PostGIS  2.5.0beta2dev-r@@SVN_REVISION@@

◆ lwcircstring_linearize()

static LWLINE* lwcircstring_linearize ( const LWCIRCSTRING icurve,
double  tol,
LW_LINEARIZE_TOLERANCE_TYPE  tolerance_type,
int  flags 
)
static

Definition at line 405 of file lwstroke.c.

References POINTARRAY::flags, FLAGS_GET_M, FLAGS_GET_Z, getPoint4d_p(), LW_TRUE, lwarc_linearize(), LWDEBUG, LWDEBUGF, lwline_construct(), POINTARRAY::npoints, LWCIRCSTRING::points, ptarray_append_point(), ptarray_construct_empty(), ptarray_free(), and LWCIRCSTRING::srid.

Referenced by lwcollection_linearize(), lwcompound_linearize(), lwcurve_linearize(), lwcurvepoly_linearize(), and lwmcurve_linearize().

408 {
409  LWLINE *oline;
410  POINTARRAY *ptarray;
411  uint32_t i, j;
412  POINT4D p1, p2, p3, p4;
413  int ret;
414 
415  LWDEBUGF(2, "lwcircstring_linearize called., dim = %d", icurve->points->flags);
416 
417  ptarray = ptarray_construct_empty(FLAGS_GET_Z(icurve->points->flags), FLAGS_GET_M(icurve->points->flags), 64);
418 
419  for (i = 2; i < icurve->points->npoints; i+=2)
420  {
421  LWDEBUGF(3, "lwcircstring_linearize: arc ending at point %d", i);
422 
423  getPoint4d_p(icurve->points, i - 2, &p1);
424  getPoint4d_p(icurve->points, i - 1, &p2);
425  getPoint4d_p(icurve->points, i, &p3);
426 
427  ret = lwarc_linearize(ptarray, &p1, &p2, &p3, tol, tolerance_type, flags);
428  if ( ret > 0 )
429  {
430  LWDEBUGF(3, "lwcircstring_linearize: generated %d points", ptarray->npoints);
431  }
432  else if ( ret == 0 )
433  {
434  LWDEBUG(3, "lwcircstring_linearize: points are colinear, returning curve points as line");
435 
436  for (j = i - 2 ; j < i ; j++)
437  {
438  getPoint4d_p(icurve->points, j, &p4);
439  ptarray_append_point(ptarray, &p4, LW_TRUE);
440  }
441  }
442  else
443  {
444  /* An error occurred, lwerror should have been called by now */
445  ptarray_free(ptarray);
446  return NULL;
447  }
448  }
449  getPoint4d_p(icurve->points, icurve->points->npoints-1, &p1);
450  ptarray_append_point(ptarray, &p1, LW_TRUE);
451 
452  oline = lwline_construct(icurve->srid, NULL, ptarray);
453  return oline;
454 }
int32_t srid
Definition: liblwgeom.h:445
POINTARRAY * ptarray_construct_empty(char hasz, char hasm, uint32_t maxpoints)
Create a new POINTARRAY with no points.
Definition: ptarray.c:70
void ptarray_free(POINTARRAY *pa)
Definition: ptarray.c:328
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:83
static int lwarc_linearize(POINTARRAY *to, const POINT4D *p1, const POINT4D *p2, const POINT4D *p3, double tol, LW_LINEARIZE_TOLERANCE_TYPE tolerance_type, int flags)
Segmentize an arc.
Definition: lwstroke.c:135
unsigned int uint32_t
Definition: uthash.h:78
int ptarray_append_point(POINTARRAY *pa, const POINT4D *pt, int allow_duplicates)
Append a point to the end of an existing POINTARRAY If allow_duplicate is LW_FALSE, then a duplicate point will not be added.
Definition: ptarray.c:156
uint8_t flags
Definition: liblwgeom.h:371
#define LW_TRUE
Return types for functions with status returns.
Definition: liblwgeom.h:75
LWLINE * lwline_construct(int srid, GBOX *bbox, POINTARRAY *points)
Definition: lwline.c:42
#define FLAGS_GET_Z(flags)
Macros for manipulating the &#39;flags&#39; byte.
Definition: liblwgeom.h:139
int getPoint4d_p(const POINTARRAY *pa, uint32_t n, POINT4D *point)
Definition: lwgeom_api.c:113
#define FLAGS_GET_M(flags)
Definition: liblwgeom.h:140
POINTARRAY * points
Definition: liblwgeom.h:446
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:88
uint32_t npoints
Definition: liblwgeom.h:373
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