PostGIS  3.1.6dev-r@@SVN_REVISION@@

◆ lwpoly_covers_lwpoly()

int lwpoly_covers_lwpoly ( const LWPOLY poly1,
const LWPOLY poly2 
)

Given a polygon1 check if all points of polygon2 are inside polygon1 and no intersections of the polygon edges occur.

return LW_TRUE if polygon is inside or on edge of polygon.

Definition at line 2605 of file lwgeodetic.c.

2606 {
2607  uint32_t i;
2608 
2609  /* Nulls and empties don't contain anything! */
2610  if ( ! poly1 || lwgeom_is_empty((LWGEOM*)poly1) )
2611  {
2612  LWDEBUG(4,"returning false, geometry1 is empty or null");
2613  return LW_FALSE;
2614  }
2615 
2616  /* Nulls and empties don't contain anything! */
2617  if ( ! poly2 || lwgeom_is_empty((LWGEOM*)poly2) )
2618  {
2619  LWDEBUG(4,"returning false, geometry2 is empty or null");
2620  return LW_FALSE;
2621  }
2622 
2623  /* check if all vertices of poly2 are inside poly1 */
2624  for (i = 0; i < poly2->nrings; i++)
2625  {
2626  if (LW_FALSE == lwpoly_covers_pointarray(poly1, poly2->rings[i]))
2627  {
2628  LWDEBUG(4,"returning false, geometry2 has point outside of geometry1");
2629  return LW_FALSE;
2630  }
2631  }
2632 
2633  /* check for any edge intersections, so nothing is partially outside of poly1 */
2634  for (i = 0; i < poly2->nrings; i++)
2635  {
2636  if (LW_TRUE == lwpoly_intersects_line(poly1, poly2->rings[i]))
2637  {
2638  LWDEBUG(4,"returning false, geometry2 is partially outside of geometry1");
2639  return LW_FALSE;
2640  }
2641  }
2642 
2643  /* no abort condition found, so the poly2 should be completly inside poly1 */
2644  return LW_TRUE;
2645 }
#define LW_FALSE
Definition: liblwgeom.h:108
#define LW_TRUE
Return types for functions with status returns.
Definition: liblwgeom.h:107
int lwpoly_intersects_line(const LWPOLY *lwpoly, const POINTARRAY *line)
Checks if any edges of lwpoly intersect with the line formed by the pointarray return LW_TRUE if any ...
Definition: lwgeodetic.c:2705
int lwpoly_covers_pointarray(const LWPOLY *lwpoly, const POINTARRAY *pta)
return LW_TRUE if all points are inside the polygon
Definition: lwgeodetic.c:2686
#define LWDEBUG(level, msg)
Definition: lwgeom_log.h:83
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:203

References LW_FALSE, LW_TRUE, LWDEBUG, lwgeom_is_empty(), lwpoly_covers_pointarray(), lwpoly_intersects_line(), LWPOLY::nrings, and LWPOLY::rings.

Referenced by lwgeom_covers_lwgeom_sphere().

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