From: Sandro Santilli <strk@keybit.net>
Date: Wed, 5 Jan 2005 09:47:58 +0000 (+0000)
Subject: collect(geom, geom) and collect_garray(geom[]) use WHEN_SIMPLE strategy
X-Git-Tag: pgis_1_0_0RC1~87
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=349ab82f65899379471deba70844616126af8eba;p=postgis

collect(geom, geom) and collect_garray(geom[]) use WHEN_SIMPLE strategy
for bbox computation. pglwgeom_serialize() honour user's AUTOCACHE_BBOX
define. BBOXCACHE_BEHAVIOURS updated.


git-svn-id: http://svn.osgeo.org/postgis/trunk@1217 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/lwgeom/BBOXCACHE_BEHAVIOURS b/lwgeom/BBOXCACHE_BEHAVIOURS
index eaf1ca499..ae5192991 100644
--- a/lwgeom/BBOXCACHE_BEHAVIOURS
+++ b/lwgeom/BBOXCACHE_BEHAVIOURS
@@ -36,6 +36,11 @@ points where some BBOX caching strategies could be enforced).
 	*EXP*	Uses deprecated LWEXPLODED, and LWEXPLODED_serialize()
 
 	*LWG*	Uses LWGEOM, pglwgeom_serialize()
+
+
+AUTOCACHE_BBOX is currently used by all functions using *LWG* 
+(pglwgeom_serialize entry point). Other functions explicitly
+listed in the AUTOCACHE_BBOX section also use it.
 	
 
 [ explicit control ]
@@ -90,6 +95,12 @@ points where some BBOX caching strategies could be enforced).
 	multi(geometry) **SRL**
 	envelope(geometry) *SRL*
 
+	### computes union of
+	### input bbox (if all available)
+	collect(geometry, geometry) *LWG*
+	collect_garray (geometry[]) *LWG*
+	
+
 	## These use LWGEOM as a mean to access and modigy SERIALIZED form
 	reverse(geometry) *LWG* **SRL**
 	ForceRHR(geometry) *LWG* **SRL**
@@ -104,11 +115,6 @@ points where some BBOX caching strategies could be enforced).
 	StartPoint(geometry) *SRL*
 	EndPoint(geometry) *SRL*
 
-	### could use WHEN_SIMPLE computing union of
-	### input bbox (if available or SIMPLE to compute: points)
-	collect(geometry, geometry) *LWG*
-	collect_garray (geometry[]) *LWG*
-	
 	makePoint(float8, float8, [float8], [float8]) *LWG*
 	makePointM(float8, float8, float8) *LWG*
 	makeline_garray (geometry[]) *LWG*
diff --git a/lwgeom/lwgeom_functions_basic.c b/lwgeom/lwgeom_functions_basic.c
index 9304a8f14..643a299d4 100644
--- a/lwgeom/lwgeom_functions_basic.c
+++ b/lwgeom/lwgeom_functions_basic.c
@@ -1572,6 +1572,7 @@ Datum LWGEOM_collect(PG_FUNCTION_ARGS)
 	PG_LWGEOM *pglwgeom1, *pglwgeom2, *result;
 	LWGEOM *lwgeoms[2], *outlwg;
 	unsigned int type1, type2, outtype;
+	BOX2DFLOAT4 *box=NULL;
 
 	// return null if both geoms are null
 	if ( (geom1_ptr == NULL) && (geom2_ptr == NULL) )
@@ -1619,9 +1620,25 @@ Datum LWGEOM_collect(PG_FUNCTION_ARGS)
 	elog(NOTICE, " outtype = %d", outtype);
 #endif
 
+	/* COMPUTE_BBOX WHEN_SIMPLE */
+	if ( lwgeoms[0]->bbox && lwgeoms[1]->bbox )
+	{
+		box = palloc(sizeof(BOX2DFLOAT4));
+		box->xmin = LW_MIN(lwgeoms[0]->bbox->xmin, lwgeoms[1]->bbox->xmin);
+		box->ymin = LW_MIN(lwgeoms[0]->bbox->ymin, lwgeoms[1]->bbox->ymin);
+		box->xmax = LW_MAX(lwgeoms[0]->bbox->xmax, lwgeoms[1]->bbox->xmax);
+		box->ymax = LW_MAX(lwgeoms[0]->bbox->ymax, lwgeoms[1]->bbox->ymax);
+	}
+
+	/* Drop input geometries bbox and SRID */
+	lwgeom_dropBBOX(lwgeoms[0]);
+	lwgeom_dropSRID(lwgeoms[0]);
+	lwgeom_dropBBOX(lwgeoms[1]);
+	lwgeom_dropSRID(lwgeoms[1]);
+
 	outlwg = (LWGEOM *)lwcollection_construct(
 		outtype, lwgeoms[0]->SRID,
-		NULL, 2, lwgeoms);
+		box, 2, lwgeoms);
 
 	result = pglwgeom_serialize(outlwg);
 
@@ -1773,6 +1790,7 @@ Datum LWGEOM_collect_garray(PG_FUNCTION_ARGS)
 	int i;
 	int SRID=-1;
 	size_t offset;
+	BOX2DFLOAT4 *box=NULL;
 
 #ifdef DEBUG
 	elog(NOTICE, "LWGEOM_collect_garray called");
@@ -1829,19 +1847,46 @@ Datum LWGEOM_collect_garray(PG_FUNCTION_ARGS)
 	elog(NOTICE, "LWGEOM_collect_garray: geom %d deserialized", i);
 #endif
 
-		// Check SRID homogeneity
-		if ( ! i ) {
+		if ( ! i )
+		{
 			/* Get first geometry SRID */
 			SRID = lwgeoms[i]->SRID; 
-		} else {
+
+			/* COMPUTE_BBOX WHEN_SIMPLE */
+			if ( lwgeoms[i]->bbox ) {
+				box = palloc(sizeof(BOX2DFLOAT4));
+				memcpy(box, lwgeoms[i]->bbox, sizeof(BOX2DFLOAT4));
+			}
+		}
+		else
+		{
+			// Check SRID homogeneity
 			if ( lwgeoms[i]->SRID != SRID )
 			{
 				elog(ERROR,
 					"Operation on mixed SRID geometries");
 				PG_RETURN_NULL();
 			}
+
+			/* COMPUTE_BBOX WHEN_SIMPLE */
+			if ( box )
+			{
+				if ( lwgeoms[i]->bbox )
+				{
+					box->xmin = LW_MIN(box->xmin, lwgeoms[i]->bbox->xmin);
+					box->ymin = LW_MIN(box->ymin, lwgeoms[i]->bbox->ymin);
+					box->xmax = LW_MAX(box->xmax, lwgeoms[i]->bbox->xmax);
+					box->ymax = LW_MAX(box->ymax, lwgeoms[i]->bbox->ymax);
+				}
+				else
+				{
+					pfree(box);
+					box = NULL;
+				}
+			}
 		}
 
+
 		lwgeom_dropSRID(lwgeoms[i]);
 		lwgeom_dropBBOX(lwgeoms[i]);
 
@@ -1868,7 +1913,7 @@ Datum LWGEOM_collect_garray(PG_FUNCTION_ARGS)
 
 	outlwg = (LWGEOM *)lwcollection_construct(
 		outtype, SRID,
-		NULL, nelems, lwgeoms);
+		box, nelems, lwgeoms);
 
 	result = pglwgeom_serialize(outlwg);
 
diff --git a/lwgeom/lwgeom_pg.c b/lwgeom/lwgeom_pg.c
index f5339f48b..411d06d51 100644
--- a/lwgeom/lwgeom_pg.c
+++ b/lwgeom/lwgeom_pg.c
@@ -106,6 +106,13 @@ pglwgeom_serialize(LWGEOM *in)
 	size_t size;
 	PG_LWGEOM *result;
 
+#if AUTOCACHE_BBOX
+	if ( ! in->bbox && is_worth_caching_lwgeom_bbox(in) )
+	{
+		lwgeom_addBBOX(in);
+	}
+#endif
+
 	size = lwgeom_serialize_size(in) + VARHDRSZ;
 	//lwnotice("lwgeom_serialize_size returned %d", size-VARHDRSZ);
 	result = palloc(size);