C++ (Cpp) lwmline_as_lwgeom Examples

Example #1

File: lwlinearreferencing.c Project: gravitystorm/postgis

static LWMPOINT*
lwmline_locate_along(const LWMLINE *lwmline, double m, double offset)
{
	LWMPOINT *lwmpoint = NULL;
	LWGEOM *lwg = lwmline_as_lwgeom(lwmline);
	int i, j;

	/* Return degenerates upwards */
	if ( (!lwmline) || (lwmline->ngeoms < 1) ) return NULL;

	/* Construct return */
	lwmpoint = lwmpoint_construct_empty(lwgeom_get_srid(lwg), lwgeom_has_z(lwg), lwgeom_has_m(lwg));

	/* Locate along each sub-line */
	for ( i = 0; i < lwmline->ngeoms; i++ )
	{
		LWMPOINT *along = lwline_locate_along(lwmline->geoms[i], m, offset);
		if ( along != NULL ) 
		{
			for ( j = 0; j < along->ngeoms; j++ ) 
			{
				lwmpoint_add_lwpoint(lwmpoint, along->geoms[i]);
			}
			/* Free the containing geometry, but leave the sub-geometries around */
			if ( along->bbox ) lwfree(along->bbox);
			lwfree(along);
		}
	}
	return lwmpoint;
}

Example #2

File: lwmline.c Project: gbroccolo/postgis

void
lwmline_release(LWMLINE *lwmline)
{
	lwgeom_release(lwmline_as_lwgeom(lwmline));
}

Example #3

File: lwlinearreferencing.c Project: gravitystorm/postgis

/**
* Clip an input MULTILINESTRING between two values, on any ordinate input.
*/
LWCOLLECTION*
lwmline_clip_to_ordinate_range(const LWMLINE *mline, char ordinate, double from, double to)
{
	LWCOLLECTION *lwgeom_out = NULL;

	if ( ! mline )
	{
		lwerror("Null input geometry.");
		return NULL;
	}

	if ( mline->ngeoms == 1)
	{
		lwgeom_out = lwline_clip_to_ordinate_range(mline->geoms[0], ordinate, from, to);
	}
	else
	{
		LWCOLLECTION *col;
		char hasz = lwgeom_has_z(lwmline_as_lwgeom(mline));
		char hasm = lwgeom_has_m(lwmline_as_lwgeom(mline));
		int i, j;
		char homogeneous = 1;
		size_t geoms_size = 0;
		lwgeom_out = lwcollection_construct_empty(MULTILINETYPE, mline->srid, hasz, hasm);
		FLAGS_SET_Z(lwgeom_out->flags, hasz);
		FLAGS_SET_M(lwgeom_out->flags, hasm);
		for ( i = 0; i < mline->ngeoms; i ++ )
		{
			col = lwline_clip_to_ordinate_range(mline->geoms[i], ordinate, from, to);
			if ( col )
			{
				/* Something was left after the clip. */
				if ( lwgeom_out->ngeoms + col->ngeoms > geoms_size )
				{
					geoms_size += 16;
					if ( lwgeom_out->geoms )
					{
						lwgeom_out->geoms = lwrealloc(lwgeom_out->geoms, geoms_size * sizeof(LWGEOM*));
					}
					else
					{
						lwgeom_out->geoms = lwalloc(geoms_size * sizeof(LWGEOM*));
					}
				}
				for ( j = 0; j < col->ngeoms; j++ )
				{
					lwgeom_out->geoms[lwgeom_out->ngeoms] = col->geoms[j];
					lwgeom_out->ngeoms++;
				}
				if ( col->type != mline->type )
				{
					homogeneous = 0;
				}
				/* Shallow free the struct, leaving the geoms behind. */
				if ( col->bbox ) lwfree(col->bbox);
				lwfree(col->geoms);
				lwfree(col);
			}
		}
		lwgeom_drop_bbox((LWGEOM*)lwgeom_out);
		lwgeom_add_bbox((LWGEOM*)lwgeom_out);
		if ( ! homogeneous )
		{
			lwgeom_out->type = COLLECTIONTYPE;
		}
	}

	if ( ! lwgeom_out || lwgeom_out->ngeoms == 0 ) /* Nothing left after clip. */
	{
		return NULL;
	}

	return lwgeom_out;

}