Progressive Mesh Algorithm Header File - C++ Implementation

The code provided is a header file for a Progressive Mesh algorithm. \n\nThe header file includes the necessary dependencies, such as the "linalg.h" library for 3D math routines. It also defines a class called "tridata" which represents a triangle in a mesh. The tridata class has an array of three integer indices (v[3]) that point to vertices in the vertex array.\n\nThe header file also declares a function called "ProgressiveMesh" which takes in four parameters: a vector of float3 representing the vertices of the mesh, a vector of tridata representing the triangles of the mesh, a vector of int representing a map (not specified what it maps), and a vector of int representing a permutation (not specified what it permutes).\n\nThe function "ProgressiveMesh" is not defined in the header file, which suggests that it is implemented in a separate source file.