Utility for doing vertex-based chart identification.

This is the code used as part of the precompute for identifying the tri groups (aka charts) in an Enlighten::IPrecompInputMesh mesh for mesh projection and packing into lightmaps. It identifies tri groups based on the index buffer and a set of explicit links. It holds the chart information in two forms for convenience:

1. A set of identified charts, with a list of triangle indices for each.

2. An array of chart indices to match the vertex array.

A triangle group is any group of triangles that do not share vertices with any other group. This definition allows us to operate on groups independently without having to worry about the changes to one group affecting another.

There are two reasons triangles may be joined together into the same group:

1. They share vertices and therefore cannot be separated

2. They reference vertices that are explicitly linked together

The index buffer specifies all the information we need to determine which vertices are between triangles. Additional explicit links can also be added as an array of index pairs. The explicit links allow an opportunity to remove any unnecessary vertex duplication that may exist, such as vertices being duplicated to incorporate additional irrelevant data. Note that the actual vertex data is not required.

public: TriGroupSelection * Create
(
    const Geo::s32 numVertices,
    const Geo::s32 * indexBuffer,
    Geo::s32 numIndices,
    const IdxLink * linkBuffer,
    Geo::s32 numLinks,
    const Geo::s16 * chartTags,
    const Geo::u8 * faceTypes
)

Create a tri group selection.