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docs/lib3x-tri_delaunay.md

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+# tri_delaunay
+
+Join a set of points to make a [Delaunay triangulation](https://en.wikipedia.org/wiki/Delaunay_triangulation).
+
+**Since:** 3.0
+
+## Parameters
+
+- `points` : A list of points.
+- `ret` : The type of returned data. Default to `"TRI_INDICES"` which returns the indices of the `points`. `"TRI_SHAPES"` returns triangle shapes. `"VORONOI_CELLS"` returns voronoi cells. `"DELAUNAY"` returns a delaunay object which can be processed by [`tri_delaunay_indices`](lib3x-tri_delaunay_indices.html), [`tri_delaunay_shapes`](lib3x-tri_delaunay_shapes.html) and [`tri_delaunay_voronoi`](lib3x-tri_delaunay_voronoi.html).  
+
+## Examples
+
+    use <triangle/tri_delaunay.scad>;
+    use <hull_polyline2d.scad>;
+
+    points = [for(i = [0:20]) rands(-100, 100, 2)]; 
+
+    tris = [for(ti = tri_delaunay(points)) [for(i = ti) points[i]]];
+	linear_extrude(1)
+	for(t = tri_delaunay(points, ret = "TRI_SHAPES")) {
+		polygon(t);
+	}	
+	
+	color("black")
+	linear_extrude(2)
+	for(t = tri_delaunay(points, ret = "TRI_SHAPES")) {
+	    offset(-1)
+		    polygon(t);
+	}	
+	
+	color("red")
+	linear_extrude(3)
+	for(t = tri_delaunay(points, ret = "VORONOI_CELLS")) {
+	    hull_polyline2d(concat(t, [t[0]]), 2);
+	}
+
+![tri_delaunay](images/lib3x-tri_delaunay-1.JPG)