GeographicLib: PolygonArea.cpp Source File (original) (raw)
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14 using namespace std;
15
16 template
17 int PolygonAreaT::transit(real lon1, real lon2) {
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27 return
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29 lon12 > 0 && ((lon1 < 0 && lon2 >= 0) ||
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31 (lon1 > 0 && lon2 == 0)) ? 1 :
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33 (lon12 < 0 && lon1 >= 0 && lon2 < 0 ? -1 : 0);
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40 }
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44 template
45 int PolygonAreaT::transitdirect(real lon1, real lon2) {
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59 return ( (lon2 >= 0 && lon2 < Math::td ? 0 : 1) -
60 (lon1 >= 0 && lon1 < Math::td ? 0 : 1) );
61 }
62
63 template
65 if (_num == 0) {
66 _lat0 = _lat1 = lat;
67 _lon0 = _lon1 = lon;
68 } else {
69 real s12, S12, t;
70 _earth.GenInverse(_lat1, _lon1, lat, lon, _mask,
71 s12, t, t, t, t, t, S12);
72 _perimetersum += s12;
73 if (!_polyline) {
74 _areasum += S12;
75 _crossings += transit(_lon1, lon);
76 }
77 _lat1 = lat; _lon1 = lon;
78 }
79 ++_num;
80 }
81
82 template
84 if (_num) {
85 real lat, lon, S12, t;
86 _earth.GenDirect(_lat1, _lon1, azi, false, s, _mask,
87 lat, lon, t, t, t, t, t, S12);
88 _perimetersum += s;
89 if (!_polyline) {
90 _areasum += S12;
91 _crossings += transitdirect(_lon1, lon);
92 }
93 _lat1 = lat; _lon1 = lon;
94 ++_num;
95 }
96 }
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98 template
100 real& perimeter, real& area) const
101 {
102 real s12, S12, t;
103 if (_num < 2) {
104 perimeter = 0;
105 if (!_polyline)
106 area = 0;
107 return _num;
108 }
109 if (_polyline) {
110 perimeter = _perimetersum();
111 return _num;
112 }
113 _earth.GenInverse(_lat1, _lon1, _lat0, _lon0, _mask,
114 s12, t, t, t, t, t, S12);
115 perimeter = _perimetersum(s12);
117 tempsum += S12;
118 int crossings = _crossings + transit(_lon1, _lon0);
119 AreaReduce(tempsum, crossings, reverse, sign);
120 area = real(0) + tempsum();
121 return _num;
122 }
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124 template
126 bool reverse, bool sign,
127 real& perimeter, real& area) const
128 {
129 if (_num == 0) {
130 perimeter = 0;
131 if (!_polyline)
132 area = 0;
133 return 1;
134 }
135 perimeter = _perimetersum();
136 real tempsum = _polyline ? 0 : _areasum();
137 int crossings = _crossings;
138 unsigned num = _num + 1;
139 for (int i = 0; i < (_polyline ? 1 : 2); ++i) {
140 real s12, S12, t;
141 _earth.GenInverse(i == 0 ? _lat1 : lat, i == 0 ? _lon1 : lon,
142 i != 0 ? _lat0 : lat, i != 0 ? _lon0 : lon,
143 _mask, s12, t, t, t, t, t, S12);
144 perimeter += s12;
145 if (!_polyline) {
146 tempsum += S12;
147 crossings += transit(i == 0 ? _lon1 : lon,
148 i != 0 ? _lon0 : lon);
149 }
150 }
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152 if (_polyline)
153 return num;
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155 AreaReduce(tempsum, crossings, reverse, sign);
156 area = real(0) + tempsum;
157 return num;
158 }
159
160 template
162 bool reverse, bool sign,
163 real& perimeter, real& area) const
164 {
165 if (_num == 0) {
167 if (!_polyline)
169 return 0;
170 }
171 unsigned num = _num + 1;
172 perimeter = _perimetersum() + s;
173 if (_polyline)
174 return num;
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176 real tempsum = _areasum();
177 int crossings = _crossings;
178 {
179 real lat, lon, s12, S12, t;
180 _earth.GenDirect(_lat1, _lon1, azi, false, s, _mask,
181 lat, lon, t, t, t, t, t, S12);
182 tempsum += S12;
183 crossings += transitdirect(_lon1, lon);
184 _earth.GenInverse(lat, lon, _lat0, _lon0, _mask,
185 s12, t, t, t, t, t, S12);
186 perimeter += s12;
187 tempsum += S12;
188 crossings += transit(lon, _lon0);
189 }
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191 AreaReduce(tempsum, crossings, reverse, sign);
192 area = real(0) + tempsum;
193 return num;
194 }
195
196 template
197 template
199 bool reverse, bool sign) const {
200 Remainder(area);
201 if (crossings & 1) area += (area < 0 ? 1 : -1) * _area0/2;
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204 if (!reverse) area *= -1;
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206 if (sign) {
207 if (area > _area0/2)
208 area -= _area0;
209 else if (area <= -_area0/2)
210 area += _area0;
211 } else {
212 if (area >= _area0)
213 area -= _area0;
214 else if (area < 0)
215 area += _area0;
216 }
217 }
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223}
#define GEOGRAPHICLIB_EXPORT
GeographicLib::Math::real real
Header for GeographicLib::PolygonAreaT class.
static T AngNormalize(T x)
static constexpr int td
degrees per turn
static T AngDiff(T x, T y, T &e)
void AddPoint(real lat, real lon)
Definition PolygonArea.cpp:64
unsigned Compute(bool reverse, bool sign, real &perimeter, real &area) const
Definition PolygonArea.cpp:99
unsigned TestPoint(real lat, real lon, bool reverse, bool sign, real &perimeter, real &area) const
Definition PolygonArea.cpp:125
void AddEdge(real azi, real s)
Definition PolygonArea.cpp:83
unsigned TestEdge(real azi, real s, bool reverse, bool sign, real &perimeter, real &area) const
Definition PolygonArea.cpp:161
Namespace for GeographicLib.