PostGIS  2.3.8dev-r@@SVN_REVISION@@

◆ gidx_inter_volume()

static float gidx_inter_volume ( GIDX *  a,
GIDX *  b 
)
static

Definition at line 299 of file gserialized_gist_nd.c.

References gidx_dimensionality_check(), and gidx_is_unknown().

Referenced by gserialized_gist_picksplit_constructsplit().

300 {
301  int i;
302  float result;
303 
304  POSTGIS_DEBUG(5,"entered function");
305 
306  if ( a == NULL || b == NULL )
307  {
308  elog(ERROR, "gidx_inter_volume received a null argument");
309  return 0.0;
310  }
311 
312  if ( gidx_is_unknown(a) || gidx_is_unknown(b) )
313  {
314  return 0.0;
315  }
316 
317  /* Ensure 'a' has the most dimensions. */
319 
320  /* Initialize with minimal length of first dimension. */
321  result = Min(GIDX_GET_MAX(a,0),GIDX_GET_MAX(b,0)) - Max(GIDX_GET_MIN(a,0),GIDX_GET_MIN(b,0));
322 
323  /* If they are disjoint (max < min) then return zero. */
324  if ( result < 0.0 ) return 0.0;
325 
326  /* Continue for remaining dimensions. */
327  for ( i = 1; i < GIDX_NDIMS(b); i++ )
328  {
329  float width = Min(GIDX_GET_MAX(a,i),GIDX_GET_MAX(b,i)) - Max(GIDX_GET_MIN(a,i),GIDX_GET_MIN(b,i));
330  if ( width < 0.0 ) return 0.0;
331  /* Multiply by minimal length of remaining dimensions. */
332  result *= width;
333  }
334  POSTGIS_DEBUGF(5, "volume( %s intersection %s ) = %.12g", gidx_to_string(a), gidx_to_string(b), result);
335  return result;
336 }
static bool gidx_is_unknown(const GIDX *a)
static void gidx_dimensionality_check(GIDX **a, GIDX **b)
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