1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>strategy::buffer::join_round</title> 5<link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../index.html" title="Chapter 1. Geometry"> 8<link rel="up" href="../strategies.html" title="Strategies"> 9<link rel="prev" href="strategy_area_geographic.html" title="strategy::area::geographic"> 10<link rel="next" href="strategy_buffer_join_miter.html" title="strategy::buffer::join_miter"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="strategy_area_geographic.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../strategies.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="strategy_buffer_join_miter.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="geometry.reference.strategies.strategy_buffer_join_round"></a><a class="link" href="strategy_buffer_join_round.html" title="strategy::buffer::join_round">strategy::buffer::join_round</a> 28</h4></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635671454480"></a><a class="indexterm" name="idm45635671453792"></a><a class="indexterm" name="idm45635671453104"></a> 31Let the buffer create rounded corners. 32 </p> 33<h6> 34<a name="geometry.reference.strategies.strategy_buffer_join_round.h0"></a> 35 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.description"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.description">Description</a> 36 </h6> 37<p> 38 This strategy can be used as JoinStrategy for the buffer algorithm. It 39 creates a rounded corners around each convex vertex. It can be applied 40 for (multi)linestrings and (multi)polygons. This strategy is only applicable 41 for Cartesian coordinate systems. 42 </p> 43<h6> 44<a name="geometry.reference.strategies.strategy_buffer_join_round.h1"></a> 45 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.synopsis"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.synopsis">Synopsis</a> 46 </h6> 47<p> 48</p> 49<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">join_round</span> 50<span class="special">{</span> 51 <span class="comment">// ...</span> 52<span class="special">};</span> 53</pre> 54<p> 55 </p> 56<h6> 57<a name="geometry.reference.strategies.strategy_buffer_join_round.h2"></a> 58 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.constructor_s_"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.constructor_s_">Constructor(s)</a> 59 </h6> 60<div class="informaltable"><table class="table"> 61<colgroup> 62<col> 63<col> 64<col> 65</colgroup> 66<thead><tr> 67<th> 68 <p> 69 Function 70 </p> 71 </th> 72<th> 73 <p> 74 Description 75 </p> 76 </th> 77<th> 78 <p> 79 Parameters 80 </p> 81 </th> 82</tr></thead> 83<tbody><tr> 84<td> 85 <p> 86</p> 87<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">join_round</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">points_per_circle</span> <span class="special">=</span> <span class="number">90</span><span class="special">)</span></pre> 88<p> 89 </p> 90 </td> 91<td> 92 <p> 93 Constructs the strategy. 94 </p> 95 </td> 96<td> 97 <p> 98 <span class="bold"><strong>std::size_t</strong></span>: <span class="emphasis"><em>points_per_circle</em></span>: 99 points which would be used for a full circle 100 </p> 101 </td> 102</tr></tbody> 103</table></div> 104<h6> 105<a name="geometry.reference.strategies.strategy_buffer_join_round.h3"></a> 106 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.header"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.header">Header</a> 107 </h6> 108<p> 109 <code class="computeroutput"><span class="preprocessor">#include</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">strategies</span><span class="special">/</span><span class="identifier">cartesian</span><span class="special">/</span><span class="identifier">buffer_join_round</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 110 </p> 111<h6> 112<a name="geometry.reference.strategies.strategy_buffer_join_round.h4"></a> 113 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.example"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.example">Example</a> 114 </h6> 115<p> 116 Shows how the join_round strategy can be used as a JoinStrategy to create 117 rounded corners 118 </p> 119<p> 120</p> 121<pre class="programlisting"><span class="preprocessor">#include</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">hpp</span><span class="special">></span> 122<span class="preprocessor">#include</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">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 123<span class="preprocessor">#include</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">geometries</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 124 125 126<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span> 127<span class="special">{</span> 128 <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"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">point</span><span class="special">;</span> 129 <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><span class="special"><</span><span class="identifier">point</span><span class="special">></span> <span class="identifier">polygon</span><span class="special">;</span> 130 131 <span class="comment">// Declare the join_round strategy with 72 points for a full circle</span> 132 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">join_round</span> <span class="identifier">join_strategy</span><span class="special">(</span><span class="number">72</span><span class="special">);</span> 133 134 <span class="comment">// Declare other strategies</span> 135 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">distance_symmetric</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="identifier">distance_strategy</span><span class="special">(</span><span class="number">1.0</span><span class="special">);</span> 136 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">end_flat</span> <span class="identifier">end_strategy</span><span class="special">;</span> 137 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">side_straight</span> <span class="identifier">side_strategy</span><span class="special">;</span> 138 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">strategy</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">::</span><span class="identifier">point_circle</span> <span class="identifier">point_strategy</span><span class="special">;</span> 139 140 <span class="comment">// Declare/fill a multi polygon</span> 141 <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">multi_polygon</span><span class="special"><</span><span class="identifier">polygon</span><span class="special">></span> <span class="identifier">mp</span><span class="special">;</span> 142 <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">"MULTIPOLYGON(((5 5,7 8,9 5,5 5)),((8 7,8 10,11 10,11 7,8 7)))"</span><span class="special">,</span> <span class="identifier">mp</span><span class="special">);</span> 143 144 <span class="comment">// Create the buffered geometry with rounded corners</span> 145 <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">multi_polygon</span><span class="special"><</span><span class="identifier">polygon</span><span class="special">></span> <span class="identifier">result</span><span class="special">;</span> 146 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">mp</span><span class="special">,</span> <span class="identifier">result</span><span class="special">,</span> 147 <span class="identifier">distance_strategy</span><span class="special">,</span> <span class="identifier">side_strategy</span><span class="special">,</span> 148 <span class="identifier">join_strategy</span><span class="special">,</span> <span class="identifier">end_strategy</span><span class="special">,</span> <span class="identifier">point_strategy</span><span class="special">);</span> 149 150 151 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 152<span class="special">}</span> 153</pre> 154<p> 155 </p> 156<h6> 157<a name="geometry.reference.strategies.strategy_buffer_join_round.h5"></a> 158 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.output"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.output">Output</a> 159 </h6> 160<p> 161 <span class="inlinemediaobject"><img src="../../../img/strategies/buffer_join_round.png" alt="buffer_join_round"></span> 162 </p> 163<h6> 164<a name="geometry.reference.strategies.strategy_buffer_join_round.h6"></a> 165 <span class="phrase"><a name="geometry.reference.strategies.strategy_buffer_join_round.see_also"></a></span><a class="link" href="strategy_buffer_join_round.html#geometry.reference.strategies.strategy_buffer_join_round.see_also">See 166 also</a> 167 </h6> 168<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 169<li class="listitem"> 170 <a class="link" href="../algorithms/buffer/buffer_7_with_strategies.html" title="buffer (with strategies)">buffer 171 (with strategies)</a> 172 </li> 173<li class="listitem"> 174 <a class="link" href="strategy_buffer_join_miter.html" title="strategy::buffer::join_miter">join_miter</a> 175 </li> 176</ul></div> 177</div> 178<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 179<td align="left"></td> 180<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 181 Wulkiewicz, Oracle and/or its affiliates<p> 182 Distributed under the Boost Software License, Version 1.0. (See accompanying 183 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>) 184 </p> 185</div></td> 186</tr></table> 187<hr> 188<div class="spirit-nav"> 189<a accesskey="p" href="strategy_area_geographic.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../strategies.html"><img src="../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="strategy_buffer_join_miter.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 190</div> 191</body> 192</html> 193
