PostGIS 3.7.0dev-r@@SVN_REVISION@@
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◆ gserialized1_from_lwgeom()

GSERIALIZED * gserialized1_from_lwgeom ( LWGEOM geom,
size_t *  size 
)

Allocate a new GSERIALIZED from an LWGEOM.

For all non-point types, a bounding box will be calculated and embedded in the serialization. The geodetic flag is used to control the box calculation (cartesian or geocentric). If set, the size pointer will contain the size of the final output, which is useful for setting the PgSQL VARSIZE information.

Definition at line 1090 of file gserialized1.c.

1091{
1092 size_t expected_size = 0;
1093 size_t return_size = 0;
1094 uint8_t *serialized = NULL;
1095 uint8_t *ptr = NULL;
1096 GSERIALIZED *g = NULL;
1097 assert(geom);
1098
1099 /*
1100 ** See if we need a bounding box, add one if we don't have one.
1101 */
1102 if ( (! geom->bbox) && lwgeom_needs_bbox(geom) && (!lwgeom_is_empty(geom)) )
1103 {
1104 lwgeom_add_bbox(geom);
1105 }
1106
1107 /*
1108 ** Harmonize the flags to the state of the lwgeom
1109 */
1110 if ( geom->bbox )
1111 FLAGS_SET_BBOX(geom->flags, 1);
1112 else
1113 FLAGS_SET_BBOX(geom->flags, 0);
1114
1115 /* Set up the uint8_t buffer into which we are going to write the serialized geometry. */
1116 expected_size = gserialized1_from_lwgeom_size(geom);
1117 serialized = lwalloc(expected_size);
1118 ptr = serialized;
1119
1120 /* Move past size, srid and flags. */
1121 ptr += 8;
1122
1123 /* Write in the serialized form of the gbox, if necessary. */
1124 if ( geom->bbox )
1125 ptr += gserialized1_from_gbox(geom->bbox, ptr);
1126
1127 /* Write in the serialized form of the geometry. */
1128 ptr += gserialized1_from_lwgeom_any(geom, ptr);
1129
1130 /* Calculate size as returned by data processing functions. */
1131 return_size = ptr - serialized;
1132
1133 if ( expected_size != return_size ) /* Uh oh! */
1134 {
1135 lwerror("Return size (%zu) not equal to expected size (%zu)!", return_size, expected_size);
1136 return NULL;
1137 }
1138
1139 if ( size ) /* Return the output size to the caller if necessary. */
1140 *size = return_size;
1141
1142 g = (GSERIALIZED*)serialized;
1143
1144 /*
1145 ** We are aping PgSQL code here, PostGIS code should use
1146 ** VARSIZE to set this for real.
1147 */
1148 g->size = return_size << 2;
1149
1150 /* Set the SRID! */
1151 gserialized1_set_srid(g, geom->srid);
1152
1153 g->gflags = lwflags_get_g1flags(geom->flags);
1154
1155 return g;
1156}
static size_t gserialized1_from_lwgeom_any(const LWGEOM *geom, uint8_t *buf)
static size_t gserialized1_from_gbox(const GBOX *gbox, uint8_t *buf)
size_t gserialized1_from_lwgeom_size(const LWGEOM *geom)
Return the memory size a GSERIALIZED will occupy for a given LWGEOM.
uint8_t lwflags_get_g1flags(lwflags_t lwflags)
void gserialized1_set_srid(GSERIALIZED *s, int32_t srid)
Write the SRID into the serialized form (it is packed into three bytes so this is a handy function).
#define FLAGS_SET_BBOX(flags, value)
Definition liblwgeom.h:174
int lwgeom_needs_bbox(const LWGEOM *geom)
Check whether or not a lwgeom is big enough to warrant a bounding box.
Definition lwgeom.c:1299
void * lwalloc(size_t size)
Definition lwutil.c:227
void lwgeom_add_bbox(LWGEOM *lwgeom)
Compute a bbox if not already computed.
Definition lwgeom.c:723
void void lwerror(const char *fmt,...) __attribute__((format(printf
Write a notice out to the error handler.
static int lwgeom_is_empty(const LWGEOM *geom)
Return true or false depending on whether a geometry is an "empty" geometry (no vertices members)
Definition lwinline.h:199
uint32_t size
Definition liblwgeom.h:444
uint8_t gflags
Definition liblwgeom.h:446
GBOX * bbox
Definition liblwgeom.h:458
int32_t srid
Definition liblwgeom.h:460
lwflags_t flags
Definition liblwgeom.h:461

References LWGEOM::bbox, LWGEOM::flags, FLAGS_SET_BBOX, GSERIALIZED::gflags, gserialized1_from_gbox(), gserialized1_from_lwgeom_any(), gserialized1_from_lwgeom_size(), gserialized1_set_srid(), lwalloc(), lwerror(), lwflags_get_g1flags(), lwgeom_add_bbox(), lwgeom_is_empty(), lwgeom_needs_bbox(), GSERIALIZED::size, and LWGEOM::srid.

Referenced by peek1_point_helper(), test_gbox_same_2d(), test_gserialized1_is_empty(), test_gserialized1_peek_gbox_p_gets_correct_box(), test_gserialized1_peek_gbox_p_no_box_when_empty(), test_lwgeom_from_gserialized(), and test_on_gser_lwgeom_count_vertices().

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