From: Sandro Santilli <strk@keybit.net>
Date: Wed, 5 Jan 2005 21:59:32 +0000 (+0000)
Subject: Simplify reworked to use LWGEOM abstraction (no more flattening of input collection).
X-Git-Tag: pgis_1_0_0RC1~82
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=5acd93a5e56ad81270b089020fd6541d69eeffa9;p=postgis

Simplify reworked to use LWGEOM abstraction (no more flattening of input collection).


git-svn-id: http://svn.osgeo.org/postgis/trunk@1222 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/lwgeom/BBOXCACHE_BEHAVIOURS b/lwgeom/BBOXCACHE_BEHAVIOURS
index bb232aff8..144c82ece 100644
--- a/lwgeom/BBOXCACHE_BEHAVIOURS
+++ b/lwgeom/BBOXCACHE_BEHAVIOURS
@@ -75,7 +75,7 @@ section also use it.
 [ TAINING ]
 	GeometryN(geometry,integer) *LWG*
 	InteriorRingN(geometry,integer) *LWG*
-	simplify(geometry, float8) *SRL* (*EXP*)
+	simplify(geometry, float8) *LWG*
 
 	#### could use WHEN_SIMPLE
 	#### translating and transforming an eventually present
diff --git a/lwgeom/lwgeom_functions_analytic.c b/lwgeom/lwgeom_functions_analytic.c
index 1c580e609..81c6eacab 100644
--- a/lwgeom/lwgeom_functions_analytic.c
+++ b/lwgeom/lwgeom_functions_analytic.c
@@ -23,8 +23,10 @@
 /* Prototypes */
 void DP_findsplit2d(POINTARRAY *pts, int p1, int p2, int *split, double *dist);
 POINTARRAY *DP_simplify2d(POINTARRAY *inpts, double epsilon);
-LWLINE *simplify2d_lwline(LWLINE *iline, double dist);
-LWPOLY *simplify2d_lwpoly(LWPOLY *ipoly, double dist);
+LWLINE *simplify2d_lwline(const LWLINE *iline, double dist);
+LWPOLY *simplify2d_lwpoly(const LWPOLY *ipoly, double dist);
+LWCOLLECTION *simplify2d_collection(const LWCOLLECTION *igeom, double dist);
+LWGEOM *simplify2d_lwgeom(const LWGEOM *igeom, double dist);
 Datum LWGEOM_simplify2d(PG_FUNCTION_ARGS);
 
 
@@ -164,7 +166,7 @@ DP_simplify2d(POINTARRAY *inpts, double epsilon)
 }
 
 LWLINE *
-simplify2d_lwline(LWLINE *iline, double dist)
+simplify2d_lwline(const LWLINE *iline, double dist)
 {
 	POINTARRAY *ipts;
 	POINTARRAY *opts;
@@ -183,7 +185,7 @@ simplify2d_lwline(LWLINE *iline, double dist)
 
 // TODO
 LWPOLY *
-simplify2d_lwpoly(LWPOLY *ipoly, double dist)
+simplify2d_lwpoly(const LWPOLY *ipoly, double dist)
 {
 	POINTARRAY *ipts;
 	POINTARRAY **orings = NULL;
@@ -250,77 +252,67 @@ elog(NOTICE, "simplify_polygon3d: simplified polygon with %d rings", norings);
 	return opoly;
 }
 
-PG_FUNCTION_INFO_V1(LWGEOM_simplify2d);
-Datum LWGEOM_simplify2d(PG_FUNCTION_ARGS)
+LWCOLLECTION *
+simplify2d_collection(const LWCOLLECTION *igeom, double dist)
 {
-	PG_LWGEOM *geom = (PG_LWGEOM *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
-	LWGEOM_EXPLODED *exp = lwgeom_explode(SERIALIZED_FORM(geom));
-	double dist = PG_GETARG_FLOAT8(1);
-	int i;
-	char **newlines;
-	int newlinesnum=0;
-	char **newpolys;
-	int newpolysnum=0;
-	PG_LWGEOM *result;
-	char *serialized;
+	unsigned int i;
+	unsigned int ngeoms=0;
+	LWGEOM **geoms = lwalloc(sizeof(LWGEOM *)*igeom->ngeoms);
+	LWCOLLECTION *out;
 
-	// no lines, no points... return input
-	if ( exp->nlines + exp->npolys == 0 )
+	for (i=0; i<igeom->ngeoms; i++)
 	{
-		pfree_exploded(exp);
-	 	PG_RETURN_POINTER(geom);
+		LWGEOM *ngeom = simplify2d_lwgeom(igeom->geoms[i], dist);
+		if ( ngeom ) geoms[ngeoms++] = ngeom;
 	}
 
-	if ( exp->nlines )
-	{
-#if VERBOSE
-		elog(NOTICE, "%d lines in exploded geom", exp->nlines);
-#endif
-		newlines = palloc(sizeof(char *)*exp->nlines);
-		for ( i=0; i<exp->nlines; i++ )
-		{
-			LWLINE *iline = lwline_deserialize(exp->lines[i]);
-#if VERBOSE
-			elog(NOTICE, " line %d deserialized", i);
-#endif
-			LWLINE *oline = simplify2d_lwline(iline, dist);
-#if VERBOSE
-			elog(NOTICE, " line %d simplified", i);
-#endif
-			if ( oline == NULL ) continue;
-			newlines[newlinesnum] = lwline_serialize(oline);
-			newlinesnum++;
-		}
-		pfree(exp->lines);
-		exp->lines = newlines;
-		exp->nlines = newlinesnum;
-	}
+	out = lwcollection_construct(TYPE_GETTYPE(igeom->type), igeom->SRID,
+		NULL, ngeoms, geoms);
+
+	return out;
+}
 
-	if ( exp->npolys )
+LWGEOM *
+simplify2d_lwgeom(const LWGEOM *igeom, double dist)
+{
+	switch(TYPE_GETTYPE(igeom->type))
 	{
-		newpolys = palloc(sizeof(char *)*exp->npolys);
-		for ( i=0; i<exp->npolys; i++ )
-		{
-			LWPOLY *ipoly = lwpoly_deserialize(exp->polys[i]);
-			LWPOLY *opoly = simplify2d_lwpoly(ipoly, dist);
-			if ( opoly == NULL ) continue;
-			newpolys[newpolysnum] = lwpoly_serialize(opoly);
-			newpolysnum++;
-		}
-		pfree(exp->polys);
-		exp->polys = newpolys;
-		exp->npolys = newpolysnum;
+		case POINTTYPE:
+		case MULTIPOINTTYPE:
+			return lwgeom_clone(igeom);
+		case LINETYPE:
+			return (LWGEOM *)simplify2d_lwline(
+				(LWLINE *)igeom, dist);
+		case POLYGONTYPE:
+			return (LWGEOM *)simplify2d_lwpoly(
+				(LWPOLY *)igeom, dist);
+		case MULTILINETYPE:
+		case MULTIPOLYGONTYPE:
+		case COLLECTIONTYPE:
+			return (LWGEOM *)simplify2d_collection(
+				(LWCOLLECTION *)igeom, dist);
+		default:
+			lwerror("simplify2d_lwgeom: unknown geometry type: %d",
+				TYPE_GETTYPE(igeom->type));
 	}
+	return NULL;
+}
+
+PG_FUNCTION_INFO_V1(LWGEOM_simplify2d);
+Datum LWGEOM_simplify2d(PG_FUNCTION_ARGS)
+{
+	PG_LWGEOM *geom = (PG_LWGEOM *) PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
+	LWGEOM *in = lwgeom_deserialize(SERIALIZED_FORM(geom));
+	LWGEOM *out;
+	PG_LWGEOM *result;
+	double dist = PG_GETARG_FLOAT8(1);
 
-	// copy 1 (when lwexploded_serialize_buf will be implemented this
-	// can be avoided)
-	serialized = lwexploded_serialize(exp, lwgeom_hasBBOX(geom->type));
-	pfree_exploded(exp);
+	out = simplify2d_lwgeom(in, dist);
 
+	/* COMPUTE_BBOX TAINTING */
+	if ( in->bbox ) lwgeom_addBBOX(out);
 
-	// copy 2 (see above)
-	result = PG_LWGEOM_construct(serialized,
-		pglwgeom_getSRID(geom), lwgeom_hasBBOX(geom->type));
+	result = pglwgeom_serialize(out);
 
 	PG_RETURN_POINTER(result);
 }