C#DT - a C# port of CDT

This is a C# port of artem-ogre's CDT library. Make sure to read the original README, it contains more information.

There may be some typos in my code. If you have found any other discrepancies or strange behavior, report it in Issues. Be aware that any bug you have found could have existed on the C++ side as well, so make sure to test both.

Adding to your project

The code is fairly small. You can simply drag and drop all .cs files from the src folder in your project. These should be able to get compiled starting with .NET 5.

If you have your own implementation of Vector2 that is 64-bit and supports element-wise arithmetic, Vector2.Distance(), Vector2.DistanceSquared(), Vector2.Min() and Vector2.Max(), you do not need Vector.cs. But be sure to link your namespace under the other 3 files.

32-bit floats will not work unless you replace all doubles with float and all Math.ScaleB(1, -52) with Math.ScaleB(1, -24) in Triangle.cs, but even then it is not recommended.

Using CDT in your code

The syntax is similar to C++:

CDT cdt = new(VertexInsertionOrder.Auto, //or AsProvided if forced order
    IntersectingConstraintEdges.Resolve, //or Ignore if no intersecting edges
    10); //unlikely to crash within this tolerance, but thin triangles phase through edges

cdt.InsertVertices(new Vector2[] { new(100, 200), new(300, 400), /* ... */ });
cdt.InsertEdges(new Edge[] { new(0, 1), new(2, 3), /* ... */ });

When InsertVertices is first called (and superGeomType is set to SuperTriangle by default), CDT makes a large triangle encompassing all vertices. The triangulation itself then occurs when outer unedged triangles, holes or the super triangle is erased:

cdt.EraseSuperTriangle();
// or
cdt.EraseOuterEdges();
// or
cdt.EraseOuterEdgesAndHoles();