# Triangulator¶

```from panda3d.core import Triangulator
```
class `Triangulator`

This class can triangulate a convex or concave polygon, even one with holes. It is adapted from an algorithm published as:

Narkhede A. and Manocha D., Fast polygon triangulation algorithm based on Seidel’s Algorithm, UNC-CH, 1994.

http://www.cs.unc.edu/~dm/CODE/GEM/chapter.html

It works strictly on 2-d points. See `Triangulator3` for 3-d points.

Inheritance diagram

`__init__`()
`__init__`(param0: Triangulator)
`addHoleVertex`(index: int)

Adds the next consecutive vertex of the current hole. This vertex should index into the vertex pool established by repeated calls to `addVertex()`.

The vertices may be listed in either clockwise or counterclockwise order. Vertices should not be repeated.

`addPolygonVertex`(index: int)

Adds the next consecutive vertex of the polygon. This vertex should index into the vertex pool established by repeated calls to `addVertex()`.

The vertices may be listed in either clockwise or counterclockwise order. Vertices should not be repeated. In particular, do not repeat the first vertex at the end.

`addVertex`(point: LPoint2d)int

Adds a new vertex to the vertex pool. Returns the vertex index number.

`addVertex`(x: float, y: float)int

Adds a new vertex to the vertex pool. Returns the vertex index number.

`beginHole`()

Finishes the previous hole, if any, and prepares to add a new hole.

`clear`()

Removes all vertices and polygon specifications from the Triangulator, and prepares it to start over.

`clearPolygon`()

Removes the current polygon definition (and its set of holes), but does not clear the vertex pool.

`getNumTriangles`()int

Returns the number of triangles generated by the previous call to `triangulate()`.

`getNumVertices`()int

Returns the number of vertices in the pool. Note that the Triangulator might append new vertices, in addition to those added by the user, if any of the polygon is self-intersecting, or if any of the holes intersect some part of the polygon edges.

`getTriangleV0`(n: int)int

Returns vertex 0 of the nth triangle generated by the previous call to `triangulate()`.

This is a zero-based index into the vertices added by repeated calls to `addVertex()`.

`getTriangleV1`(n: int)int

Returns vertex 1 of the nth triangle generated by the previous call to `triangulate()`.

This is a zero-based index into the vertices added by repeated calls to `addVertex()`.

`getTriangleV2`(n: int)int

Returns vertex 2 of the nth triangle generated by the previous call to `triangulate()`.

This is a zero-based index into the vertices added by repeated calls to `addVertex()`.

`getVertex`(n: int)LPoint2d

Returns the nth vertex.

`getVertices`()list
`isLeftWinding`()bool

Returns true if the polygon vertices are listed in counterclockwise order, or false if they appear to be listed in clockwise order.

`triangulate`()

Does the work of triangulating the specified polygon. After this call, you may retrieve the new triangles one at a time by iterating through get_triangle_v0/1/2().

property `vertices`Sequence[LPoint2d]

Returns the nth vertex.