static LWGEOM*
parse_geojson_multipolygon(json_object *geojson, bool *hasz, int *root_srid)
{
LWGEOM *geom = NULL;
int i, j, k;
json_object* poObjPolys = NULL;
if (!*root_srid)
{
geom = (LWGEOM *)lwcollection_construct_empty(MULTIPOLYGONTYPE, *root_srid, 1, 0);
}
else
{
geom = (LWGEOM *)lwcollection_construct_empty(MULTIPOLYGONTYPE, -1, 1, 0);
}
poObjPolys = findMemberByName( geojson, "coordinates" );
if ( ! poObjPolys )
geojson_lwerror("Unable to find 'coordinates' in GeoJSON string", 4);
if( json_type_array == json_object_get_type( poObjPolys ) )
{
const int nPolys = json_object_array_length( poObjPolys );
for(i = 0; i < nPolys; ++i)
{
POINTARRAY **ppa;
json_object* poObjPoly = NULL;
poObjPoly = json_object_array_get_idx( poObjPolys, i );
ppa = (POINTARRAY**) lwalloc(sizeof(POINTARRAY*));
if( json_type_array == json_object_get_type( poObjPoly ) )
{
int nPoints;
json_object* points = NULL;
int ring = json_object_array_length( poObjPoly );
ppa[0] = ptarray_construct_empty(1, 0, 1);
points = json_object_array_get_idx( poObjPoly, 0 );
nPoints = json_object_array_length( points );
for (j=0; j < nPoints; j++ )
{
json_object* coords = NULL;
coords = json_object_array_get_idx( points, j );
parse_geojson_coord(coords, hasz, ppa[0]);
}
for(j = 1; j < ring; ++j)
{
int nPoints;
ppa = (POINTARRAY**) lwrealloc((POINTARRAY *) ppa, sizeof(POINTARRAY*) * (j + 1));
ppa[i] = ptarray_construct_empty(1, 0, 1);
points = json_object_array_get_idx( poObjPoly, j );
nPoints = json_object_array_length( points );
for (k=0; k < nPoints; k++ )
{
json_object* coords = NULL;
coords = json_object_array_get_idx( points, k );
parse_geojson_coord(coords, hasz, ppa[i]);
}
}
geom = (LWGEOM*)lwmpoly_add_lwpoly((LWMPOLY*)geom,
(LWPOLY*)lwpoly_construct(*root_srid, NULL, ring, ppa));
}
}
}
return geom;
}
/* Return an LWGEOM from a Geometry */
LWGEOM *
GEOS2LWGEOM(const GEOSGeometry *geom, char want3d)
{
int type = GEOSGeomTypeId(geom) ;
int hasZ;
int SRID = GEOSGetSRID(geom);
/* GEOS's 0 is equivalent to our unknown as for SRID values */
if ( SRID == 0 ) SRID = SRID_UNKNOWN;
if ( want3d )
{
hasZ = GEOSHasZ(geom);
if ( ! hasZ )
{
LWDEBUG(3, "Geometry has no Z, won't provide one");
want3d = 0;
}
}
/*
if ( GEOSisEmpty(geom) )
{
return (LWGEOM*)lwcollection_construct_empty(COLLECTIONTYPE, SRID, want3d, 0);
}
*/
switch (type)
{
const GEOSCoordSequence *cs;
POINTARRAY *pa, **ppaa;
const GEOSGeometry *g;
LWGEOM **geoms;
uint32_t i, ngeoms;
case GEOS_POINT:
LWDEBUG(4, "lwgeom_from_geometry: it's a Point");
cs = GEOSGeom_getCoordSeq(geom);
if ( GEOSisEmpty(geom) )
return (LWGEOM*)lwpoint_construct_empty(SRID, want3d, 0);
pa = ptarray_from_GEOSCoordSeq(cs, want3d);
return (LWGEOM *)lwpoint_construct(SRID, NULL, pa);
case GEOS_LINESTRING:
case GEOS_LINEARRING:
LWDEBUG(4, "lwgeom_from_geometry: it's a LineString or LinearRing");
if ( GEOSisEmpty(geom) )
return (LWGEOM*)lwline_construct_empty(SRID, want3d, 0);
cs = GEOSGeom_getCoordSeq(geom);
pa = ptarray_from_GEOSCoordSeq(cs, want3d);
return (LWGEOM *)lwline_construct(SRID, NULL, pa);
case GEOS_POLYGON:
LWDEBUG(4, "lwgeom_from_geometry: it's a Polygon");
if ( GEOSisEmpty(geom) )
return (LWGEOM*)lwpoly_construct_empty(SRID, want3d, 0);
ngeoms = GEOSGetNumInteriorRings(geom);
ppaa = lwalloc(sizeof(POINTARRAY *)*(ngeoms+1));
g = GEOSGetExteriorRing(geom);
cs = GEOSGeom_getCoordSeq(g);
ppaa[0] = ptarray_from_GEOSCoordSeq(cs, want3d);
for (i=0; i<ngeoms; i++)
{
g = GEOSGetInteriorRingN(geom, i);
cs = GEOSGeom_getCoordSeq(g);
ppaa[i+1] = ptarray_from_GEOSCoordSeq(cs,
want3d);
}
return (LWGEOM *)lwpoly_construct(SRID, NULL,
ngeoms+1, ppaa);
case GEOS_MULTIPOINT:
case GEOS_MULTILINESTRING:
case GEOS_MULTIPOLYGON:
case GEOS_GEOMETRYCOLLECTION:
LWDEBUG(4, "lwgeom_from_geometry: it's a Collection or Multi");
ngeoms = GEOSGetNumGeometries(geom);
geoms = NULL;
if ( ngeoms )
{
geoms = lwalloc(sizeof(LWGEOM *)*ngeoms);
for (i=0; i<ngeoms; i++)
{
g = GEOSGetGeometryN(geom, i);
geoms[i] = GEOS2LWGEOM(g, want3d);
}
}
return (LWGEOM *)lwcollection_construct(type,
SRID, NULL, ngeoms, geoms);
default:
lwerror("GEOS2LWGEOM: unknown geometry type: %d", type);
return NULL;
}
}
int *
lwgeom_cluster_2d_kmeans(const LWGEOM **geoms, int ngeoms, int k)
{
int i;
int num_centroids = 0;
LWGEOM **centroids;
POINT2D *centers_raw;
const POINT2D *cp;
POINT2D min = { DBL_MAX, DBL_MAX };
POINT2D max = { -DBL_MAX, -DBL_MAX };
double dx, dy;
kmeans_config config;
kmeans_result result;
int *seen;
int sidx = 0;
assert(k>0);
assert(ngeoms>0);
assert(geoms);
/* Initialize our static structs */
memset(&config, 0, sizeof(kmeans_config));
memset(&result, 0, sizeof(kmeans_result));
if (ngeoms<k)
{
lwerror("%s: number of geometries is less than the number of clusters requested", __func__);
}
/* We'll hold the temporary centroid objects here */
centroids = lwalloc(sizeof(LWGEOM*) * ngeoms);
memset(centroids, 0, sizeof(LWGEOM*) * ngeoms);
/* The vector of cluster means. We have to allocate a */
/* chunk of memory for these because we'll be mutating them */
/* in the kmeans algorithm */
centers_raw = lwalloc(sizeof(POINT2D) * k);
memset(centers_raw, 0, sizeof(POINT2D) * k);
/* K-means configuration setup */
config.objs = lwalloc(sizeof(Pointer) * ngeoms);
config.num_objs = ngeoms;
config.clusters = lwalloc(sizeof(int) * ngeoms);
config.centers = lwalloc(sizeof(Pointer) * k);
config.k = k;
config.max_iterations = 0;
config.distance_method = lwkmeans_pt_distance;
config.centroid_method = lwkmeans_pt_centroid;
/* Clean the memory */
memset(config.objs, 0, sizeof(Pointer) * ngeoms);
memset(config.clusters, 0, sizeof(int) * ngeoms);
memset(config.centers, 0, sizeof(Pointer) * k);
/* Prepare the list of object pointers for K-means */
for (i = 0; i < ngeoms; i++)
{
const LWGEOM *geom = geoms[i];
LWPOINT *lwpoint;
/* Null/empty geometries get a NULL pointer */
if ((!geom) || lwgeom_is_empty(geom))
{
config.objs[i] = NULL;
continue;
}
/* If the input is a point, use its coordinates */
/* If its not a point, convert it to one via centroid */
if (lwgeom_get_type(geom) != POINTTYPE)
{
LWGEOM *centroid = lwgeom_centroid(geom);
if ((!centroid) || lwgeom_is_empty(centroid))
{
config.objs[i] = NULL;
continue;
}
centroids[num_centroids++] = centroid;
lwpoint = lwgeom_as_lwpoint(centroid);
}
else
{
lwpoint = lwgeom_as_lwpoint(geom);
}
/* Store a pointer to the POINT2D we are interested in */
cp = getPoint2d_cp(lwpoint->point, 0);
config.objs[i] = (Pointer)cp;
/* Since we're already here, let's calculate the extrema of the set */
if (cp->x < min.x) min.x = cp->x;
if (cp->y < min.y) min.y = cp->y;
if (cp->x > max.x) max.x = cp->x;
if (cp->y > max.y) max.y = cp->y;
}
/*
* We map a uniform assignment of points in the area covered by the set
* onto actual points in the set
*/
dx = (max.x - min.x)/k;
dy = (max.y - min.y)/k;
seen = lwalloc(sizeof(int)*config.k);
memset(seen, 0, sizeof(int)*config.k);
for (i = 0; i < k; i++)
{
int closest;
POINT2D p;
int j;
/* Calculate a point in the range */
p.x = min.x + dx * (i + 0.5);
p.y = min.y + dy * (i + 0.5);
/* Find the data point closest to the calculated point */
closest = lwkmeans_pt_closest(config.objs, config.num_objs, &p);
/* If something is terrible wrong w/ data, cannot find a closest */
if (closest < 0)
lwerror("unable to calculate cluster seed points, too many NULLs or empties?");
/* Ensure we aren't already using that point as a seed */
j = 0;
while(j < sidx)
{
if (seen[j] == closest)
{
closest = (closest + 1) % config.num_objs;
j = 0;
}
else
{
j++;
}
}
seen[sidx++] = closest;
/* Copy the point coordinates into the initial centers array */
/* This is ugly, but the centers array is an array of */
/* pointers to points, not an array of points */
centers_raw[i] = *((POINT2D*)config.objs[closest]);
config.centers[i] = &(centers_raw[i]);
}
result = kmeans(&config);
/* Before error handling, might as well clean up all the inputs */
lwfree(config.objs);
lwfree(config.centers);
lwfree(centers_raw);
lwfree(centroids);
lwfree(seen);
/* Good result */
if (result == KMEANS_OK)
return config.clusters;
/* Bad result, not going to need the answer */
lwfree(config.clusters);
if (result == KMEANS_EXCEEDED_MAX_ITERATIONS)
{
lwerror("%s did not converge after %d iterations", __func__, config.max_iterations);
return NULL;
}
/* Unknown error */
return NULL;
}
/* We supposed that the geometry is valid
we could have wrong result if not */
int lwtin_is_closed(const LWTIN *tin)
{
int i, j, k;
int narcs, carc;
int found;
tin_arcs arcs;
POINT4D pa, pb;
LWTRIANGLE *patch;
/* If surface is not 3D, it's can't be closed */
if (!FLAGS_GET_Z(tin->flags)) return 0;
/* Max theorical arcs number if no one is shared ... */
narcs = 3 * tin->ngeoms;
arcs = lwalloc(sizeof(struct struct_tin_arcs) * narcs);
for (i=0, carc=0; i < tin->ngeoms ; i++)
{
patch = (LWTRIANGLE *) tin->geoms[i];
for (j=0; j < 3 ; j++)
{
getPoint4d_p(patch->points, j, &pa);
getPoint4d_p(patch->points, j+1, &pb);
/* Make sure to order the 'lower' point first */
if ( (pa.x > pb.x) ||
(pa.x == pb.x && pa.y > pb.y) ||
(pa.x == pb.x && pa.y == pb.y && pa.z > pb.z) )
{
pa = pb;
getPoint4d_p(patch->points, j, &pb);
}
for (found=0, k=0; k < carc ; k++)
{
if ( ( arcs[k].ax == pa.x && arcs[k].ay == pa.y &&
arcs[k].az == pa.z && arcs[k].bx == pb.x &&
arcs[k].by == pb.y && arcs[k].bz == pb.z &&
arcs[k].face != i) )
{
arcs[k].cnt++;
found = 1;
/* Look like an invalid TIN
anyway not a closed one */
if (arcs[k].cnt > 2)
{
lwfree(arcs);
return 0;
}
}
}
if (!found)
{
arcs[carc].cnt=1;
arcs[carc].face=i;
arcs[carc].ax = pa.x;
arcs[carc].ay = pa.y;
arcs[carc].az = pa.z;
arcs[carc].bx = pb.x;
arcs[carc].by = pb.y;
arcs[carc].bz = pb.z;
carc++;
/* Look like an invalid TIN
anyway not a closed one */
if (carc > narcs)
{
lwfree(arcs);
return 0;
}
}
}
}
/* A TIN is closed if each edge
is shared by exactly 2 faces */
for (k=0; k < carc ; k++)
{
if (arcs[k].cnt != 2)
{
lwfree(arcs);
return 0;
}
}
lwfree(arcs);
/* Invalid TIN case */
if (carc < tin->ngeoms) return 0;
return 1;
}
GEOSGeometry*
LWGEOM_GEOS_buildArea(const GEOSGeometry* geom_in)
{
GEOSGeometry *tmp;
GEOSGeometry *geos_result, *shp;
GEOSGeometry const *vgeoms[1];
uint32_t i, ngeoms;
int srid = GEOSGetSRID(geom_in);
Face ** geoms;
vgeoms[0] = geom_in;
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Polygonizing");
#endif
geos_result = GEOSPolygonize(vgeoms, 1);
LWDEBUGF(3, "GEOSpolygonize returned @ %p", geos_result);
/* Null return from GEOSpolygonize (an exception) */
if ( ! geos_result ) return 0;
/*
* We should now have a collection
*/
#if PARANOIA_LEVEL > 0
if ( GEOSGeometryTypeId(geos_result) != COLLECTIONTYPE )
{
GEOSGeom_destroy(geos_result);
lwerror("Unexpected return from GEOSpolygonize");
return 0;
}
#endif
ngeoms = GEOSGetNumGeometries(geos_result);
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Num geometries from polygonizer: %d", ngeoms);
#endif
LWDEBUGF(3, "GEOSpolygonize: ngeoms in polygonize output: %d", ngeoms);
LWDEBUGF(3, "GEOSpolygonize: polygonized:%s",
lwgeom_to_ewkt(GEOS2LWGEOM(geos_result, 0)));
/*
* No geometries in collection, early out
*/
if ( ngeoms == 0 )
{
GEOSSetSRID(geos_result, srid);
return geos_result;
}
/*
* Return first geometry if we only have one in collection,
* to avoid the unnecessary Geometry clone below.
*/
if ( ngeoms == 1 )
{
tmp = (GEOSGeometry *)GEOSGetGeometryN(geos_result, 0);
if ( ! tmp )
{
GEOSGeom_destroy(geos_result);
return 0; /* exception */
}
shp = GEOSGeom_clone(tmp);
GEOSGeom_destroy(geos_result); /* only safe after the clone above */
GEOSSetSRID(shp, srid);
return shp;
}
LWDEBUGF(2, "Polygonize returned %d geoms", ngeoms);
/*
* Polygonizer returns a polygon for each face in the built topology.
*
* This means that for any face with holes we'll have other faces
* representing each hole. We can imagine a parent-child relationship
* between these faces.
*
* In order to maximize the number of visible rings in output we
* only use those faces which have an even number of parents.
*
* Example:
*
* +---------------+
* | L0 | L0 has no parents
* | +---------+ |
* | | L1 | | L1 is an hole of L0
* | | +---+ | |
* | | |L2 | | | L2 is an hole of L1 (which is an hole of L0)
* | | | | | |
* | | +---+ | |
* | +---------+ |
* | |
* +---------------+
*
* See http://trac.osgeo.org/postgis/ticket/1806
*
*/
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Preparing face structures");
#endif
/* Prepare face structures for later analysis */
geoms = lwalloc(sizeof(Face**)*ngeoms);
for (i=0; i<ngeoms; ++i)
geoms[i] = newFace(GEOSGetGeometryN(geos_result, i));
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Finding face holes");
#endif
/* Find faces representing other faces holes */
findFaceHoles(geoms, ngeoms);
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Colletting even ancestor faces");
#endif
/* Build a MultiPolygon composed only by faces with an
* even number of ancestors */
tmp = collectFacesWithEvenAncestors(geoms, ngeoms);
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Cleaning up");
#endif
/* Cleanup face structures */
for (i=0; i<ngeoms; ++i) delFace(geoms[i]);
lwfree(geoms);
/* Faces referenced memory owned by geos_result.
* It is safe to destroy geos_result after deleting them. */
GEOSGeom_destroy(geos_result);
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Self-unioning");
#endif
/* Run a single overlay operation to dissolve shared edges */
shp = GEOSUnionCascaded(tmp);
if ( ! shp )
{
GEOSGeom_destroy(tmp);
return 0; /* exception */
}
#ifdef LWGEOM_PROFILE_BUILDAREA
lwnotice("Final cleanup");
#endif
GEOSGeom_destroy(tmp);
GEOSSetSRID(shp, srid);
return shp;
}
/*
* Add an edge to a face in a tgeom
* Edge is describded as a starting and an ending point
* Points are really copied
* Return the new tgeom pointer
*/
static TGEOM*
tgeom_add_face_edge(TGEOM *tgeom, int face_id, POINT4D *s, POINT4D *e)
{
int nedges, edge_id;
assert(tgeom);
assert(s);
assert(e);
edge_id = tgeom_is_edge(tgeom, s, e);
if (edge_id)
{
tgeom->edges[abs(edge_id)]->count++;
LWDEBUGF(3, "face [%i] Founded Edge: %i\n",
face_id, edge_id);
}
else
{
if ((tgeom->nedges + 1) == INT_MAX)
lwerror("tgeom_add_face_edge: Unable to alloc more than %i edges", INT_MAX);
/* alloc edges array */
if (tgeom->maxedges == 0)
{
tgeom->edges = (TEDGE**) lwalloc(sizeof(TEDGE*) * 4);
tgeom->maxedges = 4;
}
if (tgeom->maxedges >= (tgeom->nedges + 1))
{
tgeom->edges = (TEDGE **) lwrealloc(tgeom->edges,
sizeof(TEDGE*) * tgeom->maxedges * 2);
tgeom->maxedges *= 2;
}
edge_id = ++tgeom->nedges; /* edge_id is 1 based */
tgeom->edges[edge_id] = (TEDGE*) lwalloc(sizeof(TEDGE));
tgeom->edges[edge_id]->s = lwalloc(sizeof(POINT4D));
tgeom->edges[edge_id]->e = lwalloc(sizeof(POINT4D));
memcpy(tgeom->edges[edge_id]->s, s, sizeof(POINT4D));
memcpy(tgeom->edges[edge_id]->e, e, sizeof(POINT4D));
tgeom->edges[edge_id]->count = 1;
LWDEBUGF(3, "face [%i] adding edge [%i] (%lf, %lf, %lf, %lf) -> (%lf, %lf, %lf, %lf)\n",
face_id, edge_id, s->x, s->y, s->z, s->m, e->x, e->y, e->z, e->m);
}
nedges = tgeom->faces[face_id]->nedges;
if (tgeom->faces[face_id]->maxedges == 0)
{
tgeom->faces[face_id]->edges = (int *) lwalloc(sizeof(int) * 4);
tgeom->faces[face_id]->maxedges = 4;
}
if (tgeom->faces[face_id]->maxedges == nedges)
{
tgeom->faces[face_id]->edges = (int *) lwrealloc(tgeom->faces[face_id]->edges,
sizeof(int) * tgeom->faces[face_id]->maxedges * 2);
tgeom->faces[face_id]->maxedges *= 2;
}
LWDEBUGF(3, "face [%i] add %i in edge array in %i pos\n",
face_id, edge_id, tgeom->faces[face_id]->nedges);
tgeom->faces[face_id]->edges[nedges]= edge_id;
tgeom->faces[face_id]->nedges++;
return tgeom;
}
/* We supposed that the geometry is valid
we could have wrong result if not */
int lwpsurface_is_closed(const LWPSURFACE *psurface)
{
int i, j, k;
int narcs, carc;
int found;
psurface_arcs arcs;
POINT4D pa, pb;
LWPOLY *patch;
/* If surface is not 3D, it's can't be closed */
if (!FLAGS_GET_Z(psurface->flags)) return 0;
/* If surface is less than 4 faces hard to be closed too */
if (psurface->ngeoms < 4) return 0;
/* Max theorical arcs number if no one is shared ... */
for (i=0, narcs=0 ; i < psurface->ngeoms ; i++)
{
patch = (LWPOLY *) psurface->geoms[i];
narcs += patch->rings[0]->npoints - 1;
}
arcs = lwalloc(sizeof(struct struct_psurface_arcs) * narcs);
for (i=0, carc=0; i < psurface->ngeoms ; i++)
{
patch = (LWPOLY *) psurface->geoms[i];
for (j=0; j < patch->rings[0]->npoints - 1; j++)
{
getPoint4d_p(patch->rings[0], j, &pa);
getPoint4d_p(patch->rings[0], j+1, &pb);
/* remove redundant points if any */
if (pa.x == pb.x && pa.y == pb.y && pa.z == pb.z) continue;
/* Make sure to order the 'lower' point first */
if ( (pa.x > pb.x) ||
(pa.x == pb.x && pa.y > pb.y) ||
(pa.x == pb.x && pa.y == pb.y && pa.z > pb.z) )
{
pa = pb;
getPoint4d_p(patch->rings[0], j, &pb);
}
for (found=0, k=0; k < carc ; k++)
{
if ( ( arcs[k].ax == pa.x && arcs[k].ay == pa.y &&
arcs[k].az == pa.z && arcs[k].bx == pb.x &&
arcs[k].by == pb.y && arcs[k].bz == pb.z &&
arcs[k].face != i) )
{
arcs[k].cnt++;
found = 1;
/* Look like an invalid PolyhedralSurface
anyway not a closed one */
if (arcs[k].cnt > 2)
{
lwfree(arcs);
return 0;
}
}
}
if (!found)
{
arcs[carc].cnt=1;
arcs[carc].face=i;
arcs[carc].ax = pa.x;
arcs[carc].ay = pa.y;
arcs[carc].az = pa.z;
arcs[carc].bx = pb.x;
arcs[carc].by = pb.y;
arcs[carc].bz = pb.z;
carc++;
/* Look like an invalid PolyhedralSurface
anyway not a closed one */
if (carc > narcs)
{
lwfree(arcs);
return 0;
}
}
}
}
/* A polyhedron is closed if each edge
is shared by exactly 2 faces */
for (k=0; k < carc ; k++)
{
if (arcs[k].cnt != 2)
{
lwfree(arcs);
return 0;
}
}
lwfree(arcs);
/* Invalid Polyhedral case */
if (carc < psurface->ngeoms) return 0;
return 1;
}
Datum BOX2D_to_LWGEOM(PG_FUNCTION_ARGS)
{
GBOX *box = (GBOX *)PG_GETARG_POINTER(0);
POINTARRAY *pa = ptarray_construct_empty(0, 0, 5);
POINT4D pt;
GSERIALIZED *result;
/*
* 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
*/
if ( (box->xmin == box->xmax) && (box->ymin == box->ymax) )
{
/* Construct and serialize point */
LWPOINT *point = lwpoint_make2d(SRID_UNKNOWN, box->xmin, box->ymin);
result = geometry_serialize(lwpoint_as_lwgeom(point));
lwpoint_free(point);
}
else if ( (box->xmin == box->xmax) || (box->ymin == box->ymax) )
{
LWLINE *line;
/* Assign coordinates to point array */
pt.x = box->xmin;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmax;
pt.y = box->ymax;
ptarray_append_point(pa, &pt, LW_TRUE);
/* Construct and serialize linestring */
line = lwline_construct(SRID_UNKNOWN, NULL, pa);
result = geometry_serialize(lwline_as_lwgeom(line));
lwline_free(line);
}
else
{
LWPOLY *poly;
POINTARRAY **ppa = lwalloc(sizeof(POINTARRAY*));
/* Assign coordinates to point array */
pt.x = box->xmin;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmin;
pt.y = box->ymax;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmax;
pt.y = box->ymax;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmax;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
pt.x = box->xmin;
pt.y = box->ymin;
ptarray_append_point(pa, &pt, LW_TRUE);
/* Construct polygon */
ppa[0] = pa;
poly = lwpoly_construct(SRID_UNKNOWN, NULL, 1, ppa);
result = geometry_serialize(lwpoly_as_lwgeom(poly));
lwpoly_free(poly);
}
PG_RETURN_POINTER(result);
}
GBOX* gbox_clone(const GBOX *gbox)
{
GBOX *g = lwalloc(sizeof(GBOX));
memcpy(g, gbox, sizeof(GBOX));
return g;
}
LWGEOM*
pta_unstroke(const POINTARRAY *points, int type, int srid)
{
int i = 0, j, k;
POINT4D a1, a2, a3, b;
POINT4D first, center;
char *edges_in_arcs;
int found_arc = LW_FALSE;
int current_arc = 1;
int num_edges;
int edge_type; /* non-zero if edge is part of an arc */
int start, end;
LWCOLLECTION *outcol;
/* Minimum number of edges, per quadrant, required to define an arc */
const unsigned int min_quad_edges = 2;
/* Die on null input */
if ( ! points )
lwerror("pta_unstroke called with null pointarray");
/* Null on empty input? */
if ( points->npoints == 0 )
return NULL;
/* We can't desegmentize anything shorter than four points */
if ( points->npoints < 4 )
{
/* Return a linestring here*/
lwerror("pta_unstroke needs implementation for npoints < 4");
}
/* Allocate our result array of vertices that are part of arcs */
num_edges = points->npoints - 1;
edges_in_arcs = lwalloc(num_edges + 1);
memset(edges_in_arcs, 0, num_edges + 1);
/* We make a candidate arc of the first two edges, */
/* And then see if the next edge follows it */
while( i < num_edges-2 )
{
unsigned int arc_edges;
double num_quadrants;
double angle;
found_arc = LW_FALSE;
/* Make candidate arc */
getPoint4d_p(points, i , &a1);
getPoint4d_p(points, i+1, &a2);
getPoint4d_p(points, i+2, &a3);
memcpy(&first, &a1, sizeof(POINT4D));
for( j = i+3; j < num_edges+1; j++ )
{
LWDEBUGF(4, "i=%d, j=%d", i, j);
getPoint4d_p(points, j, &b);
/* Does this point fall on our candidate arc? */
if ( pt_continues_arc(&a1, &a2, &a3, &b) )
{
/* Yes. Mark this edge and the two preceding it as arc components */
LWDEBUGF(4, "pt_continues_arc #%d", current_arc);
found_arc = LW_TRUE;
for ( k = j-1; k > j-4; k-- )
edges_in_arcs[k] = current_arc;
}
else
{
/* No. So we're done with this candidate arc */
LWDEBUG(4, "pt_continues_arc = false");
current_arc++;
break;
}
memcpy(&a1, &a2, sizeof(POINT4D));
memcpy(&a2, &a3, sizeof(POINT4D));
memcpy(&a3, &b, sizeof(POINT4D));
}
/* Jump past all the edges that were added to the arc */
if ( found_arc )
{
/* Check if an arc was composed by enough edges to be
* really considered an arc
* See http://trac.osgeo.org/postgis/ticket/2420
*/
arc_edges = j - 1 - i;
LWDEBUGF(4, "arc defined by %d edges found", arc_edges);
if ( first.x == b.x && first.y == b.y ) {
LWDEBUG(4, "arc is a circle");
num_quadrants = 4;
}
else {
lw_arc_center((POINT2D*)&first, (POINT2D*)&b, (POINT2D*)&a1, (POINT2D*)¢er);
angle = lw_arc_angle((POINT2D*)&first, (POINT2D*)¢er, (POINT2D*)&b);
int p2_side = lw_segment_side((POINT2D*)&first, (POINT2D*)&a1, (POINT2D*)&b);
if ( p2_side >= 0 ) angle = -angle;
if ( angle < 0 ) angle = 2 * M_PI + angle;
num_quadrants = ( 4 * angle ) / ( 2 * M_PI );
LWDEBUGF(4, "arc angle (%g %g, %g %g, %g %g) is %g (side is %d), quandrants:%g", first.x, first.y, center.x, center.y, b.x, b.y, angle, p2_side, num_quadrants);
}
/* a1 is first point, b is last point */
if ( arc_edges < min_quad_edges * num_quadrants ) {
LWDEBUGF(4, "Not enough edges for a %g quadrants arc, %g needed", num_quadrants, min_quad_edges * num_quadrants);
for ( k = j-1; k >= i; k-- )
edges_in_arcs[k] = 0;
}
i = j-1;
}
else
{
/* Mark this edge as a linear edge */
edges_in_arcs[i] = 0;
i = i+1;
}
}
#if POSTGIS_DEBUG_LEVEL > 3
{
char *edgestr = lwalloc(num_edges+1);
for ( i = 0; i < num_edges; i++ )
{
if ( edges_in_arcs[i] )
edgestr[i] = 48 + edges_in_arcs[i];
else
edgestr[i] = '.';
}
edgestr[num_edges] = 0;
LWDEBUGF(3, "edge pattern %s", edgestr);
lwfree(edgestr);
}
#endif
start = 0;
edge_type = edges_in_arcs[0];
outcol = lwcollection_construct_empty(COMPOUNDTYPE, srid, ptarray_has_z(points), ptarray_has_m(points));
for( i = 1; i < num_edges; i++ )
{
if( edge_type != edges_in_arcs[i] )
{
end = i - 1;
lwcollection_add_lwgeom(outcol, geom_from_pa(points, srid, edge_type, start, end));
start = i;
edge_type = edges_in_arcs[i];
}
}
lwfree(edges_in_arcs); /* not needed anymore */
/* Roll out last item */
end = num_edges - 1;
lwcollection_add_lwgeom(outcol, geom_from_pa(points, srid, edge_type, start, end));
/* Strip down to singleton if only one entry */
if ( outcol->ngeoms == 1 )
{
LWGEOM *outgeom = outcol->geoms[0];
outcol->ngeoms = 0; lwcollection_free(outcol);
return outgeom;
}
return lwcollection_as_lwgeom(outcol);
}
Datum LWGEOM_line_substring(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
double from = PG_GETARG_FLOAT8(1);
double to = PG_GETARG_FLOAT8(2);
LWGEOM *olwgeom;
POINTARRAY *ipa, *opa;
GSERIALIZED *ret;
int type = gserialized_get_type(geom);
if ( from < 0 || from > 1 )
{
elog(ERROR,"line_interpolate_point: 2nd arg isn't within [0,1]");
PG_RETURN_NULL();
}
if ( to < 0 || to > 1 )
{
elog(ERROR,"line_interpolate_point: 3rd arg isn't within [0,1]");
PG_RETURN_NULL();
}
if ( from > to )
{
elog(ERROR, "2nd arg must be smaller then 3rd arg");
PG_RETURN_NULL();
}
if ( type == LINETYPE )
{
LWLINE *iline = lwgeom_as_lwline(lwgeom_from_gserialized(geom));
if ( lwgeom_is_empty((LWGEOM*)iline) )
{
/* TODO return empty line */
lwline_release(iline);
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_NULL();
}
ipa = iline->points;
opa = ptarray_substring(ipa, from, to, 0);
if ( opa->npoints == 1 ) /* Point returned */
olwgeom = (LWGEOM *)lwpoint_construct(iline->srid, NULL, opa);
else
olwgeom = (LWGEOM *)lwline_construct(iline->srid, NULL, opa);
}
else if ( type == MULTILINETYPE )
{
LWMLINE *iline;
int i = 0, g = 0;
int homogeneous = LW_TRUE;
LWGEOM **geoms = NULL;
double length = 0.0, sublength = 0.0, minprop = 0.0, maxprop = 0.0;
iline = lwgeom_as_lwmline(lwgeom_from_gserialized(geom));
if ( lwgeom_is_empty((LWGEOM*)iline) )
{
/* TODO return empty collection */
lwmline_release(iline);
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_NULL();
}
/* Calculate the total length of the mline */
for ( i = 0; i < iline->ngeoms; i++ )
{
LWLINE *subline = (LWLINE*)iline->geoms[i];
if ( subline->points && subline->points->npoints > 1 )
length += ptarray_length_2d(subline->points);
}
geoms = lwalloc(sizeof(LWGEOM*) * iline->ngeoms);
/* Slice each sub-geometry of the multiline */
for ( i = 0; i < iline->ngeoms; i++ )
{
LWLINE *subline = (LWLINE*)iline->geoms[i];
double subfrom = 0.0, subto = 0.0;
if ( subline->points && subline->points->npoints > 1 )
sublength += ptarray_length_2d(subline->points);
/* Calculate proportions for this subline */
minprop = maxprop;
maxprop = sublength / length;
/* This subline doesn't reach the lowest proportion requested
or is beyond the highest proporton */
if ( from > maxprop || to < minprop )
continue;
if ( from <= minprop )
subfrom = 0.0;
if ( to >= maxprop )
subto = 1.0;
if ( from > minprop && from <= maxprop )
subfrom = (from - minprop) / (maxprop - minprop);
if ( to < maxprop && to >= minprop )
subto = (to - minprop) / (maxprop - minprop);
opa = ptarray_substring(subline->points, subfrom, subto, 0);
if ( opa && opa->npoints > 0 )
{
if ( opa->npoints == 1 ) /* Point returned */
{
geoms[g] = (LWGEOM *)lwpoint_construct(SRID_UNKNOWN, NULL, opa);
homogeneous = LW_FALSE;
}
else
{
geoms[g] = (LWGEOM *)lwline_construct(SRID_UNKNOWN, NULL, opa);
}
g++;
}
}
/* If we got any points, we need to return a GEOMETRYCOLLECTION */
if ( ! homogeneous )
type = COLLECTIONTYPE;
olwgeom = (LWGEOM*)lwcollection_construct(type, iline->srid, NULL, g, geoms);
}
else
{
elog(ERROR,"line_substring: 1st arg isn't a line");
PG_RETURN_NULL();
}
ret = geometry_serialize(olwgeom);
lwgeom_free(olwgeom);
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_POINTER(ret);
}
/*
* Deserialize a TSERIALIZED struct and
* return a TGEOM pointer
*/
TGEOM *
tgeom_deserialize(TSERIALIZED *serialized_form)
{
uint8_t type, flags;
TGEOM *result;
uint8_t *loc, *data;
int i, j;
assert(serialized_form);
assert(serialized_form->data);
data = serialized_form->data;
/* type and flags */
type = data[0];
flags = data[1];
result = tgeom_new(type, FLAGS_GET_Z(flags), FLAGS_GET_M(flags));
loc = data + 2;
/* srid */
result->srid = lw_get_int32_t(loc);
loc += 4;
/* bbox */
if (FLAGS_GET_BBOX(flags))
{
result->bbox = lwalloc(sizeof(BOX3D));
memcpy(result->bbox, loc, sizeof(BOX3D));
loc += sizeof(BOX3D);
}
else result->bbox = NULL;
/* edges number (0=> EMPTY) */
result->nedges = lw_get_int32_t(loc);
loc += 4;
/* edges */
result->edges = lwalloc(sizeof(TEDGE*) * (result->nedges + 1));
for (i=1 ; i <= result->nedges ; i++)
{
result->edges[i] = lwalloc(sizeof(TEDGE));
result->edges[i]->s = lwalloc(sizeof(POINT4D));
result->edges[i]->e = lwalloc(sizeof(POINT4D));
/* 3DM specific handle */
if (!FLAGS_GET_Z(result->flags) && FLAGS_GET_M(result->flags))
{
memcpy(result->edges[i]->s, loc, sizeof(double) * 2);
loc += sizeof(double) * 2;
memcpy(&(result->edges[i]->s->m), loc, sizeof(double));
loc += sizeof(double);
memcpy(result->edges[i]->e, loc, sizeof(double) * 2);
loc += sizeof(double) * 2;
memcpy(&(result->edges[i]->e->m), loc, sizeof(double));
loc += sizeof(double);
}
else /* 2D,3DZ && 4D */
{
memcpy(result->edges[i]->s, loc,
sizeof(double) * FLAGS_NDIMS(flags));
loc += sizeof(double) * FLAGS_NDIMS(flags);
result->edges[i]->e = lwalloc(sizeof(POINT4D));
memcpy(result->edges[i]->e, loc,
sizeof(double) * FLAGS_NDIMS(flags));
loc += sizeof(double) * FLAGS_NDIMS(flags);
}
result->edges[i]->count = lw_get_int32_t(loc);
loc += 4;
}
/* faces number */
result->nfaces = lw_get_int32_t(loc);
loc += 4;
/* faces */
result->faces = lwalloc(sizeof(TFACE*) * result->nfaces);
for (i=0 ; i < result->nfaces ; i++)
{
result->faces[i] = lwalloc(sizeof(TFACE));
/* number of edges */
result->faces[i]->nedges = lw_get_int32_t(loc);
loc += 4;
/* edges array */
result->faces[i]->edges = lwalloc(sizeof(TEDGE*)
* result->faces[i]->nedges);
memcpy(result->faces[i]->edges, loc, sizeof(TEDGE*)
* result->faces[i]->nedges);
loc += 4 * result->faces[i]->nedges;
/* number of rings */
result->faces[i]->nrings = lw_get_int32_t(loc);
loc += 4;
if (result->faces[i]->nrings)
result->faces[i]->rings = lwalloc(sizeof(POINTARRAY*)
* result->faces[i]->nrings);
for (j=0 ; j < result->faces[i]->nrings ; j++)
{
int npoints;
/* number of points */
npoints = lw_get_int32_t(loc);
loc += 4;
/* pointarray */
result->faces[i]->rings[j] = ptarray_construct_reference_data(FLAGS_GET_Z(flags), FLAGS_GET_M(flags), npoints, loc);
loc += sizeof(double)* FLAGS_NDIMS(flags) * npoints;
}
}
return result;
}
/*
* Return a LWGEOM pointer from an TGEOM struct
* Geometries are NOT copied
*/
LWGEOM*
lwgeom_from_tgeom(TGEOM *tgeom)
{
int i, j, k;
LWGEOM *geom;
POINTARRAY *dpa;
POINTARRAY **ppa;
int hasz, hasm, edge_id;
int dims=0;
assert(tgeom);
hasz=FLAGS_GET_Z(tgeom->flags);
hasm=FLAGS_GET_M(tgeom->flags);
geom = (LWGEOM *)lwcollection_construct_empty(COLLECTIONTYPE, tgeom->srid, hasz, hasm);
switch (tgeom->type)
{
case TINTYPE:
geom->type = TINTYPE;
for (i=0 ; i < tgeom->nfaces ; i++)
{
FLAGS_SET_Z(dims, hasz?1:0);
FLAGS_SET_M(dims, hasm?1:0);
dpa = ptarray_construct_empty(hasz, hasm, 4);
for (j=0 ; j < tgeom->faces[i]->nedges ; j++)
{
edge_id = tgeom->faces[i]->edges[j];
LWDEBUGF(3, "TIN edge_id: %i\n", edge_id);
assert(edge_id);
if (edge_id > 0)
ptarray_append_point(dpa, tgeom->edges[edge_id]->s, LW_TRUE);
else
ptarray_append_point(dpa, tgeom->edges[-edge_id]->e, LW_TRUE);
}
edge_id = tgeom->faces[i]->edges[0];
LWDEBUGF(3, "TIN edge_id: %i\n", edge_id);
if (edge_id > 0)
ptarray_append_point(dpa, tgeom->edges[edge_id]->s, LW_TRUE);
else
ptarray_append_point(dpa, tgeom->edges[-edge_id]->e, LW_TRUE);
geom = (LWGEOM *) lwtin_add_lwtriangle((LWTIN *) geom,
lwtriangle_construct(tgeom->srid, NULL, dpa));
}
break;
case POLYHEDRALSURFACETYPE:
geom->type = POLYHEDRALSURFACETYPE;
for (i=0 ; i < tgeom->nfaces ; i++)
{
FLAGS_SET_Z(dims, hasz?1:0);
FLAGS_SET_M(dims, hasm?1:0);;
dpa = ptarray_construct_empty(hasz, hasm, 4);
for (j=0 ; j < tgeom->faces[i]->nedges ; j++)
{
edge_id = tgeom->faces[i]->edges[j];
assert(edge_id);
LWDEBUGF(3, "POLYHEDRALSURFACE edge_id: %i\n", edge_id);
if (edge_id > 0)
ptarray_append_point(dpa, tgeom->edges[edge_id]->s, LW_TRUE);
else
ptarray_append_point(dpa, tgeom->edges[-edge_id]->e, LW_TRUE);
}
edge_id = tgeom->faces[i]->edges[0];
LWDEBUGF(3, "POLYHEDRALSURFACE edge_id: %i\n", edge_id);
if (edge_id > 0)
ptarray_append_point(dpa, tgeom->edges[edge_id]->s, LW_TRUE);
else
ptarray_append_point(dpa, tgeom->edges[-edge_id]->e, LW_TRUE);
ppa = lwalloc(sizeof(POINTARRAY*)
* (tgeom->faces[i]->nrings + 1));
ppa[0] = dpa;
for (k=0; k < tgeom->faces[i]->nrings ; k++)
ppa[k+1] = tgeom->faces[i]->rings[k];
geom = (LWGEOM *) lwpsurface_add_lwpoly((LWPSURFACE *) geom,
lwpoly_construct(tgeom->srid, NULL, k + 1, ppa));
}
break;
default:
lwerror("lwgeom_from_tgeom: Unkwnown type %i - %s\n",
tgeom->type, lwtype_name(tgeom->type));
}
if (geom->srid == 0) geom->srid = SRID_UNKNOWN;
return geom;
}
/*
* Add a LWPOLY inside a tgeom
* Copy geometries from LWPOLY
*/
static TGEOM*
tgeom_add_polygon(TGEOM *tgeom, LWPOLY *poly)
{
int i;
assert(tgeom);
assert(poly);
if ((tgeom->nfaces + 1) == INT_MAX)
lwerror("tgeom_add_polygon: Unable to alloc more than %i faces", INT_MAX);
/* Integrity checks on subgeom, dims and srid */
if (tgeom->type != POLYHEDRALSURFACETYPE)
lwerror("tgeom_add_polygon: Unable to handle %s - %s type",
tgeom->type, lwtype_name(tgeom->type));
if (FLAGS_NDIMS(tgeom->flags) != FLAGS_NDIMS(poly->flags))
lwerror("tgeom_add_polygon: Mixed dimension");
if (tgeom->srid != poly->srid && (tgeom->srid != 0 && poly->srid != SRID_UNKNOWN))
lwerror("tgeom_add_polygon: Mixed srid. Tgeom: %i / Polygon: %i",
tgeom->srid, poly->srid);
/* handle face array allocation */
if (tgeom->maxfaces == 0)
{
tgeom->faces = lwalloc(sizeof(TFACE*) * 2);
tgeom->maxfaces = 2;
}
if ((tgeom->maxfaces - 1) == tgeom->nfaces)
{
tgeom->faces = lwrealloc(tgeom->faces,
sizeof(TFACE*) * tgeom->maxfaces * 2);
tgeom->maxfaces *= 2;
}
/* add an empty face */
tgeom->faces[tgeom->nfaces] = lwalloc(sizeof(TFACE));
tgeom->faces[tgeom->nfaces]->rings = NULL;
tgeom->faces[tgeom->nfaces]->nrings = 0;
tgeom->faces[tgeom->nfaces]->nedges = 0;
tgeom->faces[tgeom->nfaces]->maxedges = 0;
/* Compute edge on poly external ring */
for (i=1 ; i < poly->rings[0]->npoints ; i++)
{
POINT4D p1, p2;
getPoint4d_p(poly->rings[0], i-1, &p1);
getPoint4d_p(poly->rings[0], i, &p2);
tgeom_add_face_edge(tgeom, tgeom->nfaces, &p1, &p2);
}
/* External ring is already handled by edges */
tgeom->faces[tgeom->nfaces]->nrings = poly->nrings - 1;
/* handle rings array allocation */
if (tgeom->faces[tgeom->nfaces]->nrings >= 1)
tgeom->faces[tgeom->nfaces]->rings = lwalloc(sizeof(POINTARRAY*)
* tgeom->faces[tgeom->nfaces]->nrings);
/* clone internal rings */
for (i=0 ; i < tgeom->faces[tgeom->nfaces]->nrings ; i++)
tgeom->faces[tgeom->nfaces]->rings[i]
= ptarray_clone_deep(poly->rings[i+1]);
tgeom->nfaces++;
return tgeom;
}
Datum LWGEOM_interiorringn_polygon(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom;
int32 wanted_index;
LWCURVEPOLY *curvepoly = NULL;
LWPOLY *poly = NULL;
POINTARRAY *ring;
LWLINE *line;
LWGEOM *lwgeom;
GSERIALIZED *result;
GBOX *bbox = NULL;
int type;
POSTGIS_DEBUG(2, "LWGEOM_interierringn_polygon called.");
wanted_index = PG_GETARG_INT32(1);
if ( wanted_index < 1 )
{
/* elog(ERROR, "InteriorRingN: ring number is 1-based"); */
PG_RETURN_NULL(); /* index out of range */
}
geom = PG_GETARG_GSERIALIZED_P(0);
type = gserialized_get_type(geom);
if ( (type != POLYGONTYPE) && (type != CURVEPOLYTYPE) )
{
elog(ERROR, "InteriorRingN: geom is not a polygon");
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_NULL();
}
lwgeom = lwgeom_from_gserialized(geom);
if( lwgeom_is_empty(lwgeom) )
{
lwpoly_free(poly);
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_NULL();
}
if ( type == POLYGONTYPE)
{
poly = lwgeom_as_lwpoly(lwgeom_from_gserialized(geom));
/* Ok, now we have a polygon. Let's see if it has enough holes */
if ( wanted_index >= poly->nrings )
{
lwpoly_free(poly);
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_NULL();
}
ring = poly->rings[wanted_index];
/* COMPUTE_BBOX==TAINTING */
if ( poly->bbox )
{
bbox = lwalloc(sizeof(GBOX));
ptarray_calculate_gbox_cartesian(ring, bbox);
}
/* This is a LWLINE constructed by interior ring POINTARRAY */
line = lwline_construct(poly->srid, bbox, ring);
result = geometry_serialize((LWGEOM *)line);
lwline_release(line);
lwpoly_free(poly);
}
else
{
curvepoly = lwgeom_as_lwcurvepoly(lwgeom_from_gserialized(geom));
if (wanted_index >= curvepoly->nrings)
{
PG_FREE_IF_COPY(geom, 0);
lwgeom_release((LWGEOM *)curvepoly);
PG_RETURN_NULL();
}
result = geometry_serialize(curvepoly->rings[wanted_index]);
lwgeom_free((LWGEOM*)curvepoly);
}
PG_FREE_IF_COPY(geom, 0);
PG_RETURN_POINTER(result);
}
/**
* Create a new internal node, calculating the new measure range for the node,
* and storing pointers to the child nodes.
*/
static CIRC_NODE*
circ_node_internal_new(CIRC_NODE** c, int num_nodes)
{
CIRC_NODE *node = NULL;
GEOGRAPHIC_POINT new_center, c1;
double new_radius;
double offset1, dist, D, r1, ri;
int i;
LWDEBUGF(3, "called with %d nodes --", num_nodes);
/* Can't do anything w/ empty input */
if ( num_nodes < 1 )
return node;
/* Initialize calculation with values of the first circle */
new_center = c[0]->center;
new_radius = c[0]->radius;
/* Merge each remaining circle into the new circle */
for ( i = 1; i < num_nodes; i++ )
{
c1 = new_center;
r1 = new_radius;
dist = sphere_distance(&c1, &(c[i]->center));
ri = c[i]->radius;
LWDEBUGF(3, "distance between new (%g %g) and %i (%g %g) is %g", c1.lon, c1.lat, i, c[i]->center.lon, c[i]->center.lat, dist);
if ( FP_EQUALS(dist, 0) )
{
LWDEBUG(3, " distance between centers is zero");
new_radius = r1 + 2*dist;
new_center = c1;
}
else if ( dist < fabs(r1 - ri) )
{
/* new contains next */
if ( r1 > ri )
{
LWDEBUG(3, " c1 contains ci");
new_center = c1;
new_radius = r1;
}
/* next contains new */
else
{
LWDEBUG(3, " ci contains c1");
new_center = c[i]->center;
new_radius = ri;
}
}
else
{
LWDEBUG(3, " calculating new center");
/* New circle diameter */
D = dist + r1 + ri;
LWDEBUGF(3," D is %g", D);
/* New radius */
new_radius = D / 2.0;
/* Distance from cn1 center to the new center */
offset1 = ri + (D - (2.0*r1 + 2.0*ri)) / 2.0;
LWDEBUGF(3," offset1 is %g", offset1);
/* Sometimes the sphere_direction function fails... this causes the center calculation */
/* to fail too. In that case, we're going to fall back ot a cartesian calculation, which */
/* is less exact, so we also have to pad the radius by (hack alert) an arbitrary amount */
/* which is hopefully always big enough to contain the input edges */
if ( circ_center_spherical(&c1, &(c[i]->center), dist, offset1, &new_center) == LW_FAILURE )
{
circ_center_cartesian(&c1, &(c[i]->center), dist, offset1, &new_center);
new_radius *= 1.1;
}
}
LWDEBUGF(3, " new center is (%g %g) new radius is %g", new_center.lon, new_center.lat, new_radius);
}
node = lwalloc(sizeof(CIRC_NODE));
node->p1 = NULL;
node->p2 = NULL;
node->center = new_center;
node->radius = new_radius;
node->num_nodes = num_nodes;
node->nodes = c;
node->edge_num = -1;
return node;
}
GBOX* gbox_copy(const GBOX *box)
{
GBOX *copy = (GBOX*)lwalloc(sizeof(GBOX));
memcpy(copy, box, sizeof(GBOX));
return copy;
}
/**
The new faster calculation comparing pointarray to another pointarray
the arrays can come from both polygons and linestrings.
The naming is not good but comes from that it compares a
chosen selection of the points not all of them
*/
int
lw_dist2d_fast_ptarray_ptarray(POINTARRAY *l1, POINTARRAY *l2,DISTPTS *dl, GBOX *box1, GBOX *box2)
{
/*here we define two lists to hold our calculated "z"-values and the order number in the geometry*/
double k, thevalue;
float deltaX, deltaY, c1m, c2m;
POINT2D theP,c1, c2;
float min1X, max1X, max1Y, min1Y,min2X, max2X, max2Y, min2Y;
int t;
int n1 = l1->npoints;
int n2 = l2->npoints;
LISTSTRUCT *list1, *list2;
list1 = (LISTSTRUCT*)lwalloc(sizeof(LISTSTRUCT)*n1);
list2 = (LISTSTRUCT*)lwalloc(sizeof(LISTSTRUCT)*n2);
LWDEBUG(2, "lw_dist2d_fast_ptarray_ptarray is called");
max1X = box1->xmax;
min1X = box1->xmin;
max1Y = box1->ymax;
min1Y = box1->ymin;
max2X = box2->xmax;
min2X = box2->xmin;
max2Y = box2->ymax;
min2Y = box2->ymin;
/*we want the center of the bboxes, and calculate the slope between the centerpoints*/
c1.x = min1X + (max1X-min1X)/2;
c1.y = min1Y + (max1Y-min1Y)/2;
c2.x = min2X + (max2X-min2X)/2;
c2.y = min2Y + (max2Y-min2Y)/2;
deltaX=(c2.x-c1.x);
deltaY=(c2.y-c1.y);
/*Here we calculate where the line perpendicular to the center-center line crosses the axes for each vertex
if the center-center line is vertical the perpendicular line will be horizontal and we find it's crossing the Y-axes with z = y-kx */
if ((deltaX*deltaX)<(deltaY*deltaY)) /*North or South*/
{
k = -deltaX/deltaY;
for (t=0; t<n1; t++) /*for each segment in L1 */
{
getPoint2d_p(l1, t, &theP);
thevalue = theP.y-(k*theP.x);
list1[t].themeasure=thevalue;
list1[t].pnr=t;
}
for (t=0; t<n2; t++) /*for each segment in L2*/
{
getPoint2d_p(l2, t, &theP);
thevalue = theP.y-(k*theP.x);
list2[t].themeasure=thevalue;
list2[t].pnr=t;
}
c1m = c1.y-(k*c1.x);
c2m = c2.y-(k*c2.x);
}
/*if the center-center line is horizontal the perpendicular line will be vertical. To eliminate problems with deviding by zero we are here mirroring the coordinate-system
and we find it's crossing the X-axes with z = x-(1/k)y */
else /*West or East*/
{
k = -deltaY/deltaX;
for (t=0; t<n1; t++) /*for each segment in L1 */
{
getPoint2d_p(l1, t, &theP);
thevalue = theP.x-(k*theP.y);
list1[t].themeasure=thevalue;
list1[t].pnr=t;
/* lwnotice("l1 %d, measure=%f",t,thevalue ); */
}
for (t=0; t<n2; t++) /*for each segment in L2*/
{
getPoint2d_p(l2, t, &theP);
thevalue = theP.x-(k*theP.y);
list2[t].themeasure=thevalue;
list2[t].pnr=t;
/* lwnotice("l2 %d, measure=%f",t,thevalue ); */
}
c1m = c1.x-(k*c1.y);
c2m = c2.x-(k*c2.y);
}
/*we sort our lists by the calculated values*/
qsort(list1, n1, sizeof(LISTSTRUCT), struct_cmp_by_measure);
qsort(list2, n2, sizeof(LISTSTRUCT), struct_cmp_by_measure);
if (c1m < c2m)
{
if (!lw_dist2d_pre_seg_seg(l1,l2,list1,list2,k,dl))
{
lwfree(list1);
lwfree(list2);
return LW_FALSE;
}
}
else
{
dl->twisted= ((dl->twisted) * (-1));
if (!lw_dist2d_pre_seg_seg(l2,l1,list2,list1,k,dl))
{
lwfree(list1);
lwfree(list2);
return LW_FALSE;
}
}
lwfree(list1);
lwfree(list2);
return LW_TRUE;
}