From: Bborie Park <bkpark at ucdavis.edu>
Date: Fri, 16 Nov 2012 01:32:02 +0000 (+0000)
Subject: If hillshade < 0, hillshade = 0 for ST_HillShade()
X-Git-Tag: 2.1.0beta2~391
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=81d92baf7d62216b1f947aa69f1f1839817907e6;p=postgis

If hillshade < 0, hillshade = 0 for ST_HillShade()

git-svn-id: http://svn.osgeo.org/postgis/trunk@10689 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/raster/rt_pg/rtpostgis.sql.in.c b/raster/rt_pg/rtpostgis.sql.in.c
index e611e8670..41f9a36df 100644
--- a/raster/rt_pg/rtpostgis.sql.in.c
+++ b/raster/rt_pg/rtpostgis.sql.in.c
@@ -3795,6 +3795,11 @@ CREATE OR REPLACE FUNCTION _st_hillshade4ma(value double precision[][][], pos in
 		END IF;
 
 		shade := _bright * ((cos(zenith) * cos(slope)) + (sin(zenith) * sin(slope) * cos(azimuth - aspect)));
+
+		IF shade < 0. THEN
+			shade := 0;
+		END IF;
+
 		RETURN shade;
 	END;
 	$$ LANGUAGE 'plpgsql' IMMUTABLE;