mirror of
https://git.osgeo.org/gitea/postgis/postgis
synced 2024-10-24 17:12:35 +00:00
bf2901b473
git-svn-id: http://svn.osgeo.org/postgis/trunk@12198 b70326c6-7e19-0410-871a-916f4a2858ee
116 lines
2.8 KiB
C
116 lines
2.8 KiB
C
/**********************************************************************
|
|
* $Id$
|
|
*
|
|
* PostGIS - Spatial Types for PostgreSQL
|
|
* http://postgis.net
|
|
* Copyright 2001-2006 Refractions Research Inc.
|
|
*
|
|
* This is free software; you can redistribute and/or modify it under
|
|
* the terms of the GNU General Public Licence. See the COPYING file.
|
|
*
|
|
**********************************************************************/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "liblwgeom_internal.h"
|
|
|
|
void
|
|
lwmline_release(LWMLINE *lwmline)
|
|
{
|
|
lwgeom_release(lwmline_as_lwgeom(lwmline));
|
|
}
|
|
|
|
LWMLINE *
|
|
lwmline_construct_empty(int srid, char hasz, char hasm)
|
|
{
|
|
LWMLINE *ret = (LWMLINE*)lwcollection_construct_empty(MULTILINETYPE, srid, hasz, hasm);
|
|
return ret;
|
|
}
|
|
|
|
|
|
|
|
LWMLINE* lwmline_add_lwline(LWMLINE *mobj, const LWLINE *obj)
|
|
{
|
|
return (LWMLINE*)lwcollection_add_lwgeom((LWCOLLECTION*)mobj, (LWGEOM*)obj);
|
|
}
|
|
|
|
/**
|
|
* Re-write the measure ordinate (or add one, if it isn't already there) interpolating
|
|
* the measure between the supplied start and end values.
|
|
*/
|
|
LWMLINE*
|
|
lwmline_measured_from_lwmline(const LWMLINE *lwmline, double m_start, double m_end)
|
|
{
|
|
int i = 0;
|
|
int hasm = 0, hasz = 0;
|
|
double length = 0.0, length_so_far = 0.0;
|
|
double m_range = m_end - m_start;
|
|
LWGEOM **geoms = NULL;
|
|
|
|
if ( lwmline->type != MULTILINETYPE )
|
|
{
|
|
lwerror("lwmline_measured_from_lmwline: only multiline types supported");
|
|
return NULL;
|
|
}
|
|
|
|
hasz = FLAGS_GET_Z(lwmline->flags);
|
|
hasm = 1;
|
|
|
|
/* Calculate the total length of the mline */
|
|
for ( i = 0; i < lwmline->ngeoms; i++ )
|
|
{
|
|
LWLINE *lwline = (LWLINE*)lwmline->geoms[i];
|
|
if ( lwline->points && lwline->points->npoints > 1 )
|
|
{
|
|
length += ptarray_length_2d(lwline->points);
|
|
}
|
|
}
|
|
|
|
if ( lwgeom_is_empty((LWGEOM*)lwmline) )
|
|
{
|
|
return (LWMLINE*)lwcollection_construct_empty(MULTILINETYPE, lwmline->srid, hasz, hasm);
|
|
}
|
|
|
|
geoms = lwalloc(sizeof(LWGEOM*) * lwmline->ngeoms);
|
|
|
|
for ( i = 0; i < lwmline->ngeoms; i++ )
|
|
{
|
|
double sub_m_start, sub_m_end;
|
|
double sub_length = 0.0;
|
|
LWLINE *lwline = (LWLINE*)lwmline->geoms[i];
|
|
|
|
if ( lwline->points && lwline->points->npoints > 1 )
|
|
{
|
|
sub_length = ptarray_length_2d(lwline->points);
|
|
}
|
|
|
|
sub_m_start = (m_start + m_range * length_so_far / length);
|
|
sub_m_end = (m_start + m_range * (length_so_far + sub_length) / length);
|
|
|
|
geoms[i] = (LWGEOM*)lwline_measured_from_lwline(lwline, sub_m_start, sub_m_end);
|
|
|
|
length_so_far += sub_length;
|
|
}
|
|
|
|
return (LWMLINE*)lwcollection_construct(lwmline->type, lwmline->srid, NULL, lwmline->ngeoms, geoms);
|
|
}
|
|
|
|
void lwmline_free(LWMLINE *mline)
|
|
{
|
|
int i;
|
|
if ( ! mline ) return;
|
|
|
|
if ( mline->bbox )
|
|
lwfree(mline->bbox);
|
|
|
|
for ( i = 0; i < mline->ngeoms; i++ )
|
|
if ( mline->geoms && mline->geoms[i] )
|
|
lwline_free(mline->geoms[i]);
|
|
|
|
if ( mline->geoms )
|
|
lwfree(mline->geoms);
|
|
|
|
lwfree(mline);
|
|
}
|