PostGIS  3.7.0dev-r@@SVN_REVISION@@

◆ ptarray_scroll_in_place()

int ptarray_scroll_in_place ( POINTARRAY pa,
const POINT4D pt 
)

Definition at line 2202 of file ptarray.c.

2203 {
2204  POINTARRAY *tmp;
2205  int found;
2206  uint32_t it;
2207  int ptsize;
2208 
2209  if ( ! ptarray_is_closed_2d(pa) )
2210  {
2211  lwerror("ptarray_scroll_in_place: input POINTARRAY is not closed");
2212  return LW_FAILURE;
2213  }
2214 
2215  ptsize = ptarray_point_size(pa);
2216 
2217  /* Find the point in the array */
2218  found = 0;
2219  for ( it = 0; it < pa->npoints; ++it )
2220  {
2221  if ( ! memcmp(getPoint_internal(pa, it), pt, ptsize) )
2222  {
2223  found = 1;
2224  break;
2225  }
2226  }
2227 
2228  if ( ! found )
2229  {
2230  lwerror("ptarray_scroll_in_place: input POINTARRAY does not contain the given point");
2231  return LW_FAILURE;
2232  }
2233 
2234  if ( 0 == it )
2235  {
2236  /* Point is already the start/end point, just clone the input */
2237  return LW_SUCCESS;
2238  }
2239 
2240  /* TODO: reduce allocations */
2242 
2243  memset(getPoint_internal(tmp, 0), 0, (size_t)ptsize * pa->npoints);
2244  /* Copy the block from found point to last point into the output array */
2245  memcpy(
2246  getPoint_internal(tmp, 0),
2247  getPoint_internal(pa, it),
2248  (size_t)ptsize * ( pa->npoints - it )
2249  );
2250 
2251  /* Copy the block from second point to the found point into the last portion of the
2252  * return */
2253  memcpy(
2254  getPoint_internal(tmp, pa->npoints - it),
2255  getPoint_internal(pa, 1),
2256  (size_t)ptsize * ( it )
2257  );
2258 
2259  /* Copy the resulting pointarray back to source one */
2260  memcpy(
2261  getPoint_internal(pa, 0),
2262  getPoint_internal(tmp, 0),
2263  (size_t)ptsize * ( pa->npoints )
2264  );
2265 
2266  ptarray_free(tmp);
2267 
2268  return LW_SUCCESS;
2269 }
#define LW_FAILURE
Definition: liblwgeom.h:96
#define LW_SUCCESS
Definition: liblwgeom.h:97
#define FLAGS_GET_Z(flags)
Definition: liblwgeom.h:165
#define FLAGS_GET_M(flags)
Definition: liblwgeom.h:166
void void lwerror(const char *fmt,...) __attribute__((format(printf
Write a notice out to the error handler.
static size_t ptarray_point_size(const POINTARRAY *pa)
Definition: lwinline.h:56
static uint8_t * getPoint_internal(const POINTARRAY *pa, uint32_t n)
Definition: lwinline.h:75
int ptarray_is_closed_2d(const POINTARRAY *in)
Definition: ptarray.c:710
POINTARRAY * ptarray_construct(char hasz, char hasm, uint32_t npoints)
Construct an empty pointarray, allocating storage and setting the npoints, but not filling in any inf...
Definition: ptarray.c:51
void ptarray_free(POINTARRAY *pa)
Definition: ptarray.c:327
lwflags_t flags
Definition: liblwgeom.h:431
uint32_t npoints
Definition: liblwgeom.h:427

References POINTARRAY::flags, FLAGS_GET_M, FLAGS_GET_Z, getPoint_internal(), LW_FAILURE, LW_SUCCESS, lwerror(), POINTARRAY::npoints, ptarray_construct(), ptarray_free(), ptarray_is_closed_2d(), and ptarray_point_size().

Referenced by _lwt_AddLine(), ST_Scroll(), and test_ptarray_scroll().

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