1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
/**********************************************************************
* $Id: CentroidLine.cpp,v 1.10 2004/07/08 19:34:49 strk Exp $
*
* GEOS - Geometry Engine Open Source
* http://geos.refractions.net
*
* Copyright (C) 2001-2002 Vivid Solutions Inc.
*
* This is free software; you can redistribute and/or modify it under
* the terms of the GNU Lesser General Public Licence as published
* by the Free Software Foundation.
* See the COPYING file for more information.
*
**********************************************************************
* $Log: CentroidLine.cpp,v $
* Revision 1.10 2004/07/08 19:34:49 strk
* Mirrored JTS interface of CoordinateSequence, factory and
* default implementations.
* Added DefaultCoordinateSequenceFactory::instance() function.
*
* Revision 1.9 2004/07/02 13:28:26 strk
* Fixed all #include lines to reflect headers layout change.
* Added client application build tips in README.
*
* Revision 1.8 2003/11/07 01:23:42 pramsey
* Add standard CVS headers licence notices and copyrights to all cpp and h
* files.
*
* Revision 1.7 2003/10/29 10:38:26 strk
* Added support for LinearRing types (treated as LineString)
*
* Revision 1.6 2003/10/16 08:50:00 strk
* Memory leak fixes. Improved performance by mean of more calls to
* new getCoordinatesRO() when applicable.
*
**********************************************************************/
#include <geos/geosAlgorithm.h>
#include <geos/platform.h>
#include <typeinfo>
namespace geos {
CentroidLine::CentroidLine() {
totalLength=0.0;
centSum=new Coordinate();
}
CentroidLine::~CentroidLine() {
delete centSum;
}
/**
* Adds the linestring(s) defined by a Geometry to the centroid total.
* If the geometry is not linear it does not contribute to the centroid
* @param geom the geometry to add
*/
void CentroidLine::add(const Geometry *geom) {
if (typeid(*geom)==typeid(LineString) || typeid(*geom)==typeid(LinearRing)) {
add(((LineString*)geom)->getCoordinatesRO());
} else if ((typeid(*geom)==typeid(GeometryCollection)) ||
(typeid(*geom)==typeid(MultiPoint)) ||
(typeid(*geom)==typeid(MultiPolygon)) ||
(typeid(*geom)==typeid(MultiLineString))) {
GeometryCollection *gc=(GeometryCollection*) geom;
for(int i=0;i<gc->getNumGeometries();i++) {
add(gc->getGeometryN(i));
}
}
}
/**
* Adds the length defined by an array of coordinates.
* @param pts an array of {@link Coordinate}s
*/
void CentroidLine::add(const CoordinateSequence *pts) {
for(int i=0;i<pts->getSize()-1;i++) {
double segmentLen=pts->getAt(i).distance(pts->getAt(i + 1));
totalLength+=segmentLen;
double midx=(pts->getAt(i).x+pts->getAt(i+1).x)/2;
centSum->x+=segmentLen*midx;
double midy=(pts->getAt(i).y+pts->getAt(i+1).y)/2;
centSum->y+=segmentLen*midy;
}
}
Coordinate* CentroidLine::getCentroid() const {
return new Coordinate(centSum->x/totalLength,centSum->y/totalLength);
}
}
|
