<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<title>GEOS: geos::operation::valid::ConsistentAreaTester Class Reference</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<link href="doxygen.css" rel="stylesheet" type="text/css"/>
</head>
<body>
<!-- Generated by Doxygen 1.7.1 -->
<div class="navigation" id="top">
<div class="tabs">
<ul class="tablist">
<li><a href="index.html"><span>Main Page</span></a></li>
<li><a href="pages.html"><span>Related Pages</span></a></li>
<li><a href="namespaces.html"><span>Namespaces</span></a></li>
<li class="current"><a href="annotated.html"><span>Classes</span></a></li>
<li><a href="files.html"><span>Files</span></a></li>
</ul>
</div>
<div class="tabs2">
<ul class="tablist">
<li><a href="annotated.html"><span>Class List</span></a></li>
<li><a href="hierarchy.html"><span>Class Hierarchy</span></a></li>
<li><a href="functions.html"><span>Class Members</span></a></li>
</ul>
</div>
<div class="navpath">
<ul>
<li><a class="el" href="namespacegeos.html">geos</a> </li>
<li><a class="el" href="namespacegeos_1_1operation.html">operation</a> </li>
<li><a class="el" href="namespacegeos_1_1operation_1_1valid.html">valid</a> </li>
<li><a class="el" href="classgeos_1_1operation_1_1valid_1_1ConsistentAreaTester.html">geos::operation::valid::ConsistentAreaTester</a> </li>
</ul>
</div>
</div>
<div class="header">
<div class="summary">
<a href="#pub-methods">Public Member Functions</a> </div>
<div class="headertitle">
<h1>geos::operation::valid::ConsistentAreaTester Class Reference</h1> </div>
</div>
<div class="contents">
<!-- doxytag: class="geos::operation::valid::ConsistentAreaTester" -->
<p>Checks that a <a class="el" href="">geomgraph::GeometryGraph</a> representing an area (a <a class="el" href="">Polygon</a> or <a class="el" href="">MultiPolygon</a> ) is consistent with the OGC-SFS semantics for area geometries.
<a href="#_details">More...</a></p>
<p><code>#include <<a class="el" href="ConsistentAreaTester_8h_source.html">ConsistentAreaTester.h</a>></code></p>
<p><a href="classgeos_1_1operation_1_1valid_1_1ConsistentAreaTester-members.html">List of all members.</a></p>
<table class="memberdecls">
<tr><td colspan="2"><h2><a name="pub-methods"></a>
Public Member Functions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top"> </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1operation_1_1valid_1_1ConsistentAreaTester.html#a964b213d70993f3ed9c71b1555cc9abd">ConsistentAreaTester</a> (geomgraph::GeometryGraph *newGeomGraph)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="el" href="classgeos_1_1geom_1_1Coordinate.html">geom::Coordinate</a> & </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1operation_1_1valid_1_1ConsistentAreaTester.html#a0ae7663edf982238c84836029a858a8e">getInvalidPoint</a> ()</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">bool </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1operation_1_1valid_1_1ConsistentAreaTester.html#a4772f1fd7dd9c24aa2d5ed38f107bcf8">isNodeConsistentArea</a> ()</td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Check all nodes to see if their labels are consistent with area topology. <a href="#a4772f1fd7dd9c24aa2d5ed38f107bcf8"></a><br/></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">bool </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1operation_1_1valid_1_1ConsistentAreaTester.html#a380c67355ef80015402cc5ff0770be32">hasDuplicateRings</a> ()</td></tr>
</table>
<hr/><a name="_details"></a><h2>Detailed Description</h2>
<p>Checks that a <a class="el" href="">geomgraph::GeometryGraph</a> representing an area (a <a class="el" href="">Polygon</a> or <a class="el" href="">MultiPolygon</a> ) is consistent with the OGC-SFS semantics for area geometries. </p>
<p>Checks include:</p>
<ul>
<li>testing for rings which self-intersect (both properly and at nodes)</li>
<li>testing for duplicate rings</li>
</ul>
<p>If an inconsistency if found the location of the problem is recorded. Checks that a geomgraph::GeometryGraph representing an area (a <a class="el" href="classgeos_1_1geom_1_1Polygon.html" title="Represents a linear polygon, which may include holes.">geom::Polygon</a> or <a class="el" href="classgeos_1_1geom_1_1MultiPolygon.html" title="Basic implementation of MultiPolygon.">geom::MultiPolygon</a>) has consistent semantics for area geometries. This check is required for any reasonable polygonal model (including the OGC-SFS model, as well as models which allow ring self-intersection at single points) Checks include:</p>
<ul>
<li>test for rings which properly intersect (but not for ring self-intersection, or intersections at vertices)</li>
<li>test for consistent labelling at all node points (this detects vertex intersections with invalid topology, i.e. where the exterior side of an edge lies in the interior of the area)</li>
<li>test for duplicate rings</li>
</ul>
<p>If an inconsistency is found the location of the problem is recorded and is available to the caller. </p>
<hr/><h2>Constructor & Destructor Documentation</h2>
<a class="anchor" id="a964b213d70993f3ed9c71b1555cc9abd"></a><!-- doxytag: member="geos::operation::valid::ConsistentAreaTester::ConsistentAreaTester" ref="a964b213d70993f3ed9c71b1555cc9abd" args="(geomgraph::GeometryGraph *newGeomGraph)" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">geos::operation::valid::ConsistentAreaTester::ConsistentAreaTester </td>
<td>(</td>
<td class="paramtype">geomgraph::GeometryGraph * </td>
<td class="paramname"> <em>newGeomGraph</em></td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>Creates a new tester for consistent areas.</p>
<dl><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>geomGraph</em> </td><td>the topology graph of the area geometry. Caller keeps responsibility for its deletion </td></tr>
</table>
</dd>
</dl>
</div>
</div>
<hr/><h2>Member Function Documentation</h2>
<a class="anchor" id="a0ae7663edf982238c84836029a858a8e"></a><!-- doxytag: member="geos::operation::valid::ConsistentAreaTester::getInvalidPoint" ref="a0ae7663edf982238c84836029a858a8e" args="()" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname"><a class="el" href="classgeos_1_1geom_1_1Coordinate.html">geom::Coordinate</a>& geos::operation::valid::ConsistentAreaTester::getInvalidPoint </td>
<td>(</td>
<td class="paramname"></td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<dl class="return"><dt><b>Returns:</b></dt><dd>the intersection point, or <code>null</code> if none was found </dd></dl>
</div>
</div>
<a class="anchor" id="a380c67355ef80015402cc5ff0770be32"></a><!-- doxytag: member="geos::operation::valid::ConsistentAreaTester::hasDuplicateRings" ref="a380c67355ef80015402cc5ff0770be32" args="()" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">bool geos::operation::valid::ConsistentAreaTester::hasDuplicateRings </td>
<td>(</td>
<td class="paramname"></td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>Checks for two duplicate rings in an area. Duplicate rings are rings that are topologically equal (that is, which have the same sequence of points up to point order). If the area is topologically consistent (determined by calling the <code>isNodeConsistentArea</code>, duplicate rings can be found by checking for EdgeBundles which contain more than one <a class="el" href="classgeos_1_1geomgraph_1_1EdgeEnd.html" title="Models the end of an edge incident on a node.">geomgraph::EdgeEnd</a>. (This is because topologically consistent areas cannot have two rings sharing the same line segment, unless the rings are equal). The start point of one of the equal rings will be placed in invalidPoint.</p>
<dl class="return"><dt><b>Returns:</b></dt><dd>true if this area Geometry is topologically consistent but has two duplicate rings </dd></dl>
</div>
</div>
<a class="anchor" id="a4772f1fd7dd9c24aa2d5ed38f107bcf8"></a><!-- doxytag: member="geos::operation::valid::ConsistentAreaTester::isNodeConsistentArea" ref="a4772f1fd7dd9c24aa2d5ed38f107bcf8" args="()" -->
<div class="memitem">
<div class="memproto">
<table class="memname">
<tr>
<td class="memname">bool geos::operation::valid::ConsistentAreaTester::isNodeConsistentArea </td>
<td>(</td>
<td class="paramname"></td>
<td> ) </td>
<td></td>
</tr>
</table>
</div>
<div class="memdoc">
<p>Check all nodes to see if their labels are consistent with area topology. </p>
<dl class="return"><dt><b>Returns:</b></dt><dd><code>true</code> if this area has a consistent node labelling </dd></dl>
</div>
</div>
<hr/>The documentation for this class was generated from the following file:<ul>
<li><a class="el" href="ConsistentAreaTester_8h_source.html">ConsistentAreaTester.h</a></li>
</ul>
</div>
<hr class="footer"/><address class="footer"><small>Generated on Thu Jul 22 2010 for GEOS by
<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.7.1 </small></address>
</body>
</html>
