static void
lwgeom_collect_endpoints(const LWGEOM* lwg, LWMPOINT* col)
{
int i, n;
LWLINE* l;
switch (lwg->type)
{
case MULTILINETYPE:
for ( i = 0,
n = lwgeom_ngeoms(lwg);
i < n; ++i )
{
lwgeom_collect_endpoints(
lwgeom_subgeom(lwg, i),
col);
}
break;
case LINETYPE:
l = (LWLINE*)lwg;
col = lwmpoint_add_lwpoint(col,
lwline_get_lwpoint(l, 0));
col = lwmpoint_add_lwpoint(col,
lwline_get_lwpoint(l, l->points->npoints-1));
break;
default:
lwerror("lwgeom_collect_endpoints: invalid type %s",
lwtype_name(lwg->type));
break;
}
}
LWPOINT*
lwcompound_get_lwpoint(const LWCOMPOUND *lwcmp, int where)
{
int i;
int count = 0;
int npoints = 0;
if ( lwgeom_is_empty((LWGEOM*)lwcmp) )
return NULL;
npoints = lwgeom_count_vertices((LWGEOM*)lwcmp);
if ( where < 0 || where >= npoints )
{
lwerror("%s: index %d is not in range of number of vertices (%d) in input", __func__, where, npoints);
return NULL;
}
for ( i = 0; i < lwcmp->ngeoms; i++ )
{
LWGEOM* part = lwcmp->geoms[i];
int npoints_part = lwgeom_count_vertices(part);
if ( where >= count && where < count + npoints_part )
{
return lwline_get_lwpoint((LWLINE*)part, where - count);
}
else
{
count += npoints_part;
}
}
return NULL;
}
Datum LWGEOM_pointn_linestring(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
int where = PG_GETARG_INT32(1);
LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
LWPOINT *lwpoint = NULL;
int type = lwgeom->type;
/* Can't handle crazy index! */
if ( where < 1 )
PG_RETURN_NULL();
if ( type == LINETYPE || type == CIRCSTRINGTYPE )
{
/* OGC index starts at one, so we substract first. */
lwpoint = lwline_get_lwpoint((LWLINE*)lwgeom, where - 1);
}
lwgeom_free(lwgeom);
PG_FREE_IF_COPY(geom, 0);
if ( ! lwpoint )
PG_RETURN_NULL();
PG_RETURN_POINTER(geometry_serialize(lwpoint_as_lwgeom(lwpoint)));
}
Datum LWGEOM_endpoint_linestring(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom = PG_GETARG_GSERIALIZED_P(0);
LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
LWPOINT *lwpoint = NULL;
int type = lwgeom->type;
if ( type == LINETYPE || type == CIRCSTRINGTYPE )
{
LWLINE *line = (LWLINE*)lwgeom;
if ( line->points )
lwpoint = lwline_get_lwpoint((LWLINE*)lwgeom, line->points->npoints - 1);
}
else if ( type == COMPOUNDTYPE )
{
lwpoint = lwcompound_get_endpoint((LWCOMPOUND*)lwgeom);
}
lwgeom_free(lwgeom);
PG_FREE_IF_COPY(geom, 0);
if ( ! lwpoint )
PG_RETURN_NULL();
PG_RETURN_POINTER(geometry_serialize(lwpoint_as_lwgeom(lwpoint)));
}
LWPOINT *
lwcompound_get_endpoint(const LWCOMPOUND *lwcmp)
{
LWLINE *lwline;
if ( lwcmp->ngeoms < 1 )
{
return NULL;
}
lwline = (LWLINE*)(lwcmp->geoms[lwcmp->ngeoms-1]);
if ( (!lwline) || (!lwline->points) || (lwline->points->npoints < 1) )
{
return NULL;
}
return lwline_get_lwpoint(lwline, lwline->points->npoints-1);
}
Datum LWGEOM_startpoint_linestring(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom = (GSERIALIZED*)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
LWGEOM *lwgeom = lwgeom_from_gserialized(geom);
LWPOINT *lwpoint = NULL;
int type = lwgeom->type;
if ( type == LINETYPE || type == CIRCSTRINGTYPE )
{
lwpoint = lwline_get_lwpoint((LWLINE*)lwgeom, 0);
}
lwgeom_free(lwgeom);
PG_FREE_IF_COPY(geom, 0);
if ( ! lwpoint )
PG_RETURN_NULL();
PG_RETURN_POINTER(geometry_serialize(lwpoint_as_lwgeom(lwpoint)));
}
Datum LWGEOM_dumppoints(PG_FUNCTION_ARGS) {
FuncCallContext *funcctx;
MemoryContext oldcontext, newcontext;
GSERIALIZED *pglwgeom;
LWCOLLECTION *lwcoll;
LWGEOM *lwgeom;
struct dumpstate *state;
struct dumpnode *node;
HeapTuple tuple;
Datum pathpt[2]; /* used to construct the composite return value */
bool isnull[2] = {0,0}; /* needed to say neither value is null */
Datum result; /* the actual composite return value */
if (SRF_IS_FIRSTCALL()) {
funcctx = SRF_FIRSTCALL_INIT();
newcontext = funcctx->multi_call_memory_ctx;
oldcontext = MemoryContextSwitchTo(newcontext);
/* get a local copy of what we're doing a dump points on */
pglwgeom = PG_GETARG_GSERIALIZED_P_COPY(0);
lwgeom = lwgeom_from_gserialized(pglwgeom);
/* return early if nothing to do */
if (!lwgeom || lwgeom_is_empty(lwgeom)) {
MemoryContextSwitchTo(oldcontext);
funcctx = SRF_PERCALL_SETUP();
SRF_RETURN_DONE(funcctx);
}
/* Create function state */
state = lwalloc(sizeof *state);
state->root = lwgeom;
state->stacklen = 0;
state->pathlen = 0;
state->pt = 0;
state->ring = 0;
funcctx->user_fctx = state;
/*
* Push a struct dumpnode on the state stack
*/
state->stack[0].idx = 0;
state->stack[0].geom = lwgeom;
state->stacklen++;
/*
* get tuple description for return type
*/
if (get_call_result_type(fcinfo, 0, &funcctx->tuple_desc) != TYPEFUNC_COMPOSITE) {
ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
}
BlessTupleDesc(funcctx->tuple_desc);
/* get and cache data for constructing int4 arrays */
get_typlenbyvalalign(INT4OID, &state->typlen, &state->byval, &state->align);
MemoryContextSwitchTo(oldcontext);
}
/* stuff done on every call of the function */
funcctx = SRF_PERCALL_SETUP();
newcontext = funcctx->multi_call_memory_ctx;
/* get state */
state = funcctx->user_fctx;
while (1) {
node = &state->stack[state->stacklen-1];
lwgeom = node->geom;
/* need to return a point from this geometry */
if (!lwgeom_is_collection(lwgeom)) {
/* either return a point, or pop the stack */
/* TODO use a union? would save a tiny amount of stack space.
* probably not worth the bother
*/
LWLINE *line;
LWCIRCSTRING *circ;
LWPOLY *poly;
LWTRIANGLE *tri;
LWPOINT *lwpoint = NULL;
POINT4D pt;
/*
* net result of switch should be to set lwpoint to the
* next point to return, or leave at NULL if there
* are no more points in the geometry
*/
switch(lwgeom->type) {
case TRIANGLETYPE:
tri = lwgeom_as_lwtriangle(lwgeom);
if (state->pt == 0) {
state->path[state->pathlen++] = Int32GetDatum(state->ring+1);
}
if (state->pt <= 3) {
getPoint4d_p(tri->points, state->pt, &pt);
lwpoint = lwpoint_make(tri->srid,
FLAGS_GET_Z(tri->points->flags),
FLAGS_GET_M(tri->points->flags),
&pt);
}
if (state->pt > 3) {
state->pathlen--;
}
break;
case POLYGONTYPE:
poly = lwgeom_as_lwpoly(lwgeom);
if (state->pt == poly->rings[state->ring]->npoints) {
state->pt = 0;
state->ring++;
state->pathlen--;
}
if (state->pt == 0 && state->ring < poly->nrings) {
/* handle new ring */
state->path[state->pathlen] = Int32GetDatum(state->ring+1);
state->pathlen++;
}
if (state->ring == poly->nrings) {
} else {
/* TODO should be able to directly get the point
* into the point array of a fixed lwpoint
*/
/* can't get the point directly from the ptarray because
* it might be aligned wrong, so at least one memcpy
* seems unavoidable
* It might be possible to pass it directly to gserialized
* depending how that works, it might effectively be gserialized
* though a brief look at the code indicates not
*/
getPoint4d_p(poly->rings[state->ring], state->pt, &pt);
lwpoint = lwpoint_make(poly->srid,
FLAGS_GET_Z(poly->rings[state->ring]->flags),
FLAGS_GET_M(poly->rings[state->ring]->flags),
&pt);
}
break;
case POINTTYPE:
if (state->pt == 0) lwpoint = lwgeom_as_lwpoint(lwgeom);
break;
case LINETYPE:
line = lwgeom_as_lwline(lwgeom);
if (line->points && state->pt <= line->points->npoints) {
lwpoint = lwline_get_lwpoint((LWLINE*)lwgeom, state->pt);
}
break;
case CIRCSTRINGTYPE:
circ = lwgeom_as_lwcircstring(lwgeom);
if (circ->points && state->pt <= circ->points->npoints) {
lwpoint = lwcircstring_get_lwpoint((LWCIRCSTRING*)lwgeom, state->pt);
}
break;
default:
ereport(ERROR, (errcode(ERRCODE_DATA_EXCEPTION),
errmsg("Invalid Geometry type %d passed to ST_DumpPoints()", lwgeom->type)));
}
/*
* At this point, lwpoint is either NULL, in which case
* we need to pop the geometry stack and get the next
* geometry, if amy, or lwpoint is set and we construct
* a record type with the integer array of geometry
* indexes and the point number, and the actual point
* geometry itself
*/
if (!lwpoint) {
/* no point, so pop the geom and look for more */
if (--state->stacklen == 0) SRF_RETURN_DONE(funcctx);
state->pathlen--;
continue;
} else {
/* write address of current geom/pt */
state->pt++;
state->path[state->pathlen] = Int32GetDatum(state->pt);
pathpt[0] = PointerGetDatum(construct_array(state->path, state->pathlen+1,
INT4OID, state->typlen, state->byval, state->align));
pathpt[1] = PointerGetDatum(gserialized_from_lwgeom((LWGEOM*)lwpoint,0,0));
tuple = heap_form_tuple(funcctx->tuple_desc, pathpt, isnull);
result = HeapTupleGetDatum(tuple);
SRF_RETURN_NEXT(funcctx, result);
}
}
lwcoll = (LWCOLLECTION*)node->geom;
/* if a collection and we have more geoms */
if (node->idx < lwcoll->ngeoms) {
/* push the next geom on the path and the stack */
lwgeom = lwcoll->geoms[node->idx++];
state->path[state->pathlen++] = Int32GetDatum(node->idx);
node = &state->stack[state->stacklen++];
node->idx = 0;
node->geom = lwgeom;
state->pt = 0;
state->ring = 0;
/* loop back to beginning, which will then check whatever node we just pushed */
continue;
}
/* no more geometries in the current collection */
if (--state->stacklen == 0) SRF_RETURN_DONE(funcctx);
state->pathlen--;
state->stack[state->stacklen-1].idx++;
}
}
