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docs/lib3x-tri_ear_clipping.md

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+# tri_ear_clipping
+
+Given a 2D shape. This function performs a polygon triangulation based on [Ear clipping](https://en.wikipedia.org/wiki/Polygon_triangulation#Ear_clipping_method).
+
+**Since:** 3.0
+
+## Parameters
+
+- `shape_pts` : The shape points.
+- `ret` : The type of returned data. Default to `"TRI_INDICES"` which returns the indices of the `shape_pts`. If `"TRI_SHAPES"` is given, return triangle shapes.
+- `epsilon` : An upper bound on the relative error due to rounding in floating point arithmetic. Default to 0.0001.
+
+## Examples
+
+    use <triangle/tri_ear_clipping.scad>; 
+
+    shape = [
+        [0, 0],
+        [10, 0],
+        [12, 5],
+        [5, 10],
+        [10, 15],
+        [0, 20],
+        [-5, 18],
+        [-18, 3],
+        [-4, 10]
+    ];
+
+    all_indices = tri_ear_clipping(shape);
+
+    for(tri_indices = all_indices) {
+        offset(-.1)
+            polygon([for(i = tri_indices) shape[i]]);
+    }
+
+![tri_ear_clipping](images/lib3x-tri_ear_clipping-1.JPG)
+
+    use <triangle/tri_ear_clipping.scad>; 
+
+    shape = [
+        [0, 0],
+        [10, 0],
+        [12, 5],
+        [5, 10],
+        [10, 15],
+        [0, 20],
+        [-5, 18],
+        [-18, 3],
+        [-4, 10]
+    ];
+
+    tris = tri_ear_clipping(shape, ret = "TRI_SHAPES");
+
+    for(tri = tris) {
+        offset(-.1)
+            polygon(tri);
+    }
+
+![tri_ear_clipping](images/lib3x-tri_ear_clipping-1.JPG)