libs/geometry/doc/html/geometry/reference/algorithms/correct.html

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  26 <div class="titlepage"><div><div><h4 class="title">
  27 <a name="geometry.reference.algorithms.correct"></a><a class="link" href="correct.html" title="correct">correct</a>
  28 </h4></div></div></div>
  29 <p>
  30           <a class="indexterm" name="idp91699120"></a>
  31 Corrects a geometry.
  32         </p>
  33 <h6>
  34 <a name="geometry.reference.algorithms.correct.h0"></a>
  35           <span class="phrase"><a name="geometry.reference.algorithms.correct.description"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.description">Description</a>
  36         </h6>
  37 <p>
  38           Corrects a geometry: all rings which are wrongly oriented with respect
  39           to their expected orientation are reversed. To all rings which do not have
  40           a closing point and are typed as they should have one, the first point
  41           is appended. Also boxes can be corrected.
  42         </p>
  43 <h6>
  44 <a name="geometry.reference.algorithms.correct.h1"></a>
  45           <span class="phrase"><a name="geometry.reference.algorithms.correct.synopsis"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.synopsis">Synopsis</a>
  46         </h6>
  47 <p>
  48 </p>
  49 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">&gt;</span>
  50 <span class="keyword">void</span> <span class="identifier">correct</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="special">&amp;</span> <span class="identifier">geometry</span><span class="special">)</span></pre>
  51 <p>
  52         </p>
  53 <h6>
  54 <a name="geometry.reference.algorithms.correct.h2"></a>
  55           <span class="phrase"><a name="geometry.reference.algorithms.correct.parameters"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.parameters">Parameters</a>
  56         </h6>
  57 <div class="informaltable"><table class="table">
  58 <colgroup>
  59 <col>
  60 <col>
  61 <col>
  62 <col>
  63 </colgroup>
  64 <thead><tr>
  65 <th>
  66                   <p>
  67                     Type
  68                   </p>
  69                 </th>
  70 <th>
  71                   <p>
  72                     Concept
  73                   </p>
  74                 </th>
  75 <th>
  76                   <p>
  77                     Name
  78                   </p>
  79                 </th>
  80 <th>
  81                   <p>
  82                     Description
  83                   </p>
  84                 </th>
  85 </tr></thead>
  86 <tbody><tr>
  87 <td>
  88                   <p>
  89                     Geometry &amp;
  90                   </p>
  91                 </td>
  92 <td>
  93                   <p>
  94                     Any type fulfilling a Geometry Concept
  95                   </p>
  96                 </td>
  97 <td>
  98                   <p>
  99                     geometry
 100                   </p>
 101                 </td>
 102 <td>
 103                   <p>
 104                     A model of the specified concept which will be corrected if necessary
 105                   </p>
 106                 </td>
 107 </tr></tbody>
 108 </table></div>
 109 <h6>
 110 <a name="geometry.reference.algorithms.correct.h3"></a>
 111           <span class="phrase"><a name="geometry.reference.algorithms.correct.header"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.header">Header</a>
 112         </h6>
 113 <p>
 114           Either
 115         </p>
 116 <p>
 117           <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
 118         </p>
 119 <p>
 120           Or
 121         </p>
 122 <p>
 123           <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">algorithms</span><span class="special">/</span><span class="identifier">correct</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
 124         </p>
 125 <h6>
 126 <a name="geometry.reference.algorithms.correct.h4"></a>
 127           <span class="phrase"><a name="geometry.reference.algorithms.correct.conformance"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.conformance">Conformance</a>
 128         </h6>
 129 <p>
 130           The function correct is not defined by OGC.
 131         </p>
 132 <h6>
 133 <a name="geometry.reference.algorithms.correct.h5"></a>
 134           <span class="phrase"><a name="geometry.reference.algorithms.correct.supported_geometries"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.supported_geometries">Supported
 135           geometries</a>
 136         </h6>
 137 <div class="informaltable"><table class="table">
 138 <colgroup>
 139 <col>
 140 <col>
 141 </colgroup>
 142 <thead><tr>
 143 <th>
 144                   <p>
 145                     Geometry
 146                   </p>
 147                 </th>
 148 <th>
 149                   <p>
 150                     Status
 151                   </p>
 152                 </th>
 153 </tr></thead>
 154 <tbody>
 155 <tr>
 156 <td>
 157                   <p>
 158                     Point
 159                   </p>
 160                 </td>
 161 <td>
 162                   <p>
 163                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 164                   </p>
 165                 </td>
 166 </tr>
 167 <tr>
 168 <td>
 169                   <p>
 170                     Segment
 171                   </p>
 172                 </td>
 173 <td>
 174                   <p>
 175                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 176                   </p>
 177                 </td>
 178 </tr>
 179 <tr>
 180 <td>
 181                   <p>
 182                     Box
 183                   </p>
 184                 </td>
 185 <td>
 186                   <p>
 187                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 188                   </p>
 189                 </td>
 190 </tr>
 191 <tr>
 192 <td>
 193                   <p>
 194                     Linestring
 195                   </p>
 196                 </td>
 197 <td>
 198                   <p>
 199                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 200                   </p>
 201                 </td>
 202 </tr>
 203 <tr>
 204 <td>
 205                   <p>
 206                     Ring
 207                   </p>
 208                 </td>
 209 <td>
 210                   <p>
 211                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 212                   </p>
 213                 </td>
 214 </tr>
 215 <tr>
 216 <td>
 217                   <p>
 218                     Polygon
 219                   </p>
 220                 </td>
 221 <td>
 222                   <p>
 223                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 224                   </p>
 225                 </td>
 226 </tr>
 227 <tr>
 228 <td>
 229                   <p>
 230                     MultiPoint
 231                   </p>
 232                 </td>
 233 <td>
 234                   <p>
 235                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 236                   </p>
 237                 </td>
 238 </tr>
 239 <tr>
 240 <td>
 241                   <p>
 242                     MultiLinestring
 243                   </p>
 244                 </td>
 245 <td>
 246                   <p>
 247                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 248                   </p>
 249                 </td>
 250 </tr>
 251 <tr>
 252 <td>
 253                   <p>
 254                     MultiPolygon
 255                   </p>
 256                 </td>
 257 <td>
 258                   <p>
 259                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 260                   </p>
 261                 </td>
 262 </tr>
 263 <tr>
 264 <td>
 265                   <p>
 266                     Variant
 267                   </p>
 268                 </td>
 269 <td>
 270                   <p>
 271                     <span class="inlinemediaobject"><img src="../../../img/ok.png" alt="ok"></span>
 272                   </p>
 273                 </td>
 274 </tr>
 275 </tbody>
 276 </table></div>
 277 <h6>
 278 <a name="geometry.reference.algorithms.correct.h6"></a>
 279           <span class="phrase"><a name="geometry.reference.algorithms.correct.behavior"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.behavior">Behavior</a>
 280         </h6>
 281 <div class="informaltable"><table class="table">
 282 <colgroup>
 283 <col>
 284 <col>
 285 </colgroup>
 286 <thead><tr>
 287 <th>
 288                   <p>
 289                     Case
 290                   </p>
 291                 </th>
 292 <th>
 293                   <p>
 294                     Behavior
 295                   </p>
 296                 </th>
 297 </tr></thead>
 298 <tbody>
 299 <tr>
 300 <td>
 301                   <p>
 302                     Ring
 303                   </p>
 304                 </td>
 305 <td>
 306                   <p>
 307                     Ring is corrected
 308                   </p>
 309                 </td>
 310 </tr>
 311 <tr>
 312 <td>
 313                   <p>
 314                     Polygon
 315                   </p>
 316                 </td>
 317 <td>
 318                   <p>
 319                     Polygon is corrected
 320                   </p>
 321                 </td>
 322 </tr>
 323 <tr>
 324 <td>
 325                   <p>
 326                     Multi Polygon
 327                   </p>
 328                 </td>
 329 <td>
 330                   <p>
 331                     Multi Polygon is corrected
 332                   </p>
 333                 </td>
 334 </tr>
 335 <tr>
 336 <td>
 337                   <p>
 338                     Box
 339                   </p>
 340                 </td>
 341 <td>
 342                   <p>
 343                     Box is corrected with respect to minimal and maximal corners
 344                   </p>
 345                 </td>
 346 </tr>
 347 <tr>
 348 <td>
 349                   <p>
 350                     Other geometries
 351                   </p>
 352                 </td>
 353 <td>
 354                   <p>
 355                     Nothing happens, geometry is unchanged
 356                   </p>
 357                 </td>
 358 </tr>
 359 </tbody>
 360 </table></div>
 361 <h6>
 362 <a name="geometry.reference.algorithms.correct.h7"></a>
 363           <span class="phrase"><a name="geometry.reference.algorithms.correct.complexity"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.complexity">Complexity</a>
 364         </h6>
 365 <p>
 366           Linear
 367         </p>
 368 <h6>
 369 <a name="geometry.reference.algorithms.correct.h8"></a>
 370           <span class="phrase"><a name="geometry.reference.algorithms.correct.example"></a></span><a class="link" href="correct.html#geometry.reference.algorithms.correct.example">Example</a>
 371         </h6>
 372 <p>
 373           Shows how to correct a polygon with respect to its orientation and closure
 374         </p>
 375 <p>
 376 </p>
 377 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>
 378
 379 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 380 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 381 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">adapted</span><span class="special">/</span><span class="identifier">boost_tuple</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 382
 383 <span class="identifier">BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS</span><span class="special">(</span><span class="identifier">cs</span><span class="special">::</span><span class="identifier">cartesian</span><span class="special">)</span>
 384
 385 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">assign</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 386
 387 <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
 388 <span class="special">{</span>
 389     <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">assign</span><span class="special">::</span><span class="identifier">tuple_list_of</span><span class="special">;</span>
 390
 391     <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">polygon</span>
 392         <span class="special">&lt;</span>
 393             <span class="identifier">boost</span><span class="special">::</span><span class="identifier">tuple</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">&gt;</span>
 394         <span class="special">&gt;</span> <span class="identifier">clockwise_closed_polygon</span><span class="special">;</span>
 395
 396     <span class="identifier">clockwise_closed_polygon</span> <span class="identifier">cwcp</span><span class="special">;</span>
 397
 398     <span class="comment">// Fill it counterclockwise (so wrongly), forgetting the closing point</span>
 399     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">exterior_ring</span><span class="special">(</span><span class="identifier">cwcp</span><span class="special">)</span> <span class="special">=</span> <span class="identifier">tuple_list_of</span><span class="special">(</span><span class="number">0</span><span class="special">,</span> <span class="number">0</span><span class="special">)(</span><span class="number">10</span><span class="special">,</span> <span class="number">10</span><span class="special">)(</span><span class="number">0</span><span class="special">,</span> <span class="number">9</span><span class="special">);</span>
 400
 401     <span class="comment">// Add a counterclockwise closed inner ring (this is correct)</span>
 402     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">interior_rings</span><span class="special">(</span><span class="identifier">cwcp</span><span class="special">).</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">tuple_list_of</span><span class="special">(</span><span class="number">1</span><span class="special">,</span> <span class="number">2</span><span class="special">)(</span><span class="number">4</span><span class="special">,</span> <span class="number">6</span><span class="special">)(</span><span class="number">2</span><span class="special">,</span> <span class="number">8</span><span class="special">)(</span><span class="number">1</span><span class="special">,</span> <span class="number">2</span><span class="special">));</span>
 403
 404     <span class="comment">// Its area should be negative (because of wrong orientation)</span>
 405     <span class="comment">//     and wrong (because of omitted closing point)</span>
 406     <span class="keyword">double</span> <span class="identifier">area_before</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">area</span><span class="special">(</span><span class="identifier">cwcp</span><span class="special">);</span>
 407
 408     <span class="comment">// Correct it!</span>
 409     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">correct</span><span class="special">(</span><span class="identifier">cwcp</span><span class="special">);</span>
 410
 411     <span class="comment">// Check its new area</span>
 412     <span class="keyword">double</span> <span class="identifier">area_after</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">area</span><span class="special">(</span><span class="identifier">cwcp</span><span class="special">);</span>
 413
 414     <span class="comment">// And output it</span>
 415     <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">dsv</span><span class="special">(</span><span class="identifier">cwcp</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
 416     <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="identifier">area_before</span> <span class="special">&lt;&lt;</span> <span class="string">" -&gt; "</span> <span class="special">&lt;&lt;</span> <span class="identifier">area_after</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
 417
 418     <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
 419 <span class="special">}</span>
 420 </pre>
 421 <p>
 422         </p>
 423 <p>
 424           Output:
 425         </p>
 426 <pre class="programlisting">(((0, 0), (0, 9), (10, 10), (0, 0)), ((1, 2), (4, 6), (2, 8), (1, 2)))
 427 -7 -&gt; 38
 428 </pre>
 429 </div>
 430 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 431 <td align="left"></td>
 432 <td align="right"><div class="copyright-footer">Copyright &#169; 2009-2017 Barend
 433       Gehrels, Bruno Lalande, Mateusz Loskot, Adam Wulkiewicz, Oracle and/or its
 434       affiliates<p>
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