From: Regina Obe <lr@pcorp.us>
Date: Sun, 27 Aug 2017 15:17:39 +0000 (+0000)
Subject: Allow signed distance for ST_Project (Darafei Praliaskouski)
X-Git-Tag: 2.4.0beta1~15
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3aeee83286e2493365e62ab0439c42e6e42ee7ac;p=postgis

Allow signed distance for ST_Project (Darafei Praliaskouski)
Closes https://github.com/postgis/postgis/pull/138
Closes #3709

git-svn-id: http://svn.osgeo.org/postgis/trunk@15598 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/NEWS b/NEWS
index 50d29b5c1..5f36c701a 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,7 @@ PostGIS 2.4.0
   - Most aggregates (raster and geometry),
     and all stable / immutable (raster and geometry) marked as parallel safe
   - #2249, ST_MakeEmptyCoverage for raster (David Zwarg, ainomieli)
+  - #3709, Allow signed distance for ST_Project (Darafei Praliaskouski)
 
 * Enhancements *
 
diff --git a/doc/reference_measure.xml b/doc/reference_measure.xml
index dbeb9566a..dcde1a9e0 100644
--- a/doc/reference_measure.xml
+++ b/doc/reference_measure.xml
@@ -4344,6 +4344,7 @@ SELECT ST_AsEWKT(ST_PointOnSurface(ST_GeomFromEWKT('LINESTRING(0 5 1, 0 0 1, 0 1
 			<para>The distance is given in meters.</para>
 
 			<para>Availability: 2.0.0</para>
+			<para>Enhanced: 2.4.0 Allow negative distance and non-normalized azimuth.</para>
 
 		  </refsection>
 
diff --git a/liblwgeom/lwgeodetic.c b/liblwgeom/lwgeodetic.c
index b48a90868..e96b95840 100644
--- a/liblwgeom/lwgeodetic.c
+++ b/liblwgeom/lwgeodetic.c
@@ -2009,18 +2009,20 @@ LWPOINT* lwgeom_project_spheroid(const LWPOINT *r, const SPHEROID *spheroid, dou
 	double x, y;
 	POINTARRAY *pa;
 	LWPOINT *lwp;
-
-	/* Check the azimuth validity, convert to radians */
-	if ( azimuth < -2.0 * M_PI || azimuth > 2.0 * M_PI )
-	{
-		lwerror("Azimuth must be between -2PI and 2PI");
-		return NULL;
+	
+	/* Normalize distance to be positive*/
+	if ( distance < 0.0 ) {
+		distance = -distance;
+		azimuth += M_PI;
 	}
+	
+	/* Normalize azimuth */
+	azimuth -= 2.0 * M_PI * floor(azimuth / (2.0 * M_PI));
 
 	/* Check the distance validity */
-	if ( distance < 0.0 || distance > (M_PI * spheroid->radius) )
+	if ( distance > (M_PI * spheroid->radius) )
 	{
-		lwerror("Distance must be between 0 and %g", M_PI * spheroid->radius);
+		lwerror("Distance must not be greater than %g", M_PI * spheroid->radius);
 		return NULL;
 	}
 		
diff --git a/regress/tickets.sql b/regress/tickets.sql
index 61582dcfd..fab5d78d8 100644
--- a/regress/tickets.sql
+++ b/regress/tickets.sql
@@ -1015,5 +1015,8 @@ SELECT '#3627b', ST_Equals(geom, ST_LineFromEncodedPolyline(ST_AsEncodedPolyline
 -- #3704
 SELECT '#3704', ST_AsX3D('LINESTRING EMPTY') = '';
 
+-- #3709
+select '#3709', ST_SnapToGrid(ST_Project('SRID=4326;POINT(1 1)'::geography, 100000, 20)::geometry, 0.0001) = ST_SnapToGrid(ST_Project('SRID=4326;POINT(1 1)'::geography, -100000, 20+pi())::geometry, 0.0001);
+
 -- Clean up
 DELETE FROM spatial_ref_sys;
diff --git a/regress/tickets_expected b/regress/tickets_expected
index cbe200c62..452503060 100644
--- a/regress/tickets_expected
+++ b/regress/tickets_expected
@@ -302,3 +302,4 @@ ERROR:  invalid KML representation
 #3627a|o}~~|AdshNoSsBgd@eGoBlm@wKhj@~@?
 #3627b|t
 #3704|t
+#3709|t