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| <title>Boost Polygon Library: Polygon Concept</title> |
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| <h3 class="navbar">Contents</h3> |
| <ul> |
| <li><a href="index.htm">Boost.Polygon Main Page</a></li> |
| <li><a href="gtl_design_overview.htm">Design Overview</a></li> |
| <li><a href="gtl_isotropy.htm">Isotropy</a></li> |
| <li><a href="gtl_coordinate_concept.htm">Coordinate Concept</a></li> |
| <li><a href="gtl_interval_concept.htm">Interval Concept</a></li> |
| <li><a href="gtl_point_concept.htm">Point Concept</a></li> |
| <li><a href="gtl_rectangle_concept.htm">Rectangle Concept</a></li> |
| <li><a href="gtl_polygon_90_concept.htm">Polygon 90 Concept</a></li> |
| <li><a href="gtl_polygon_90_with_holes_concept.htm">Polygon 90 With Holes Concept</a></li> |
| <li><a href="gtl_polygon_45_concept.htm">Polygon 45 Concept</a></li> |
| <li><a href="gtl_polygon_45_with_holes_concept.htm">Polygon 45 With Holes Concept</a></li> |
| <li>Polygon Concept</li> |
| <li><a href="gtl_polygon_with_holes_concept.htm">Polygon With Holes Concept</a></li> |
| <li><a href="gtl_polygon_90_set_concept.htm">Polygon 90 Set Concept</a></li> |
| <li><a href="gtl_polygon_45_set_concept.htm">Polygon 45 Set Concept</a></li> |
| <li><a href="gtl_polygon_set_concept.htm">Polygon Set Concept</a></li> |
| <li><a href="gtl_connectivity_extraction_90.htm">Connectivity Extraction 90</a></li> |
| <li><a href="gtl_connectivity_extraction_45.htm">Connectivity Extraction 45</a></li> |
| <li><a href="gtl_connectivity_extraction.htm">Connectivity Extraction</a></li> |
| <li><a href="gtl_property_merge_90.htm">Property Merge 90</a></li> |
| <li><a href="gtl_property_merge_45.htm">Property Merge 45</a></li> |
| <li><a href="gtl_property_merge.htm">Property Merge</a></li> |
| </ul> |
| <h3 class="navbar">Other Resources</h3> |
| <ul> |
| <li><a href="GTL_boostcon2009.pdf">GTL Boostcon 2009 Paper</a></li> |
| <li><a href="GTL_boostcon_draft03.pdf">GTL Boostcon 2009 |
| Presentation</a></li> |
| <li><a href="analysis.htm">Performance Analysis</a></li> |
| <li><a href="gtl_tutorial.htm">Layout Versus Schematic Tutorial</a></li> |
| <li><a href="gtl_minkowski_tutorial.htm">Minkowski Sum Tutorial</a></li> |
| </ul> |
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| <h3 class="navbar">Polygon Sponsor</h3> |
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| |
| <br> |
| <p> |
| </p><h1>Polygon Concept</h1> |
| |
| <p> |
| <p>The polygon concept tag is <font face="Courier New"> |
| polygon_concept</font></p> |
| <p> |
| To register a user defined type as a model of |
| <font face="Times New Roman">polygon </font>concept, specialize the |
| geometry concept meta-function for that type. In the example below CPolygon is registered as a model of |
| polygon concept.<p> |
| <font face="Courier New">template <><br> |
| struct geometry_concept<CPolygon> { typedef polygon_concept type; };</font><p> |
| <font face="Times New Roman">The semantic of a polygon is that it can provide |
| iterators over the points that represent its vertices. It is acceptable to |
| have the last edge explict with the first and last point equal to each other or |
| implied by this segement that would connect the first and last point. A |
| mutable polygon must also be able to set its geometry based on an interator |
| range over such points. A std::vector<point_data<int> > or std::list<point_data<int> |
| > |
| could be made models of polygon_concept by simply providing access to their |
| iterators through traits. Library functions that create polygon objects |
| require that those objects provide a default constructor.</font><p> |
| <font face="Times New Roman">Below is shown the default polygon traits. |
| Specialization of these traits is required for types that don't conform to the |
| default behavior. Note that these same traits are also used by several |
| other polygon concepts through SFINE enable template parameter. The SFINE |
| enable parameter also allows the library to provide default specialization that |
| work for any object that models the 90 degree polygon concepts.</font><p> |
| <font face="Courier New">template <typename T, typename enable = gtl_yes><br> |
| struct polygon_traits {};<br> |
| <br> |
| template <typename T><br> |
| struct polygon_traits<T, <br> |
| typename gtl_or_4<<br> |
| typename gtl_same_type<typename geometry_concept<T>::type, |
| polygon_concept>::type,<br> |
| typename gtl_same_type<typename geometry_concept<T>::type, |
| polygon_concept>::type,<br> |
| typename gtl_same_type<typename geometry_concept<T>::type, |
| polygon_with_holes_concept>::type,<br> |
| typename gtl_same_type<typename geometry_concept<T>::type, |
| polygon_with_holes_concept>::type<br> |
| >::type> {<br> |
| typedef typename T::coordinate_type coordinate_type;<br> |
| typedef typename T::iterator_type iterator_type;<br> |
| typedef typename T::point_type point_type;<br> |
| static inline iterator_type begin_points(const T& t) {<br> |
| return t.begin();<br> |
| }<br> |
| static inline iterator_type end_points(const T& t) {<br> |
| return t.end();<br> |
| }<br> |
| static inline unsigned int size(const T& t) {<br> |
| return t.size();<br> |
| }<br> |
| static inline winding_direction winding(const T& t) {<br> |
| return unknown_winding;<br> |
| }<br> |
| };</font></p> |
| <p><font face="Courier New">template <typename T, typename enable = void><br> |
| struct polygon_mutable_traits {<br> |
| template <typename iT><br> |
| static inline T& set_points(T& t, iT input_begin, iT |
| input_end) {<br> |
| t.set(input_begin, |
| input_end);<br> |
| return t;<br> |
| }<br> |
| };</font></p> |
| <p>Example code <a href="gtl_custom_polygon.htm">custom_polygon.cpp</a> |
| demonstrates mapping a |
| user defined polygon class to the library polygon_concept</p> |
| <p>An object that is a model of <font face="Courier New"> |
| polygon_concept</font> can be viewed as a model of any of its |
| refinements if it is determined at runtime to conform to the restriction of |
| those concepts. This concept casting is accomplished through the |
| <font face="Courier New">view_as<>()</font> function.</p> |
| <p><font face="Courier New">view_as<rectangle_concept>(polygon_object)</font><br> |
| <font face="Courier New">view_as<polygon_90_concept>(polygon_object)</font><br> |
| <font face="Courier New">view_as<polygon_45_concept>(polygon_object)</font></p> |
| <p>The return value of <font face="Courier New">view_as<>()</font> can be |
| passed into any interface that expects an object of the conceptual type |
| specified in its template parameter. </p> |
| <h2>Functions</h2> |
| <table border="1" width="100%" id="table1"> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| point_iterator_type <b>begin_points</b>(const T& polygon)</font></td> |
| <td><font face="Times New Roman">Expects a model of polygon. |
| Returns the begin iterator over the range of points that correspond to |
| vertices of the polygon.</font></td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| point_iterator_type <b>end_points</b>(const T& polygon)</font></td> |
| <td><font face="Times New Roman">Expects a model of polygon. |
| Returns the end iterator over the range of points that correspond to |
| vertices of the polygon.</font></td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T, typename |
| iterator><br> |
| void <b>set_points</b>(T& polygon, iterator b, iterator e)</font></td> |
| <td><font face="Times New Roman">Expects a model of polygon. |
| Sets the polygon to the point data range [b,e) that corresponds to |
| vertices of a manhattan polygon.</font></td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| unsigned int <b>size</b>(const T& polygon)</font></td> |
| <td><font face="Times New Roman">Returns the number of edges in the |
| polygon.</font></td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T1, typename |
| T2><br> |
| T1& <b>assign</b>(T1& left, const T2& right)</font></td> |
| <td>Copies data from right object that models polygon into left object |
| that models polygon.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T, |
| typename point_type><br> |
| bool <b>contains</b>(const T&, const point_type& point, <br> |
| |
| bool consider_touch=true)</font></td> |
| <td>Given an object that models polygon and an object that models |
| point, returns true |
| if the polygon contains the point. If the consider_touch |
| flag is true will return true if the point lies along the boundary of |
| the polygon. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">// get the center coordinate<br> |
| template <typename T, typename point_type><br> |
| void <b>center</b>(point_type& p, const T& polygon)</font></td> |
| <td>Sets object that models point to the center point of the bounding |
| box of an object that models polygon. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T, |
| typename rectangle_type><br> |
| bool <b>extents</b>(rectangle_type& bbox, const T& polygon)</font></td> |
| <td>Sets object that models rectangle to the bounding box of an object |
| that models polygon and returns true. Returns false and leaves |
| bbox unchanged if polygon is empty. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| area_type <b>area</b>(const T& polygon)</font></td> |
| <td>Returns the area of an object |
| that models polygon. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| direction_1d <b>winding</b>(const T& polygon)</font></td> |
| <td>Returns the winding direction of an object |
| that models polygon, LOW == CLOCKWISE, HIGH = COUNTERCLOCKWISE. |
| Complexity depends upon winding trait.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| coordinate_distance <b>perimeter</b>(const T& polygon)</font></td> |
| <td>Returns the perimeter length of an object |
| that models polygon. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T, |
| typename transform_type><br> |
| T& <b>transform</b>(T& polygon, const transform_type&)</font></td> |
| <td>Applies transform() on the vertices of polygon and sets the polygon to that described by the result of |
| transforming its vertices. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| T& <b>scale_up</b>(T& polygon, unsigned_area_type factor)</font></td> |
| <td>Scales up coordinate of an object that models |
| polygon by unsigned factor. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| T& <b>scale_down</b>(T& polygon, unsigned_area_type factor)</font></td> |
| <td>Scales down coordinates of an object that models |
| polygon by unsigned factor. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T, scaling_type><br> |
| T& <b>scale</b>(T& rectangle, double scaling) </font></td> |
| <td>Scales coordinates of an object that models polygon by floating |
| point factor. Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T><br> |
| T& <b>move</b>(T& polygon, orientation_2d,<br> |
| coordinate_difference displacement)</font></td> |
| <td>Adds displacement value to coordinate indicated by orientation_2d of |
| vertices of an object that models polygon . Linear wrt. vertices.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename polygon_type, typename point_type><br> |
| polygon_type& <b>convolve</b>(polygon_type& polygon,<br> |
| |
| const point_type& point)</font></td> |
| <td>Convolves coordinate values of point with vertices of an |
| object that models polygon. Linear wrt. vertices.</td> |
| </tr> |
| </table> |
| <h1>Polygon Data</h1> |
| |
| <p> |
| <p>The library provides a model of polygon concept declared |
| <font face="Courier New"> |
| template<typename T> polygon_data </font>where T is the coordinate type.</p> |
| <p>This data type is used internally when a polygon is needed and is available |
| to the library user who finds it convenient to use a library polygon data type |
| instead of providing their own. The data type is implemented to be |
| convenient to use with the library traits.</p> |
| <p>Example code <a href="gtl_polygon_usage.htm">polygon_usage.cpp</a> |
| demonstrates using |
| the library provided polygon data types and functions</p> |
| <h2>Members</h2> |
| <table border="1" width="100%" id="table2"> |
| <tr> |
| <td width="586"><b><font face="Courier New">geometry_type</font></b></td> |
| <td><font face="Times New Roman">polygon_concept</font></td> |
| </tr> |
| <tr> |
| <td width="586"><b><font face="Courier New">coordinate_type</font></b></td> |
| <td><font face="Times New Roman">T</font></td> |
| </tr> |
| <tr> |
| <td width="586"><b><font face="Courier New">iterator_type</font></b></td> |
| <td>Iterator over vertices point_data<T> vertices of polygon</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New"><b>polygon_data</b>()</font></td> |
| <td><font face="Times New Roman">Default constructs the </font>polygon.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New"><b>polygon_data</b>(const |
| polygon_data& that)</font></td> |
| <td><font face="Times New Roman">Copy construct</font></td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">polygon_data& <b>operator=</b>(const |
| polygon_data& that)</font></td> |
| <td>Assignment operator.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename T2><b> |
| <br> </b>polygon_data& <b>operator=</b>(const T2& that) const</font></td> |
| <td>Assign from an object that is a model of polygon.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">iterator_type <b>begin</b>() |
| const</font></td> |
| <td>Get the begin iterator over vertices of the polygon.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">iterator_type <b>end</b>() |
| const</font></td> |
| <td>Get the end iterator over vertices of the polygon.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">std::size_t <b>size</b>() const</font></td> |
| <td>Get the number of elements in the sequence stored to the polygon, |
| usually equal to the number of edges of the polygon.</td> |
| </tr> |
| <tr> |
| <td width="586"><font face="Courier New">template <typename iT><b> |
| <br> </b>void <b>set</b>(iT begin_points, iT end_points)</font></td> |
| <td>Sets the polygon to the iterator range of points. </td> |
| </tr> |
| </table> |
| <tr> |
| <td style="background-color: rgb(238, 238, 238);" nowrap="1" valign="top"> |
| </td> |
| <td style="padding-left: 10px; padding-right: 10px; padding-bottom: 10px;" valign="top" width="100%"> |
| |
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| <col class="docinfo-name"><col class="docinfo-content"> |
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| <tbody vAlign="top"> |
| <tr> |
| <th class="docinfo-name">Copyright:</th> |
| <td>Copyright © Intel Corporation 2008-2010.</td> |
| </tr> |
| <tr class="field"> |
| <th class="docinfo-name">License:</th> |
| <td class="field-body">Distributed under the Boost Software License, |
| Version 1.0. (See accompanying file <tt class="literal"> |
| <span class="pre">LICENSE_1_0.txt</span></tt> or copy at |
| <a class="reference" target="_top" href="http://www.boost.org/LICENSE_1_0.txt"> |
| http://www.boost.org/LICENSE_1_0.txt</a>)</td> |
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