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pub mod space;
pub mod state;
mod tests;
pub use self::space::*;
pub use self::state::*;
use error::*;
use id::*;
use petgraph::algo::astar;
use petgraph::graphmap::UnGraphMap;
use std::collections::HashMap;
/// Object that represents quantized density fields.
///
/// # Concept
/// QDF does not exists in any space - it IS the space, it defines it,
/// it describes it so there are no space coordinates and it is your responsibility to deliver it.
/// In future releases this crate will have module for projecting QDF into Euclidean space
/// and will have a satelite crate to easlyy traverse and visualize space.
///
/// To sample specified region you have to know some space ID and gather the rest of information
/// based on it neighbors spaces.
/// It gives the ability to cotrol space density at specified locations, which can be used
/// for example to simulate space curvature based on gravity.
#[derive(Debug)]
pub struct QDF<S>
where
S: State,
{
id: ID,
graph: UnGraphMap<ID, ()>,
spaces: HashMap<ID, Space<S>>,
root: ID,
dimensions: usize,
}
impl<S> QDF<S>
where
S: State,
{
/// Creates new QDF information universe.
///
/// # Arguments
/// * `dimensions` - Number of dimensions which space contains.
/// * `root_state` - State of root space.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// // Creates 2d space with `16` as root state.
/// let qdf = QDF::new(2, 9);
/// assert_eq!(*qdf.state(), 9);
/// ```
pub fn new(dimensions: usize, root_state: S) -> Self {
let mut graph = UnGraphMap::new();
let mut spaces = HashMap::new();
let id = ID::new();
graph.add_node(id);
spaces.insert(id, Space::with_id(id, root_state));
Self {
id: ID::new(),
graph,
spaces,
root: id,
dimensions,
}
}
/// Gets QDF id.
#[inline]
pub fn id(&self) -> ID {
self.id
}
/// Gets QDF root space node id.
#[inline]
pub fn root(&self) -> ID {
self.root
}
/// Gets QDF dimensions number.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let qdf = QDF::new(2, 9);
/// assert_eq!(qdf.dimensions(), 2);
/// ```
#[inline]
pub fn dimensions(&self) -> usize {
self.dimensions
}
/// Gets QDF dimensions number.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let qdf = QDF::new(2, 9);
/// assert_eq!(*qdf.state(), 9);
/// ```
#[inline]
pub fn state(&self) -> &S {
self.spaces[&self.root].state()
}
/// Tells if space with given id exists in QDF.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let qdf = QDF::new(2, 9);
/// assert!(qdf.space_exists(qdf.root()));
/// ```
#[inline]
pub fn space_exists(&self, id: ID) -> bool {
self.spaces.contains_key(&id)
}
/// Try to get given space.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let qdf = QDF::new(2, 9);
/// if let Some(space) = qdf.try_get_space(qdf.root()) {
/// assert_eq!(*space.state(), 9);
/// }
/// ```
#[inline]
pub fn try_get_space(&self, id: ID) -> Option<&Space<S>> {
self.spaces.get(&id)
}
/// Get given space or throw error if space does not exists.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let qdf = QDF::new(2, 9);
/// if let Ok(space) = qdf.get_space(qdf.root()) {
/// assert_eq!(*space.state(), 9);
/// }
/// ```
#[inline]
pub fn get_space(&self, id: ID) -> Result<&Space<S>> {
if let Some(space) = self.spaces.get(&id) {
Ok(space)
} else {
Err(QDFError::SpaceDoesNotExists(id))
}
}
/// Get given space or panic if space does not exists.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let qdf = QDF::new(2, 9);
/// assert_eq!(*qdf.space(qdf.root()).state(), 9);
/// ```
#[inline]
pub fn space(&self, id: ID) -> &Space<S> {
&self.spaces[&id]
}
/// Try to set given space state.
///
/// # Arguments
/// * `id` - space id.
/// * `state` - state.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let mut qdf = QDF::new(2, 9);
/// let id = qdf.root();
/// assert!(qdf.try_set_space_state(id, 3));
/// ```
#[inline]
pub fn try_set_space_state(&mut self, id: ID, state: S) -> bool {
self.set_space_state(id, state).is_ok()
}
/// Set given space state or throw error if space does not exists.
///
/// # Arguments
/// * `id` - space id.
/// * `state` - state.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let mut qdf = QDF::new(2, 9);
/// let id = qdf.root();
/// assert!(qdf.set_space_state(id, 3).is_ok());
/// ```
#[inline]
pub fn set_space_state(&mut self, id: ID, state: S) -> Result<()> {
if self.space_exists(id) {
let substate = state.subdivide(self.dimensions + 1);
let mut space = self.spaces[&id].clone();
space.apply_state(state);
for s in space.subspace() {
self.set_space_state(*s, substate.clone())?;
}
let mut parent = space.parent();
self.spaces.insert(id, space);
while parent.is_some() {
parent = self.recalculate_state(parent.unwrap());
}
Ok(())
} else {
Err(QDFError::SpaceDoesNotExists(id))
}
}
/// Get list of IDs of given space neighbors or throws error if space does not exists.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let mut qdf = QDF::new(2, 9);
/// let id = qdf.root();
/// qdf.increase_space_density(id);
/// let subs = qdf.space(qdf.root()).subspace();
/// assert_eq!(qdf.find_space_neighbors(subs[0]).unwrap(), vec![subs[1], subs[2]]);
/// ```
#[inline]
pub fn find_space_neighbors(&self, id: ID) -> Result<Vec<ID>> {
if self.graph.contains_node(id) {
Ok(self.graph.neighbors(id).collect())
} else {
Err(QDFError::SpaceDoesNotExists(id))
}
}
/// Gets list of space IDs that defines shortest path between two spaces,
/// or throws error if space does not exists.
///
/// # Arguments
/// * `from` - source space id.
/// * `to` - target space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let mut qdf = QDF::new(2, 9);
/// let id = qdf.root();
/// qdf.increase_space_density(id);
/// let subs = qdf.space(qdf.root()).subspace().to_vec();
/// qdf.increase_space_density(subs[0]);
/// let subs2 = qdf.space(subs[0]).subspace();
/// assert_eq!(qdf.find_path(subs2[0], subs[2]).unwrap(), vec![subs2[0], subs2[1], subs[2]]);
/// ```
pub fn find_path(&self, from: ID, to: ID) -> Result<Vec<ID>> {
if !self.space_exists(from) {
return Err(QDFError::SpaceDoesNotExists(from));
}
if !self.space_exists(to) {
return Err(QDFError::SpaceDoesNotExists(to));
}
if let Some((_, spaces)) = astar(&self.graph, from, |f| f == to, |_| 0, |_| 0) {
Ok(spaces)
} else {
Ok(vec![])
}
}
/// Increases given space density (subdivide space and rebind it properly to its neighbors),
/// or throws error if space does not exists.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let mut qdf = QDF::new(2, 9);
/// let id = qdf.root();
/// qdf.increase_space_density(id);
/// assert_eq!(qdf.space(qdf.root()).subspace().len(), 3);
/// ```
pub fn increase_space_density(&mut self, id: ID) -> Result<()> {
if self.space_exists(id) {
let mut space = self.spaces[&id].clone();
if !space.is_platonic() {
for s in space.subspace() {
self.increase_space_density(*s)?;
}
} else {
let subs = self.dimensions + 1;
let substate = space.state().subdivide(subs);
let spaces = (0..subs)
.map(|_| Space::with_id_parent_state(ID::new(), id, substate.clone()))
.collect::<Vec<Space<S>>>();
let subspace = spaces.iter().map(|s| s.id()).collect::<Vec<ID>>();
for s in spaces {
let id = s.id();
self.spaces.insert(id, s);
self.graph.add_node(id);
}
for a in &subspace {
for b in &subspace {
if a != b {
self.graph.add_edge(*a, *b, ());
}
}
}
let neighbors = self.graph.neighbors(id).collect::<Vec<ID>>();
for (i, n) in neighbors.iter().enumerate() {
self.graph.remove_edge(*n, id);
self.graph.add_edge(*n, subspace[i], ());
}
space.apply_subspace(subspace);
self.spaces.insert(id, space);
}
Ok(())
} else {
Err(QDFError::SpaceDoesNotExists(id))
}
}
/// Decreases given space density (merge space children and rebind them properly to theirs
/// neighbors if space has 1 level of subdivision, otherwise perform this operation on its
/// subspaces), or throws error if space does not exists.
///
/// # Arguments
/// * `id` - space id.
///
/// # Examples
/// ```
/// use quantized_density_fields::QDF;
///
/// let mut qdf = QDF::new(2, 9);
/// let id = qdf.root();
/// qdf.increase_space_density(id);
/// assert_eq!(qdf.space(qdf.root()).subspace().len(), 3);
/// qdf.decrease_space_density(id);
/// assert!(qdf.space(qdf.root()).is_platonic());
/// ```
pub fn decrease_space_density(&mut self, id: ID) -> Result<bool> {
if self.space_exists(id) {
let mut space = self.spaces[&id].clone();
if space.is_platonic() {
Ok(true)
} else {
let merge = space
.subspace()
.iter()
.map(|id| {
if self.spaces[id].is_platonic() {
Ok(true)
} else {
self.decrease_space_density(*id)
}
}).collect::<Result<Vec<bool>>>()?
.iter()
.all(|v| *v);
if merge {
let neighbors = space
.subspace()
.iter()
.flat_map(|s| self.graph.neighbors(*s).collect::<Vec<ID>>())
.filter(|s| !space.subspace().contains(s))
.collect::<Vec<ID>>();
for n in neighbors {
self.graph.add_edge(id, n, ());
}
for s in space.subspace() {
self.graph.remove_node(*s);
self.spaces.remove(s);
}
space.apply_subspace(vec![]);
self.spaces.insert(id, space);
}
Ok(false)
}
} else {
Err(QDFError::SpaceDoesNotExists(id))
}
}
/// Decreases given space density (merge space children and rebind them properly to theirs
/// neighbors), or throws error if space does not exists. Basically it works like
/// `Self::decrease_space_density()` but merges space to make it completely platonic.
///
/// # Arguments
/// * `id` - space id.
#[inline]
pub fn decrease_space_density_level(&mut self, id: ID) -> Result<()> {
while !self.decrease_space_density(id)? {}
Ok(())
}
fn recalculate_state(&mut self, id: ID) -> Option<ID> {
let mut space = self.spaces[&id].clone();
let states = space
.subspace()
.iter()
.map(|s| self.spaces[&s].state().clone())
.collect::<Vec<S>>();
space.apply_state(Subdividable::merge(&states));
let parent = space.parent();
self.spaces.insert(id, space);
parent
}
}