PostGIS  2.5.0dev-r@@SVN_REVISION@@
static float gidx_inter_volume ( GIDX *  a,
GIDX *  b 
)
static

Definition at line 365 of file gserialized_gist_nd.c.

References gidx_dimensionality_check(), and gidx_is_unknown().

Referenced by gserialized_gist_picksplit_constructsplit().

366 {
367  uint32_t i;
368  float result;
369 
370  POSTGIS_DEBUG(5,"entered function");
371 
372  if ( a == NULL || b == NULL )
373  {
374  elog(ERROR, "gidx_inter_volume received a null argument");
375  return 0.0;
376  }
377 
378  if ( gidx_is_unknown(a) || gidx_is_unknown(b) )
379  {
380  return 0.0;
381  }
382 
383  /* Ensure 'a' has the most dimensions. */
385 
386  /* Initialize with minimal length of first dimension. */
387  result = Min(GIDX_GET_MAX(a,0),GIDX_GET_MAX(b,0)) - Max(GIDX_GET_MIN(a,0),GIDX_GET_MIN(b,0));
388 
389  /* If they are disjoint (max < min) then return zero. */
390  if ( result < 0.0 ) return 0.0;
391 
392  /* Continue for remaining dimensions. */
393  for ( i = 1; i < GIDX_NDIMS(b); i++ )
394  {
395  float width = Min(GIDX_GET_MAX(a,i),GIDX_GET_MAX(b,i)) - Max(GIDX_GET_MIN(a,i),GIDX_GET_MIN(b,i));
396  if ( width < 0.0 ) return 0.0;
397  /* Multiply by minimal length of remaining dimensions. */
398  result *= width;
399  }
400  POSTGIS_DEBUGF(5, "volume( %s intersection %s ) = %.12g", gidx_to_string(a), gidx_to_string(b), result);
401  return result;
402 }
static void gidx_dimensionality_check(GIDX **a, GIDX **b)
unsigned int uint32_t
Definition: uthash.h:78
bool gidx_is_unknown(const GIDX *a)

Here is the call graph for this function:

Here is the caller graph for this function: