[postgis-commits] svn - r2713 - trunk/lwgeom
postgis-commits at postgis.refractions.net
postgis-commits at postgis.refractions.net
Mon Oct 29 06:44:31 PDT 2007
Author: mcayland
Date: 2007-10-29 06:44:29 -0700 (Mon, 29 Oct 2007)
New Revision: 2713
Modified:
trunk/lwgeom/lwgeom_box2dfloat4.c
trunk/lwgeom/lwgeom_box3d.c
trunk/lwgeom/lwgeom_functions_basic.c
Log:
Commit Charlie Savage's patches (with additional comments) to the bounding box/envelope functions to ensure that valid geometries are always returned; in more specific terms, if a bounding box is a point then a POINT is returned, and if a bounding box is 1-dimensional a LINESTRING is returned. Otherwise a POLYGON is returned as per the old behaviour. For details see the thread in the postgis-users archives Sept 2007 'How to get the centroid of an bounding box using st_extent'.
Modified: trunk/lwgeom/lwgeom_box2dfloat4.c
===================================================================
--- trunk/lwgeom/lwgeom_box2dfloat4.c 2007-10-29 12:34:17 UTC (rev 2712)
+++ trunk/lwgeom/lwgeom_box2dfloat4.c 2007-10-29 13:44:29 UTC (rev 2713)
@@ -456,32 +456,69 @@
Datum BOX2DFLOAT4_to_LWGEOM(PG_FUNCTION_ARGS)
{
BOX2DFLOAT4 *box = (BOX2DFLOAT4 *)PG_GETARG_POINTER(0);
- POINT2D *pts = palloc(sizeof(POINT2D)*5);
- POINTARRAY *pa[1];
- LWPOLY *poly;
+ POINTARRAY *pa;
int wantbbox = 0;
PG_LWGEOM *result;
uchar *ser;
- /* Assign coordinates to POINT2D array */
- pts[0].x = box->xmin; pts[0].y = box->ymin;
- pts[1].x = box->xmin; pts[1].y = box->ymax;
- pts[2].x = box->xmax; pts[2].y = box->ymax;
- pts[3].x = box->xmax; pts[3].y = box->ymin;
- pts[4].x = box->xmin; pts[4].y = box->ymin;
- /* Construct point array */
- pa[0] = palloc(sizeof(POINTARRAY));
- pa[0]->serialized_pointlist = (uchar *)pts;
- TYPE_SETZM(pa[0]->dims, 0, 0);
- pa[0]->npoints = 5;
+ /*
+ * Alter BOX2D cast so that a valid geometry is always
+ * returned depending upon the size of the BOX2D. The
+ * code makes the following assumptions:
+ * - If the BOX2D is a single point then return a
+ * POINT geometry
+ * - If the BOX2D represents either a horizontal or
+ * vertical line, return a LINESTRING geometry
+ * - Otherwise return a POLYGON
+ */
- /* Construct polygon */
- poly = lwpoly_construct(-1, NULL, 1, pa);
+ if (box->xmin == box->xmax &&
+ box->ymin == box->ymax)
+ {
+ /* Construct and serialize point */
+ LWPOINT *point = make_lwpoint2d(-1, box->xmin, box->ymin);
+ ser = lwpoint_serialize(point);
+ }
+ else if (box->xmin == box->xmax ||
+ box->ymin == box->ymax)
+ {
+ LWLINE *line;
+ POINT2D *pts = palloc(sizeof(POINT2D)*2);
+
+ /* Assign coordinates to POINT2D array */
+ pts[0].x = box->xmin; pts[0].y = box->ymin;
+ pts[1].x = box->xmax; pts[1].y = box->ymax;
+
+ /* Construct point array */
+ pa = pointArray_construct((uchar *)pts, 0, 0, 2);
- /* Serialize polygon */
- ser = lwpoly_serialize(poly);
+ /* Construct and serialize linestring */
+ line = lwline_construct(-1, NULL, pa);
+ ser = lwline_serialize(line);
+ }
+ else
+ {
+ LWPOLY *poly;
+ POINT2D *pts = palloc(sizeof(POINT2D)*5);
+ /* Assign coordinates to POINT2D array */
+ pts[0].x = box->xmin; pts[0].y = box->ymin;
+ pts[1].x = box->xmin; pts[1].y = box->ymax;
+ pts[2].x = box->xmax; pts[2].y = box->ymax;
+ pts[3].x = box->xmax; pts[3].y = box->ymin;
+ pts[4].x = box->xmin; pts[4].y = box->ymin;
+
+ /* Construct point array */
+ pa = pointArray_construct((uchar *)pts, 0, 0, 5);
+
+ /* Construct polygon */
+ poly = lwpoly_construct(-1, NULL, 1, &pa);
+
+ /* Serialize polygon */
+ ser = lwpoly_serialize(poly);
+ }
+
/* Construct PG_LWGEOM */
result = PG_LWGEOM_construct(ser, -1, wantbbox);
Modified: trunk/lwgeom/lwgeom_box3d.c
===================================================================
--- trunk/lwgeom/lwgeom_box3d.c 2007-10-29 12:34:17 UTC (rev 2712)
+++ trunk/lwgeom/lwgeom_box3d.c 2007-10-29 13:44:29 UTC (rev 2713)
@@ -162,32 +162,69 @@
Datum BOX3D_to_LWGEOM(PG_FUNCTION_ARGS)
{
BOX3D *box = (BOX3D *)PG_GETARG_POINTER(0);
- POINT2D *pts = palloc(sizeof(POINT2D)*5);
- POINTARRAY *pa[1];
- LWPOLY *poly;
+ POINTARRAY *pa;
int wantbbox = 0;
PG_LWGEOM *result;
uchar *ser;
- /* Assign coordinates to POINT2D array */
- pts[0].x = box->xmin; pts[0].y = box->ymin;
- pts[1].x = box->xmin; pts[1].y = box->ymax;
- pts[2].x = box->xmax; pts[2].y = box->ymax;
- pts[3].x = box->xmax; pts[3].y = box->ymin;
- pts[4].x = box->xmin; pts[4].y = box->ymin;
- /* Construct point array */
- pa[0] = palloc(sizeof(POINTARRAY));
- pa[0]->serialized_pointlist = (uchar *)pts;
- TYPE_SETZM(pa[0]->dims, 0, 0);
- pa[0]->npoints = 5;
+ /*
+ * Alter BOX3D cast so that a valid geometry is always
+ * returned depending upon the size of the BOX3D. The
+ * code makes the following assumptions:
+ * - If the BOX3D is a single point then return a
+ * POINT geometry
+ * - If the BOX3D represents either a horizontal or
+ * vertical line, return a LINESTRING geometry
+ * - Otherwise return a POLYGON
+ */
- /* Construct polygon */
- poly = lwpoly_construct(-1, NULL, 1, pa);
+ if (box->xmin == box->xmax &&
+ box->ymin == box->ymax)
+ {
+ /* Construct and serialize point */
+ LWPOINT *point = make_lwpoint2d(-1, box->xmin, box->ymin);
+ ser = lwpoint_serialize(point);
+ }
+ else if (box->xmin == box->xmax ||
+ box->ymin == box->ymax)
+ {
+ LWLINE *line;
+ POINT2D *pts = palloc(sizeof(POINT2D)*2);
+
+ /* Assign coordinates to POINT2D array */
+ pts[0].x = box->xmin; pts[0].y = box->ymin;
+ pts[1].x = box->xmax; pts[1].y = box->ymax;
+
+ /* Construct point array */
+ pa = pointArray_construct((uchar *)pts, 0, 0, 2);
- /* Serialize polygon */
- ser = lwpoly_serialize(poly);
+ /* Construct and serialize linestring */
+ line = lwline_construct(-1, NULL, pa);
+ ser = lwline_serialize(line);
+ }
+ else
+ {
+ LWPOLY *poly;
+ POINT2D *pts = palloc(sizeof(POINT2D)*5);
+ /* Assign coordinates to POINT2D array */
+ pts[0].x = box->xmin; pts[0].y = box->ymin;
+ pts[1].x = box->xmin; pts[1].y = box->ymax;
+ pts[2].x = box->xmax; pts[2].y = box->ymax;
+ pts[3].x = box->xmax; pts[3].y = box->ymin;
+ pts[4].x = box->xmin; pts[4].y = box->ymin;
+
+ /* Construct point array */
+ pa = pointArray_construct((uchar *)pts, 0, 0, 5);
+
+ /* Construct polygon */
+ poly = lwpoly_construct(-1, NULL, 1, &pa);
+
+ /* Serialize polygon */
+ ser = lwpoly_serialize(poly);
+ }
+
/* Construct PG_LWGEOM */
result = PG_LWGEOM_construct(ser, -1, wantbbox);
Modified: trunk/lwgeom/lwgeom_functions_basic.c
===================================================================
--- trunk/lwgeom/lwgeom_functions_basic.c 2007-10-29 12:34:17 UTC (rev 2712)
+++ trunk/lwgeom/lwgeom_functions_basic.c 2007-10-29 13:44:29 UTC (rev 2713)
@@ -2493,56 +2493,86 @@
Datum LWGEOM_envelope(PG_FUNCTION_ARGS)
{
PG_LWGEOM *geom = (PG_LWGEOM *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
- BOX2DFLOAT4 box;
- POINT2D *pts = lwalloc(sizeof(POINT2D)*5);
- POINTARRAY *pa[1];
- LWPOLY *poly;
+ BOX3D box;
int SRID;
+ POINTARRAY *pa;
PG_LWGEOM *result;
- uchar *ser;
+ uchar *ser = NULL;
- if (lwgeom_getType(geom->type) == POINTTYPE ||
- (lwgeom_getType(geom->type) == MULTIPOINTTYPE && lwgeom_getnumgeometries(SERIALIZED_FORM(geom)) == 1))
- {
- int srid = lwgeom_getsrid(SERIALIZED_FORM(geom));
- LWPOINT* point = lwgeom_getpoint(SERIALIZED_FORM(geom), 0);
- LWPOINT* envelope = lwpoint_construct(srid, NULL, point->point);
- ser = lwpoint_serialize(envelope);
- result = PG_LWGEOM_construct(ser, srid, 0);
- PG_RETURN_POINTER(result);
- }
/* get bounding box */
- if ( ! getbox2d_p(SERIALIZED_FORM(geom), &box) )
+ if ( ! compute_serialized_box3d_p(SERIALIZED_FORM(geom), &box) )
{
/* must be the EMPTY geometry */
PG_RETURN_POINTER(geom);
}
-
+
/* get geometry SRID */
SRID = lwgeom_getsrid(SERIALIZED_FORM(geom));
- PG_FREE_IF_COPY(geom, 0);
+
+ /*
+ * Alter envelope type so that a valid geometry is always
+ * returned depending upon the size of the geometry. The
+ * code makes the following assumptions:
+ * - If the bounding box is a single point then return a
+ * POINT geometry
+ * - If the bounding box represents either a horizontal or
+ * vertical line, return a LINESTRING geometry
+ * - Otherwise return a POLYGON
+ */
- /* Assign coordinates to POINT2D array */
- pts[0].x = box.xmin; pts[0].y = box.ymin;
- pts[1].x = box.xmin; pts[1].y = box.ymax;
- pts[2].x = box.xmax; pts[2].y = box.ymax;
- pts[3].x = box.xmax; pts[3].y = box.ymin;
- pts[4].x = box.xmin; pts[4].y = box.ymin;
- /* Construct point array */
- pa[0] = lwalloc(sizeof(POINTARRAY));
- pa[0]->serialized_pointlist = (uchar *)pts;
- TYPE_SETZM(pa[0]->dims, 0, 0);
- pa[0]->npoints = 5;
+ if (box.xmin == box.xmax &&
+ box.ymin == box.ymax)
+ {
+ /* Construct and serialize point */
+ LWPOINT *point = make_lwpoint2d(SRID, box.xmin, box.ymin);
+ ser = lwpoint_serialize(point);
+ }
+ else if (box.xmin == box.xmax ||
+ box.ymin == box.ymax)
+ {
+ LWLINE *line;
+ POINT2D *pts = palloc(sizeof(POINT2D)*2);
- /* Construct polygon */
- poly = lwpoly_construct(SRID, box2d_clone(&box), 1, pa);
+ /* Assign coordinates to POINT2D array */
+ pts[0].x = box.xmin; pts[0].y = box.ymin;
+ pts[1].x = box.xmax; pts[1].y = box.ymax;
- /* Serialize polygon */
- ser = lwpoly_serialize(poly);
+ /* Construct point array */
+ pa = pointArray_construct((uchar *)pts, 0, 0, 2);
+ /* Construct and serialize linestring */
+ line = lwline_construct(SRID, NULL, pa);
+ ser = lwline_serialize(line);
+ }
+ else
+ {
+ LWPOLY *poly;
+ POINT2D *pts = lwalloc(sizeof(POINT2D)*5);
+ BOX2DFLOAT4 box2d;
+ getbox2d_p(SERIALIZED_FORM(geom), &box2d);
+
+ /* Assign coordinates to POINT2D array */
+ pts[0].x = box2d.xmin; pts[0].y = box2d.ymin;
+ pts[1].x = box2d.xmin; pts[1].y = box2d.ymax;
+ pts[2].x = box2d.xmax; pts[2].y = box2d.ymax;
+ pts[3].x = box2d.xmax; pts[3].y = box2d.ymin;
+ pts[4].x = box2d.xmin; pts[4].y = box2d.ymin;
+
+ /* Construct point array */
+ pa = pointArray_construct((uchar *)pts, 0, 0, 5);
+
+ /* Construct polygon */
+ poly = lwpoly_construct(SRID, box2d_clone(&box2d), 1, &pa);
+
+ /* Serialize polygon */
+ ser = lwpoly_serialize(poly);
+ }
+
+ PG_FREE_IF_COPY(geom, 0);
+
/* Construct PG_LWGEOM */
result = PG_LWGEOM_construct(ser, SRID, 1);
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