*err = 1;
return raster;
}
+
+
+LWPOLY*
+rt_raster_pixel_as_polygon(rt_raster rast, int x, int y)
+{
+ double scale_x, scale_y;
+ double skew_x, skew_y;
+ double ul_x, ul_y;
+ int srid;
+ POINTARRAY **points;
+ POINT4D p, p0;
+ LWPOLY *poly;
+
+ scale_x = rt_raster_get_x_scale(rast);
+ scale_y = rt_raster_get_y_scale(rast);
+ skew_x = rt_raster_get_x_skew(rast);
+ skew_y = rt_raster_get_y_skew(rast);
+ ul_x = rt_raster_get_x_offset(rast);
+ ul_y = rt_raster_get_y_offset(rast);
+ srid = rt_raster_get_srid(rast);
+
+ points = rtalloc(sizeof(POINTARRAY *)*1);
+ points[0] = ptarray_construct(0, 0, 5);
+
+ p0.x = scale_x * x + skew_x * y + ul_x;
+ p0.y = scale_y * y + skew_y * x + ul_y;
+ ptarray_set_point4d(points[0], 0, &p0);
+
+ p.x = p0.x + scale_x;
+ p.y = p0.y + skew_y;
+ ptarray_set_point4d(points[0], 1, &p);
+
+ p.x = p0.x + scale_x + skew_x;
+ p.y = p0.y + scale_y + skew_y;
+ ptarray_set_point4d(points[0], 2, &p);
+
+ p.x = p0.x + skew_x;
+ p.y = p0.y + scale_y;
+ ptarray_set_point4d(points[0], 3, &p);
+
+ /* close it */
+ ptarray_set_point4d(points[0], 4, &p0);
+
+ poly = lwpoly_construct(srid, NULL, 1, points);
+
+ return poly;
+}
*/
LWPOLY* rt_raster_get_convex_hull(rt_raster raster);
+/**
+ * Get a raster pixel as a polygon.
+ *
+ * The pixel shape is a 4 vertices (5 to be closed) single
+ * ring polygon bearing the raster's rotation
+ * and using projection coordinates
+ *
+ * @param raster : the raster to get pixel from
+ * @param x : the column number
+ * @param y : the row number
+ *
+ * @return the pixel polygon, or NULL on error.
+ *
+ */
+LWPOLY* rt_raster_pixel_as_polygon(rt_raster raster, int x, int y);
+
/**
* Returns a set of "geomval" value, one for each group of pixel
/* Set pixel value */
Datum RASTER_setPixelValue(PG_FUNCTION_ARGS);
+/* Get pixel geographical shape */
+Datum RASTER_getPixelPolygon(PG_FUNCTION_ARGS);
+
/* Raster and band creation */
Datum RASTER_makeEmpty(PG_FUNCTION_ARGS);
Datum RASTER_addband(PG_FUNCTION_ARGS);
PG_RETURN_POINTER(pgraster);
}
+/**
+ * Return the geographical shape of a single pixel.
+ * Pixel location is specified by
+ * X,Y coordinates (X <= RT_Width(raster) and Y <= RT_Height(raster)).
+ *
+ */
+PG_FUNCTION_INFO_V1(RASTER_getPixelPolygon);
+Datum RASTER_getPixelPolygon(PG_FUNCTION_ARGS)
+{
+ rt_pgraster *pgraster = NULL;
+ rt_raster raster = NULL;
+ LWPOLY *poly;
+ int32_t x = 0;
+ int32_t y = 0;
+ GSERIALIZED* gser = NULL;
+
+
+ /* Deserialize raster */
+ pgraster = (rt_pgraster *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
+
+ x = PG_GETARG_INT32(1);
+
+ y = PG_GETARG_INT32(2);
+
+ POSTGIS_RT_DEBUGF(3, "Pixel coordinates (%d, %d)", x, y);
+
+ raster = rt_raster_deserialize(pgraster, FALSE);
+ if (!raster) {
+ elog(ERROR, "RASTER_getPixelValue: Could not deserialize raster");
+ PG_RETURN_NULL();
+ }
+
+ /* Fetch pixel shape */
+ poly = rt_raster_pixel_as_polygon(raster, x - 1, y - 1);
+ if (!poly) {
+ elog(ERROR, "RASTER_getPixelPolygon: could not get raster's pixel polygon");
+ rt_raster_destroy(raster);
+ PG_RETURN_NULL();
+ }
+
+ {
+ size_t gser_size;
+ gser = gserialized_from_lwgeom(lwpoly_as_lwgeom(poly), 0, &gser_size);
+ SET_VARSIZE(gser, gser_size);
+ }
+
+ rt_raster_destroy(raster);
+ lwfree(poly);
+
+ PG_RETURN_POINTER(gser);
+}
+
/**
* Add a band to the given raster at the given position.
*/
$$
LANGUAGE 'SQL' IMMUTABLE STRICT;
-CREATE OR REPLACE FUNCTION st_pixelaspolygon(rast raster, band integer, x integer, y integer)
- RETURNS geometry AS
- $$
- DECLARE
- w int;
- h int;
- scale_x float8;
- scale_y float8;
- skew_x float8;
- skew_y float8;
- ul_x float8;
- ul_y float8;
- sr_id int;
- x1 float8;
- y1 float8;
- x2 float8;
- y2 float8;
- x3 float8;
- y3 float8;
- x4 float8;
- y4 float8;
- BEGIN
- SELECT scalex, scaley, skewx, skewy, upperleftx, upperlefty, srid INTO scale_x, scale_y, skew_x, skew_y, ul_x, ul_y, sr_id FROM ST_Metadata(rast);
- x1 := scale_x * (x - 1) + skew_x * (y - 1) + ul_x;
- y1 := scale_y * (y - 1) + skew_y * (x - 1) + ul_y;
- x2 := x1 + scale_x;
- y2 := y1 + skew_y;
- x3 := x1 + scale_x + skew_x;
- y3 := y1 + scale_y + skew_y;
- x4 := x1 + skew_x;
- y4 := y1 + scale_y;
- RETURN 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)]
- )
- ),
- sr_id
- );
- END;
- $$
- LANGUAGE 'plpgsql' IMMUTABLE STRICT;
-
CREATE OR REPLACE FUNCTION st_pixelaspolygon(rast raster, x integer, y integer)
+ RETURNS geometry
+ AS 'MODULE_PATHNAME','RASTER_getPixelPolygon'
+ LANGUAGE 'C' IMMUTABLE STRICT;
+
+-- TODO: deprecate
+CREATE OR REPLACE FUNCTION st_pixelaspolygon(rast raster, band integer, x integer, y integer)
RETURNS geometry AS
- $$ SELECT st_pixelaspolygon($1, 1, $2, $3) $$
- LANGUAGE SQL IMMUTABLE STRICT;
+ $$ SELECT st_pixelaspolygon($1, $3, $4); $$
+ LANGUAGE 'sql' IMMUTABLE STRICT;
-----------------------------------------------------------------------
-- ST_PixelAsPolygons
projects / postgis / commitdiff