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<h1>qwt_clipper.cpp</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************</span>
21
<a name="l00002"></a>00002 <span class="comment"> * Qwt Widget Library</span>
22
<a name="l00003"></a>00003 <span class="comment"> * Copyright (C) 1997 Josef Wilgen</span>
23
<a name="l00004"></a>00004 <span class="comment"> * Copyright (C) 2002 Uwe Rathmann</span>
24
<a name="l00005"></a>00005 <span class="comment"> * </span>
25
<a name="l00006"></a>00006 <span class="comment"> * This library is free software; you can redistribute it and/or</span>
26
<a name="l00007"></a>00007 <span class="comment"> * modify it under the terms of the Qwt License, Version 1.0</span>
27
<a name="l00008"></a>00008 <span class="comment"> *****************************************************************************/</span>
28
<a name="l00009"></a>00009
29
<a name="l00010"></a>00010 <span class="preprocessor">#include <qrect.h></span>
30
<a name="l00011"></a>00011 <span class="preprocessor">#include "qwt_math.h"</span>
31
<a name="l00012"></a>00012 <span class="preprocessor">#include "qwt_clipper.h"</span>
32
<a name="l00013"></a>00013
33
<a name="l00014"></a>00014 <span class="keyword">static</span> <span class="keyword">inline</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> boundingRect(<span class="keyword">const</span> QwtPolygonF &polygon)
34
<a name="l00015"></a>00015 {
35
<a name="l00016"></a>00016 <span class="preprocessor">#if QT_VERSION < 0x040000</span>
36
<a name="l00017"></a>00017 <span class="preprocessor"></span> <span class="keywordflow">if</span> (polygon.isEmpty())
37
<a name="l00018"></a>00018 <span class="keywordflow">return</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a>(0, 0, 0, 0);
38
<a name="l00019"></a>00019
39
<a name="l00020"></a>00020 <span class="keyword">register</span> <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> *pd = polygon.data();
40
<a name="l00021"></a>00021
41
<a name="l00022"></a>00022 <span class="keywordtype">double</span> minx, maxx, miny, maxy;
42
<a name="l00023"></a>00023 minx = maxx = pd->x();
43
<a name="l00024"></a>00024 miny = maxy = pd->y();
44
<a name="l00025"></a>00025 pd++;
45
<a name="l00026"></a>00026
46
<a name="l00027"></a>00027 <span class="keywordflow">for</span> (uint i = 1; i < polygon.size(); i++, pd++)
47
<a name="l00028"></a>00028 {
48
<a name="l00029"></a>00029 <span class="keywordflow">if</span> (pd->x() < minx)
49
<a name="l00030"></a>00030 minx = pd->x();
50
<a name="l00031"></a>00031 <span class="keywordflow">else</span> <span class="keywordflow">if</span> (pd->x() > maxx)
51
<a name="l00032"></a>00032 maxx = pd->x();
52
<a name="l00033"></a>00033 <span class="keywordflow">if</span> (pd->y() < miny)
53
<a name="l00034"></a>00034 miny = pd->y();
54
<a name="l00035"></a>00035 <span class="keywordflow">else</span> <span class="keywordflow">if</span> (pd->y() > maxy)
55
<a name="l00036"></a>00036 maxy = pd->y();
56
<a name="l00037"></a>00037 }
57
<a name="l00038"></a>00038 <span class="keywordflow">return</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a>(minx, miny, maxx - minx, maxy - miny);
58
<a name="l00039"></a>00039 <span class="preprocessor">#else</span>
59
<a name="l00040"></a>00040 <span class="preprocessor"></span> <span class="keywordflow">return</span> polygon.boundingRect();
60
<a name="l00041"></a>00041 <span class="preprocessor">#endif</span>
61
<a name="l00042"></a>00042 <span class="preprocessor"></span>}
62
<a name="l00043"></a>00043
63
<a name="l00044"></a>00044 <span class="keyword">enum</span> Edge
64
<a name="l00045"></a>00045 {
65
<a name="l00046"></a>00046 Left,
66
<a name="l00047"></a>00047 Top,
67
<a name="l00048"></a>00048 Right,
68
<a name="l00049"></a>00049 Bottom,
69
<a name="l00050"></a>00050 NEdges
70
<a name="l00051"></a>00051 };
71
<a name="l00052"></a>00052
72
<a name="l00053"></a>00053 <span class="keyword">class </span>QwtPolygonClipper: <span class="keyword">public</span> QRect
73
<a name="l00054"></a>00054 {
74
<a name="l00055"></a>00055 <span class="keyword">public</span>:
75
<a name="l00056"></a>00056 QwtPolygonClipper(<span class="keyword">const</span> QRect &r);
76
<a name="l00057"></a>00057
77
<a name="l00058"></a>00058 QwtPolygon clipPolygon(<span class="keyword">const</span> QwtPolygon &) <span class="keyword">const</span>;
78
<a name="l00059"></a>00059
79
<a name="l00060"></a>00060 <span class="keyword">private</span>:
80
<a name="l00061"></a>00061 <span class="keywordtype">void</span> clipEdge(Edge, <span class="keyword">const</span> QwtPolygon &, QwtPolygon &) <span class="keyword">const</span>;
81
<a name="l00062"></a>00062 <span class="keywordtype">bool</span> insideEdge(<span class="keyword">const</span> QPoint &, Edge edge) <span class="keyword">const</span>;
82
<a name="l00063"></a>00063 QPoint intersectEdge(<span class="keyword">const</span> QPoint &p1,
83
<a name="l00064"></a>00064 <span class="keyword">const</span> QPoint &p2, Edge edge) <span class="keyword">const</span>;
84
<a name="l00065"></a>00065
85
<a name="l00066"></a>00066 <span class="keywordtype">void</span> addPoint(QwtPolygon &, uint pos, <span class="keyword">const</span> QPoint &point) <span class="keyword">const</span>;
86
<a name="l00067"></a>00067 };
87
<a name="l00068"></a>00068
88
<a name="l00069"></a>00069 <span class="keyword">class </span>QwtPolygonClipperF: <span class="keyword">public</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a>
89
<a name="l00070"></a>00070 {
90
<a name="l00071"></a>00071 <span class="keyword">public</span>:
91
<a name="l00072"></a>00072 QwtPolygonClipperF(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> &r);
92
<a name="l00073"></a>00073 QwtPolygonF clipPolygon(<span class="keyword">const</span> QwtPolygonF &) <span class="keyword">const</span>;
93
<a name="l00074"></a>00074
94
<a name="l00075"></a>00075 <span class="keyword">private</span>:
95
<a name="l00076"></a>00076 <span class="keywordtype">void</span> clipEdge(Edge, <span class="keyword">const</span> QwtPolygonF &, QwtPolygonF &) <span class="keyword">const</span>;
96
<a name="l00077"></a>00077 <span class="keywordtype">bool</span> insideEdge(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &, Edge edge) <span class="keyword">const</span>;
97
<a name="l00078"></a>00078 <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> intersectEdge(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &p1,
98
<a name="l00079"></a>00079 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &p2, Edge edge) <span class="keyword">const</span>;
99
<a name="l00080"></a>00080
100
<a name="l00081"></a>00081 <span class="keywordtype">void</span> addPoint(QwtPolygonF &, uint pos, <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &point) <span class="keyword">const</span>;
101
<a name="l00082"></a>00082 };
102
<a name="l00083"></a>00083
103
<a name="l00084"></a>00084 <span class="preprocessor">#if QT_VERSION >= 0x040000</span>
104
<a name="l00085"></a>00085 <span class="preprocessor"></span><span class="keyword">class </span>QwtCircleClipper: <span class="keyword">public</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a>
105
<a name="l00086"></a>00086 {
106
<a name="l00087"></a>00087 <span class="keyword">public</span>:
107
<a name="l00088"></a>00088 QwtCircleClipper(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> &r);
108
<a name="l00089"></a>00089 QwtArray<QwtDoubleInterval> clipCircle(
109
<a name="l00090"></a>00090 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &, <span class="keywordtype">double</span> radius) <span class="keyword">const</span>;
110
<a name="l00091"></a>00091
111
<a name="l00092"></a>00092 <span class="keyword">private</span>:
112
<a name="l00093"></a>00093 QList<QwtDoublePoint> cuttingPoints(
113
<a name="l00094"></a>00094 Edge, <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &pos, <span class="keywordtype">double</span> radius) <span class="keyword">const</span>;
114
<a name="l00095"></a>00095 <span class="keywordtype">double</span> toAngle(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &, <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &) <span class="keyword">const</span>;
115
<a name="l00096"></a>00096 };
116
<a name="l00097"></a>00097 <span class="preprocessor">#endif</span>
117
<a name="l00098"></a>00098 <span class="preprocessor"></span>
118
<a name="l00099"></a>00099 QwtPolygonClipper::QwtPolygonClipper(<span class="keyword">const</span> QRect &r):
119
<a name="l00100"></a>00100 QRect(r)
120
<a name="l00101"></a>00101 {
121
<a name="l00102"></a>00102 }
122
<a name="l00103"></a>00103
123
<a name="l00104"></a>00104 <span class="keyword">inline</span> <span class="keywordtype">void</span> QwtPolygonClipper::addPoint(
124
<a name="l00105"></a>00105 QwtPolygon &pa, uint pos, <span class="keyword">const</span> QPoint &point)<span class="keyword"> const</span>
125
<a name="l00106"></a>00106 <span class="keyword"></span>{
126
<a name="l00107"></a>00107 <span class="keywordflow">if</span> ( uint(pa.size()) <= pos )
127
<a name="l00108"></a>00108 pa.resize(pos + 5);
128
<a name="l00109"></a>00109
129
<a name="l00110"></a>00110 pa.setPoint(pos, point);
130
<a name="l00111"></a>00111 }
131
<a name="l00112"></a>00112
132
<a name="l00114"></a>00114 QwtPolygon QwtPolygonClipper::clipPolygon(<span class="keyword">const</span> QwtPolygon &pa)<span class="keyword"> const</span>
133
<a name="l00115"></a>00115 <span class="keyword"></span>{
134
<a name="l00116"></a>00116 <span class="keywordflow">if</span> ( contains( pa.boundingRect() ) )
135
<a name="l00117"></a>00117 <span class="keywordflow">return</span> pa;
136
<a name="l00118"></a>00118
137
<a name="l00119"></a>00119 QwtPolygon cpa(pa.size());
138
<a name="l00120"></a>00120
139
<a name="l00121"></a>00121 clipEdge((Edge)0, pa, cpa);
140
<a name="l00122"></a>00122
141
<a name="l00123"></a>00123 <span class="keywordflow">for</span> ( uint edge = 1; edge < NEdges; edge++ )
142
<a name="l00124"></a>00124 {
143
<a name="l00125"></a>00125 <span class="keyword">const</span> QwtPolygon rpa = cpa;
144
<a name="l00126"></a>00126 <span class="preprocessor">#if QT_VERSION < 0x040000</span>
145
<a name="l00127"></a>00127 <span class="preprocessor"></span> cpa.detach();
146
<a name="l00128"></a>00128 <span class="preprocessor">#endif</span>
147
<a name="l00129"></a>00129 <span class="preprocessor"></span> clipEdge((Edge)edge, rpa, cpa);
148
<a name="l00130"></a>00130 }
149
<a name="l00131"></a>00131
150
<a name="l00132"></a>00132 <span class="keywordflow">return</span> cpa;
151
<a name="l00133"></a>00133 }
152
<a name="l00134"></a>00134
153
<a name="l00135"></a>00135 <span class="keywordtype">bool</span> QwtPolygonClipper::insideEdge(<span class="keyword">const</span> QPoint &p, Edge edge)<span class="keyword"> const</span>
154
<a name="l00136"></a>00136 <span class="keyword"></span>{
155
<a name="l00137"></a>00137 <span class="keywordflow">switch</span>(edge)
156
<a name="l00138"></a>00138 {
157
<a name="l00139"></a>00139 <span class="keywordflow">case</span> Left:
158
<a name="l00140"></a>00140 <span class="keywordflow">return</span> p.x() > left();
159
<a name="l00141"></a>00141 <span class="keywordflow">case</span> Top:
160
<a name="l00142"></a>00142 <span class="keywordflow">return</span> p.y() > top();
161
<a name="l00143"></a>00143 <span class="keywordflow">case</span> Right:
162
<a name="l00144"></a>00144 <span class="keywordflow">return</span> p.x() < right();
163
<a name="l00145"></a>00145 <span class="keywordflow">case</span> Bottom:
164
<a name="l00146"></a>00146 <span class="keywordflow">return</span> p.y() < bottom();
165
<a name="l00147"></a>00147 <span class="keywordflow">default</span>:
166
<a name="l00148"></a>00148 <span class="keywordflow">break</span>;
167
<a name="l00149"></a>00149 }
168
<a name="l00150"></a>00150
169
<a name="l00151"></a>00151 <span class="keywordflow">return</span> <span class="keyword">false</span>;
170
<a name="l00152"></a>00152 }
171
<a name="l00153"></a>00153
172
<a name="l00154"></a>00154 QPoint QwtPolygonClipper::intersectEdge(<span class="keyword">const</span> QPoint &p1,
173
<a name="l00155"></a>00155 <span class="keyword">const</span> QPoint &p2, Edge edge )<span class="keyword"> const</span>
174
<a name="l00156"></a>00156 <span class="keyword"></span>{
175
<a name="l00157"></a>00157 <span class="keywordtype">int</span> x=0, y=0;
176
<a name="l00158"></a>00158 <span class="keywordtype">double</span> m = 0;
177
<a name="l00159"></a>00159
178
<a name="l00160"></a>00160 <span class="keyword">const</span> <span class="keywordtype">double</span> dy = p2.y() - p1.y();
179
<a name="l00161"></a>00161 <span class="keyword">const</span> <span class="keywordtype">double</span> dx = p2.x() - p1.x();
180
<a name="l00162"></a>00162
181
<a name="l00163"></a>00163 <span class="keywordflow">switch</span> ( edge )
182
<a name="l00164"></a>00164 {
183
<a name="l00165"></a>00165 <span class="keywordflow">case</span> Left:
184
<a name="l00166"></a>00166 x = left();
185
<a name="l00167"></a>00167 m = double(qwtAbs(p1.x() - x)) / qwtAbs(dx);
186
<a name="l00168"></a>00168 y = p1.y() + int(dy * m);
187
<a name="l00169"></a>00169 <span class="keywordflow">break</span>;
188
<a name="l00170"></a>00170 <span class="keywordflow">case</span> Top:
189
<a name="l00171"></a>00171 y = top();
190
<a name="l00172"></a>00172 m = double(qwtAbs(p1.y() - y)) / qwtAbs(dy);
191
<a name="l00173"></a>00173 x = p1.x() + int(dx * m);
192
<a name="l00174"></a>00174 <span class="keywordflow">break</span>;
193
<a name="l00175"></a>00175 <span class="keywordflow">case</span> Right:
194
<a name="l00176"></a>00176 x = right();
195
<a name="l00177"></a>00177 m = double(qwtAbs(p1.x() - x)) / qwtAbs(dx);
196
<a name="l00178"></a>00178 y = p1.y() + int(dy * m);
197
<a name="l00179"></a>00179 <span class="keywordflow">break</span>;
198
<a name="l00180"></a>00180 <span class="keywordflow">case</span> Bottom:
199
<a name="l00181"></a>00181 y = bottom();
200
<a name="l00182"></a>00182 m = double(qwtAbs(p1.y() - y)) / qwtAbs(dy);
201
<a name="l00183"></a>00183 x = p1.x() + int(dx * m);
202
<a name="l00184"></a>00184 <span class="keywordflow">break</span>;
203
<a name="l00185"></a>00185 <span class="keywordflow">default</span>:
204
<a name="l00186"></a>00186 <span class="keywordflow">break</span>;
205
<a name="l00187"></a>00187 }
206
<a name="l00188"></a>00188
207
<a name="l00189"></a>00189 <span class="keywordflow">return</span> QPoint(x,y);
208
<a name="l00190"></a>00190 }
209
<a name="l00191"></a>00191
210
<a name="l00192"></a>00192 <span class="keywordtype">void</span> QwtPolygonClipper::clipEdge(Edge edge,
211
<a name="l00193"></a>00193 <span class="keyword">const</span> QwtPolygon &pa, QwtPolygon &cpa)<span class="keyword"> const</span>
212
<a name="l00194"></a>00194 <span class="keyword"></span>{
213
<a name="l00195"></a>00195 <span class="keywordflow">if</span> ( pa.count() == 0 )
214
<a name="l00196"></a>00196 {
215
<a name="l00197"></a>00197 cpa.resize(0);
216
<a name="l00198"></a>00198 <span class="keywordflow">return</span>;
217
<a name="l00199"></a>00199 }
218
<a name="l00200"></a>00200
219
<a name="l00201"></a>00201 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> count = 0;
220
<a name="l00202"></a>00202
221
<a name="l00203"></a>00203 QPoint p1 = pa.point(0);
222
<a name="l00204"></a>00204 <span class="keywordflow">if</span> ( insideEdge(p1, edge) )
223
<a name="l00205"></a>00205 addPoint(cpa, count++, p1);
224
<a name="l00206"></a>00206
225
<a name="l00207"></a>00207 <span class="keyword">const</span> uint nPoints = pa.size();
226
<a name="l00208"></a>00208 <span class="keywordflow">for</span> ( uint i = 1; i < nPoints; i++ )
227
<a name="l00209"></a>00209 {
228
<a name="l00210"></a>00210 <span class="keyword">const</span> QPoint p2 = pa.point(i);
229
<a name="l00211"></a>00211 <span class="keywordflow">if</span> ( insideEdge(p2, edge) )
230
<a name="l00212"></a>00212 {
231
<a name="l00213"></a>00213 <span class="keywordflow">if</span> ( insideEdge(p1, edge) )
232
<a name="l00214"></a>00214 addPoint(cpa, count++, p2);
233
<a name="l00215"></a>00215 <span class="keywordflow">else</span>
234
<a name="l00216"></a>00216 {
235
<a name="l00217"></a>00217 addPoint(cpa, count++, intersectEdge(p1, p2, edge));
236
<a name="l00218"></a>00218 addPoint(cpa, count++, p2);
237
<a name="l00219"></a>00219 }
238
<a name="l00220"></a>00220 }
239
<a name="l00221"></a>00221 <span class="keywordflow">else</span>
240
<a name="l00222"></a>00222 {
241
<a name="l00223"></a>00223 <span class="keywordflow">if</span> ( insideEdge(p1, edge) )
242
<a name="l00224"></a>00224 addPoint(cpa, count++, intersectEdge(p1, p2, edge));
243
<a name="l00225"></a>00225 }
244
<a name="l00226"></a>00226 p1 = p2;
245
<a name="l00227"></a>00227 }
246
<a name="l00228"></a>00228 cpa.resize(count);
247
<a name="l00229"></a>00229 }
248
<a name="l00230"></a>00230
249
<a name="l00231"></a>00231 QwtPolygonClipperF::QwtPolygonClipperF(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> &r):
250
<a name="l00232"></a>00232 <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a>(r)
251
<a name="l00233"></a>00233 {
252
<a name="l00234"></a>00234 }
253
<a name="l00235"></a>00235
254
<a name="l00236"></a>00236 <span class="keyword">inline</span> <span class="keywordtype">void</span> QwtPolygonClipperF::addPoint(QwtPolygonF &pa, uint pos, <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &point)<span class="keyword"> const</span>
255
<a name="l00237"></a>00237 <span class="keyword"></span>{
256
<a name="l00238"></a>00238 <span class="keywordflow">if</span> ( uint(pa.size()) <= pos )
257
<a name="l00239"></a>00239 pa.resize(pos + 5);
258
<a name="l00240"></a>00240
259
<a name="l00241"></a>00241 pa[(int)pos] = point;
260
<a name="l00242"></a>00242 }
261
<a name="l00243"></a>00243
262
<a name="l00245"></a>00245 QwtPolygonF QwtPolygonClipperF::clipPolygon(<span class="keyword">const</span> QwtPolygonF &pa)<span class="keyword"> const</span>
263
<a name="l00246"></a>00246 <span class="keyword"></span>{
264
<a name="l00247"></a>00247 <span class="keywordflow">if</span> ( contains( ::boundingRect(pa) ) )
265
<a name="l00248"></a>00248 <span class="keywordflow">return</span> pa;
266
<a name="l00249"></a>00249
267
<a name="l00250"></a>00250 QwtPolygonF cpa(pa.size());
268
<a name="l00251"></a>00251
269
<a name="l00252"></a>00252 clipEdge((Edge)0, pa, cpa);
270
<a name="l00253"></a>00253
271
<a name="l00254"></a>00254 <span class="keywordflow">for</span> ( uint edge = 1; edge < NEdges; edge++ )
272
<a name="l00255"></a>00255 {
273
<a name="l00256"></a>00256 <span class="keyword">const</span> QwtPolygonF rpa = cpa;
274
<a name="l00257"></a>00257 <span class="preprocessor">#if QT_VERSION < 0x040000</span>
275
<a name="l00258"></a>00258 <span class="preprocessor"></span> cpa.detach();
276
<a name="l00259"></a>00259 <span class="preprocessor">#endif</span>
277
<a name="l00260"></a>00260 <span class="preprocessor"></span> clipEdge((Edge)edge, rpa, cpa);
278
<a name="l00261"></a>00261 }
279
<a name="l00262"></a>00262
280
<a name="l00263"></a>00263 <span class="keywordflow">return</span> cpa;
281
<a name="l00264"></a>00264 }
282
<a name="l00265"></a>00265
283
<a name="l00266"></a>00266 <span class="keywordtype">bool</span> QwtPolygonClipperF::insideEdge(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &p, Edge edge)<span class="keyword"> const</span>
284
<a name="l00267"></a>00267 <span class="keyword"></span>{
285
<a name="l00268"></a>00268 <span class="keywordflow">switch</span>(edge)
286
<a name="l00269"></a>00269 {
287
<a name="l00270"></a>00270 <span class="keywordflow">case</span> Left:
288
<a name="l00271"></a>00271 <span class="keywordflow">return</span> p.x() > left();
289
<a name="l00272"></a>00272 <span class="keywordflow">case</span> Top:
290
<a name="l00273"></a>00273 <span class="keywordflow">return</span> p.y() > top();
291
<a name="l00274"></a>00274 <span class="keywordflow">case</span> Right:
292
<a name="l00275"></a>00275 <span class="keywordflow">return</span> p.x() < right();
293
<a name="l00276"></a>00276 <span class="keywordflow">case</span> Bottom:
294
<a name="l00277"></a>00277 <span class="keywordflow">return</span> p.y() < bottom();
295
<a name="l00278"></a>00278 <span class="keywordflow">default</span>:
296
<a name="l00279"></a>00279 <span class="keywordflow">break</span>;
297
<a name="l00280"></a>00280 }
298
<a name="l00281"></a>00281
299
<a name="l00282"></a>00282 <span class="keywordflow">return</span> <span class="keyword">false</span>;
300
<a name="l00283"></a>00283 }
301
<a name="l00284"></a>00284
302
<a name="l00285"></a>00285 <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> QwtPolygonClipperF::intersectEdge(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &p1,
303
<a name="l00286"></a>00286 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &p2, Edge edge )<span class="keyword"> const</span>
304
<a name="l00287"></a>00287 <span class="keyword"></span>{
305
<a name="l00288"></a>00288 <span class="keywordtype">double</span> x=0.0, y=0.0;
306
<a name="l00289"></a>00289 <span class="keywordtype">double</span> m = 0;
307
<a name="l00290"></a>00290
308
<a name="l00291"></a>00291 <span class="keyword">const</span> <span class="keywordtype">double</span> dy = p2.y() - p1.y();
309
<a name="l00292"></a>00292 <span class="keyword">const</span> <span class="keywordtype">double</span> dx = p2.x() - p1.x();
310
<a name="l00293"></a>00293
311
<a name="l00294"></a>00294 <span class="keywordflow">switch</span> ( edge )
312
<a name="l00295"></a>00295 {
313
<a name="l00296"></a>00296 <span class="keywordflow">case</span> Left:
314
<a name="l00297"></a>00297 x = left();
315
<a name="l00298"></a>00298 m = double(qwtAbs(p1.x() - x)) / qwtAbs(dx);
316
<a name="l00299"></a>00299 y = p1.y() + int(dy * m);
317
<a name="l00300"></a>00300 <span class="keywordflow">break</span>;
318
<a name="l00301"></a>00301 <span class="keywordflow">case</span> Top:
319
<a name="l00302"></a>00302 y = top();
320
<a name="l00303"></a>00303 m = double(qwtAbs(p1.y() - y)) / qwtAbs(dy);
321
<a name="l00304"></a>00304 x = p1.x() + int(dx * m);
322
<a name="l00305"></a>00305 <span class="keywordflow">break</span>;
323
<a name="l00306"></a>00306 <span class="keywordflow">case</span> Right:
324
<a name="l00307"></a>00307 x = right();
325
<a name="l00308"></a>00308 m = double(qwtAbs(p1.x() - x)) / qwtAbs(dx);
326
<a name="l00309"></a>00309 y = p1.y() + int(dy * m);
327
<a name="l00310"></a>00310 <span class="keywordflow">break</span>;
328
<a name="l00311"></a>00311 <span class="keywordflow">case</span> Bottom:
329
<a name="l00312"></a>00312 y = bottom();
330
<a name="l00313"></a>00313 m = double(qwtAbs(p1.y() - y)) / qwtAbs(dy);
331
<a name="l00314"></a>00314 x = p1.x() + int(dx * m);
332
<a name="l00315"></a>00315 <span class="keywordflow">break</span>;
333
<a name="l00316"></a>00316 <span class="keywordflow">default</span>:
334
<a name="l00317"></a>00317 <span class="keywordflow">break</span>;
335
<a name="l00318"></a>00318 }
336
<a name="l00319"></a>00319
337
<a name="l00320"></a>00320 <span class="keywordflow">return</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a>(x,y);
338
<a name="l00321"></a>00321 }
339
<a name="l00322"></a>00322
340
<a name="l00323"></a>00323 <span class="keywordtype">void</span> QwtPolygonClipperF::clipEdge(Edge edge,
341
<a name="l00324"></a>00324 <span class="keyword">const</span> QwtPolygonF &pa, QwtPolygonF &cpa)<span class="keyword"> const</span>
342
<a name="l00325"></a>00325 <span class="keyword"></span>{
343
<a name="l00326"></a>00326 <span class="keywordflow">if</span> ( pa.count() == 0 )
344
<a name="l00327"></a>00327 {
345
<a name="l00328"></a>00328 cpa.resize(0);
346
<a name="l00329"></a>00329 <span class="keywordflow">return</span>;
347
<a name="l00330"></a>00330 }
348
<a name="l00331"></a>00331
349
<a name="l00332"></a>00332 <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> count = 0;
350
<a name="l00333"></a>00333
351
<a name="l00334"></a>00334 <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> p1 = pa[0];
352
<a name="l00335"></a>00335 <span class="keywordflow">if</span> ( insideEdge(p1, edge) )
353
<a name="l00336"></a>00336 addPoint(cpa, count++, p1);
354
<a name="l00337"></a>00337
355
<a name="l00338"></a>00338 <span class="keyword">const</span> uint nPoints = pa.size();
356
<a name="l00339"></a>00339 <span class="keywordflow">for</span> ( uint i = 1; i < nPoints; i++ )
357
<a name="l00340"></a>00340 {
358
<a name="l00341"></a>00341 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> p2 = pa[(<span class="keywordtype">int</span>)i];
359
<a name="l00342"></a>00342 <span class="keywordflow">if</span> ( insideEdge(p2, edge) )
360
<a name="l00343"></a>00343 {
361
<a name="l00344"></a>00344 <span class="keywordflow">if</span> ( insideEdge(p1, edge) )
362
<a name="l00345"></a>00345 addPoint(cpa, count++, p2);
363
<a name="l00346"></a>00346 <span class="keywordflow">else</span>
364
<a name="l00347"></a>00347 {
365
<a name="l00348"></a>00348 addPoint(cpa, count++, intersectEdge(p1, p2, edge));
366
<a name="l00349"></a>00349 addPoint(cpa, count++, p2);
367
<a name="l00350"></a>00350 }
368
<a name="l00351"></a>00351 }
369
<a name="l00352"></a>00352 <span class="keywordflow">else</span>
370
<a name="l00353"></a>00353 {
371
<a name="l00354"></a>00354 <span class="keywordflow">if</span> ( insideEdge(p1, edge) )
372
<a name="l00355"></a>00355 addPoint(cpa, count++, intersectEdge(p1, p2, edge));
373
<a name="l00356"></a>00356 }
374
<a name="l00357"></a>00357 p1 = p2;
375
<a name="l00358"></a>00358 }
376
<a name="l00359"></a>00359 cpa.resize(count);
377
<a name="l00360"></a>00360 }
378
<a name="l00361"></a>00361
379
<a name="l00362"></a>00362 <span class="preprocessor">#if QT_VERSION >= 0x040000</span>
380
<a name="l00363"></a>00363 <span class="preprocessor"></span>
381
<a name="l00364"></a>00364 QwtCircleClipper::QwtCircleClipper(<span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> &r):
382
<a name="l00365"></a>00365 <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a>(r)
383
<a name="l00366"></a>00366 {
384
<a name="l00367"></a>00367 }
385
<a name="l00368"></a>00368
386
<a name="l00369"></a>00369 QwtArray<QwtDoubleInterval> QwtCircleClipper::clipCircle(
387
<a name="l00370"></a>00370 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &pos, <span class="keywordtype">double</span> radius)<span class="keyword"> const</span>
388
<a name="l00371"></a>00371 <span class="keyword"></span>{
389
<a name="l00372"></a>00372 QList<QwtDoublePoint> points;
390
<a name="l00373"></a>00373 <span class="keywordflow">for</span> ( <span class="keywordtype">int</span> edge = 0; edge < NEdges; edge++ )
391
<a name="l00374"></a>00374 points += cuttingPoints((Edge)edge, pos, radius);
392
<a name="l00375"></a>00375
393
<a name="l00376"></a>00376 QwtArray<QwtDoubleInterval> intv;
394
<a name="l00377"></a>00377 <span class="keywordflow">if</span> ( points.size() <= 0 )
395
<a name="l00378"></a>00378 {
396
<a name="l00379"></a>00379 <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> cRect(0, 0, 2 * radius, 2* radius);
397
<a name="l00380"></a>00380 cRect.moveCenter(pos);
398
<a name="l00381"></a>00381 <span class="keywordflow">if</span> ( contains(cRect) )
399
<a name="l00382"></a>00382 intv += <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a>(0.0, 2 * M_PI);
400
<a name="l00383"></a>00383 }
401
<a name="l00384"></a>00384 <span class="keywordflow">else</span>
402
<a name="l00385"></a>00385 {
403
<a name="l00386"></a>00386 QList<double> angles;
404
<a name="l00387"></a>00387 <span class="keywordflow">for</span> ( <span class="keywordtype">int</span> i = 0; i < points.size(); i++ )
405
<a name="l00388"></a>00388 angles += toAngle(pos, points[i]);
406
<a name="l00389"></a>00389 qSort(angles);
407
<a name="l00390"></a>00390
408
<a name="l00391"></a>00391 <span class="keyword">const</span> <span class="keywordtype">int</span> in = contains(qwtPolar2Pos(pos, radius,
409
<a name="l00392"></a>00392 angles[0] + (angles[1] - angles[0]) / 2));
410
<a name="l00393"></a>00393 <span class="keywordflow">if</span> ( in )
411
<a name="l00394"></a>00394 {
412
<a name="l00395"></a>00395 <span class="keywordflow">for</span> ( <span class="keywordtype">int</span> i = 0; i < angles.size() - 1; i += 2)
413
<a name="l00396"></a>00396 intv += <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a>(angles[i], angles[i+1]);
414
<a name="l00397"></a>00397 }
415
<a name="l00398"></a>00398 <span class="keywordflow">else</span>
416
<a name="l00399"></a>00399 {
417
<a name="l00400"></a>00400 <span class="keywordflow">for</span> ( <span class="keywordtype">int</span> i = 1; i < angles.size() - 1; i += 2)
418
<a name="l00401"></a>00401 intv += <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a>(angles[i], angles[i+1]);
419
<a name="l00402"></a>00402 intv += <a class="code" href="class_qwt_double_interval.html">QwtDoubleInterval</a>(angles.last(), angles.first());
420
<a name="l00403"></a>00403 }
421
<a name="l00404"></a>00404 }
422
<a name="l00405"></a>00405
423
<a name="l00406"></a>00406 <span class="keywordflow">return</span> intv;
424
<a name="l00407"></a>00407 }
425
<a name="l00408"></a>00408
426
<a name="l00409"></a>00409 <span class="keywordtype">double</span> QwtCircleClipper::toAngle(
427
<a name="l00410"></a>00410 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &from, <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &to)<span class="keyword"> const</span>
428
<a name="l00411"></a>00411 <span class="keyword"></span>{
429
<a name="l00412"></a>00412 <span class="keywordflow">if</span> ( from.x() == to.x() )
430
<a name="l00413"></a>00413 <span class="keywordflow">return</span> from.y() <= to.y() ? M_PI / 2.0 : 3 * M_PI / 2.0;
431
<a name="l00414"></a>00414
432
<a name="l00415"></a>00415 <span class="keyword">const</span> <span class="keywordtype">double</span> m = qwtAbs((to.y() - from.y()) / (to.x() - from.x()) );
433
<a name="l00416"></a>00416
434
<a name="l00417"></a>00417 <span class="keywordtype">double</span> angle = ::atan(m);
435
<a name="l00418"></a>00418 <span class="keywordflow">if</span> ( to.x() > from.x() )
436
<a name="l00419"></a>00419 {
437
<a name="l00420"></a>00420 <span class="keywordflow">if</span> ( to.y() > from.y() )
438
<a name="l00421"></a>00421 angle = 2 * M_PI - angle;
439
<a name="l00422"></a>00422 }
440
<a name="l00423"></a>00423 <span class="keywordflow">else</span>
441
<a name="l00424"></a>00424 {
442
<a name="l00425"></a>00425 <span class="keywordflow">if</span> ( to.y() > from.y() )
443
<a name="l00426"></a>00426 angle = M_PI + angle;
444
<a name="l00427"></a>00427 <span class="keywordflow">else</span>
445
<a name="l00428"></a>00428 angle = M_PI - angle;
446
<a name="l00429"></a>00429 }
447
<a name="l00430"></a>00430
448
<a name="l00431"></a>00431 <span class="keywordflow">return</span> angle;
449
<a name="l00432"></a>00432 }
450
<a name="l00433"></a>00433
451
<a name="l00434"></a>00434 QList<QwtDoublePoint> QwtCircleClipper::cuttingPoints(
452
<a name="l00435"></a>00435 Edge edge, <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &pos, <span class="keywordtype">double</span> radius)<span class="keyword"> const</span>
453
<a name="l00436"></a>00436 <span class="keyword"></span>{
454
<a name="l00437"></a>00437 QList<QwtDoublePoint> points;
455
<a name="l00438"></a>00438
456
<a name="l00439"></a>00439 <span class="keywordflow">if</span> ( edge == Left || edge == Right )
457
<a name="l00440"></a>00440 {
458
<a name="l00441"></a>00441 <span class="keyword">const</span> <span class="keywordtype">double</span> x = (edge == Left) ? left() : right();
459
<a name="l00442"></a>00442 <span class="keywordflow">if</span> ( qwtAbs(pos.x() - x) < radius )
460
<a name="l00443"></a>00443 {
461
<a name="l00444"></a>00444 <span class="keyword">const</span> <span class="keywordtype">double</span> off = ::sqrt(qwtSqr(radius) - qwtSqr(pos.x() - x));
462
<a name="l00445"></a>00445 <span class="keyword">const</span> <span class="keywordtype">double</span> y1 = pos.y() + off;
463
<a name="l00446"></a>00446 <span class="keywordflow">if</span> ( y1 >= top() && y1 <= bottom() )
464
<a name="l00447"></a>00447 points += <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a>(x, y1);
465
<a name="l00448"></a>00448 <span class="keyword">const</span> <span class="keywordtype">double</span> y2 = pos.y() - off;
466
<a name="l00449"></a>00449 <span class="keywordflow">if</span> ( y2 >= top() && y2 <= bottom() )
467
<a name="l00450"></a>00450 points += <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a>(x, y2);
468
<a name="l00451"></a>00451 }
469
<a name="l00452"></a>00452 }
470
<a name="l00453"></a>00453 <span class="keywordflow">else</span>
471
<a name="l00454"></a>00454 {
472
<a name="l00455"></a>00455 <span class="keyword">const</span> <span class="keywordtype">double</span> y = (edge == Top) ? top() : bottom();
473
<a name="l00456"></a>00456 <span class="keywordflow">if</span> ( qwtAbs(pos.y() - y) < radius )
474
<a name="l00457"></a>00457 {
475
<a name="l00458"></a>00458 <span class="keyword">const</span> <span class="keywordtype">double</span> off = ::sqrt(qwtSqr(radius) - qwtSqr(pos.y() - y));
476
<a name="l00459"></a>00459 <span class="keyword">const</span> <span class="keywordtype">double</span> x1 = pos.x() + off;
477
<a name="l00460"></a>00460 <span class="keywordflow">if</span> ( x1 >= left() && x1 <= right() )
478
<a name="l00461"></a>00461 points += <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a>(x1, y);
479
<a name="l00462"></a>00462 <span class="keyword">const</span> <span class="keywordtype">double</span> x2 = pos.x() - off;
480
<a name="l00463"></a>00463 <span class="keywordflow">if</span> ( x2 >= left() && x2 <= right() )
481
<a name="l00464"></a>00464 points += <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a>(x2, y);
482
<a name="l00465"></a>00465 }
483
<a name="l00466"></a>00466 }
484
<a name="l00467"></a>00467 <span class="keywordflow">return</span> points;
485
<a name="l00468"></a>00468 }
486
<a name="l00469"></a>00469 <span class="preprocessor">#endif</span>
487
<a name="l00470"></a>00470 <span class="preprocessor"></span>
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<a name="l00471"></a><a class="code" href="class_qwt_clipper.html#fa6c30e4e0fdc606ba4b99a4624cbff5">00471</a> QwtPolygon <a class="code" href="class_qwt_clipper.html#fa6c30e4e0fdc606ba4b99a4624cbff5">QwtClipper::clipPolygon</a>(
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<a name="l00472"></a>00472 <span class="keyword">const</span> QRect &clipRect, <span class="keyword">const</span> QwtPolygon &polygon)
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<a name="l00473"></a>00473 {
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<a name="l00474"></a>00474 QwtPolygonClipper clipper(clipRect);
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<a name="l00475"></a>00475 <span class="keywordflow">return</span> clipper.clipPolygon(polygon);
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<a name="l00476"></a>00476 }
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<a name="l00477"></a>00477
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<a name="l00478"></a><a class="code" href="class_qwt_clipper.html#ab22c9e2ad48386c3fe3c5d708bc14f6">00478</a> QwtPolygonF <a class="code" href="class_qwt_clipper.html#ab22c9e2ad48386c3fe3c5d708bc14f6">QwtClipper::clipPolygonF</a>(
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<a name="l00479"></a>00479 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> &clipRect, <span class="keyword">const</span> QwtPolygonF &polygon)
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<a name="l00480"></a>00480 {
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<a name="l00481"></a>00481 QwtPolygonClipperF clipper(clipRect);
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<a name="l00482"></a>00482 <span class="keywordflow">return</span> clipper.clipPolygon(polygon);
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<a name="l00483"></a>00483 }
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<a name="l00484"></a>00484
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<a name="l00485"></a>00485 <span class="preprocessor">#if QT_VERSION >= 0x040000</span>
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<a name="l00486"></a><a class="code" href="class_qwt_clipper.html#0687a8246c76cfd30702ff5408ddcec6">00486</a> <span class="preprocessor"></span>QwtArray<QwtDoubleInterval> <a class="code" href="class_qwt_clipper.html#0687a8246c76cfd30702ff5408ddcec6">QwtClipper::clipCircle</a>(
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<a name="l00487"></a>00487 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#0c0dc4d33592fac4ad94734d8e9c4152">QwtDoubleRect</a> &clipRect,
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<a name="l00488"></a>00488 <span class="keyword">const</span> <a class="code" href="qwt__double__rect_8h.html#5fdf5abc59b6e6cee5c11d355906927a">QwtDoublePoint</a> &center, <span class="keywordtype">double</span> radius)
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<a name="l00489"></a>00489 {
507
<a name="l00490"></a>00490 QwtCircleClipper clipper(clipRect);
508
<a name="l00491"></a>00491 <span class="keywordflow">return</span> clipper.clipCircle(center, radius);
509
<a name="l00492"></a>00492 }
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<a name="l00493"></a>00493 <span class="preprocessor">#endif</span>
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</pre></div><hr size="1"><address style="align: right;"><small>Generated on Sun Mar 22 16:54:06 2009 for Qwt User's Guide by
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<a href="http://www.doxygen.org/index.html">
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<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.0 </small></address>
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