Add orx-triangulation

orx-triangulation/README.md

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+# orx-triangulation
+
+An extension for triangulating a set of points using the **Delaunay** triangulation method. From that triangulation we can also derive a **Voronoi** diagram.
+
+The functionality comes from a Javascript port of the following libraries:
+
+* [delaunator](https://github.com/ricardomatias/delaunator) (external)
+* [d3-delaunay](https://github.com/d3/d3-delaunay) (the port is included in this package)
+
+## Usage
+
+### Delaunay
+
+The entry point is the `Delaunay` class.
+
+```kotlin
+    val points: List<Vector2>
+    val delaunay = Delaunay.from(points)
+
+    // or
+    val flatPoints: DoubleArray // (x0, y0, x1, x1, x2, y2)
+    val delaunay = Delaunay(flatPoints)
+```
+
+This is how you retrieve the triangulation results:
+
+```kotlin
+val triangles: List<Triangle> = delaunay.triangles()
+val halfedges: List<ShapeContour> = delaunay.halfedges()
+val hull: ShapeContour = delaunay.hull()
+
+// Updates the triangulation after the points have been modified in-place.
+delaunay.update()
+```
+
+### Voronoi
+
+The bounds specifices where the Voronoi diagram will be clipped.
+
+```kotlin
+val bounds: Rectangle
+
+val delaunay = Delaunay.from(points)
+val voronoi = delaunay.voronoi(bounds)
+// or
+val voronoi = Voronoi(Delaunay.from(points), bounds)
+```
+
+See [To Infinity and Back Again](https://observablehq.com/@mbostock/to-infinity-and-back-again) for an interactive explanation of Voronoi cell clipping.
+
+This is how you retrieve th results:
+
+```kotlin
+val cells: List<ShapeContour> = voronoi.cellsPolygons()
+val cell: ShapeContour = voronoi.cellPolygon(int) // index
+val circumcenters: List<Vector2> = voronoi.circumcenters()
+
+// Returns true if the cell with the specified index i contains the specified vector
+val contaisVector = voronoi.contains(int, Vector2)
+
+// Updates the Voronoi diagram and underlying triangulation
+// after the points have been modified in-place
+voronoi.update()
+```
+
+
+### Author
+
+Ricardo Matias / [@ricardomatias](https://github.com/ricardomatias)