Datum LWGEOM_line_locate_point(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom1 = PG_GETARG_GSERIALIZED_P(0);
GSERIALIZED *geom2 = PG_GETARG_GSERIALIZED_P(1);
LWLINE *lwline;
LWPOINT *lwpoint;
POINTARRAY *pa;
POINT4D p, p_proj;
double ret;
if ( gserialized_get_type(geom1) != LINETYPE )
{
elog(ERROR,"line_locate_point: 1st arg isn't a line");
PG_RETURN_NULL();
}
if ( gserialized_get_type(geom2) != POINTTYPE )
{
elog(ERROR,"line_locate_point: 2st arg isn't a point");
PG_RETURN_NULL();
}
error_if_srid_mismatch(gserialized_get_srid(geom1), gserialized_get_srid(geom2));
lwline = lwgeom_as_lwline(lwgeom_from_gserialized(geom1));
lwpoint = lwgeom_as_lwpoint(lwgeom_from_gserialized(geom2));
pa = lwline->points;
lwpoint_getPoint4d_p(lwpoint, &p);
ret = ptarray_locate_point(pa, &p, NULL, &p_proj);
PG_RETURN_FLOAT8(ret);
}
double
lwgeom_interpolate_point(const LWGEOM *lwin, const LWPOINT *lwpt)
{
POINT4D p, p_proj;
double ret = 0.0;
if ( ! lwin )
lwerror("lwgeom_interpolate_point: null input geometry!");
if ( ! lwgeom_has_m(lwin) )
lwerror("Input geometry does not have a measure dimension");
if ( lwgeom_is_empty(lwin) || lwpoint_is_empty(lwpt) )
lwerror("Input geometry is empty");
switch ( lwin->type )
{
case LINETYPE:
{
LWLINE *lwline = lwgeom_as_lwline(lwin);
lwpoint_getPoint4d_p(lwpt, &p);
ret = ptarray_locate_point(lwline->points, &p, NULL, &p_proj);
ret = p_proj.m;
break;
}
default:
lwerror("This function does not accept %s geometries.", lwtype_name(lwin->type));
}
return ret;
}
static void test_ptarray_locate_point(void)
{
LWLINE *line;
double loc, dist;
POINT4D p, l;
line = lwgeom_as_lwline(lwgeom_from_text("LINESTRING(0 3,20 4)"));
p = getPoint4d(line->points, 0);
loc = ptarray_locate_point(line->points, &p, &dist, &l);
CU_ASSERT_EQUAL(loc, 0);
CU_ASSERT_EQUAL(dist, 0.0);
p = getPoint4d(line->points, 1);
loc = ptarray_locate_point(line->points, &p, &dist, &l);
CU_ASSERT_EQUAL(loc, 1);
CU_ASSERT_EQUAL(dist, 0.0);
p.x = 21; p.y = 4;
loc = ptarray_locate_point(line->points, &p, &dist, NULL);
CU_ASSERT_EQUAL(loc, 1);
CU_ASSERT_EQUAL(dist, 1.0);
p.x = 0; p.y = 2;
loc = ptarray_locate_point(line->points, &p, &dist, &l);
CU_ASSERT_EQUAL(loc, 0);
CU_ASSERT_EQUAL(dist, 1.0);
lwline_free(line);
line = lwgeom_as_lwline(lwgeom_from_text("LINESTRING(0 0,20 0,40 0)"));
p.x = 20; p.y = 0;
loc = ptarray_locate_point(line->points, &p, &dist, &l);
CU_ASSERT_EQUAL(loc, 0.5);
CU_ASSERT_EQUAL(dist, 0.0);
lwline_free(line);
line = lwgeom_as_lwline(lwgeom_from_text("LINESTRING(-40 0,0 0,20 0,40 0)"));
p.x = 20; p.y = 0;
loc = ptarray_locate_point(line->points, &p, &dist, &l);
CU_ASSERT_EQUAL(loc, 0.75);
CU_ASSERT_EQUAL(dist, 0.0);
lwline_free(line);
line = lwgeom_as_lwline(lwgeom_from_text("LINESTRING M (0 0 0, 10 0 20)"));
p.x = 5; p.y = 0;
loc = ptarray_locate_point(line->points, &p, &dist, &l);
CU_ASSERT_EQUAL(loc, 0.5);
CU_ASSERT_EQUAL(dist, 0.0);
CU_ASSERT_EQUAL(l.m, 10.0);
lwline_free(line);
}
Datum LWGEOM_line_locate_point(PG_FUNCTION_ARGS)
{
GSERIALIZED *geom1 = (GSERIALIZED *)PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
GSERIALIZED *geom2 = (GSERIALIZED *)PG_DETOAST_DATUM(PG_GETARG_DATUM(1));
LWLINE *lwline;
LWPOINT *lwpoint;
POINTARRAY *pa;
POINT2D p;
double ret;
if ( gserialized_get_type(geom1) != LINETYPE )
{
elog(ERROR,"line_locate_point: 1st arg isnt a line");
PG_RETURN_NULL();
}
if ( gserialized_get_type(geom2) != POINTTYPE )
{
elog(ERROR,"line_locate_point: 2st arg isnt a point");
PG_RETURN_NULL();
}
if ( gserialized_get_srid(geom1) != gserialized_get_srid(geom2) )
{
elog(ERROR, "Operation on two geometries with different SRIDs");
PG_RETURN_NULL();
}
lwline = lwgeom_as_lwline(lwgeom_from_gserialized(geom1));
lwpoint = lwgeom_as_lwpoint(lwgeom_from_gserialized(geom2));
pa = lwline->points;
lwpoint_getPoint2d_p(lwpoint, &p);
ret = ptarray_locate_point(pa, &p, NULL);
PG_RETURN_FLOAT8(ret);
}
int
lwline_split_by_point_to(const LWLINE* lwline_in, const LWPOINT* blade_in,
LWMLINE* v)
{
double loc, dist;
POINT4D pt, pt_projected;
POINTARRAY* pa1;
POINTARRAY* pa2;
double vstol; /* vertex snap tolerance */
/* Possible outcomes:
*
* 1. The point is not on the line or on the boundary
* -> Leave collection untouched, return 0
* 2. The point is on the boundary
* -> Push 1 element on the collection:
* o the original line
* -> Return 1
* 3. The point is in the line
* -> Push 2 elements on the collection:
* o start_point - cut_point
* o cut_point - last_point
* -> Return 2
*/
getPoint4d_p(blade_in->point, 0, &pt);
loc = ptarray_locate_point(lwline_in->points, &pt, &dist, &pt_projected);
/* lwnotice("Location: %g -- Distance: %g", loc, dist); */
if ( dist > 0 ) /* TODO: accept a tolerance ? */
{
/* No intersection */
return 0;
}
if ( loc == 0 || loc == 1 )
{
/* Intersection is on the boundary */
return 1;
}
/* There is a real intersection, let's get two substrings */
/* Compute vertex snap tolerance based on line length
* TODO: take as parameter ? */
vstol = ptarray_length_2d(lwline_in->points) / 1e14;
pa1 = ptarray_substring(lwline_in->points, 0, loc, vstol);
pa2 = ptarray_substring(lwline_in->points, loc, 1, vstol);
/* NOTE: I've seen empty pointarrays with loc != 0 and loc != 1 */
if ( pa1->npoints == 0 || pa2->npoints == 0 ) {
ptarray_free(pa1);
ptarray_free(pa2);
/* Intersection is on the boundary */
return 1;
}
lwmline_add_lwline(v, lwline_construct(SRID_UNKNOWN, NULL, pa1));
lwmline_add_lwline(v, lwline_construct(SRID_UNKNOWN, NULL, pa2));
return 2;
}
