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<h1>boost/geometry/algorithms/area.hpp</h1><a href="algorithms_2area_8hpp.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// Boost.Geometry (aka GGL, Generic Geometry Library)</span>
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<a name="l00002"></a>00002 <span class="comment">//</span>
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<a name="l00003"></a>00003 <span class="comment">// Copyright Barend Gehrels 2007-2009, Geodan, Amsterdam, the Netherlands.</span>
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<a name="l00004"></a>00004 <span class="comment">// Copyright Bruno Lalande 2008, 2009</span>
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<a name="l00005"></a>00005 <span class="comment">// Use, modification and distribution is subject to the Boost Software License,</span>
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||
<a name="l00006"></a>00006 <span class="comment">// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at</span>
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<a name="l00007"></a>00007 <span class="comment">// http://www.boost.org/LICENSE_1_0.txt)</span>
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<a name="l00008"></a>00008
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<a name="l00009"></a>00009 <span class="preprocessor">#ifndef BOOST_GEOMETRY_ALGORITHMS_AREA_HPP</span>
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<a name="l00010"></a>00010 <span class="preprocessor"></span><span class="preprocessor">#define BOOST_GEOMETRY_ALGORITHMS_AREA_HPP</span>
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<a name="l00011"></a>00011 <span class="preprocessor"></span>
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<a name="l00012"></a>00012 <span class="preprocessor">#include <boost/mpl/if.hpp></span>
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<a name="l00013"></a>00013 <span class="preprocessor">#include <boost/range/functions.hpp></span>
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<a name="l00014"></a>00014 <span class="preprocessor">#include <boost/range/metafunctions.hpp></span>
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<a name="l00015"></a>00015
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<a name="l00016"></a>00016
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<a name="l00017"></a>00017 <span class="preprocessor">#include <<a class="code" href="point__order_8hpp.html">boost/geometry/core/point_order.hpp</a>></span>
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<a name="l00018"></a>00018 <span class="preprocessor">#include <<a class="code" href="exterior__ring_8hpp.html">boost/geometry/core/exterior_ring.hpp</a>></span>
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||
<a name="l00019"></a>00019 <span class="preprocessor">#include <<a class="code" href="interior__rings_8hpp.html">boost/geometry/core/interior_rings.hpp</a>></span>
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<a name="l00020"></a>00020 <span class="preprocessor">#include <<a class="code" href="core_2ring__type_8hpp.html">boost/geometry/core/ring_type.hpp</a>></span>
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<a name="l00021"></a>00021
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<a name="l00022"></a>00022 <span class="preprocessor">#include <<a class="code" href="geometries_2concepts_2check_8hpp.html">boost/geometry/geometries/concepts/check.hpp</a>></span>
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<a name="l00023"></a>00023
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<a name="l00024"></a>00024 <span class="preprocessor">#include <<a class="code" href="calculate__null_8hpp.html">boost/geometry/algorithms/detail/calculate_null.hpp</a>></span>
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<a name="l00025"></a>00025 <span class="preprocessor">#include <<a class="code" href="calculate__sum_8hpp.html">boost/geometry/algorithms/detail/calculate_sum.hpp</a>></span>
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<a name="l00026"></a>00026
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<a name="l00027"></a>00027 <span class="preprocessor">#include <<a class="code" href="strategies_2area_8hpp.html">boost/geometry/strategies/area.hpp</a>></span>
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<a name="l00028"></a>00028 <span class="preprocessor">#include <<a class="code" href="area__result_8hpp.html">boost/geometry/strategies/area_result.hpp</a>></span>
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<a name="l00029"></a>00029
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<a name="l00030"></a>00030 <span class="preprocessor">#include <<a class="code" href="area__concept_8hpp.html">boost/geometry/strategies/concepts/area_concept.hpp</a>></span>
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<a name="l00031"></a>00031
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<a name="l00032"></a>00032 <span class="preprocessor">#include <<a class="code" href="math_8hpp.html">boost/geometry/util/math.hpp</a>></span>
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<a name="l00033"></a>00033
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<a name="l00059"></a>00059 <span class="keyword">namespace </span>boost { <span class="keyword">namespace </span>geometry
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<a name="l00060"></a>00060 {
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<a name="l00061"></a>00061
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<a name="l00062"></a>00062 <span class="preprocessor">#ifndef DOXYGEN_NO_DETAIL</span>
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<a name="l00063"></a>00063 <span class="preprocessor"></span><span class="keyword">namespace </span>detail { <span class="keyword">namespace </span><a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a> {
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<a name="l00064"></a>00064
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<a name="l00065"></a>00065 <span class="keyword">template</span><<span class="keyword">typename</span> Box, <span class="keyword">typename</span> Strategy>
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<a name="l00066"></a>00066 <span class="keyword">struct </span>box_area
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<a name="l00067"></a>00067 {
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<a name="l00068"></a>00068 <span class="keyword">typedef</span> <span class="keyword">typename</span> coordinate_type<Box>::type return_type;
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||
<a name="l00069"></a>00069
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||
<a name="l00070"></a>00070 <span class="keyword">static</span> <span class="keyword">inline</span> return_type apply(Box <span class="keyword">const</span>& box, Strategy <span class="keyword">const</span>&)
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||
<a name="l00071"></a>00071 {
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<a name="l00072"></a>00072 <span class="comment">// Currently only works for 2D Cartesian boxes</span>
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<a name="l00073"></a>00073 assert_dimension<Box, 2>();
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<a name="l00074"></a>00074
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||
<a name="l00075"></a>00075 return_type <span class="keyword">const</span> dx = get<max_corner, 0>(box)
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||
<a name="l00076"></a>00076 - get<min_corner, 0>(box);
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||
<a name="l00077"></a>00077 return_type <span class="keyword">const</span> dy = get<max_corner, 1>(box)
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<a name="l00078"></a>00078 - get<min_corner, 1>(box);
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<a name="l00079"></a>00079
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||
<a name="l00080"></a>00080 <span class="keywordflow">return</span> dx * dy;
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<a name="l00081"></a>00081 }
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||
<a name="l00082"></a>00082 };
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||
<a name="l00083"></a>00083
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||
<a name="l00084"></a>00084
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||
<a name="l00085"></a>00085
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||
<a name="l00086"></a>00086
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||
<a name="l00090"></a>00090 <span class="keyword">template</span>
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||
<a name="l00091"></a>00091 <
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||
<a name="l00092"></a>00092 <span class="keyword">typename</span> Ring,
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||
<a name="l00093"></a>00093 <a class="code" href="namespaceboost_1_1geometry.html#0af1c124acb76f0892024d6d4ab2bc8c">order_selector</a> Order,
|
||
<a name="l00094"></a>00094 <span class="comment">// closing_selector Closed -- for now assuming CLOSED, p(0) == p(n-1)</span>
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||
<a name="l00095"></a>00095 <span class="keyword">typename</span> Strategy
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||
<a name="l00096"></a>00096 >
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||
<a name="l00097"></a>00097 <span class="keyword">struct </span>ring_area
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||
<a name="l00098"></a>00098 {};
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||
<a name="l00099"></a>00099
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<a name="l00100"></a>00100
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||
<a name="l00101"></a>00101 <span class="keyword">template</span><<span class="keyword">typename</span> Ring, <span class="keyword">typename</span> Strategy>
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||
<a name="l00102"></a>00102 <span class="keyword">struct </span>ring_area<Ring, <a class="code" href="namespaceboost_1_1geometry.html#0af1c124acb76f0892024d6d4ab2bc8c29458b1c5c6f01e41bc529cff7cdbec2">clockwise</a>, Strategy>
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||
<a name="l00103"></a>00103 {
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||
<a name="l00104"></a>00104 BOOST_CONCEPT_ASSERT( (geometry::concept::AreaStrategy<Strategy>) );
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||
<a name="l00105"></a>00105
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||
<a name="l00106"></a>00106 <span class="keyword">typedef</span> <span class="keyword">typename</span> Strategy::return_type type;
|
||
<a name="l00107"></a>00107
|
||
<a name="l00108"></a>00108 <span class="keyword">static</span> <span class="keyword">inline</span> type apply(Ring <span class="keyword">const</span>& ring, Strategy <span class="keyword">const</span>& strategy)
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||
<a name="l00109"></a>00109 {
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||
<a name="l00110"></a>00110 assert_dimension<Ring, 2>();
|
||
<a name="l00111"></a>00111
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||
<a name="l00112"></a>00112 <span class="comment">// A closed linear_ring has at least four points,</span>
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||
<a name="l00113"></a>00113 <span class="comment">// if not, there is no (zero) area</span>
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||
<a name="l00114"></a>00114 <span class="keywordflow">if</span> (boost::size(ring) < 4)
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||
<a name="l00115"></a>00115 {
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||
<a name="l00116"></a>00116 <span class="keywordflow">return</span> type();
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||
<a name="l00117"></a>00117 }
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||
<a name="l00118"></a>00118
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||
<a name="l00119"></a>00119 <span class="keyword">typedef</span> <span class="keyword">typename</span> boost::range_const_iterator<Ring>::type iterator_type;
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||
<a name="l00120"></a>00120
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||
<a name="l00121"></a>00121 <span class="keyword">typename</span> Strategy::state_type state;
|
||
<a name="l00122"></a>00122
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||
<a name="l00123"></a>00123 iterator_type it = boost::begin(ring);
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||
<a name="l00124"></a>00124 <span class="keywordflow">for</span> (iterator_type previous = it++;
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||
<a name="l00125"></a>00125 it != boost::end(ring);
|
||
<a name="l00126"></a>00126 previous = it++)
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||
<a name="l00127"></a>00127 {
|
||
<a name="l00128"></a>00128 strategy.apply(*previous, *it, state);
|
||
<a name="l00129"></a>00129 }
|
||
<a name="l00130"></a>00130 <span class="keywordflow">return</span> strategy.result(state);
|
||
<a name="l00131"></a>00131
|
||
<a name="l00132"></a>00132 }
|
||
<a name="l00133"></a>00133 };
|
||
<a name="l00134"></a>00134
|
||
<a name="l00135"></a>00135 <span class="keyword">template</span><<span class="keyword">typename</span> Ring, <span class="keyword">typename</span> Strategy>
|
||
<a name="l00136"></a>00136 <span class="keyword">struct </span>ring_area<Ring, <a class="code" href="namespaceboost_1_1geometry.html#0af1c124acb76f0892024d6d4ab2bc8c3a0efd1027a55cf48cfc5f9b57391468">counterclockwise</a>, Strategy>
|
||
<a name="l00137"></a>00137 {
|
||
<a name="l00138"></a>00138 <span class="keyword">typedef</span> <span class="keyword">typename</span> Strategy::return_type type;
|
||
<a name="l00139"></a>00139 <span class="keyword">static</span> <span class="keyword">inline</span> type apply(Ring <span class="keyword">const</span>& ring, Strategy <span class="keyword">const</span>& strategy)
|
||
<a name="l00140"></a>00140 {
|
||
<a name="l00141"></a>00141 <span class="comment">// Counter clockwise rings negate the area result</span>
|
||
<a name="l00142"></a>00142 <span class="keywordflow">return</span> -ring_area<Ring, clockwise, Strategy>::apply(ring, strategy);
|
||
<a name="l00143"></a>00143 }
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||
<a name="l00144"></a>00144 };
|
||
<a name="l00145"></a>00145
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||
<a name="l00146"></a>00146
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||
<a name="l00147"></a>00147 }} <span class="comment">// namespace detail::area</span>
|
||
<a name="l00148"></a>00148
|
||
<a name="l00149"></a>00149 <span class="preprocessor">#endif // DOXYGEN_NO_DETAIL</span>
|
||
<a name="l00150"></a>00150 <span class="preprocessor"></span>
|
||
<a name="l00151"></a>00151
|
||
<a name="l00152"></a>00152 <span class="preprocessor">#ifndef DOXYGEN_NO_DISPATCH</span>
|
||
<a name="l00153"></a>00153 <span class="preprocessor"></span><span class="keyword">namespace </span>dispatch {
|
||
<a name="l00154"></a>00154
|
||
<a name="l00155"></a>00155 <span class="keyword">template</span>
|
||
<a name="l00156"></a>00156 <
|
||
<a name="l00157"></a>00157 <span class="keyword">typename</span> Tag,
|
||
<a name="l00158"></a>00158 <span class="keyword">typename</span> Geometry,
|
||
<a name="l00159"></a>00159 <a class="code" href="namespaceboost_1_1geometry.html#0af1c124acb76f0892024d6d4ab2bc8c">order_selector</a> Order,
|
||
<a name="l00160"></a>00160 <span class="keyword">typename</span> Strategy
|
||
<a name="l00161"></a>00161 >
|
||
<a name="l00162"></a>00162 <span class="keyword">struct </span><a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a>
|
||
<a name="l00163"></a>00163 : detail::calculate_null
|
||
<a name="l00164"></a>00164 <
|
||
<a name="l00165"></a>00165 typename Strategy::return_type,
|
||
<a name="l00166"></a>00166 Geometry,
|
||
<a name="l00167"></a>00167 Strategy
|
||
<a name="l00168"></a>00168 > {};
|
||
<a name="l00169"></a>00169
|
||
<a name="l00170"></a>00170
|
||
<a name="l00171"></a>00171 <span class="keyword">template</span> <<span class="keyword">typename</span> Geometry, order_selector Order, <span class="keyword">typename</span> Strategy>
|
||
<a name="l00172"></a>00172 <span class="keyword">struct </span><a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a><box_tag, Geometry, Order, Strategy>
|
||
<a name="l00173"></a>00173 : detail::<a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a>::box_area<Geometry, Strategy>
|
||
<a name="l00174"></a>00174 {};
|
||
<a name="l00175"></a>00175
|
||
<a name="l00176"></a>00176
|
||
<a name="l00177"></a>00177 <span class="comment">// Area of ring currently returns area of closed rings but it might be argued</span>
|
||
<a name="l00178"></a>00178 <span class="comment">// that it is 0.0, because a ring is just a line.</span>
|
||
<a name="l00179"></a>00179 <span class="keyword">template</span> <<span class="keyword">typename</span> Geometry, order_selector Order, <span class="keyword">typename</span> Strategy>
|
||
<a name="l00180"></a>00180 <span class="keyword">struct </span><a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a><ring_tag, Geometry, Order, Strategy>
|
||
<a name="l00181"></a>00181 : detail::<a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a>::ring_area<Geometry, Order, Strategy>
|
||
<a name="l00182"></a>00182 {};
|
||
<a name="l00183"></a>00183
|
||
<a name="l00184"></a>00184 <span class="keyword">template</span> <<span class="keyword">typename</span> Polygon, order_selector Order, <span class="keyword">typename</span> Strategy>
|
||
<a name="l00185"></a>00185 <span class="keyword">struct </span><a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a><polygon_tag, Polygon, Order, Strategy>
|
||
<a name="l00186"></a>00186 : detail::calculate_polygon_sum
|
||
<a name="l00187"></a>00187 <
|
||
<a name="l00188"></a>00188 typename Strategy::return_type,
|
||
<a name="l00189"></a>00189 Polygon,
|
||
<a name="l00190"></a>00190 Strategy,
|
||
<a name="l00191"></a>00191 detail::area::ring_area
|
||
<a name="l00192"></a>00192 <
|
||
<a name="l00193"></a>00193 typename ring_type<Polygon>::type,
|
||
<a name="l00194"></a>00194 Order,
|
||
<a name="l00195"></a>00195 Strategy
|
||
<a name="l00196"></a>00196 >
|
||
<a name="l00197"></a>00197 >
|
||
<a name="l00198"></a>00198 {};
|
||
<a name="l00199"></a>00199
|
||
<a name="l00200"></a>00200
|
||
<a name="l00201"></a>00201 } <span class="comment">// namespace dispatch</span>
|
||
<a name="l00202"></a>00202 <span class="preprocessor">#endif // DOXYGEN_NO_DISPATCH</span>
|
||
<a name="l00203"></a>00203 <span class="preprocessor"></span>
|
||
<a name="l00204"></a>00204
|
||
<a name="l00205"></a>00205
|
||
<a name="l00217"></a>00217 <span class="keyword">template</span> <<span class="keyword">typename</span> Geometry>
|
||
<a name="l00218"></a><a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136">00218</a> <span class="keyword">inline</span> <span class="keyword">typename</span> <a class="code" href="structboost_1_1geometry_1_1area__result.html" title="Meta-function defining return type of area function.">area_result<Geometry>::type</a> <a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a>(Geometry <span class="keyword">const</span>& geometry)
|
||
<a name="l00219"></a>00219 {
|
||
<a name="l00220"></a>00220 concept::check<const Geometry>();
|
||
<a name="l00221"></a>00221
|
||
<a name="l00222"></a>00222 <span class="keyword">typedef</span> <span class="keyword">typename</span> <a class="code" href="structboost_1_1geometry_1_1strategy_1_1not__implemented.html" title="Indicate compiler/library user that strategy is not implemented.">area_result<Geometry>::strategy_type</a> strategy_type;
|
||
<a name="l00223"></a>00223
|
||
<a name="l00224"></a>00224 <span class="keywordflow">return</span> <a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">dispatch::area</a>
|
||
<a name="l00225"></a>00225 <
|
||
<a name="l00226"></a>00226 <span class="keyword">typename</span> <a class="code" href="structboost_1_1geometry_1_1geometry__not__recognized__tag.html" title="&quot;default&quot; tag">tag<Geometry>::type</a>,
|
||
<a name="l00227"></a>00227 Geometry,
|
||
<a name="l00228"></a>00228 <a class="code" href="structboost_1_1geometry_1_1point__order.html" title="Meta-function which defines point type of any geometry.">geometry::point_order<Geometry>::value</a>,
|
||
<a name="l00229"></a>00229 strategy_type
|
||
<a name="l00230"></a>00230 >::apply(geometry, strategy_type());
|
||
<a name="l00231"></a>00231 }
|
||
<a name="l00232"></a>00232
|
||
<a name="l00242"></a>00242 <span class="keyword">template</span> <<span class="keyword">typename</span> Geometry, <span class="keyword">typename</span> Strategy>
|
||
<a name="l00243"></a><a class="code" href="group__area.html#g23205bfa2a4af1b3aa0d86e8c5088d8b">00243</a> <span class="keyword">inline</span> <span class="keyword">typename</span> Strategy::return_type <a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">area</a>(
|
||
<a name="l00244"></a>00244 Geometry <span class="keyword">const</span>& geometry, Strategy <span class="keyword">const</span>& strategy)
|
||
<a name="l00245"></a>00245 {
|
||
<a name="l00246"></a>00246 concept::check<const Geometry>();
|
||
<a name="l00247"></a>00247
|
||
<a name="l00248"></a>00248 <span class="keywordflow">return</span> <a class="code" href="group__area.html#gd0e9e99685a9d45895162bd1fd96a136" title="Calculate area of a geometry.">dispatch::area</a>
|
||
<a name="l00249"></a>00249 <
|
||
<a name="l00250"></a>00250 <span class="keyword">typename</span> <a class="code" href="structboost_1_1geometry_1_1geometry__not__recognized__tag.html" title="&quot;default&quot; tag">tag<Geometry>::type</a>,
|
||
<a name="l00251"></a>00251 Geometry,
|
||
<a name="l00252"></a>00252 <a class="code" href="structboost_1_1geometry_1_1point__order.html" title="Meta-function which defines point type of any geometry.">geometry::point_order<Geometry>::value</a>,
|
||
<a name="l00253"></a>00253 Strategy
|
||
<a name="l00254"></a>00254 >::apply(geometry, strategy);
|
||
<a name="l00255"></a>00255 }
|
||
<a name="l00256"></a>00256
|
||
<a name="l00257"></a>00257 }} <span class="comment">// namespace boost::geometry</span>
|
||
<a name="l00258"></a>00258
|
||
<a name="l00259"></a>00259 <span class="preprocessor">#endif // BOOST_GEOMETRY_ALGORITHMS_AREA_HPP</span>
|
||
</pre></div></div>
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<hr size="1">
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<table width="100%">
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<tbody>
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<tr>
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<td align="left"><small>
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||
<p>December 1, 2009</p>
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||
</small></td>
|
||
<td align="right">
|
||
<small>Copyright <20> 1995-2009 Barend Gehrels, Geodan, Amsterdam<br>
|
||
Copyright <20> 2008-2009 Bruno Lalande, Paris<br>
|
||
Copyright <20> 2009 Mateusz Loskot, Cadcorp, London<br>
|
||
</small>
|
||
</td>
|
||
</tr>
|
||
</tbody>
|
||
</table>
|
||
|
||
<address style="text-align: right;"><small>
|
||
Documentation is generated by <a href="http://www.doxygen.org/index.html">Doxygen</a>
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