Added LWGEOM_snaptogrid_pointoff and gridspec utility funx

git-svn-id: http://svn.osgeo.org/postgis/trunk@2132 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/lwgeom/lwgeom_functions_analytic.c b/lwgeom/lwgeom_functions_analytic.c
index 1d37cc6784373f0259f0a6487f6a50fa4abd5121..6894bc19c7d288787f946875d5c09e2cc185c0a5 100644 (file)
--- a/lwgeom/lwgeom_functions_analytic.c
+++ b/lwgeom/lwgeom_functions_analytic.c
@@ -511,6 +511,7 @@ typedef struct gridspec_t {
    double msize;
 } gridspec;
 
+
 /* Forward declarations */
 LWGEOM *lwgeom_grid(LWGEOM *lwgeom, gridspec *grid);
 LWCOLLECTION *lwcollection_grid(LWCOLLECTION *coll, gridspec *grid);
@@ -519,6 +520,29 @@ LWPOLY * lwpoly_grid(LWPOLY *poly, gridspec *grid);
 LWLINE *lwline_grid(LWLINE *line, gridspec *grid);
 POINTARRAY *ptarray_grid(POINTARRAY *pa, gridspec *grid);
 Datum LWGEOM_snaptogrid(PG_FUNCTION_ARGS);
+Datum LWGEOM_snaptogrid_pointoff(PG_FUNCTION_ARGS);
+static int grid_isNull(const gridspec *grid);
+static void grid_print(const gridspec *grid, lwreporter printer);
+
+/* A NULL grid is a grid in which size in all dimensions is 0 */
+static int
+grid_isNull(const gridspec *grid)
+{
+       if ( grid->xsize==0 &&
+               grid->ysize==0 &&
+               grid->zsize==0 &&
+               grid->msize==0 ) return 1;
+       else return 0;
+}
+
+/* Print grid using given reporter */
+static void
+grid_print(const gridspec *grid, lwreporter printer)
+{
+       printer("GRID(%g %g %g %g, %g %g %g %g)",
+               grid->ipx, grid->ipy, grid->ipz, grid->ipm,
+               grid->xsize, grid->ysize, grid->zsize, grid->msize);
+}
 
 /*
  * Stick an array of points to the given gridspec.
@@ -773,8 +797,11 @@ Datum LWGEOM_snaptogrid(PG_FUNCTION_ARGS)
        /* Do not support gridding Z and M values for now */
        grid.ipz=grid.ipm=grid.zsize=grid.msize=0;
 
-       /* 0-sided grid == grid */
-       if ( grid.xsize == 0 && grid.ysize == 0 ) PG_RETURN_POINTER(in_geom);
+       /* Return input geometry if grid is null */
+       if ( grid_isNull(&grid) )
+       {
+               PG_RETURN_POINTER(in_geom);
+       }
 
        in_lwgeom = lwgeom_deserialize(SERIALIZED_FORM(in_geom));
 
@@ -810,6 +837,97 @@ Datum LWGEOM_snaptogrid(PG_FUNCTION_ARGS)
 
        PG_RETURN_POINTER(out_geom);
 }
+
+PG_FUNCTION_INFO_V1(LWGEOM_snaptogrid_pointoff);
+Datum LWGEOM_snaptogrid_pointoff(PG_FUNCTION_ARGS)
+{
+       Datum datum;
+       PG_LWGEOM *in_geom, *in_point;
+       LWGEOM *in_lwgeom;
+       LWPOINT *in_lwpoint;
+       PG_LWGEOM *out_geom = NULL;
+       LWGEOM *out_lwgeom;
+       gridspec grid;
+       BOX3D box3d;
+       POINT4D offsetpoint;
+
+       if ( PG_ARGISNULL(0) ) PG_RETURN_NULL();
+       datum = PG_GETARG_DATUM(0);
+       in_geom = (PG_LWGEOM *)PG_DETOAST_DATUM(datum);
+
+       if ( PG_ARGISNULL(1) ) PG_RETURN_NULL();
+       datum = PG_GETARG_DATUM(1);
+       in_point = (PG_LWGEOM *)PG_DETOAST_DATUM(datum);
+       in_lwpoint = lwpoint_deserialize(SERIALIZED_FORM(in_point));
+       if ( in_lwpoint == NULL )
+       {
+               lwerror("Offset geometry must be a point");
+       }
+
+       if ( PG_ARGISNULL(2) ) PG_RETURN_NULL();
+       grid.xsize = PG_GETARG_FLOAT8(2);
+
+       if ( PG_ARGISNULL(3) ) PG_RETURN_NULL();
+       grid.ysize = PG_GETARG_FLOAT8(3);
+
+       if ( PG_ARGISNULL(4) ) PG_RETURN_NULL();
+       grid.zsize = PG_GETARG_FLOAT8(4);
+
+       if ( PG_ARGISNULL(5) ) PG_RETURN_NULL();
+       grid.msize = PG_GETARG_FLOAT8(5);
+
+       /* Take offsets from point geometry */
+       getPoint4d_p(in_lwpoint->point, 0, &offsetpoint);
+       grid.ipx = offsetpoint.x;
+       grid.ipy = offsetpoint.y;
+       if (TYPE_HASZ(in_lwpoint->type) ) grid.ipz = offsetpoint.z;
+       else grid.ipz=0;
+       if (TYPE_HASM(in_lwpoint->type) ) grid.ipm = offsetpoint.m;
+       else grid.ipm=0;
+
+       //grid_print(&grid, lwnotice);
+
+       /* Return input geometry if grid is null */
+       if ( grid_isNull(&grid) )
+       {
+               PG_RETURN_POINTER(in_geom);
+       }
+
+       in_lwgeom = lwgeom_deserialize(SERIALIZED_FORM(in_geom));
+
+#if VERBOSE
+       elog(NOTICE, "SnapToGrid got a %s", lwgeom_typename(TYPE_GETTYPE(in_lwgeom->type)));
+#endif
+
+       out_lwgeom = lwgeom_grid(in_lwgeom, &grid);
+       if ( out_lwgeom == NULL ) PG_RETURN_NULL();
+
+       /* COMPUTE_BBOX WHEN_SIMPLE */
+       if ( in_lwgeom->bbox )
+       {
+               box2df_to_box3d_p(in_lwgeom->bbox, &box3d);
+
+               box3d.xmin = rint((box3d.xmin - grid.ipx)/grid.xsize)
+                       * grid.xsize + grid.ipx;
+               box3d.xmax = rint((box3d.xmax - grid.ipx)/grid.xsize)
+                       * grid.xsize + grid.ipx;
+               box3d.ymin = rint((box3d.ymin - grid.ipy)/grid.ysize)
+                       * grid.ysize + grid.ipy;
+               box3d.ymax = rint((box3d.ymax - grid.ipy)/grid.ysize)
+                       * grid.ysize + grid.ipy;
+
+               out_lwgeom->bbox = box3d_to_box2df(&box3d);
+       }
+
+#if VERBOSE
+       elog(NOTICE, "SnapToGrid made a %s", lwgeom_typename(TYPE_GETTYPE(out_lwgeom->type)));
+#endif
+
+       out_geom = pglwgeom_serialize(out_lwgeom);
+
+       PG_RETURN_POINTER(out_geom);
+}
+
 /***********************************************************************
  * --strk@keybit.net
  ***********************************************************************/