From: Paul Ramsey <pramsey@cleverelephant.ca>
Date: Wed, 7 Oct 2009 14:26:21 +0000 (+0000)
Subject: Make the calculation of gboxes a little simpler in the db level code.
X-Git-Tag: 1.5.0b1~395
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e2da8b5140f3532915357ac47d632936aea41fdb;p=postgis

Make the calculation of gboxes a little simpler in the db level code.


git-svn-id: http://svn.osgeo.org/postgis/trunk@4620 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/liblwgeom/g_box.c b/liblwgeom/g_box.c
index b465200b9..bf4b91975 100644
--- a/liblwgeom/g_box.c
+++ b/liblwgeom/g_box.c
@@ -195,6 +195,51 @@ size_t gbox_serialized_size(uchar flags)
         return 2 * FLAGS_NDIMS(flags) * sizeof(float);
 }
 
+int gbox_from_gserialized(GSERIALIZED *g, GBOX *gbox)
+{
+	
+	/* Null input! */
+	if( ! g ) return G_FAILURE;
+	
+	/* Initialize the flags on the box */
+	gbox->flags = g->flags;
+	
+	if ( FLAGS_GET_BBOX(g->flags) )
+	{
+		int i = 0;
+		float *fbox = (float*)(g->data);
+		gbox->xmin = fbox[i]; i++;	
+		gbox->xmax = fbox[i]; i++;
+		gbox->ymin = fbox[i]; i++;
+		gbox->ymax = fbox[i]; i++;
+		if ( FLAGS_GET_GEODETIC(g->flags) )
+		{
+			gbox->zmin = fbox[i]; i++;
+			gbox->zmax = fbox[i]; i++;
+			return G_SUCCESS;
+		}
+		if ( FLAGS_GET_Z(g->flags) )
+		{
+			gbox->zmin = fbox[i]; i++;
+			gbox->zmax = fbox[i]; i++;
+		}
+		if ( FLAGS_GET_M(g->flags) )
+		{
+			gbox->mmin = fbox[i]; i++;
+			gbox->mmax = fbox[i]; i++;
+		}
+		return G_SUCCESS;
+	}
+
+	LWDEBUG(4, "calculating new box from scratch"); 
+	if( gserialized_calculate_gbox_geocentric_p(g, gbox) == G_FAILURE )
+	{
+		LWDEBUG(4, "calculated null bbox, returning failure");
+		return G_FAILURE;
+	}
+	return G_SUCCESS;
+}
+
 
 /* ********************************************************************************
 ** Compute cartesian bounding GBOX boxes from LWGEOM.
diff --git a/liblwgeom/libgeom.h b/liblwgeom/libgeom.h
index e89f47789..030621ced 100644
--- a/liblwgeom/libgeom.h
+++ b/liblwgeom/libgeom.h
@@ -425,6 +425,11 @@ extern GBOX* gbox_copy(GBOX *gbox);
 */
 extern GBOX* gbox_from_string(char *str);
 
+/**
+* Given a serialized form, extract the box if it exists, calculate it if it does not.
+*/
+extern int gbox_from_gserialized(GSERIALIZED *g, GBOX *gbox);
+
 /**
 * Return #LW_TRUE if the #GBOX overlaps, #LW_FALSE otherwise. 
 */
diff --git a/postgis/geography_distance.c b/postgis/geography_distance.c
index af79d370c..b6455741c 100644
--- a/postgis/geography_distance.c
+++ b/postgis/geography_distance.c
@@ -45,20 +45,19 @@ Datum geography_distance_sphere(PG_FUNCTION_ARGS)
 	double tolerance;
 	double distance;
 	
-	/* We need the bounding boxes in case of polygon calculations,
-	   which requires them to generate a stab-line to test point-in-polygon. */
-	geography_datum_gidx(PG_GETARG_DATUM(0), gidx1);
-	geography_datum_gidx(PG_GETARG_DATUM(0), gidx2);
-	gbox_from_gidx(gidx1, &gbox1);
-	gbox_from_gidx(gidx2, &gbox2);
-	gbox1.flags = FLAGS_SET_GEODETIC(gbox1.flags,1);
-	gbox2.flags = FLAGS_SET_GEODETIC(gbox2.flags,1);
-	pfree(gidx1);
-	pfree(gidx2);
-	
 	/* Get our geometry objects loaded into memory. */
 	g1 = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
 	g2 = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
+	
+	/* We need the bounding boxes in case of polygon calculations,
+	   which requires them to generate a stab-line to test point-in-polygon. */
+	if( ! gbox_from_gserialized(g1, &gbox1) ||
+	    ! gbox_from_gserialized(g2, &gbox2) )
+	{
+		elog(ERROR, "Error in gbox_from_gserialized calculation.");
+		PG_RETURN_NULL();
+	}
+	
 	lwgeom1 = lwgeom_from_gserialized(g1);
 	lwgeom2 = lwgeom_from_gserialized(g2);