-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--
-- $Id: rtpostgis.sql.in.c 5687 2010-06-07 15:18:29Z pracine $
--
-- WKTRaster - Raster Type for PostGIS
-- http://postgis.refractions.net/support/wiki/index.php?WKTRasterHomePage
--
-- Copyright (c) 2009-2010 Sandro Santilli <strk@keybit.net>, David Zwarg <dzwarg@avencia.com>, Pierre Racine <pierre.racine@sbf.ulaval.ca>
--
-- This is free software; you can redistribute and/or modify it under
-- the terms of the GNU General Public Licence. See the COPYING file.
--
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
--
-- WARNING: Any change in this file must be evaluated for compatibility.
--
-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

-- BEGIN;

------------------------------------------------------------------------------
-- RASTER Type
------------------------------------------------------------------------------

CREATE OR REPLACE FUNCTION raster_in(cstring)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_in'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION raster_out(raster)
    RETURNS cstring
    AS '$libdir/rtpostgis','RASTER_out'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE TYPE raster (
    alignment = double,
    internallength = variable,
    input = raster_in,
    output = raster_out,
    storage = extended
);

------------------------------------------------------------------------------
-- FUNCTIONS
------------------------------------------------------------------------------

-----------------------------------------------------------------------
-- RasterLib Version
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION postgis_raster_lib_version()
    RETURNS text
    AS '$libdir/rtpostgis', 'RASTER_lib_version'
    LANGUAGE 'C' IMMUTABLE; -- a new lib will require a new session

CREATE OR REPLACE FUNCTION postgis_raster_lib_build_date()
    RETURNS text
    AS '$libdir/rtpostgis', 'RASTER_lib_build_date'
    LANGUAGE 'C' IMMUTABLE; -- a new lib will require a new session

-----------------------------------------------------------------------
-- Constructors ST_MakeEmptyRaster
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_makeemptyraster(width int, height int, upperleftx float8, upperlefty float8, pixelsizex float8, pixelsizey float8, skewx float8, skewy float8, srid int4)
    RETURNS RASTER
    AS '$libdir/rtpostgis', 'RASTER_makeEmpty'
    LANGUAGE 'C' IMMUTABLE; -- a new lib will require a new session

-----------------------------------------------------------------------
-- Raster Accessors
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_convexhull(raster)
    RETURNS geometry
    AS '$libdir/rtpostgis','RASTER_convex_hull'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_box2d(raster)
    RETURNS box2d
    AS 'select st_box2d(st_convexhull($1))'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_envelope(raster)
    RETURNS geometry
    AS 'select st_envelope(st_convexhull($1))'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_height(raster)
    RETURNS integer
    AS '$libdir/rtpostgis','RASTER_getHeight'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_numbands(raster)
    RETURNS integer
    AS '$libdir/rtpostgis','RASTER_getNumBands'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_pixelsizex(raster)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getXPixelSize'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_pixelsizey(raster)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getYPixelSize'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_skewx(raster)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getXSkew'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_skewy(raster)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getYSkew'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_srid(raster)
    RETURNS integer
    AS '$libdir/rtpostgis','RASTER_getSRID'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_upperleftx(raster)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getXUpperLeft'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_upperlefty(raster)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getYUpperLeft'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_width(raster)
    RETURNS integer
    AS '$libdir/rtpostgis','RASTER_getWidth'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_metadata(rast raster,
                                       OUT upperleftx float8,
                                       OUT upperlefty float8,
                                       OUT width int,
                                       OUT height int,
                                       OUT pixelsizex float8,
                                       OUT pixelsizey float8,
                                       OUT skewx float8,
                                       OUT skewy float8,
                                       OUT srid int,
                                       OUT numbands int
                                      )
    AS $$
    SELECT st_upperleftx($1),
           st_upperlefty($1),
           st_width($1),
           st_height($1),
           st_pixelsizex($1),
           st_pixelsizey($1),
           st_skewx($1),
           st_skewy($1),
           st_srid($1),
           st_numbands($1)
    $$
    LANGUAGE SQL;


-----------------------------------------------------------------------
-- Raster Band Accessors
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_bandhasnodatavalue(rast raster, band integer)
    RETURNS boolean
    AS '$libdir/rtpostgis','RASTER_getBandHasNoDataValue'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_bandhasnodatavalue(raster)
    RETURNS boolean
    AS $$ SELECT st_bandhasnodatavalue($1, 1) $$
    LANGUAGE SQL;

CREATE OR REPLACE FUNCTION st_bandnodatavalue(rast raster, band integer)
    RETURNS float4
    AS '$libdir/rtpostgis','RASTER_getBandNoDataValue'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_bandnodatavalue(raster)
    RETURNS float4
    AS $$ SELECT st_bandnodatavalue($1, 1) $$
    LANGUAGE SQL;

CREATE OR REPLACE FUNCTION st_bandpath(rast raster, band integer)
    RETURNS text
    AS '$libdir/rtpostgis','RASTER_getBandPath'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_bandpath(raster)
    RETURNS text
    AS $$ SELECT st_bandpath($1, 1) $$
    LANGUAGE SQL;

CREATE OR REPLACE FUNCTION st_bandpixeltype(rast raster, band integer)
    RETURNS text
    AS '$libdir/rtpostgis','RASTER_getBandPixelTypeName'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_bandpixeltype(raster)
    RETURNS text
    AS $$ SELECT st_bandpixeltype($1, 1) $$
    LANGUAGE SQL;

CREATE OR REPLACE FUNCTION st_bandmetadata(rast raster, 
                                           band int, 
                                           OUT pixeltype text, 
                                           OUT hasnodatavalue boolean, 
                                           OUT nodatavalue float4, 
                                           OUT isoutdb boolean, 
                                           OUT path text)
    AS $$
    SELECT st_bandpixeltype($1, $2), 
       st_bandhasnodatavalue($1, $2), 
       st_bandnodatavalue($1, $2), 
       st_bandpath($1, $2) IS NOT NULL, 
       st_bandpath($1, $2)
    $$
    LANGUAGE SQL;

CREATE OR REPLACE FUNCTION st_bandmetadata(rast raster, 
                                           OUT pixeltype text, 
                                           OUT hasnodatavalue boolean, 
                                           OUT nodatavalue float4, 
                                           OUT isoutdb boolean, 
                                           OUT path text)
    AS $$
    SELECT st_bandpixeltype($1, 1), 
       st_bandhasnodatavalue($1, 1), 
       st_bandnodatavalue($1, 1), 
       st_bandpath($1, 1) IS NOT NULL, 
       st_bandpath($1, 1)
    $$
    LANGUAGE SQL;

-----------------------------------------------------------------------
-- Raster Pixel Accessors
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_value(rast raster, band integer, x integer, y integer)
    RETURNS float8
    AS '$libdir/rtpostgis','RASTER_getPixelValue'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_value(rast raster, x integer, y integer)
    RETURNS float8
    AS $$ SELECT st_value($1, 1, $2, $3) $$
    LANGUAGE SQL;
    
CREATE OR REPLACE FUNCTION st_value(rast raster, band integer, pt geometry) 
    RETURNS float8 AS
    $$
    DECLARE
        val float8 := 0.0;
        x float8;
        y float8;
        gtype text;
    BEGIN
        SELECT st_geometrytype(pt) 
        INTO gtype;
        IF ( gtype != 'ST_Point' ) THEN
            RAISE EXCEPTION 'Attempting to get the value of a pixel with a non-point geometry';
        END IF;
        SELECT st_x(pt), st_y(pt) INTO x, y;
        SELECT st_value(rast, 
                        band, 
                        st_world2rastercoordx(rast, x, y), 
                        st_world2rastercoordy(rast, x, y)) 
        INTO val;
        RETURN val;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_value(rast raster, pt geometry)
    RETURNS float8
    AS $$ SELECT st_value($1, 1, $2) $$
    LANGUAGE SQL;

-----------------------------------------------------------------------
-- Raster Accessors ST_Georeference()
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_georeference(rast raster, format text) 
    RETURNS text AS
    $$
    DECLARE
        x numeric;
        result text;
    BEGIN
            SELECT st_pixelsizex(rast)::numeric INTO x;
            result = trunc(x, 10) || E'\n';

            SELECT st_skewy(rast)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';

            SELECT st_skewx(rast)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';

            SELECT st_pixelsizey(rast)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';

        IF format = 'ESRI' THEN
            SELECT (st_upperleftx(rast) + st_pixelsizex(rast)*0.5)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';

            SELECT (st_upperlefty(rast) + st_pixelsizey(rast)*0.5)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';
        ELSE -- IF format = 'GDAL' THEN
            SELECT st_upperleftx(rast)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';

            SELECT st_upperlefty(rast)::numeric INTO x;
            result = result || trunc(x, 10) || E'\n';
        END IF;

        RETURN result;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT; -- WITH (isstrict);

CREATE OR REPLACE FUNCTION st_georeference(raster)
    RETURNS text
    AS $$ select st_georeference($1,'GDAL') $$
    LANGUAGE 'SQL' IMMUTABLE STRICT;
    
-----------------------------------------------------------------------
-- Raster Editors
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_setpixelsize(rast raster, pixelsize float8)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setPixelSize'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setpixelsize(rast raster, pixelsizex float8, pixelsizey float8)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setPixelSizeXY'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setskew(rast raster, skew float8)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setSkew'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setskew(rast raster, skewx float8, skewy float8)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setSkewXY'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setsrid(rast raster, srid integer)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setSRID'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setupperleft(rast raster, upperleftx float8, upperlefty float8)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setUpperLeftXY'
    LANGUAGE 'C' IMMUTABLE STRICT;

-----------------------------------------------------------------------
-- Raster Editors ST_SetGeoreference()
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_setgeoreference(rast raster, georef text)
    RETURNS raster AS 
    $$
    DECLARE
        result raster;
    BEGIN
        SELECT st_setgeoreference(rast, georef, 'GDAL') INTO result;
        RETURN result;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT; -- WITH (isstrict);

CREATE OR REPLACE FUNCTION st_setgeoreference(rast raster, georef text, format text) 
    RETURNS raster AS
    $$
    DECLARE
        params text[];
        rastout raster;
    BEGIN
        IF rast IS NULL THEN
            RAISE WARNING 'Cannot set georeferencing on a null raster in st_setgeoreference.';
            RETURN rastout;
        END IF;

        SELECT regexp_matches(georef,
            E'(-?\\d+(?:\\.\\d+)?)\\s(-?\\d+(?:\\.\\d+)?)\\s(-?\\d+(?:\\.\\d+)?)\\s' || 
            E'(-?\\d+(?:\\.\\d+)?)\\s(-?\\d+(?:\\.\\d+)?)\\s(-?\\d+(?:\\.\\d+)?)') INTO params;

        IF NOT FOUND THEN
            RAISE EXCEPTION 'st_setgeoreference requires a string with 6 floating point values.';
        END IF;

        IF format = 'ESRI' THEN
            -- params array is now:
            -- {pixelsizex, skewy, skewx, pixelsizey, upperleftx, upperlefty}
            SELECT st_setpixelsize(rast, params[1]::float8, params[4]::float8) INTO rastout;
            SELECT st_setskew(rastout, params[3]::float8, params[2]::float8) INTO rastout;
            SELECT st_setupperleft(rastout, 
                                   params[5]::float8 - (params[1]::float8 * 0.5),
                                   params[6]::float8 - (params[4]::float8 * 0.5)) INTO rastout;
        ELSE
            IF format != 'GDAL' THEN
                RAISE WARNING E'Format \'%\' is not recognized, defaulting to GDAL format.', format;
            END IF;
            -- params array is now:
            -- {pixelsizex, skewy, skewx, pixelsizey, upperleftx, upperlefty}

            SELECT st_setpixelsize(rast, params[1]::float8, params[4]::float8) INTO rastout;
            SELECT st_setskew( rastout, params[3]::float8, params[2]::float8) INTO rastout;
            SELECT st_setupperleft(rastout, params[5]::float8, params[6]::float8) INTO rastout;
        END IF;
        RETURN rastout;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT; -- WITH (isstrict);

-----------------------------------------------------------------------
-- Raster Band Editors
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_setbandhasnodatavalue(rast raster, band integer, hasnodatavalue boolean)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setBandHasNoDataValue'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setbandhasnodatavalue(rast raster, hasnodatavalue boolean)
    RETURNS raster
    AS $$ SELECT st_setbandhasnodatavalue($1, 1, $2) $$
    LANGUAGE SQL;

CREATE OR REPLACE FUNCTION st_setbandnodatavalue(rast raster, band integer, nodatavalue float8)
    RETURNS raster
    AS '$libdir/rtpostgis','RASTER_setBandNoDataValue'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_setbandnodatavalue(rast raster, nodatavalue float8)
    RETURNS raster
    AS $$ SELECT st_setbandnodatavalue($1, 1, $2) $$
    LANGUAGE SQL;
   
-----------------------------------------------------------------------
-- Raster Pixel Editors
-----------------------------------------------------------------------

-- TODO: To be implemented
--CREATE OR REPLACE FUNCTION st_setvalue(rast raster, band integer, x integer, y integer, newvalue float8)
--    RETURNS float8
--    AS '$libdir/rtpostgis','RASTER_setPixelValue'
--    LANGUAGE 'C' IMMUTABLE STRICT;

-----------------------------------------------------------------------
-- Raster Processing Functions
-----------------------------------------------------------------------

CREATE TYPE geomval AS (
    geom geometry,
    val double precision
);

CREATE TYPE wktgeomval AS (
    wktgeom text,
    val double precision,
    srid int 
);

CREATE OR REPLACE FUNCTION dumpaswktpolygons(rast raster, band integer)
    RETURNS SETOF wktgeomval
    AS '$libdir/rtpostgis','RASTER_dumpAsWKTPolygons'
    LANGUAGE 'C' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_dumpaspolygons(rast raster, band integer) 
    RETURNS SETOF geomval AS 
    $$
    SELECT st_geomfromtext(wktgeomval.wktgeom, wktgeomval.srid), wktgeomval.val
    FROM dumpaswktpolygons($1, $2) AS wktgeomval;
    $$ 
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_dumpaspolygons(raster) 
    RETURNS SETOF geomval AS 
    $$
    SELECT st_geomfromtext(wktgeomval.wktgeom, wktgeomval.srid), wktgeomval.val
    FROM dumpaswktpolygons($1, 1) AS wktgeomval;
    $$ 
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_polygon(rast raster, band integer) 
    RETURNS geometry AS 
    $$
    SELECT st_union(f.geom) AS singlegeom 
    FROM (SELECT (st_dumpaspolygons($1, $2)).geom AS geom) AS f;
    $$ 
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_polygon(raster) 
    RETURNS geometry AS 
    $$        
    SELECT st_union(f.geom) AS singlegeom 
    FROM (SELECT (st_dumpaspolygons($1, 1)).geom AS geom) AS f;
    $$ 
    LANGUAGE 'SQL' IMMUTABLE STRICT;
    
CREATE OR REPLACE FUNCTION st_pixelaspolygon(rast raster, band integer, x integer, y integer) 
    RETURNS geometry AS 
    $$
    DECLARE
        w integer;
        h integer;
        pxsizex float8;
        pxsizey float8;
        skewx float8;
        skewy float8;
        x1 float8;
        y1 float8;
        x2 float8;
        y2 float8;
        x3 float8;
        y3 float8;
        x4 float8;
        y4 float8;
        result geometry;
    BEGIN
        SELECT st_pixelsizex(rast) INTO pxsizex;
        SELECT st_skewy(rast) INTO skewx;
        SELECT st_skewx(rast) INTO skewy;
        SELECT st_pixelsizey(rast) INTO pxsizey;
        SELECT pxsizex * (x - 1) + skewx * (y - 1) + st_upperleftx(rast) INTO x1;
        SELECT pxsizey * (y - 1) + skewy * (x - 1) + st_upperlefty(rast) INTO y1;
        SELECT x1 + pxsizex INTO x2;
        SELECT y1 + skewy, 8 INTO y2;
        SELECT x1 + pxsizex + skewx INTO x3;
        SELECT y1 + pxsizey + skewy INTO y3;
        SELECT x1 + skewx, 8 INTO x4;
        SELECT y1 + pxsizey INTO y4;
        SELECT st_setsrid(st_makepolygon(st_makeline(ARRAY[st_makepoint(x1, y1), 
                                                           st_makepoint(x2, y2), 
                                                           st_makepoint(x3, y3), 
                                                           st_makepoint(x4, y4), 
                                                           st_makepoint(x1, y1)])), 
                                                     st_srid(rast)) 
        INTO result;
        RETURN result;
    END;
    $$
    LANGUAGE 'plpgsql';

CREATE FUNCTION st_pixelaspolygon(rast raster, x integer, y integer) 
    RETURNS geometry AS 
    $$
        SELECT st_pixelaspolygon($1, 1, $2, $3)
    $$
    LANGUAGE SQL;


-----------------------------------------------------------------------
-- Raster Utility Functions
-----------------------------------------------------------------------

---------------------------------------------------------------------------------
-- ST_World2RasterCoordX(rast raster, xw float8, yw float8)
-- Returns the column number of the pixel covering the provided X and Y world 
-- coordinates. 
-- This function works even if the world coordinates are outside the raster extent. 
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_world2rastercoordx(rast raster, xw float8, yw float8) 
    RETURNS int AS
    $$
    DECLARE
        a float8 := 0.0;
        b float8 := 0.0;
        c float8 := 0.0;
        d float8 := 0.0;
        e float8 := 0.0;
        f float8 := 0.0;
        xr numeric := 0.0;
    BEGIN
        SELECT st_pixelsizex(rast), 
               st_skewy(rast), 
               st_skewx(rast), 
               st_pixelsizey(rast), 
               st_upperleftx(rast), 
               st_upperlefty(rast) 
        INTO a, d, b, e, c, f;
        IF ( b * d - a * e = 0 ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate on a raster with pixel size equal to 0';
        END IF;
        xr := (b * (yw - f) - e * (xw - c)) / (b * d - a * e);
        RETURN floor(xr) + 1;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_World2RasteCoordX(rast raster, xw float8)
-- Returns the column number of the pixels covering the provided world X coordinate 
-- for a non-rotated raster. 
-- This function works even if the world coordinate is outside the raster extent. 
-- This function returns an error if the raster is rotated. In this case you must 
-- also provide a Y.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_world2rastercoordx(rast raster, xw float8) 
    RETURNS int AS
    $$
    DECLARE
        a float8 := 0.0;
        b float8 := 0.0;
        c float8 := 0.0;
        d float8 := 0.0;
        e float8 := 0.0;
        f float8 := 0.0;
        xr numeric := 0.0;
    BEGIN
        SELECT st_pixelsizex(rast), 
               st_skewy(rast), 
               st_skewx(rast), 
               st_pixelsizey(rast), 
               st_upperleftx(rast), 
               st_upperlefty(rast) 
        INTO a, d, b, e, c, f;
        IF ( b * d - a * e = 0 ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate on a raster with pixel size equal to 0';
        END IF;
        IF ( b != 0 OR d != 0) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate on a raster with rotation providing x only. A y must also be provided';
        END IF;
        xr := (e * (xw - c)) / (a * e);
        RETURN floor(xr) + 1;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_World2RasterCoordX(rast raster, pt geometry)
-- Returns the column number of the pixel covering the provided point geometry.
-- This function works even if the point is outside the raster extent.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_world2rastercoordx(rast raster, pt geometry) 
    RETURNS float8 AS
    $$
    DECLARE
        xr int := 0;
        gtype text;
    BEGIN
        SELECT st_geometrytype(pt)
        INTO gtype;
        IF ( gtype != 'ST_Point' ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate with a non-point geometry';
        END IF;
        SELECT st_world2rastercoordx($1, st_x(pt), st_y(pt)) INTO xr;
        RETURN xr;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;
    
---------------------------------------------------------------------------------
-- ST_World2RasterCoordY(rast raster, xw float8, yw float8)
-- Returns the row number of the pixel covering the provided X and Y world 
-- coordinates. 
-- This function works even if the world coordinates are outside the raster extent. 
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_world2rastercoordy(rast raster, xw float8, yw float8) 
    RETURNS int AS
    $$
    DECLARE
        a float8 := 0.0;
        b float8 := 0.0;
        c float8 := 0.0;
        d float8 := 0.0;
        e float8 := 0.0;
        f float8 := 0.0;
        yr numeric := 0.0;
    BEGIN
        SELECT st_pixelsizex(rast), 
               st_skewy(rast), 
               st_skewx(rast), 
               st_pixelsizey(rast), 
               st_upperleftx(rast), 
               st_upperlefty(rast) 
        INTO a, d, b, e, c, f;
        IF ( b * d - a * e = 0 ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate on a raster with pixel size equal to 0';
        END IF;
        yr := (a * (yw - f) + d * (c - xw)) / (a * e - b * d);
        RETURN floor(yr) + 1;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_World2RasterCoordY(rast raster, yw float8)
-- Returns the row number of the pixels covering the provided world Y coordinate 
-- for a non-rotated raster. 
-- This function works even if the world coordinate is outside the raster extent. 
-- This function returns an error if the raster is rotated. In this case you must 
-- also provide an X.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_world2rastercoordy(rast raster, yw float8) 
    RETURNS int AS
    $$
    DECLARE
        a float8 := 0.0;
        b float8 := 0.0;
        c float8 := 0.0;
        d float8 := 0.0;
        e float8 := 0.0;
        f float8 := 0.0;
        yr numeric := 0.0;
    BEGIN
        SELECT st_pixelsizex(rast), 
               st_skewy(rast), 
               st_skewx(rast), 
               st_pixelsizey(rast), 
               st_upperleftx(rast), 
               st_upperlefty(rast) 
        INTO a, d, b, e, c, f;
        IF ( b * d - a * e = 0 ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate on a raster with pixel size equal to 0';
        END IF;
        IF ( b != 0 OR d != 0) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate on a raster with rotation providing y only. A x must also be provided';
        END IF;
        yr := (a * (yw - f)) / (a * e);
        RETURN floor(yr) + 1;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_World2RasterCoordY(rast raster, pt geometry)
-- Returns the row number of the pixel covering the provided point geometry.
-- This function works even if the point is outside the raster extent.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_world2rastercoordy(rast raster, pt geometry) 
    RETURNS float8 AS
    $$
    DECLARE
        yr int := 0;
        gtype text;
    BEGIN
        SELECT st_geometrytype(pt)
        INTO gtype;
        IF ( gtype != 'ST_Point' ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinate with a non-point geometry';
        END IF;
        SELECT st_world2rastercoordy($1, st_x(pt), st_y(pt)) INTO yr;
        RETURN yr;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_Raster2WorldCoordX(rast raster, xr int, yr int)
-- Returns the X world coordinate of the upper left corner of the pixel located at 
-- the provided column and row numbers.
-- This function works even if the provided raster column and row are beyond or 
-- below the raster width and height.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_raster2worldcoordx(rast raster, xr int, yr int)
    RETURNS float8 AS
    $$
    DECLARE
        a float8 := 0.0;
        b float8 := 0.0;
        c float8 := 0.0;
        xw numeric := 0.0;
    BEGIN
        SELECT st_pixelsizex(rast), 
               st_skewx(rast), 
               st_upperleftx(rast)
        INTO a, b, c;
        xw := (a::numeric * (xr::numeric - 1.0) + b::numeric * (yr::numeric - 1.0) + c::numeric)::numeric;
        RETURN xw;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_Raster2WorldCoordX(rast raster, xr int)
-- Returns the X world coordinate of the upper left corner of the pixel located at 
-- the provided column number for a non-rotated raster.
-- This function works even if the provided raster column is beyond or below the 
-- raster width.
-- This function returns an error if the raster is rotated. In this case you must 
-- also provide a Y.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_raster2worldcoordx(rast raster, xr int) 
    RETURNS float8 AS
    $$
    DECLARE
        a float8 := 0.0;
        b float8 := 0.0;
        c float8 := 0.0;
        xw numeric := 0.0;
    BEGIN
        SELECT st_pixelsizex(rast), 
               st_skewx(rast), 
               st_upperleftx(rast)
        INTO a, b, c;
        IF ( b != 0 ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinates on a raster with rotation providing X only. A Y coordinate must also be provided';
        END IF;
        xw := (a::numeric * (xr::numeric - 1.0) + c::numeric)::numeric;
        RETURN xw;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_Raster2WorldCoordY(rast raster, xr int, yr int)
-- Returns the Y world coordinate of the upper left corner of the pixel located at 
-- the provided column and row numbers.
-- This function works even if the provided raster column and row are beyond or 
-- below the raster width and height.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_raster2worldcoordy(rast raster, xr int, yr int) 
    RETURNS float8 AS
    $$
    DECLARE
        d float8 := 0.0;
        e float8 := 0.0;
        f float8 := 0.0;
        yw numeric := 0.0;
    BEGIN
        SELECT st_skewy(rast), 
               st_pixelsizey(rast), 
               st_upperlefty(rast)
        INTO d, e, f;
        yw := (d::numeric * (xr::numeric - 1.0) + e::numeric * (yr::numeric - 1.0) + f::numeric)::numeric;
        RETURN yw;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;

---------------------------------------------------------------------------------
-- ST_Raster2WorldCoordY(rast raster, yr int)
-- Returns the Y world coordinate of the upper left corner of the pixel located at 
-- the provided row number for a non-rotated raster.
-- This function works even if the provided raster row is beyond or below the 
-- raster height.
-- This function returns an error if the raster is rotated. In this case you must 
-- also provide an X.
---------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_raster2worldcoordy(rast raster, yr int) 
    RETURNS float8 AS
    $$
    DECLARE
        d float8 := 0.0;
        e float8 := 0.0;
        f float8 := 0.0;
        yw numeric := 0.0;
    BEGIN
        SELECT st_skewy(rast), 
               st_pixelsizey(rast), 
               st_upperlefty(rast)
        INTO d, e, f;
        IF ( d != 0 ) THEN
            RAISE EXCEPTION 'Attempting to compute raster coordinates on a raster with rotation providing Y only. An X coordinate must also be provided';
        END IF;
        yw := (e::numeric * (yr::numeric - 1.0) + f::numeric)::numeric;
        RETURN yw;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;


-----------------------------------------------------------------------
-- Raster Outputs
-----------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_asbinary(raster)
    RETURNS bytea
    AS '$libdir/rtpostgis', 'RASTER_to_binary'
    LANGUAGE 'C' IMMUTABLE;

CREATE OR REPLACE FUNCTION st_bytea(raster)
    RETURNS bytea
    AS '$libdir/rtpostgis', 'RASTER_to_bytea'
    LANGUAGE 'C' IMMUTABLE;

------------------------------------------------------------------------------
--  Casts
------------------------------------------------------------------------------

CREATE CAST (raster AS box2d)
    WITH FUNCTION st_box2d(raster) AS IMPLICIT;

CREATE CAST (raster AS geometry)
    WITH FUNCTION st_convexhull(raster) AS IMPLICIT;

CREATE CAST (raster AS bytea)
    WITH FUNCTION st_bytea(raster) AS IMPLICIT;

------------------------------------------------------------------------------
--  GiST index OPERATOR support functions
------------------------------------------------------------------------------

CREATE OR REPLACE FUNCTION st_overleft(raster, raster)
    RETURNS bool
    AS 'select geometry_overleft($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_overright(raster, raster)
    RETURNS bool
    AS 'select geometry_overright($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_left(raster, raster)
    RETURNS bool
    AS 'select geometry_left($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_right(raster, raster)
    RETURNS bool
    AS 'select geometry_right($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_overabove(raster, raster)
    RETURNS bool
    AS 'select geometry_overabove($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_overbelow(raster, raster)
    RETURNS bool
    AS 'select geometry_overbelow($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_above(raster, raster)
    RETURNS bool
    AS 'select geometry_above($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_below(raster, raster)
    RETURNS bool
    AS 'select geometry_below($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_same(raster, raster)
    RETURNS bool
    AS 'select geometry_same($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_contained(raster, raster)
    RETURNS bool
    AS 'select geometry_contained($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_contain(raster, raster)
    RETURNS bool
    AS 'select geometry_contain($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

CREATE OR REPLACE FUNCTION st_overlap(raster, raster)
    RETURNS bool
    AS 'select geometry_overlap($1::geometry, $2::geometry)'
    LANGUAGE 'SQL' IMMUTABLE STRICT;

------------------------------------------------------------------------------
--  GiST index OPERATORs
------------------------------------------------------------------------------

CREATE OPERATOR << (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_left,
    COMMUTATOR = '>>',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR &< (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_overleft,
    COMMUTATOR = '&>',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR <<| (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_below,
    COMMUTATOR = '|>>',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR &<| (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_overbelow,
    COMMUTATOR = '|&>',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR && (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_overlap,
    COMMUTATOR = '&&',
    RESTRICT = postgis_gist_sel, JOIN = postgis_gist_joinsel
    );

CREATE OPERATOR &> (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_overright,
    COMMUTATOR = '&<',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR >> (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_right,
    COMMUTATOR = '<<',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR |&> (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_overabove,
    COMMUTATOR = '&<|',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR |>> (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_above,
    COMMUTATOR = '<<|',
    RESTRICT = positionsel, JOIN = positionjoinsel
    );

CREATE OPERATOR ~= (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_same,
    COMMUTATOR = '~=',
    RESTRICT = eqsel, JOIN = eqjoinsel
    );

CREATE OPERATOR @ (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_contained,
    COMMUTATOR = '~',
    RESTRICT = contsel, JOIN = contjoinsel
    );

CREATE OPERATOR ~ (
    LEFTARG = raster, RIGHTARG = raster, PROCEDURE = st_contain,
    COMMUTATOR = '@',
    RESTRICT = contsel, JOIN = contjoinsel
    );

-----------------------------------------------------------------------
-- Raster/Geometry Spatial Relationship
-----------------------------------------------------------------------

-----------------------------------------------------------------------
-- _st_intersects(geomin geometry, rast raster, band integer)
-- Check for the presence of withvalue pixels in the area shared by the 
-- raster and the geometry. If only nodatavalue pixel are found, the 
-- geometry does not intersect with the raster.
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION _st_intersects(geomin geometry, rast raster, band integer) 
    RETURNS boolean AS
    $$
    DECLARE
        hasnodata boolean := FALSE;
        nodata float8 := 0.0;
        geomintersect geometry;
        x1w double precision := 0.0;
        x2w double precision := 0.0;
        y1w double precision := 0.0;
        y2w double precision := 0.0;
        x1 integer := 0;
        x2 integer := 0;
        x3 integer := 0;
        x4 integer := 0;
        y1 integer := 0;
        y2 integer := 0;
        y3 integer := 0;
        y4 integer := 0;
        x integer := 0;
        y integer := 0;
        xinc integer := 0;
        yinc integer := 0;
        pixelval double precision;
        bempty boolean := FALSE;
        bintersect boolean := FALSE;
        gtype text;
        psize float8;
    BEGIN
    
        -- Get the intersection between with the geometry. 
        -- We will search for withvalue pixel only in this area.
        SELECT st_intersection(geomin, st_convexhull(rast))
        INTO geomintersect;
        
--RAISE NOTICE 'geomintersect1=%', astext(geomintersect);

        -- If the intersection is empty, return false
        SELECT st_isempty(geomintersect) INTO bempty;
        IF bempty THEN
            RETURN FALSE;
        END IF;

        -- If the band does not have a nodatavalue, there is no need to search for with value pixels
        SELECT st_bandhasnodatavalue(rast, band)
        INTO hasnodata;
        IF not hasnodata THEN
            RETURN TRUE;
        END IF;

        -- We create a minimalistic buffer around the intersection in order to scan every pixels 
        -- that would touch the edge or intersect with the geometry
        SELECT st_pixelsizex(rast) + st_skewy(rast)
        INTO psize;
        SELECT st_buffer(geomintersect, psize / 1000000)
        INTO geomintersect;
--RAISE NOTICE 'geomintersect2=%', astext(geomintersect);
        
        -- Find the world coordinates of the bounding box of the intersecting area
        SELECT st_xmin(geomintersect),
               st_ymin(geomintersect),
               st_xmax(geomintersect),
               st_ymax(geomintersect), 
               st_bandnodatavalue(rast, band)
        INTO x1w, y1w, x2w, y2w, nodata;
--RAISE NOTICE 'x1w=%, y1w=%, x2w=%, y2w=%', x1w, y1w, x2w, y2w;

        -- Convert world coordinates to raster coordinates
        SELECT st_world2rastercoordx(rast, x1w, y1w),
               st_world2rastercoordy(rast, x1w, y1w),
               st_world2rastercoordx(rast, x2w, y1w),
               st_world2rastercoordy(rast, x2w, y1w),
               st_world2rastercoordx(rast, x1w, y2w),
               st_world2rastercoordy(rast, x1w, y2w),
               st_world2rastercoordx(rast, x2w, y2w),
               st_world2rastercoordy(rast, x2w, y2w)
        INTO x1, y1, x2, y2, x3, y3, x4, y4;
--RAISE NOTICE 'x1=%, y1=%, x2=%, y2=%, x3=%, y3=%, x4=%, y4=%', x1, y1, x2, y2, x3, y3, x4, y4;

        -- Order the raster coordinates for the upcoming FOR loop.
        SELECT int4smaller(int4smaller(int4smaller(x1, x2), x3), x4),
               int4smaller(int4smaller(int4smaller(y1, y2), y3), y4),
               int4larger(int4larger(int4larger(x1, x2), x3), x4),
               int4larger(int4larger(int4larger(y1, y2), y3), y4)
        INTO x1, y1, x2, y2;

        -- Make sure the range is not lower than 1. 
        -- This can happen when world coordinate are exactly on the left border 
        -- of the raster and that they do not span on more than one pixel.
        SELECT int4smaller(int4larger(x1, 1), st_width(rast)),
               int4smaller(int4larger(y1, 1), st_height(rast))
        INTO x1, y1;

        -- Also make sure the range does not exceed the width and height of the raster. 
        -- This can happen when world coordinate are exactly on the lower right border 
        -- of the raster.
        SELECT int4smaller(x2, st_width(rast)),
               int4smaller(y2, st_height(rast))
        INTO x2, y2;
--RAISE NOTICE 'x1=%, y1=%, x2=%, y2=%', x1, y1, x2, y2;

        -- Search exhaustively for withvalue pixel on a moving 3x3 grid 
        -- (very often more efficient than searching on a mere 1x1 grid)
        FOR xinc in 0..2 LOOP
            FOR yinc in 0..2 LOOP
                FOR x IN x1+xinc..x2 BY 3 LOOP
                    FOR y IN y1+yinc..y2 BY 3 LOOP
                        -- Check first if the pixel intersects with the geometry. Often many won't.
                        SELECT NOT st_isempty(st_intersection(st_pixelaspolygon(rast, band, x, y), geomin)) 
                        INTO bintersect;

                        IF bintersect THEN
                            -- If the pixel really intersects, check its value. Return TRUE if with value.
                            SELECT st_value(rast, band, x, y) 
                            INTO pixelval;
                            IF pixelval != nodata THEN
                                RETURN TRUE;
                            END IF;
                        END IF;
                    END LOOP;
                END LOOP;
            END LOOP;
        END LOOP;
        RETURN FALSE;
    END;
    $$
    LANGUAGE 'plpgsql' IMMUTABLE STRICT;


CREATE OR REPLACE FUNCTION st_intersects(geometry, raster, integer) 
    RETURNS boolean AS 
    $$ SELECT $1 && $2 AND _st_intersects($1, $2, $3);
    $$ LANGUAGE 'SQL' IMMUTABLE;

CREATE OR REPLACE FUNCTION st_intersects(raster, integer, geometry) 
    RETURNS boolean AS 
    $$ SELECT st_intersects($3, $1, $2);
    $$ LANGUAGE 'SQL' IMMUTABLE;

CREATE OR REPLACE FUNCTION st_intersects(geometry, raster) 
    RETURNS boolean AS 
    $$ SELECT st_intersects($1, $2, 1);
    $$ LANGUAGE 'SQL' IMMUTABLE;

CREATE OR REPLACE FUNCTION st_intersects(raster, geometry) 
    RETURNS boolean AS 
    $$ SELECT st_intersects($2, $1, 1);
    $$ LANGUAGE 'SQL' IMMUTABLE;

-----------------------------------------------------------------------
-- _st_intersection(geom geometry, rast raster, band integer)
-- Returns a geometry set that represents the shared portion of the 
-- provided geometry and the geometries produced by the vectorization of rast. 
-- Return an empty geometry if the geometry does not intersect with the 
-- raster.
-- Raster nodata value areas are not vectorized and hence do not intersect 
-- with any geometries.
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION st_intersection(geom geometry, rast raster, band integer) 
    RETURNS SETOF geomval AS 
    $$
        -- Return the intersections of the geometry with the vectorized parts of 
        -- the raster and the values associated with those parts, if really their 
        -- intersection is not empty.
        SELECT intgeom, val
        FROM (
            SELECT ST_Intersection((gv).geom, $1) intgeom, (gv).val 
            FROM ST_DumpAsPolygons($2, $3) gv
            WHERE ST_Intersects((gv).geom, $1) AND ST_Intersects($1, $2, $3)) foo
        WHERE NOT st_isempty(intgeom)  -- eliminate empty intersections
        UNION ALL
        -- If the geometry does not intersect with the raster, return an empty 
        -- geometry and a null value
        SELECT emptygeom, NULL FROM
        ST_GeomCollFromText('GEOMETRYCOLLECTION EMPTY', st_srid($1)) emptygeom
        WHERE NOT ST_Intersects($1, $2, $3);
    $$   
    LANGUAGE SQL IMMUTABLE;

CREATE OR REPLACE FUNCTION st_intersection(rast raster, geom geometry) 
    RETURNS SETOF geomval AS 
    $$
        SELECT (gv).geom, (gv).val FROM st_intersection($2, $1, 1) gv;
    $$   
    LANGUAGE SQL IMMUTABLE;

CREATE OR REPLACE FUNCTION st_intersection(geom geometry, rast raster) 
    RETURNS SETOF geomval AS 
    $$
        SELECT (gv).geom, (gv).val FROM st_intersection($1, $2, 1) gv;
    $$   
    LANGUAGE SQL IMMUTABLE;

CREATE OR REPLACE FUNCTION st_intersection(rast raster, band integer, geom geometry) 
    RETURNS SETOF geomval AS 
    $$
        SELECT (gv).geom, (gv).val FROM st_intersection($3, $1, $2) gv;
    $$   
    LANGUAGE SQL IMMUTABLE;

------------------------------------------------------------------------------
-- RASTER_COLUMNS
--
-- The metadata is documented in the WKT Raster specification:
-- http://trac.osgeo.org/postgis/wiki/WKTRaster/SpecificationFinal01
------------------------------------------------------------------------------
CREATE TABLE raster_columns (
    r_table_catalog varchar(256) not null,
    r_table_schema varchar(256) not null,
    r_table_name varchar(256) not null,
    r_column varchar(256) not null,
    srid integer not null,
    pixel_types varchar[] not null,
    out_db boolean not null,
    regular_blocking boolean not null,
    nodata_values double precision[],
    pixelsize_x double precision,
    pixelsize_y double precision,
    blocksize_x double precision,
    blocksize_y double precision,
    extent geometry,

    CONSTRAINT raster_columns_pk primary key (
        r_table_catalog,
        r_table_schema,
        r_table_name,
        r_column )
    ) WITH OIDS;


------------------------------------------------------------------------------
-- AddRasterColumn
-------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION AddRasterColumn(p_catalog_name varchar,
                                           p_schema_name varchar,
                                           p_table_name varchar,
                                           p_column_name varchar,
                                           p_srid integer,
                                           p_pixel_types varchar[],
                                           p_out_db boolean,
                                           p_regular_blocking boolean,
                                           p_nodata_values double precision[],
                                           p_pixelsize_x double precision,
                                           p_pixelsize_y double precision,
                                           p_blocksize_x integer,
                                           p_blocksize_y integer,
                                           p_extent geometry)

    RETURNS text AS
    $$
    DECLARE
        sql text;
        real_schema name;
        srid_into varchar;
        geometry_op_into varchar;
        pixel_types varchar[];
        pixel_types_size integer := 0;
        pixel_types_found integer := 0;
        nodata_values_size integer := 0;

    BEGIN

        RAISE DEBUG 'Parameters: catalog=%, schema=%, table=%, column=%, srid=%, pixel_types=%, out_db=%, regular_blocking=%, nodata_values=%, pixelsize_x=%, pixelsize_y=%, blocksize_x=%, blocksize_y=%',
                     p_catalog_name, p_schema_name, p_table_name, p_column_name, p_srid, p_pixel_types, p_out_db, p_regular_blocking, p_nodata_values, p_pixelsize_x, p_pixelsize_y, p_blocksize_x, p_blocksize_y;

        -- Validate required parametersa and combinations
        IF ( (p_catalog_name IS NULL) OR (p_schema_name IS NULL)
              OR (p_table_name IS NULL) OR (p_column_name IS NULL) ) THEN
            RAISE EXCEPTION 'Name of catalog, schema, table or column IS NULL, value expected';
            RETURN 'fail';
        END IF;

        IF ( p_srid IS NULL ) THEN
            RAISE EXCEPTION 'SRID IS NULL, value expected';
            RETURN 'fail';
        END IF;

        IF ( p_pixel_types IS NULL ) THEN
            RAISE EXCEPTION 'Array of pixel types IS NULL, value expected';
            RETURN 'fail';
        END IF;

        IF ( p_out_db IS NULL ) THEN
            RAISE EXCEPTION 'out_db IS NULL, value expected';
            RETURN 'fail';
        END IF;

        IF ( p_regular_blocking IS NULL ) THEN
            RAISE EXCEPTION 'regular_blocking IS NULL, value expected';
            RETURN 'fail';
        END IF;

        IF ( p_regular_blocking = true ) THEN
           IF ( p_blocksize_x IS NULL or p_blocksize_y IS NULL ) THEN
               RAISE EXCEPTION 'blocksize_x/blocksize_y IS NULL, value expected if regular_blocking is TRUE';
               RETURN 'fail';
           END IF;
        ELSE
           IF ( p_blocksize_x IS NOT NULL or p_blocksize_y IS NOT NULL ) THEN
               RAISE EXCEPTION 'blocksize_x/blocksize_y values given, but regular_blocking is FALSE';
               RETURN 'fail';
           END IF;
        END IF;


        -- Verify SRID
        IF ( (p_srid != 0) AND (p_srid != -1) ) THEN
            SELECT SRID INTO srid_into FROM spatial_ref_sys WHERE SRID = p_srid;
            IF NOT FOUND THEN
                RAISE EXCEPTION 'Invalid SRID';
                RETURN 'fail';
            END IF;
            RAISE DEBUG 'Verified SRID = %', p_srid;
        END IF;


        -- Verify PIXEL TYPE
        -- TODO: If only PostgreSQL 8.2+ supported, use @> operator instead of brute-force lookup
        --       SELECT p_pixel_types <@ pixel_types INTO pixel_types_found_into; -- boolean
        pixel_types := ARRAY['1BB','2BUI','4BUI','8BSI','8BUI','16BSI','16BUI','32BSI','32BUI','16BF','32BF','64BF'];

        FOR npti IN array_lower(p_pixel_types, 1) .. array_upper(p_pixel_types, 1) LOOP

            pixel_types_found := 0;
            FOR pti IN array_lower(pixel_types, 1) .. array_upper(pixel_types, 1) LOOP
                IF p_pixel_types[npti] = pixel_types[pti] THEN
                    pixel_types_found := 1;
                    RAISE DEBUG 'Identified pixel type %', p_pixel_types[npti];
                END IF;
            END LOOP;

            IF pixel_types_found = 0 THEN
                RAISE EXCEPTION 'Invalid pixel type % - valid ones are %', p_pixel_types[npti], pixel_types;
                RETURN 'fail';
            END IF;

            pixel_types_size := pixel_types_size + 1;
        END LOOP;

        -- Verify NODATA
        -- TODO: Validate if NODATA values matche range of corresponding pixel types
        nodata_values_size := 1 + array_upper(p_nodata_values, 1) - array_lower(p_nodata_values, 1);
        IF ( pixel_types_size != nodata_values_size ) THEN
            RAISE EXCEPTION 'Number of pixel types (%) and NODATA values (%) do not match',
                            pixel_types_size, nodata_values_size;
            RETURN 'fail';
        END IF;


        -- Verify extent geometry
        IF ( p_extent IS NOT NULL ) THEN

            -- Verify POLYGON type
            SELECT GeometryType(p_extent) INTO geometry_op_into;
            IF ( NOT ( geometry_op_into = 'POLYGON' ) ) THEN
                RAISE EXCEPTION 'extent is of invalid type (%), expected simple and non-rotated POLYGON', geometry_op_into;
                RETURN 'fail';
            END IF;

            -- Verify SRID
            SELECT ST_SRID(p_extent) INTO srid_into;
            IF ( p_srid != srid_into::integer ) THEN
                RAISE EXCEPTION 'SRID values for raster (%) and extent (%) do not match', p_srid, srid_into;
                RETURN 'fail';
            END IF;
        END IF;


        -- Verify regular_blocking
        IF ( p_regular_blocking = true ) THEN

            IF ( p_blocksize_x IS NULL or p_blocksize_y IS NULL ) THEN
                RAISE EXCEPTION 'unexpected NULL for blocksize_x or blocksize_y';
                RETURN 'fail';
            END IF;

            -- Verify extent is non-rotated rectangle
            IF ( p_extent IS NOT NULL ) THEN
                -- TODO: Replace with bounding box overlapping test (&&)
                SELECT ST_Equals(p_extent, ST_Envelope(p_extent)) INTO geometry_op_into;
                IF ( NOT ( geometry_op_into = 't' ) ) THEN
                    RAISE EXCEPTION 'extent does not represent non-rotated rectangle';
                    RETURN 'fail';
                END IF;
            END IF;

            -- TODO: Set number of constraints on target table:
            --       - all tiles have the same size (blocksize_x and blocksize_y)
            --       - all tiles do not overlap
            --       - all tiles appear on the regular block grid
            --       - top left block start at the top left corner of the extent
        END IF;



        -- Verify SCHEMA
        IF ( p_schema_name IS NOT NULL AND p_schema_name != '' ) THEN
            sql := 'SELECT nspname FROM pg_namespace '
                || 'WHERE text(nspname) = ' || quote_literal(p_schema_name)
                || 'LIMIT 1';
            RAISE DEBUG '%', sql;
            EXECUTE sql INTO real_schema;

            IF ( real_schema IS NULL ) THEN
                RAISE EXCEPTION 'Schema % is not a valid schemaname', quote_literal(p_schema_name);
                RETURN 'fail';
            END IF;
        END IF;

        IF ( real_schema IS NULL ) THEN
            RAISE DEBUG 'Detecting schema';
            sql := 'SELECT n.nspname AS schemaname '
                || 'FROM pg_catalog.pg_class c '
                || 'JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace '
                || 'WHERE c.relkind = ' || quote_literal('r')
                || ' AND n.nspname NOT IN ('
                || quote_literal('pg_catalog') || ', ' || quote_literal('pg_toast') || ')'
                || ' AND pg_catalog.pg_table_is_visible(c.oid)'
                || ' AND c.relname = ' || quote_literal(p_table_name);
            RAISE DEBUG '%', sql;
            EXECUTE sql INTO real_schema;

            IF ( real_schema IS NULL ) THEN
                RAISE EXCEPTION 'Table % does not occur in the search_path',
                                quote_literal(p_table_name);
                RETURN 'fail';
            END IF;
        END IF;


        -- Add raster column to target table
        sql := 'ALTER TABLE '
            || quote_ident(real_schema) || '.' || quote_ident(p_table_name)
            || ' ADD COLUMN ' || quote_ident(p_column_name) ||  ' raster ';
        RAISE DEBUG '%', sql;
        EXECUTE sql;


        -- Delete stale record in RASTER_COLUMNS (if any)
        sql := 'DELETE FROM raster_columns '
            || ' WHERE r_table_catalog = ' || quote_literal('')
            || ' AND r_table_schema = ' || quote_literal(real_schema)
            || ' AND r_table_name = ' || quote_literal(p_table_name)
            || ' AND r_column = ' || quote_literal(p_column_name);
        RAISE DEBUG '%', sql;
        EXECUTE sql;


        -- Add record in RASTER_COLUMNS
        sql := 'INSERT INTO raster_columns '
            || '(r_table_catalog, r_table_schema, r_table_name, r_column, srid, '
            || 'pixel_types, out_db, regular_blocking, nodata_values, '
            || 'pixelsize_x, pixelsize_y, blocksize_x, blocksize_y, extent) '
            || 'VALUES ('
            || quote_literal('') || ','
            || quote_literal(real_schema) || ','
            || quote_literal(p_table_name) || ','
            || quote_literal(p_column_name) || ','
            || p_srid::text || ','
            || quote_literal(p_pixel_types::text) || ','
            || p_out_db::text || ','
            || p_regular_blocking::text || ','
            || COALESCE(quote_literal(p_nodata_values::text), 'NULL') || ','
            || COALESCE(quote_literal(p_pixelsize_x), 'NULL') || ','
            || COALESCE(quote_literal(p_pixelsize_y), 'NULL') || ','
            || COALESCE(quote_literal(p_blocksize_x), 'NULL') || ','
            || COALESCE(quote_literal(p_blocksize_y), 'NULL') || ','
            || COALESCE(quote_literal(p_extent::text), 'NULL') || ')';
        RAISE DEBUG '%', sql;
        EXECUTE sql;


        -- Add CHECK for SRID
        sql := 'ALTER TABLE '
            || quote_ident(real_schema) || '.' || quote_ident(p_table_name)
            || ' ADD CONSTRAINT '
            || quote_ident('enforce_srid_' || p_column_name)
            || ' CHECK (ST_SRID(' || quote_ident(p_column_name)
            || ') = ' || p_srid::text || ')';
        RAISE DEBUG '%', sql;
        EXECUTE sql;


        -- TODO: Add more CHECKs
        -- - Add CHECK for pixel types
        -- - Add CHECK for pixel size
        -- - Do we need CHECK for NODATA values?


        RETURN p_schema_name || '.' || p_table_name || '.' || p_column_name
            || ' srid:' || p_srid::text
            || ' pixel_types:' || p_pixel_types::text
            || ' out_db:' || p_out_db::text
            || ' regular_blocking:' || p_regular_blocking::text
            || ' nodata_values:' || COALESCE(quote_literal(p_nodata_values::text), 'NULL')
            || ' pixelsize_x:' || COALESCE(quote_literal(p_pixelsize_x), 'NULL')
            || ' pixelsize_y:' || COALESCE(quote_literal(p_pixelsize_y), 'NULL')
            || ' blocksize_x:' || COALESCE(quote_literal(p_blocksize_x), 'NULL')
            || ' blocksize_y:' || COALESCE(quote_literal(p_blocksize_y), 'NULL')
            || ' extent:' || COALESCE(ST_AsText(p_extent), 'NULL');

    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE;


------------------------------------------------------------------------------
-- AddRasterColumn (with default catalog)
-------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION AddRasterColumn(schema varchar, 
                                           p_table varchar, 
                                           p_column varchar, 
                                           p_srid integer, 
                                           p_pixel_types varchar[],
                                           p_out_db boolean, 
                                           p_regular_blocking boolean, 
                                           p_nodata_values double precision[],
                                           p_pixelsize_x double precision, 
                                           p_pixelsize_y double precision,
                                           p_blocksize_x integer, 
                                           p_blocksize_y integer, 
                                           p_extent geometry)
    RETURNS text AS
    $$
    DECLARE
        ret text;
    BEGIN
        SELECT AddRasterColumn('',$1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13) INTO ret;
        RETURN ret;
    END;
    $$
    LANGUAGE 'plpgsql' STABLE;


------------------------------------------------------------------------------
-- AddRasterColumn (with default catalog and schema)
-------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION AddRasterColumn(p_table varchar, 
                                           p_column varchar, 
                                           p_srid integer, 
                                           p_pixel_types varchar[],
                                           p_out_db boolean, 
                                           p_regular_blocking boolean, 
                                           p_nodata_values double precision[],
                                           p_pixelsize_x double precision, 
                                           p_pixelsize_y double precision,
                                           p_blocksize_x integer, 
                                           p_blocksize_y integer, 
                                           p_extent geometry)
    RETURNS text AS
    $$
    DECLARE
        ret text;
    BEGIN
        SELECT AddRasterColumn('','',$1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12) INTO ret;
        RETURN ret;
    END;
    $$
    LANGUAGE 'plpgsql' STABLE;


-------------------------------------------------------------------------------
-- DropRasterColumn
-------------------------------------------------------------------------------
-- FIXME: Use 'name' type for table,column and other names
-------------------------------------------------------------------------------
CREATE OR REPLACE FUNCTION DropRasterColumn(catalog_name varchar, 
                                            schema_name varchar,
                                            table_name varchar, 
                                            column_name varchar)
    RETURNS text AS 
    $$
    DECLARE
        myrec record;
        real_schema name;
        okay boolean;
    BEGIN
        -- Find, check or fix schema_name
        IF ( schema_name != '' ) THEN
            okay = 'f';

            FOR myrec IN SELECT nspname FROM pg_namespace WHERE text(nspname) = schema_name LOOP
                okay := 't';
            END LOOP;

            IF ( okay <> 't' ) THEN
                RAISE NOTICE 'invalid schema name - using current_schema()';
                SELECT current_schema() INTO real_schema;
            ELSE
                real_schema = schema_name;
            END IF;
        ELSE
            SELECT current_schema() INTO real_schema;
        END IF;

        -- Find out if the column is in the raster_columns table
        okay = 'f';
        FOR myrec IN SELECT * FROM raster_columns WHERE r_table_schema = text(real_schema)
                     AND r_table_name = table_name AND r_column = column_name LOOP
            okay := 't';
        END LOOP;
        IF (okay <> 't') THEN
            RAISE EXCEPTION 'column % not found in raster_columns table', column_name;
            RETURN 'f';
        END IF;

        -- Remove ref from raster_columns table
        EXECUTE 'DELETE FROM raster_columns WHERE r_table_schema = '
                || quote_literal(real_schema) || ' AND r_table_name = '
                || quote_literal(table_name)  || ' AND r_column = '
                || quote_literal(column_name);

        -- Remove table column
        EXECUTE 'ALTER TABLE ' || quote_ident(real_schema) || '.'
                || quote_ident(table_name) || ' DROP COLUMN '
                || quote_ident(column_name);

        RETURN schema_name || '.' || table_name || '.' || column_name ||' effectively removed.';
    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE STRICT; -- WITH (isstrict);


-----------------------------------------------------------------------
-- DropRasterColumn (with default catalog name)
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION DropRasterColumn(schema_name varchar, 
                                            table_name varchar,
                                            column_name varchar)
    RETURNS text AS
    $$
    DECLARE
        ret text;
    BEGIN
        SELECT DropRasterColumn('', schema_name, table_name, column_name) INTO ret;
        RETURN ret;
    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE STRICT; -- WITH (isstrict);

-----------------------------------------------------------------------
-- DropRasterColumn (with default catalog and schema name)
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION DropRasterColumn(table_name varchar, 
                                            column_name varchar)
    RETURNS text AS
    $$
    DECLARE
        ret text;
    BEGIN
        SELECT DropRasterColumn('', '', table_name, column_name) INTO ret;
        RETURN ret;
    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE STRICT; -- WITH (isstrict);

-----------------------------------------------------------------------
-- DropRasterTable
-- Drop a table and all its references in raster_columns
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION DropRasterTable(catalog_name varchar, 
                                           schema_name varchar,
                                           table_name varchar)
    RETURNS text AS
    $$
    DECLARE
        real_schema name;
    BEGIN
        IF ( schema_name = '' ) THEN
            SELECT current_schema() into real_schema;
        ELSE
            real_schema = schema_name;
        END IF;

        -- Remove refs from raster_columns table
        EXECUTE 'DELETE FROM raster_columns WHERE '
                || 'r_table_schema = ' || quote_literal(real_schema)
                || ' AND ' || ' r_table_name = ' || quote_literal(table_name);

        -- Remove table
        EXECUTE 'DROP TABLE ' || quote_ident(real_schema) || '.'
                || quote_ident(table_name);

        RETURN real_schema || '.' || table_name || ' effectively dropped.';
    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE STRICT; -- WITH (isstrict);

-----------------------------------------------------------------------
-- DropRasterTable (with default catalog name)
-- Drop a table and all its references in raster_columns
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION DropRasterTable(schema_name varchar, 
                                           table_name varchar)
    RETURNS text AS
    $$
    DECLARE
        ret text;
    BEGIN
        SELECT DropRasterTable('', schema_name, table_name) INTO ret;
        RETURN ret;
    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE STRICT; -- WITH (isstrict);

-----------------------------------------------------------------------
-- DropRasterTable (with default catalog and schema name)
-- Drop a table and all its references in raster_columns
-- For PG>=73 use current_schema()
-----------------------------------------------------------------------
CREATE OR REPLACE FUNCTION DropRasterTable(table_name varchar)
    RETURNS text AS
    $$
    DECLARE
        ret text;
    BEGIN
        SELECT DropRasterTable('', '', table_name) INTO ret;
        RETURN ret;
    END;
    $$
    LANGUAGE 'plpgsql' VOLATILE STRICT; -- WITH (isstrict);

-------------------------------------------------------------------
--  END
-------------------------------------------------------------------

-- COMMIT;

