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OffsetSegmentString.h
1 /**********************************************************************
2 *
3 * GEOS - Geometry Engine Open Source
4 * http://geos.osgeo.org
5 *
6 * Copyright (C) 2011 Sandro Santilli <strk@keybit.net>
7 * Copyright (C) 2007 Refractions Research Inc.
8 *
9 * This is free software; you can redistribute and/or modify it under
10 * the terms of the GNU Lesser General Public Licence as published
11 * by the Free Software Foundation.
12 * See the COPYING file for more information.
13 *
14 **********************************************************************
15 *
16 * Last port: operation/buffer/OffsetSegmentString.java r378 (JTS-1.12)
17 *
18 **********************************************************************/
19
20 #ifndef GEOS_OP_BUFFER_OFFSETSEGMENTSTRING_H
21 #define GEOS_OP_BUFFER_OFFSETSEGMENTSTRING_H
22
23 #include <geos/geom/Coordinate.h> // for inlines
24 #include <geos/geom/CoordinateSequence.h> // for inlines
25 #include <geos/geom/CoordinateArraySequence.h> // for composition
26 #include <geos/geom/PrecisionModel.h> // for inlines
27
28 #include <vector>
29 #include <memory>
30 #include <cassert>
31
32 namespace geos {
33 namespace operation { // geos.operation
34 namespace buffer { // geos.operation.buffer
35
37 //
43 class OffsetSegmentString
44 {
45
46 private:
47
48 geom::CoordinateArraySequence* ptList;
49
50 const geom::PrecisionModel* precisionModel;
51
58 double minimumVertexDistance;
59
67 bool isRedundant(const geom::Coordinate& pt) const
68 {
69 if (ptList->size() < 1)
70 return false;
71 const geom::Coordinate& lastPt = ptList->back();
72 double ptDist = pt.distance(lastPt);
73 if (ptDist < minimumVertexDistance)
74 return true;
75 return false;
76 }
77
78
79 public:
80
81 friend std::ostream& operator<< (std::ostream& os, const OffsetSegmentString& node);
82
83 OffsetSegmentString()
84 :
85 ptList(new geom::CoordinateArraySequence()),
86 precisionModel(NULL),
87 minimumVertexDistance (0.0)
88 {
89 }
90
91 ~OffsetSegmentString()
92 {
93 delete ptList;
94 }
95
96 void reset()
97 {
98 if ( ptList ) ptList->clear();
99 else ptList = new geom::CoordinateArraySequence();
100
101 precisionModel = NULL;
102 minimumVertexDistance = 0.0;
103 }
104
105 void setPrecisionModel(const geom::PrecisionModel* nPrecisionModel)
106 {
107 precisionModel = nPrecisionModel;
108 }
109
110 void setMinimumVertexDistance(double nMinVertexDistance)
111 {
112 minimumVertexDistance = nMinVertexDistance;
113 }
114
115 void addPt(const geom::Coordinate& pt)
116 {
117 assert(precisionModel);
118
119 geom::Coordinate bufPt = pt;
120 precisionModel->makePrecise(bufPt);
121 // don't add duplicate (or near-duplicate) points
122 if (isRedundant(bufPt))
123 {
124 return;
125 }
126 // we ask to allow repeated as we checked this ourself
127 // (JTS uses a vector for ptList, not a CoordinateSequence,
128 // we should do the same)
129 ptList->add(bufPt, true);
130 }
131
132 void addPts(const geom::CoordinateSequence& pts, bool isForward)
133 {
134 if ( isForward ) {
135 for (size_t i=0, n=pts.size(); i<n; ++i) {
136 addPt(pts[i]);
137 }
138 } else {
139 for (size_t i=pts.size(); i>0; --i) {
140 addPt(pts[i-1]);
141 }
142 }
143 }
144
146 //
148 void closeRing()
149 {
150 if (ptList->size() < 1) return;
151 const geom::Coordinate& startPt = ptList->front();
152 const geom::Coordinate& lastPt = ptList->back();
153 if (startPt.equals(lastPt)) return;
154 // we ask to allow repeated as we checked this ourself
155 ptList->add(startPt, true);
156 }
157
159 //
166 geom::CoordinateSequence* getCoordinates()
167 {
168 closeRing();
169 geom::CoordinateSequence* ret = ptList;
170 ptList = 0;
171 return ret;
172 }
173
174 inline size_t size() const { return ptList ? ptList->size() : 0 ; }
175
176 };
177
178 inline std::ostream& operator<< (std::ostream& os,
179 const OffsetSegmentString& lst)
180 {
181 if ( lst.ptList )
182 {
183 os << *(lst.ptList);
184 }
185 else
186 {
187 os << "empty (consumed?)";
188 }
189 return os;
190 }
191
192 } // namespace geos.operation.buffer
193 } // namespace geos.operation
194 } // namespace geos
195
196
197 #endif // ndef GEOS_OP_BUFFER_OFFSETSEGMENTSTRING_H
198