C# Class FarseerPhysics.Common.Decomposition.EarclipDecomposer

Show file Open project: prime31/Nez Class Usage Examples

Public Methods

Method Description
ConvexPartition ( Vertices vertices, float tolerance = 0.001f ) : List

Decompose the polygon into several smaller non-concave polygon. Each resulting polygon will have no more than Settings.MaxPolygonVertices vertices.

Private Methods

Method Description
IsEar ( int i, float xv, float yv, int xvLength ) : bool

Checks if vertex i is the tip of an ear in polygon defined by xv[] and yv[].

Assumes clockwise orientation of polygon.

Remainder ( int x, int modulus ) : int

Fix for obnoxious behavior for the % operator for negative numbers...

ResolvePinchPoint ( Vertices pin, Vertices &poutA, Vertices &poutB, float tolerance ) : bool

Finds and fixes "pinch points," points where two polygon vertices are at the same point. If a pinch point is found, pin is broken up into poutA and poutB and true is returned; otherwise, returns false. Mostly for internal use. O(N^2) time, which sucks...

TriangulatePolygon ( Vertices vertices, float tolerance ) : List

Triangulates a polygon using simple ear-clipping algorithm. Returns size of Triangle array unless the polygon can't be triangulated. This should only happen if the polygon self-intersects, though it will not _always_ return null for a bad polygon - it is the caller's responsibility to check for self-intersection, and if it doesn't, it should at least check that the return value is non-null before using. You're warned! Triangles may be degenerate, especially if you have identical points in the input to the algorithm. Check this before you use them. This is totally unoptimized, so for large polygons it should not be part of the simulation loop.

Only works on simple polygons.

Method Details

ConvexPartition() public static method

Decompose the polygon into several smaller non-concave polygon. Each resulting polygon will have no more than Settings.MaxPolygonVertices vertices.
public static ConvexPartition ( Vertices vertices, float tolerance = 0.001f ) : List
vertices Vertices The vertices.
tolerance float The tolerance.
return List