PostGIS 3.0.6dev-r@@SVN_REVISION@@
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◆ lwcircstring_linearize()

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

Definition at line 512 of file lwstroke.c.

515{
516 LWLINE *oline;
517 POINTARRAY *ptarray;
518 uint32_t i, j;
519 POINT4D p1, p2, p3, p4;
520 int ret;
521
522 LWDEBUGF(2, "lwcircstring_linearize called., dim = %d", icurve->points->flags);
523
524 ptarray = ptarray_construct_empty(FLAGS_GET_Z(icurve->points->flags), FLAGS_GET_M(icurve->points->flags), 64);
525
526 for (i = 2; i < icurve->points->npoints; i+=2)
527 {
528 LWDEBUGF(3, "lwcircstring_linearize: arc ending at point %d", i);
529
530 getPoint4d_p(icurve->points, i - 2, &p1);
531 getPoint4d_p(icurve->points, i - 1, &p2);
532 getPoint4d_p(icurve->points, i, &p3);
533
534 ret = lwarc_linearize(ptarray, &p1, &p2, &p3, tol, tolerance_type, flags);
535 if ( ret > 0 )
536 {
537 LWDEBUGF(3, "lwcircstring_linearize: generated %d points", ptarray->npoints);
538 }
539 else if ( ret == 0 )
540 {
541 LWDEBUG(3, "lwcircstring_linearize: points are colinear, returning curve points as line");
542
543 for (j = i - 2 ; j < i ; j++)
544 {
545 getPoint4d_p(icurve->points, j, &p4);
546 ptarray_append_point(ptarray, &p4, LW_TRUE);
547 }
548 }
549 else
550 {
551 /* An error occurred, lwerror should have been called by now */
552 ptarray_free(ptarray);
553 return NULL;
554 }
555 }
556 getPoint4d_p(icurve->points, icurve->points->npoints-1, &p1);
557 ptarray_append_point(ptarray, &p1, LW_FALSE);
558
559 oline = lwline_construct(icurve->srid, NULL, ptarray);
560 return oline;
561}
#define LW_FALSE
Definition liblwgeom.h:108
POINTARRAY * ptarray_construct_empty(char hasz, char hasm, uint32_t maxpoints)
Create a new POINTARRAY with no points.
Definition ptarray.c:59
#define FLAGS_GET_Z(flags)
Definition liblwgeom.h:179
LWLINE * lwline_construct(int32_t srid, GBOX *bbox, POINTARRAY *points)
Definition lwline.c:42
#define FLAGS_GET_M(flags)
Definition liblwgeom.h:180
int getPoint4d_p(const POINTARRAY *pa, uint32_t n, POINT4D *point)
Definition lwgeom_api.c:125
void ptarray_free(POINTARRAY *pa)
Definition ptarray.c:327
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,...
Definition ptarray.c:147
#define LW_TRUE
Return types for functions with status returns.
Definition liblwgeom.h:107
#define LWDEBUG(level, msg)
Definition lwgeom_log.h:83
#define LWDEBUGF(level, msg,...)
Definition lwgeom_log.h:88
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:239
int32_t srid
Definition liblwgeom.h:494
POINTARRAY * points
Definition liblwgeom.h:493
lwflags_t flags
Definition liblwgeom.h:417
uint32_t npoints
Definition liblwgeom.h:413

References POINTARRAY::flags, FLAGS_GET_M, FLAGS_GET_Z, getPoint4d_p(), LW_FALSE, 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().

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