From: Bborie Park <bkpark at ucdavis.edu>
Date: Sun, 27 Jul 2014 17:06:54 +0000 (+0000)
Subject: shortcut ST_Clip if clipping geometry extent fully contains raster extent. Ticket... 
X-Git-Tag: 2.2.0rc1~933
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d053d965951498ceba9ac8cb4366f2d69a768583;p=postgis

shortcut ST_Clip if clipping geometry extent fully contains raster extent. Ticket #2829

git-svn-id: http://svn.osgeo.org/postgis/trunk@12833 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/NEWS b/NEWS
index 890f3b2ff..b59c50e2f 100644
--- a/NEWS
+++ b/NEWS
@@ -56,6 +56,8 @@ PostGIS 2.2.0
   - #2754, SFCGAL can now be installed with CREATE EXTENSION
        Vincent Mora (Oslandia)
   - #2828, Convert ST_Envelope(raster) from SQL to C
+  - #2829, Shortcut ST_Clip(raster) if geometry fully contains the raster
+           and no NODATA specified
 
  * Bug Fixes *
 
diff --git a/raster/rt_pg/rtpostgis.sql.in b/raster/rt_pg/rtpostgis.sql.in
index f90eee62b..205bd907e 100644
--- a/raster/rt_pg/rtpostgis.sql.in
+++ b/raster/rt_pg/rtpostgis.sql.in
@@ -6602,7 +6602,7 @@ CREATE AGGREGATE st_union(raster, text) (
 -- ST_Clip
 -----------------------------------------------------------------------
 
-CREATE OR REPLACE FUNCTION st_clip(
+CREATE OR REPLACE FUNCTION _st_clip(
 	rast raster, nband integer[],
 	geom geometry,
 	nodataval double precision[] DEFAULT NULL, crop boolean DEFAULT TRUE
@@ -6611,6 +6611,25 @@ CREATE OR REPLACE FUNCTION st_clip(
 	AS 'MODULE_PATHNAME', 'RASTER_clip'
 	LANGUAGE 'c' IMMUTABLE;
 
+CREATE OR REPLACE FUNCTION st_clip(
+	rast raster, nband integer[],
+	geom geometry,
+	nodataval double precision[] DEFAULT NULL, crop boolean DEFAULT TRUE
+)
+	RETURNS raster
+ 	AS $$
+	DECLARE
+		contains boolean;
+	BEGIN
+		-- short-cut if geometry's extent fully contains raster's extent
+		IF (nodataval IS NULL OR array_length(nodataval, 1) < 1) AND geom ~ ST_Envelope(rast) THEN
+			RETURN rast;
+		END IF;
+
+		RETURN _ST_Clip($1, $2, $3, $4, $5);
+	END;
+	$$ LANGUAGE 'plpgsql' IMMUTABLE;
+
 CREATE OR REPLACE FUNCTION st_clip(
 	rast raster, nband integer,
 	geom geometry,