From 4f0da9b33ccbe8a827cdfe16814adcdd07cb0eb7 Mon Sep 17 00:00:00 2001
From: Sandro Santilli <strk@keybit.net>
Date: Tue, 24 Aug 2004 14:47:25 +0000
Subject: [PATCH] Added LWGEOM_construct() function to easy the work of dealing
 with SRID/BBOX optional embedding.

git-svn-id: http://svn.osgeo.org/postgis/trunk@735 b70326c6-7e19-0410-871a-916f4a2858ee
---
 lwgeom/lwgeom.h     | 11 +++++++++
 lwgeom/lwgeom_api.c | 58 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/lwgeom/lwgeom.h b/lwgeom/lwgeom.h
index b56d0dafc..1013b2735 100644
--- a/lwgeom/lwgeom.h
+++ b/lwgeom/lwgeom.h
@@ -179,6 +179,17 @@ extern int  lwgeom_getType(unsigned char type); // returns the tttt value
 extern unsigned char lwgeom_makeType(int ndims, char hasSRID, int type);
 extern unsigned char lwgeom_makeType_full(int ndims, char hasSRID, int type, bool hasBBOX);
 
+/*
+ * Construct a full LWGEOM type (including size header)
+ * from a serialized form.
+ * The constructed LWGEOM object will be allocated using palloc
+ * and the serialized form will be copied.
+ * If you specify a SRID other then -1 it will be set.
+ * If you request bbox (wantbbox=1) it will be extracted or computed
+ * from the serialized form.
+ */
+extern LWGEOM *LWGEOM_construct(char *serialized, int SRID, int wantbbox);
+
 // all the base types (point/line/polygon) will have a
 // basic constructor, basic de-serializer, basic serializer, and
 // bounding box finder.
diff --git a/lwgeom/lwgeom_api.c b/lwgeom/lwgeom_api.c
index f6a8184b0..a61db323c 100644
--- a/lwgeom/lwgeom_api.c
+++ b/lwgeom/lwgeom_api.c
@@ -2382,3 +2382,61 @@ LWGEOM *lwgeom_setSRID(LWGEOM *lwgeom, int32 newSRID)
 	}
 	return result;
 }
+
+LWGEOM *
+LWGEOM_construct(char *ser, int SRID, int wantbbox)
+{
+	int size;
+	char *iptr, *optr, *eptr;
+	int wantsrid = 0;
+	BOX2DFLOAT4 box;
+	LWGEOM *result;
+
+	size = lwgeom_seralizedformlength_simple(ser);
+	eptr = ser+size; // end of subgeom
+
+	iptr = ser+1; // skip type
+	if ( lwgeom_hasSRID(ser[0]) )
+	{
+		iptr += 4; // skip SRID
+		size -= 4;
+	}
+	if ( lwgeom_hasBBOX(ser[0]) )
+	{
+		iptr += sizeof(BOX2DFLOAT4); // skip BBOX
+		size -= sizeof(BOX2DFLOAT4);
+	}
+
+	if ( SRID != -1 )
+	{
+		wantsrid = 1;
+		size += 4;
+	}
+	if ( wantbbox )
+	{
+		size += sizeof(BOX2DFLOAT4);
+		getbox2d_p(ser, &box);
+	}
+
+	size+=4; // size header
+
+	result = palloc(size);
+	result->size = size;
+
+	result->type = lwgeom_makeType_full(lwgeom_ndims(ser[0]),
+		wantsrid, lwgeom_getType(ser[0]), wantbbox);
+	optr = result->data;
+	if ( wantbbox )
+	{
+		memcpy(optr, &box, sizeof(BOX2DFLOAT4));
+		optr += sizeof(BOX2DFLOAT4);
+	}
+	if ( wantsrid )
+	{
+		memcpy(optr, &SRID, 4);
+		optr += 4;
+	}
+	memcpy(optr, iptr, eptr-iptr);
+
+	return result;
+}
-- 
2.49.0