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
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
/**********************************************************************
* $Id: CentroidArea.cpp 1986 2007-06-08 15:27:42Z mloskot $
*
* GEOS - Geometry Engine Open Source
* http://geos.refractions.net
*
* Copyright (C) 2001-2002 Vivid Solutions Inc.
* Copyright (C) 2006 Refractions Research 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.
*
**********************************************************************
*
**********************************************************************/
#include <geos/algorithm/CentroidArea.h>
#include <geos/algorithm/CGAlgorithms.h>
#include <geos/geom/Coordinate.h>
#include <geos/geom/CoordinateSequence.h>
#include <geos/geom/Geometry.h>
#include <geos/geom/GeometryCollection.h>
#include <geos/geom/LineString.h>
#include <geos/geom/Polygon.h>
#include <typeinfo>
using namespace geos::geom;
namespace geos {
namespace algorithm { // geos.algorithm
/*public*/
void
CentroidArea::add(const Geometry *geom)
{
if(const Polygon *poly=dynamic_cast<const Polygon*>(geom)) {
setBasePoint(poly->getExteriorRing()->getCoordinateN(0));
add(poly);
}
else if(const GeometryCollection *gc=dynamic_cast<const GeometryCollection*>(geom))
{
for(std::size_t i=0, n=gc->getNumGeometries(); i<n; ++i)
{
add(gc->getGeometryN(i));
}
}
}
/*public*/
void
CentroidArea::add(const CoordinateSequence *ring)
{
setBasePoint(ring->getAt(0));
addShell(ring);
}
Coordinate*
CentroidArea::getCentroid() const
{
Coordinate *cent = new Coordinate();
cent->x = cg3.x/3.0/areasum2;
cent->y = cg3.y/3.0/areasum2;
return cent;
}
bool
CentroidArea::getCentroid(Coordinate& ret) const
{
if ( areasum2 == 0.0 ) return false;
ret=Coordinate(cg3.x/3.0/areasum2, cg3.y/3.0/areasum2);
return true;
}
void
CentroidArea::setBasePoint(const Coordinate &newbasePt)
{
basePt=newbasePt;
}
void
CentroidArea::add(const Polygon *poly)
{
addShell(poly->getExteriorRing()->getCoordinatesRO());
for(size_t i=0, n=poly->getNumInteriorRing(); i<n; ++i)
{
addHole(poly->getInteriorRingN(i)->getCoordinatesRO());
}
}
void
CentroidArea::addShell(const CoordinateSequence *pts)
{
bool isPositiveArea=!CGAlgorithms::isCCW(pts);
std::size_t const n=pts->getSize()-1;
for(std::size_t i=0; i<n; ++i)
{
addTriangle(basePt, pts->getAt(i), pts->getAt(i+1), isPositiveArea);
}
}
void
CentroidArea::addHole(const CoordinateSequence *pts)
{
bool isPositiveArea=CGAlgorithms::isCCW(pts);
std::size_t const n=pts->getSize()-1;
for(std::size_t i=0; i<n; ++i)
{
addTriangle(basePt, pts->getAt(i), pts->getAt(i+1), isPositiveArea);
}
}
void
CentroidArea::addTriangle(const Coordinate &p0, const Coordinate &p1,
const Coordinate &p2, bool isPositiveArea)
{
double sign=(isPositiveArea)?1.0:-1.0;
centroid3(p0,p1,p2,triangleCent3);
double area2res=area2(p0,p1,p2);
cg3.x+=sign*area2res*triangleCent3.x;
cg3.y+=sign*area2res*triangleCent3.y;
areasum2+=sign*area2res;
}
/**
* Returns three times the centroid of the triangle p1-p2-p3.
* The factor of 3 is
* left in to permit division to be avoided until later.
*/
void
CentroidArea::centroid3(const Coordinate &p1, const Coordinate &p2,
const Coordinate &p3, Coordinate &c)
{
c.x=p1.x+p2.x+p3.x;
c.y=p1.y+p2.y+p3.y;
}
/**
* Returns twice the signed area of the triangle p1-p2-p3,
* positive if a,b,c are oriented ccw, and negative if cw.
*/
double
CentroidArea::area2(const Coordinate &p1, const Coordinate &p2, const Coordinate &p3)
{
return (p2.x-p1.x)*(p3.y-p1.y)-(p3.x-p1.x)*(p2.y-p1.y);
}
} // namespace geos.algorithm
} //namespace geos
/**********************************************************************
* $Log$
* Revision 1.24 2006/06/08 17:58:57 strk
* Polygon::getNumInteriorRing() return size_t, Polygon::interiorRingN() takes size_t.
*
* Revision 1.23 2006/04/07 09:54:28 strk
* Geometry::getNumGeometries() changed to return 'unsigned int'
* rather then 'int'
*
* Revision 1.22 2006/03/21 11:12:23 strk
* Cleanups: headers inclusion and Log section
*
* Revision 1.21 2006/03/09 16:46:45 strk
* geos::geom namespace definition, first pass at headers split
*
**********************************************************************/
|
