Utility functions. More...

Modules
	Assert and errors
	Assertions and exceptions.

	Miscellaneous
	Useful functions that don't have their place anywhere else.

	Warnings
	Managing compiler warnings.

Classes
class	AdjacencyList< Index >
	Adjacency list. More...

class	BitField< EnumType_ >
	Bit field utility class. More...

struct	ChainEdgesOptions
	Options for chain_directed_edges and chain_undirected_edges. More...

struct	ChainEdgesResult< Index >
	Result struct holding the loops and chains extracted from a set of edges. More...

class	DisjointSets< IndexType >
	Disjoint sets computation. More...

class	SmallVector< T, N >
	Hybrid vector that uses the stack upto a maximum size, and the heap beyond that. More...

struct	StackSet< T, N >
	Stack-allocated set with a maximum size. More...

struct	StackVector< T, N >
	Stack-allocated vector with a maximum size. More...

Functions
template<typename Index >
ChainEdgesResult< Index >	chain_directed_edges (const span< const Index > edges, const ChainEdgesOptions &options={})
	Chain a set of directed edges into loops and chains. More...

template<typename Index >
ChainEdgesResult< Index >	chain_undirected_edges (const span< const Index > edges, const ChainEdgesOptions &options={})
	Chain a set of undirected edges into loops and chains. More...

template<class T , size_t N>
bool	operator== (const StackSet< T, N > &lhs, const StackSet< T, N > &rhs)

template<class T , size_t N>
bool	operator== (const StackVector< T, N > &lhs, const StackVector< T, N > &rhs)

Detailed Description

Utility functions.

A simple loop is defined as a set of connected edges whose starting and ending vertex is the same.

All vertices involved in a simple loop has exact two incident edges. For example, the letter O contains one simple loop.

An ear loop is defined as a set of connected edges whose starting and ending vertex is the same. All vertices except the start/end vertex has exact two incident edges. For example, the digit 8 contains two ear loops.

A chain is defined as a set of connected edges whose starting and ending vertex is different. All vertices in a chain except the end points have exactly two incident edges. For example, the digit 2 contains one chain.

A chain is called a simple chain its both of its end points are not connected to any other edges. I.e. they have degree 1. For example, the = sign has two simple chains.

A chain is called a hanging chain if one of its end vertices is not connected to any other edges. For example, the digit 6 contains 1 hanging chain and a ear loop.

Function Documentation

◆ chain_directed_edges()

ChainEdgesResult< Index > chain_directed_edges	(	const span< const Index >	edges,
		const ChainEdgesOptions &	options = `{}`
	)

#include <lagrange/utils/chain_edges.h>

Chain a set of directed edges into loops and chains.

This methods guarantees that all simple loops and simple chains are extracted. This method will also iteratively extract all ear loops and hanging chains.

Template Parameters

Index The Index type.

Parameters

edges	The input set of edges.
options	Options controlling the behavior of this function.

Returns: A set of loops and chains extracted from the input edge set.

Both loops and chains are stored as an array of edges indices if options.output_edge_index is true, otherwise, they are an array of vertex indices.

If options.output_edge_vertex is false and options.close_loop_with_identical_vertices is true, the first and last vertices of a loop is identical.

See also: chain_undirected_edges

◆ chain_undirected_edges()

ChainEdgesResult< Index > chain_undirected_edges	(	const span< const Index >	edges,
		const ChainEdgesOptions &	options = `{}`
	)