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|Pack logicmoo_workspace -- node_modules/d3-polygon/README.md|
This module provides a few basic geometric operations for two-dimensional polygons. Each polygon is represented as an array of two-element arrays [[<i>x1</i>, <i>y1</i>], [<i>x2</i>, <i>y2</i>], …], and may either be closed (wherein the first and last point are the same) or open (wherein they are not). Typically polygons are in counterclockwise order, assuming a coordinate system where the origin ⟨0,0⟩ is in the top-left corner.
If you use NPM, `npm install d3-polygon`. Otherwise, download the latest release. You can also load directly from d3js.org, either as a standalone library or as part of D3. AMD, CommonJS, and vanilla environments are supported. In vanilla, a
d3 global is exported:
<script src="https://d3js.org/d3-polygon.v1.min.js"></script> <script> var hull = d3.polygonHull(points); </script>
<a href="#polygonArea" name="polygonArea">#</a> d3.<b>polygonArea</b>(<i>polygon</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/area.js#L1 "Source Code")
Returns the signed area of the specified polygon. If the vertices of the polygon are in counterclockwise order (assuming a coordinate system where the origin ⟨0,0⟩ is in the top-left corner), the returned area is positive; otherwise it is negative, or zero.
<a href="#polygonCentroid" name="polygonCentroid">#</a> d3.<b>polygonCentroid</b>(<i>polygon</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/centroid.js#L1 "Source Code")
Returns the centroid of the specified polygon.
<a href="#polygonHull" name="polygonHull">#</a> d3.<b>polygonHull</b>(<i>points</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/hull.js#L23 "Source Code")
<a href="http://bl.ocks.org/mbostock/6f14f7b7f267a85f7cdc"><img src="https://raw.githubusercontent.com/d3/d3-polygon/master/img/hull.png" width="250" height="250"></a>
Returns the convex hull of the specified points using Andrew’s monotone chain algorithm. The returned hull is represented as an array containing a subset of the input points arranged in counterclockwise order. Returns null if points has fewer than three elements.
<a href="#polygonContains" name="polygonContains">#</a> d3.<b>polygonContains</b>(<i>polygon</i>, <i>point</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/contains.js#L1 "Source Code")
Returns true if and only if the specified point is inside the specified polygon.
<a href="#polygonLength" name="polygonLength">#</a> d3.<b>polygonLength</b>(<i>polygon</i>) [<>](https://github.com/d3/d3-polygon/blob/master/src/length.js#L1 "Source Code")
Returns the length of the perimeter of the specified polygon.