libs/geometry/doc/html/geometry/reference/algorithms/for_each/for_each_point.html


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<div class="titlepage"><div><div><h5 class="title">
<a name="geometry.reference.algorithms.for_each.for_each_point"></a><a class="link" href="for_each_point.html" title="for_each_point">for_each_point</a>
</h5></div></div></div>
<p>
            <a class="indexterm" name="idp116723440"></a>
Applies function <span class="bold"><strong>f</strong></span> to each point.
          </p>
<h6>
<a name="geometry.reference.algorithms.for_each.for_each_point.h0"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.for_each.for_each_point.description"></a></span><a class="link" href="for_each_point.html#geometry.reference.algorithms.for_each.for_each_point.description">Description</a>
          </h6>
<p>
            Applies a function <span class="bold"><strong>f</strong></span> (functor, having
            operator() defined) to each point making up the geometry
          </p>
<h6>
<a name="geometry.reference.algorithms.for_each.for_each_point.h1"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.for_each.for_each_point.synopsis"></a></span><a class="link" href="for_each_point.html#geometry.reference.algorithms.for_each.for_each_point.synopsis">Synopsis</a>
          </h6>
<p>
</p>
<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">,</span> <span class="keyword">typename</span> <span class="identifier">Functor</span><span class="special">&gt;</span>
<span class="identifier">Functor</span> <span class="identifier">for_each_point</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="special">&amp;</span> <span class="identifier">geometry</span><span class="special">,</span> <span class="identifier">Functor</span> <span class="identifier">f</span><span class="special">)</span></pre>
<p>
          </p>
<h6>
<a name="geometry.reference.algorithms.for_each.for_each_point.h2"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.for_each.for_each_point.parameters"></a></span><a class="link" href="for_each_point.html#geometry.reference.algorithms.for_each.for_each_point.parameters">Parameters</a>
          </h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                    <p>
                      Type
                    </p>
                  </th>
<th>
                    <p>
                      Concept
                    </p>
                  </th>
<th>
                    <p>
                      Name
                    </p>
                  </th>
<th>
                    <p>
                      Description
                    </p>
                  </th>
</tr></thead>
<tbody>
<tr>
<td>
                    <p>
                      Geometry &amp;
                    </p>
                  </td>
<td>
                    <p>
                      Any type fulfilling a Geometry Concept
                    </p>
                  </td>
<td>
                    <p>
                      geometry
                    </p>
                  </td>
<td>
                    <p>
                      A model of the specified concept
                    </p>
                  </td>
</tr>
<tr>
<td>
                    <p>
                      Functor
                    </p>
                  </td>
<td>
                    <p>
                      Function or class with operator()
                    </p>
                  </td>
<td>
                    <p>
                      f
                    </p>
                  </td>
<td>
                    <p>
                      Unary function, taking a point as argument
                    </p>
                  </td>
</tr>
</tbody>
</table></div>
<h6>
<a name="geometry.reference.algorithms.for_each.for_each_point.h3"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.for_each.for_each_point.header"></a></span><a class="link" href="for_each_point.html#geometry.reference.algorithms.for_each.for_each_point.header">Header</a>
          </h6>
<p>
            Either
          </p>
<p>
            <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>
          </p>
<p>
            Or
          </p>
<p>
            <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">for_each</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
          </p>
<h6>
<a name="geometry.reference.algorithms.for_each.for_each_point.h4"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.for_each.for_each_point.conformance"></a></span><a class="link" href="for_each_point.html#geometry.reference.algorithms.for_each.for_each_point.conformance">Conformance</a>
          </h6>
<p>
            The function for_each_point is not defined by OGC.
          </p>
<p>
            The function for_each_point conforms to the std::for_each function of
            the C++ std-library.
          </p>
<h6>
<a name="geometry.reference.algorithms.for_each.for_each_point.h5"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.for_each.for_each_point.example"></a></span><a class="link" href="for_each_point.html#geometry.reference.algorithms.for_each.for_each_point.example">Example</a>
          </h6>
<p>
            Convenient usage of for_each_point, rounding all points of a geometry
          </p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>

<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>
<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">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<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>


<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Point</span><span class="special">&gt;</span>
<span class="keyword">class</span> <span class="identifier">round_coordinates</span>
<span class="special">{</span>
<span class="keyword">private</span> <span class="special">:</span>
    <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">coordinate_type</span><span class="special">&lt;</span><span class="identifier">Point</span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">coordinate_type</span><span class="special">;</span>
    <span class="identifier">coordinate_type</span> <span class="identifier">factor</span><span class="special">;</span>

    <span class="keyword">inline</span> <span class="identifier">coordinate_type</span> <span class="identifier">round</span><span class="special">(</span><span class="identifier">coordinate_type</span> <span class="identifier">value</span><span class="special">)</span>
    <span class="special">{</span>
        <span class="keyword">return</span> <span class="identifier">floor</span><span class="special">(</span><span class="number">0.5</span> <span class="special">+</span> <span class="special">(</span><span class="identifier">value</span> <span class="special">/</span> <span class="identifier">factor</span><span class="special">))</span> <span class="special">*</span> <span class="identifier">factor</span><span class="special">;</span>
    <span class="special">}</span>

<span class="keyword">public</span> <span class="special">:</span>
    <span class="identifier">round_coordinates</span><span class="special">(</span><span class="identifier">coordinate_type</span> <span class="identifier">f</span><span class="special">)</span>
        <span class="special">:</span> <span class="identifier">factor</span><span class="special">(</span><span class="identifier">f</span><span class="special">)</span>
    <span class="special">{}</span>

    <span class="keyword">inline</span> <span class="keyword">void</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">Point</span><span class="special">&amp;</span> <span class="identifier">p</span><span class="special">)</span>
    <span class="special">{</span>
        <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">get</span><span class="special">;</span>
        <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">set</span><span class="special">;</span>
        <span class="identifier">set</span><span class="special">&lt;</span><span class="number">0</span><span class="special">&gt;(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">round</span><span class="special">(</span><span class="identifier">get</span><span class="special">&lt;</span><span class="number">0</span><span class="special">&gt;(</span><span class="identifier">p</span><span class="special">)));</span>
        <span class="identifier">set</span><span class="special">&lt;</span><span class="number">1</span><span class="special">&gt;(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">round</span><span class="special">(</span><span class="identifier">get</span><span class="special">&lt;</span><span class="number">1</span><span class="special">&gt;(</span><span class="identifier">p</span><span class="special">)));</span>
    <span class="special">}</span>
<span class="special">};</span>


<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <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">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;</span> <span class="identifier">point</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">model</span><span class="special">::</span><span class="identifier">polygon</span><span class="special">&lt;</span><span class="identifier">point</span><span class="special">&gt;</span> <span class="identifier">poly</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">read_wkt</span><span class="special">(</span><span class="string">"POLYGON((0 0,1.123 9.987,8.876 2.234,0 0),(3.345 4.456,7.654 8.765,9.123 5.432,3.345 4.456))"</span><span class="special">,</span> <span class="identifier">poly</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">for_each_point</span><span class="special">(</span><span class="identifier">poly</span><span class="special">,</span> <span class="identifier">round_coordinates</span><span class="special">&lt;</span><span class="identifier">point</span><span class="special">&gt;(</span><span class="number">0.1</span><span class="special">));</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Rounded: "</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">wkt</span><span class="special">(</span><span class="identifier">poly</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>
    <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
          </p>
<p>
            Output:
          </p>
<pre class="programlisting">Rounded: POLYGON((0 0,1.1 10,8.9 2.2,0 0),(3.3 4.5,7.7 8.8,9.1 5.4,3.3 4.5))
</pre>
<p>
            Sample using for_each_point, using a function to list coordinates
          </p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>

<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>
<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">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<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>


<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Point</span><span class="special">&gt;</span>
<span class="keyword">void</span> <span class="identifier">list_coordinates</span><span class="special">(</span><span class="identifier">Point</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">p</span><span class="special">)</span>
<span class="special">{</span>
    <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">get</span><span class="special">;</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"x = "</span> <span class="special">&lt;&lt;</span> <span class="identifier">get</span><span class="special">&lt;</span><span class="number">0</span><span class="special">&gt;(</span><span class="identifier">p</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="string">" y = "</span> <span class="special">&lt;&lt;</span> <span class="identifier">get</span><span class="special">&lt;</span><span class="number">1</span><span class="special">&gt;(</span><span class="identifier">p</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>
<span class="special">}</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <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">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;</span> <span class="identifier">point</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">model</span><span class="special">::</span><span class="identifier">polygon</span><span class="special">&lt;</span><span class="identifier">point</span><span class="special">&gt;</span> <span class="identifier">poly</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">read_wkt</span><span class="special">(</span><span class="string">"POLYGON((0 0,0 4,4 0,0 0))"</span><span class="special">,</span> <span class="identifier">poly</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">for_each_point</span><span class="special">(</span><span class="identifier">poly</span><span class="special">,</span> <span class="identifier">list_coordinates</span><span class="special">&lt;</span><span class="identifier">point</span><span class="special">&gt;);</span>
    <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
          </p>
<p>
            Output:
          </p>
<pre class="programlisting">x = 0 y = 0
x = 0 y = 4
x = 4 y = 0
x = 0 y = 0
</pre>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2009-2014 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam
      Wulkiewicz, Oracle and/or its affiliates<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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