From a60b0c7d2e643f0f96a3dddcf0c9571e6135d92c Mon Sep 17 00:00:00 2001
From: Sandro Santilli <strk@keybit.net>
Date: Tue, 22 Feb 2011 14:25:15 +0000
Subject: [PATCH] Add LW_GML_SHORTLINE flag to prefer <LineString> over <Curve>
 tag for lines GML3 output [RT-SIGTA]

git-svn-id: http://svn.osgeo.org/postgis/trunk@6850 b70326c6-7e19-0410-871a-916f4a2858ee
---
 liblwgeom/liblwgeom.h |  6 +++--
 liblwgeom/lwout_gml.c | 62 +++++++++++++++++++++++++++++++++----------
 2 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/liblwgeom/liblwgeom.h b/liblwgeom/liblwgeom.h
index b06e5df66..81da1db24 100644
--- a/liblwgeom/liblwgeom.h
+++ b/liblwgeom/liblwgeom.h
@@ -1788,9 +1788,11 @@ extern LWCOLLECTION *lwcollection_segmentize2d(LWCOLLECTION *coll, double dist);
  * @{
  */
 /** For GML3 only, include srsDimension attribute in output */
-#define LW_GML_IS_DIMS   (1<<0)
+#define LW_GML_IS_DIMS     (1<<0)
 /** For GML3 only, declare that datas are lat/lon. Swaps axis order */
-#define LW_GML_IS_DEGREE (1<<1)
+#define LW_GML_IS_DEGREE   (1<<1)
+/** For GML3, use <LineString> rather than <Curve> for lines */
+#define LW_GML_SHORTLINE   (1<<2)
 
 #define IS_DIMS(x) ((x) & LW_GML_IS_DIMS)
 #define IS_DEGREE(x) ((x) & LW_GML_IS_DEGREE)
diff --git a/liblwgeom/lwout_gml.c b/liblwgeom/lwout_gml.c
index 025f61cc3..98e4918f7 100644
--- a/liblwgeom/lwout_gml.c
+++ b/liblwgeom/lwout_gml.c
@@ -650,7 +650,20 @@ asgml3_line_size(const LWLINE *line, char *srs, int precision, int opts, const c
 	size_t prefixlen = strlen(prefix);
 
 	size = pointArray_GMLsize(line->points, precision);
-	size += ( sizeof("<Curve><segments><LineStringSegment><posList>/") + ( prefixlen * 4 ) ) * 2;
+	if ( opts & LW_GML_SHORTLINE )
+	{
+		size += (
+		  sizeof("<LineString><posList>/") +
+		  ( prefixlen * 2 )
+		) * 2;
+	}
+	else
+	{
+		size += (
+		  sizeof("<Curve><segments><LineStringSegment><posList>/") +
+		  ( prefixlen * 4 )
+		) * 2;
+	}
 	if (srs)     size += strlen(srs) + sizeof(" srsName=..");
 	if (IS_DIMS(opts)) size += sizeof(" srsDimension='x'");
 	return size;
@@ -661,24 +674,45 @@ asgml3_line_buf(const LWLINE *line, char *srs, char *output, int precision, int
 {
 	char *ptr=output;
 	int dimension=2;
+	int shortline = ( opts & LW_GML_SHORTLINE );
 
 	if (FLAGS_GET_Z(line->flags)) dimension = 3;
-	if ( srs )
-	{
-		ptr += sprintf(ptr, "<%sCurve srsName=\"%s\">", prefix, srs);
+
+	if ( shortline ) {
+		ptr += sprintf(ptr, "<%sLineString", prefix);
+	} else {
+		ptr += sprintf(ptr, "<%sCurve", prefix);
 	}
-	else
-	{
-		ptr += sprintf(ptr, "<%sCurve>", prefix);
+
+	if ( srs ) {
+		ptr += sprintf(ptr, " srsName=\"%s\">", srs);
+	} else {
+		ptr += sprintf(ptr, ">");
 	}
-	ptr += sprintf(ptr, "<%ssegments>", prefix);
-	ptr += sprintf(ptr, "<%sLineStringSegment>", prefix);
-	if (IS_DIMS(opts)) ptr += sprintf(ptr, "<%sposList srsDimension=\"%d\">", prefix, dimension);
-	else         ptr += sprintf(ptr, "<%sposList>", prefix);
+
+	if ( ! shortline ) {
+		ptr += sprintf(ptr, "<%ssegments>", prefix);
+		ptr += sprintf(ptr, "<%sLineStringSegment>", prefix);
+	}
+
+	if (IS_DIMS(opts)) {
+		ptr += sprintf(ptr, "<%sposList srsDimension=\"%d\">",
+			prefix, dimension);
+	} else {
+		ptr += sprintf(ptr, "<%sposList>", prefix);
+	}
+
 	ptr += pointArray_toGML3(line->points, ptr, precision, opts);
-	ptr += sprintf(ptr, "</%sposList></%sLineStringSegment>", prefix, prefix);
-	ptr += sprintf(ptr, "</%ssegments>", prefix);
-	ptr += sprintf(ptr, "</%sCurve>", prefix);
+
+	ptr += sprintf(ptr, "</%sposList>", prefix);
+
+	if ( shortline ) {
+		ptr += sprintf(ptr, "</%sLineString>", prefix);
+	} else {
+		ptr += sprintf(ptr, "</%sLineStringSegment>", prefix);
+		ptr += sprintf(ptr, "</%ssegments>", prefix);
+		ptr += sprintf(ptr, "</%sCurve>", prefix);
+	}
 
 	return (ptr-output);
 }
-- 
2.50.1