PostGIS  2.3.8dev-r@@SVN_REVISION@@

◆ lw_dist2d_ptarray_ptarray()

int lw_dist2d_ptarray_ptarray ( POINTARRAY l1,
POINTARRAY l2,
DISTPTS dl 
)

test each segment of l1 against each segment of l2.

Definition at line 1131 of file measures.c.

References DIST_MAX, DIST_MIN, DISTPTS::distance, getPoint2d_cp(), lw_dist2d_pt_pt(), lw_dist2d_seg_seg(), LW_TRUE, LWDEBUGF, DISTPTS::mode, POINTARRAY::npoints, DISTPTS::tolerance, and DISTPTS::twisted.

Referenced by lw_dist2d_line_line(), lw_dist2d_line_poly(), and lw_dist2d_poly_poly().

1132 {
1133  int t,u;
1134  const POINT2D *start, *end;
1135  const POINT2D *start2, *end2;
1136  int twist = dl->twisted;
1137 
1138  LWDEBUGF(2, "lw_dist2d_ptarray_ptarray called (points: %d-%d)",l1->npoints, l2->npoints);
1139 
1140  if (dl->mode == DIST_MAX)/*If we are searching for maxdistance we go straight to point-point calculation since the maxdistance have to be between two vertexes*/
1141  {
1142  for (t=0; t<l1->npoints; t++) /*for each segment in L1 */
1143  {
1144  start = getPoint2d_cp(l1, t);
1145  for (u=0; u<l2->npoints; u++) /*for each segment in L2 */
1146  {
1147  start2 = getPoint2d_cp(l2, u);
1148  lw_dist2d_pt_pt(start, start2, dl);
1149  LWDEBUGF(4, "maxdist_ptarray_ptarray; seg %i * seg %i, dist = %g\n",t,u,dl->distance);
1150  LWDEBUGF(3, " seg%d-seg%d dist: %f, mindist: %f",
1151  t, u, dl->distance, dl->tolerance);
1152  }
1153  }
1154  }
1155  else
1156  {
1157  start = getPoint2d_cp(l1, 0);
1158  for (t=1; t<l1->npoints; t++) /*for each segment in L1 */
1159  {
1160  end = getPoint2d_cp(l1, t);
1161  start2 = getPoint2d_cp(l2, 0);
1162  for (u=1; u<l2->npoints; u++) /*for each segment in L2 */
1163  {
1164  end2 = getPoint2d_cp(l2, u);
1165  dl->twisted=twist;
1166  lw_dist2d_seg_seg(start, end, start2, end2, dl);
1167  LWDEBUGF(4, "mindist_ptarray_ptarray; seg %i * seg %i, dist = %g\n",t,u,dl->distance);
1168  LWDEBUGF(3, " seg%d-seg%d dist: %f, mindist: %f",
1169  t, u, dl->distance, dl->tolerance);
1170  if (dl->distance<=dl->tolerance && dl->mode == DIST_MIN) return LW_TRUE; /*just a check if the answer is already given*/
1171  start2 = end2;
1172  }
1173  start = end;
1174  }
1175  }
1176  return LW_TRUE;
1177 }
int npoints
Definition: liblwgeom.h:370
int mode
Definition: measures.h:51
double tolerance
Definition: measures.h:53
#define DIST_MIN
Definition: measures.h:41
const POINT2D * getPoint2d_cp(const POINTARRAY *pa, int n)
Returns a POINT2D pointer into the POINTARRAY serialized_ptlist, suitable for reading from...
Definition: lwgeom_api.c:485
#define LW_TRUE
Return types for functions with status returns.
Definition: liblwgeom.h:75
int lw_dist2d_seg_seg(const POINT2D *A, const POINT2D *B, const POINT2D *C, const POINT2D *D, DISTPTS *dl)
Finds the shortest distance between two segments.
Definition: measures.c:1816
int twisted
Definition: measures.h:52
double distance
Definition: measures.h:48
#define DIST_MAX
Definition: measures.h:40
#define LWDEBUGF(level, msg,...)
Definition: lwgeom_log.h:88
int lw_dist2d_pt_pt(const POINT2D *thep1, const POINT2D *thep2, DISTPTS *dl)
Compares incomming points and stores the points closest to each other or most far away from each othe...
Definition: measures.c:2279
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