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| <div class="titlepage"><div><div><h4 class="title"> |
| <a name="geometry.reference.concepts.concept_point"></a><a class="link" href="concept_point.html" title="Point Concept">Point Concept</a> |
| </h4></div></div></div> |
| <h6> |
| <a name="geometry.reference.concepts.concept_point.h0"></a> |
| <span class="phrase"><a name="geometry.reference.concepts.concept_point.description"></a></span><a class="link" href="concept_point.html#geometry.reference.concepts.concept_point.description">Description</a> |
| </h6> |
| <p> |
| The Point Concept describes the requirements for a point type. All algorithms |
| in Boost.Geometry will check any geometry arguments against the concept |
| requirements. |
| </p> |
| <p> |
| A point is <span class="emphasis"><em>an entity that has a location in space or on a plane, |
| but has no extent</em></span> (<a href="http://en.wikipedia.org/wiki/Point_(geometry)" target="_top">wiki</a>). |
| The point is the most basic geometry of Boost.Geometry, most other geometries |
| consist of points. <span class="emphasis"><em>(Exceptions are box and segment, which might |
| consist of two points but that is not necessarily the case.)</em></span> |
| </p> |
| <h6> |
| <a name="geometry.reference.concepts.concept_point.h1"></a> |
| <span class="phrase"><a name="geometry.reference.concepts.concept_point.concept_definition"></a></span><a class="link" href="concept_point.html#geometry.reference.concepts.concept_point.concept_definition">Concept |
| Definition</a> |
| </h6> |
| <p> |
| The Point Concept is defined as following: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> |
| <li class="listitem"> |
| there must be a specialization of <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">tag</span></code>, |
| defining <code class="computeroutput"><span class="identifier">point_tag</span></code> |
| as type |
| </li> |
| <li class="listitem"> |
| there must be a specialization of <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">coordinate_type</span></code>, |
| defining the type of its coordinates |
| </li> |
| <li class="listitem"> |
| there must be a specialization of <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">coordinate_system</span></code>, |
| defining its coordinate system (cartesian, spherical, etc) |
| </li> |
| <li class="listitem"> |
| there must be a specialization of <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">dimension</span></code>, |
| defining its number of dimensions (2, 3, ...) (hint: derive it conveniently |
| from <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span><span class="special"><</span><span class="identifier">X</span><span class="special">></span></code> |
| for X Dimensional) |
| </li> |
| <li class="listitem"> |
| there must be a specialization of <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">access</span></code>, |
| per dimension, with two functions: |
| <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; "> |
| <li class="listitem"> |
| <code class="computeroutput"><span class="identifier">get</span></code> to get a |
| coordinate value |
| </li> |
| <li class="listitem"> |
| <code class="computeroutput"><span class="identifier">set</span></code> to set a |
| coordinate value (this one is not checked for ConstPoint) |
| </li> |
| </ul></div> |
| </li> |
| </ul></div> |
| <h6> |
| <a name="geometry.reference.concepts.concept_point.h2"></a> |
| <span class="phrase"><a name="geometry.reference.concepts.concept_point.available_models"></a></span><a class="link" href="concept_point.html#geometry.reference.concepts.concept_point.available_models">Available |
| Models</a> |
| </h6> |
| <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> |
| <li class="listitem"> |
| <a class="link" href="../models/model_point.html" title="model::point">model::point</a> |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../models/model_d2_point_xy.html" title="model::d2::point_xy">model::d2::point_xy</a> |
| </li> |
| <li class="listitem"> |
| a lat long point (currently in an extension) |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../adapted/c_array.html" title="C array">C array</a> |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../adapted/boost_array.html" title="Boost.Array">Boost.Array</a> |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../adapted/boost_fusion.html" title="Boost.Fusion">Boost.Fusion</a> |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../adapted/boost_polygon.html" title="Boost.Polygon">Boost.Polygon</a> |
| </li> |
| <li class="listitem"> |
| <a class="link" href="../adapted/boost_tuple.html" title="Boost.Tuple">Boost.Tuple</a> |
| </li> |
| <li class="listitem"> |
| other point types, adapted e.g. using one of the <a class="link" href="../adapted.html" title="Adapted models">registration |
| macro's</a> |
| </li> |
| </ul></div> |
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| <td align="right"><div class="copyright-footer">Copyright © 2009-2015 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>) |
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