If there is padding, move past that too. */
1340  ordinate_ptr += 4;
1341  }
1342  else /* Empty polygon */
1343  {
1344  poly->rings = NULL;
1345  poly->maxrings = 0;
1346  }
1347 
1348  for ( i = 0; i < nrings; i++ )
1349  {
1350  uint32_t npoints = 0;
1351 
1352  /* Read in the number of points. */
1353  npoints = gserialized_get_uint32_t(data_ptr);
1354  data_ptr += 4;
1355 
1356  /* Make a point array for the ring, and move the ordinate pointer past the ring ordinates. */
1357  poly->rings[i] = ptarray_construct_reference_data(FLAGS_GET_Z(g_flags), FLAGS_GET_M(g_flags), npoints, ordinate_ptr);
1358 
1359  ordinate_ptr += sizeof(double) * FLAGS_NDIMS(g_flags) * npoints;
1360  }
1361 
1362  if ( g_size )
1363  *g_size = ordinate_ptr - start_ptr;
1364 
1365  return poly;
1366 }
#define POLYGONTYPE
Definition: liblwgeom.h:86
GBOX * bbox
Definition: liblwgeom.h:455
uint32_t nrings
Definition: liblwgeom.h:457
unsigned int uint32_t
Definition: uthash.h:78
uint8_t type
Definition: liblwgeom.h:453
uint32_t maxrings
Definition: liblwgeom.h:458
#define SRID_UNKNOWN
Unknown SRID value.
Definition: liblwgeom.h:187
POINTARRAY * ptarray_construct_reference_data(char hasz, char hasm, uint32_t npoints, uint8_t *ptlist)
Construct a new POINTARRAY, referencing to the data from ptlist.
Definition: ptarray.c:293
POINTARRAY ** rings
Definition: liblwgeom.h:459
#define FLAGS_GET_Z(flags)
Macros for manipulating the &#39;flags&#39; byte.
Definition: liblwgeom.h:139
int32_t srid
Definition: liblwgeom.h:456
#define FLAGS_GET_M(flags)
Definition: liblwgeom.h:140
tuple g_size
Definition: genraster.py:41
uint8_t flags
Definition: liblwgeom.h:454
void * lwalloc(size_t size)
Definition: lwutil.c:229
static uint32_t gserialized_get_uint32_t(const uint8_t *loc)
Definition: g_serialized.c:35
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:88
#define FLAGS_NDIMS(flags)
Definition: liblwgeom.h:151
unsigned char uint8_t
Definition: uthash.h:79
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