use core::convert::From;
use std::cmp::Reverse;
use std::collections::{BTreeSet, BinaryHeap};
use std::ops::Bound::{Excluded, Unbounded};
use crate::geometries::{Point, Segment};
use crate::operations::{
IntersectCrossingSegments, Orient, SegmentsCountable,
ToCorrectlyOrientedSegments,
};
use crate::oriented::Orientation;
use crate::sweeping::traits::{EventsContainer, EventsQueue, SweepLine};
use crate::traits::{Elemental, Segmental};
use super::constants::UNDEFINED_INDEX;
use super::event::is_event_right;
use super::event::{
is_event_left, left_event_to_position, segment_id_to_left_event,
segment_id_to_right_event, Event,
};
use super::events_queue_key::EventsQueueKey;
use super::operation_kind::{DIFFERENCE, INTERSECTION};
use super::sweep_line_key::SweepLineKey;
use super::traits::ReduceEvents;
pub(crate) struct Operation<Point, const FIRST_IS_LINEAR: bool, const KIND: u8>
{
first_segments_count: usize,
are_from_result: Vec<bool>,
#[allow(clippy::box_collection)]
endpoints: Box<Vec<Point>>,
events_queue_data: BinaryHeap<Reverse<EventsQueueKey<Point>>>,
have_interior_to_left: Vec<bool>,
have_overlap: Vec<bool>,
#[allow(clippy::box_collection)]
opposites: Box<Vec<Event>>,
other_have_interior_to_left: Vec<bool>,
segments_ids: Vec<usize>,
starts_ids: Vec<usize>,
sweep_line_data: BTreeSet<SweepLineKey<Point>>,
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
> From<(&Polygon, &Segment)> for Operation<Point, false, INTERSECTION>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&Polygon, &Segment)) -> Self {
let mut result = Self::with_capacity(first.segments_count(), 1);
result.extend(first.to_correctly_oriented_segments());
result.extend(std::iter::once(second.clone()));
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
> From<(&[&Polygon], &Segment)> for Operation<Point, false, INTERSECTION>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&[&Polygon], &Segment)) -> Self {
let mut result = Self::with_capacity(
first
.iter()
.copied()
.map(SegmentsCountable::segments_count)
.sum::<usize>(),
1,
);
for &polygon in first {
result.extend(polygon.to_correctly_oriented_segments());
}
result.extend(std::iter::once(second.clone()));
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
> From<(&Polygon, &[&Segment])> for Operation<Point, false, INTERSECTION>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&Polygon, &[&Segment])) -> Self {
let mut result =
Self::with_capacity(first.segments_count(), second.len());
result.extend(first.to_correctly_oriented_segments());
result.extend(second.iter().copied().cloned());
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
> From<(&[&Polygon], &[&Segment])>
for Operation<Point, false, INTERSECTION>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&[&Polygon], &[&Segment])) -> Self {
let mut result = Self::with_capacity(
first
.iter()
.copied()
.map(SegmentsCountable::segments_count)
.sum::<usize>(),
second.len(),
);
for &polygon in first {
result.extend(polygon.to_correctly_oriented_segments());
}
result.extend(second.iter().copied().cloned());
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
const KIND: u8,
> From<(&Segment, &Polygon)> for Operation<Point, true, KIND>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&Segment, &Polygon)) -> Self {
let mut result = Self::with_capacity(1, second.segments_count());
result.extend(std::iter::once(first.clone()));
result.extend(second.to_correctly_oriented_segments());
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
const KIND: u8,
> From<(&[&Segment], &Polygon)> for Operation<Point, true, KIND>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&[&Segment], &Polygon)) -> Self {
let mut result =
Self::with_capacity(first.len(), second.segments_count());
result.extend(first.iter().copied().cloned());
result.extend(second.to_correctly_oriented_segments());
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
const KIND: u8,
> From<(&Segment, &[&Polygon])> for Operation<Point, true, KIND>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&Segment, &[&Polygon])) -> Self {
let mut result = Self::with_capacity(
1,
second
.iter()
.copied()
.map(SegmentsCountable::segments_count)
.sum::<usize>(),
);
result.extend(std::iter::once(first.clone()));
for &polygon in second {
result.extend(polygon.to_correctly_oriented_segments());
}
result
}
}
impl<
Point: Ord,
Polygon,
Segment: Clone + Segmental<Endpoint = Point>,
Segments: Iterator<Item = Segment>,
const KIND: u8,
> From<(&[&Segment], &[&Polygon])> for Operation<Point, true, KIND>
where
for<'a> &'a Point: Orient,
for<'a> &'a Polygon:
SegmentsCountable + ToCorrectlyOrientedSegments<Output = Segments>,
{
fn from((first, second): (&[&Segment], &[&Polygon])) -> Self {
let mut result = Self::with_capacity(
first.len(),
second
.iter()
.copied()
.map(SegmentsCountable::segments_count)
.sum::<usize>(),
);
result.extend(first.iter().copied().cloned());
for &polygon in second {
result.extend(polygon.to_correctly_oriented_segments());
}
result
}
}
trait DetectIfLeftEventFromResult {
fn detect_if_left_event_from_result(&self, event: Event) -> bool;
}
impl<Point, const FIRST_IS_LINEAR: bool> DetectIfLeftEventFromResult
for Operation<Point, FIRST_IS_LINEAR, INTERSECTION>
{
fn detect_if_left_event_from_result(&self, event: Event) -> bool {
self.is_left_event_from_first_operand(event) == FIRST_IS_LINEAR
&& !self.is_left_event_outside(event)
}
}
impl<Point> DetectIfLeftEventFromResult
for Operation<Point, true, DIFFERENCE>
{
fn detect_if_left_event_from_result(&self, event: Event) -> bool {
self.is_left_event_from_first_operand(event)
&& self.is_left_event_outside(event)
}
}
impl<
Point: Clone + PartialOrd,
const FIRST_IS_LINEAR: bool,
const KIND: u8,
> Iterator for Operation<Point, FIRST_IS_LINEAR, KIND>
where
Self: EventsQueue<Event = Event>
+ DetectIfLeftEventFromResult
+ SweepLine<Event = Event>,
for<'a> &'a Point:
Elemental + IntersectCrossingSegments<Output = Point> + Orient,
for<'a> <&'a Point as Elemental>::Coordinate: PartialEq,
{
type Item = Event;
fn next(&mut self) -> Option<Self::Item> {
while let Some(event) = self.pop() {
if is_event_right(event) {
let opposite_event = self.to_opposite_event(event);
debug_assert!(is_event_left(opposite_event));
if let Some(equal_segment_event) =
<Self as SweepLine>::find(self, opposite_event)
{
let (maybe_above_event, maybe_below_event) = (
self.above(equal_segment_event),
self.below(equal_segment_event),
);
self.remove(equal_segment_event);
if let (Some(above_event), Some(below_event)) =
(maybe_above_event, maybe_below_event)
{
self.detect_intersection(below_event, above_event);
}
}
return Some(event);
} else if self.insert(event) {
debug_assert!(is_event_left(event));
let maybe_below_event = self.below(event);
self.compute_left_event_fields(event, maybe_below_event);
if let Some(above_event) = self.above(event) {
if self.detect_intersection(event, above_event) {
self.compute_left_event_fields(
event,
maybe_below_event,
);
self.compute_left_event_fields(
above_event,
Some(event),
);
}
}
if let Some(below_event) = maybe_below_event {
if self.detect_intersection(below_event, event) {
let below_below_event = self.below(below_event);
self.compute_left_event_fields(
below_event,
below_below_event,
);
self.compute_left_event_fields(
event,
maybe_below_event,
);
}
}
return Some(event);
}
}
None
}
fn size_hint(&self) -> (usize, Option<usize>) {
(0, Some(2 * self.events_queue_data.len()))
}
}
impl<Scalar, const FIRST_IS_LINEAR: bool, const KIND: u8> ReduceEvents
for Operation<Point<Scalar>, FIRST_IS_LINEAR, KIND>
where
Segment<Scalar>: From<(Point<Scalar>, Point<Scalar>)>,
Point<Scalar>: Clone,
{
type Output = Vec<Segment<Scalar>>;
fn reduce_events(&self, events: Vec<Event>) -> Self::Output {
events
.into_iter()
.filter(|&event| self.is_event_from_result(event))
.map(|event| {
Segment::from((
self.get_event_start(event).clone(),
self.get_event_end(event).clone(),
))
})
.collect()
}
}
impl<Point, const FIRST_IS_LINEAR: bool, const KIND: u8> EventsContainer
for Operation<Point, FIRST_IS_LINEAR, KIND>
{
type Endpoint = Point;
type Event = Event;
fn get_event_end(&self, event: Self::Event) -> &Self::Endpoint {
&self.endpoints[self.to_opposite_event(event)]
}
fn get_event_start(&self, event: Self::Event) -> &Self::Endpoint {
&self.endpoints[event]
}
}
impl<Point, const FIRST_IS_LINEAR: bool, const KIND: u8>
Operation<Point, FIRST_IS_LINEAR, KIND>
{
pub(crate) fn to_opposite_event(&self, event: Event) -> Event {
self.opposites[event]
}
fn compute_left_event_fields(
&mut self,
event: Event,
maybe_below_event: Option<Event>,
) where
Self: DetectIfLeftEventFromResult,
for<'a> &'a Point: Elemental,
for<'a> <&'a Point as Elemental>::Coordinate: PartialEq,
{
let event_position = left_event_to_position(event);
if let Some(below_event) = maybe_below_event {
let below_event_position = left_event_to_position(below_event);
self.other_have_interior_to_left[event_position] = {
if self.is_left_event_from_first_operand(event)
== self.is_left_event_from_first_operand(below_event)
{
self.other_have_interior_to_left[below_event_position]
} else {
self.have_interior_to_left
[self.left_event_to_segment_id(below_event)]
}
};
}
self.are_from_result[event_position] =
self.detect_if_left_event_from_result(event);
}
fn get_endpoints(&self) -> &Vec<Point> {
&self.endpoints
}
fn get_opposites(&self) -> &Vec<Event> {
&self.opposites
}
fn is_event_from_first_operand(&self, event: Event) -> bool {
self.is_left_event_from_first_operand(self.to_left_event(event))
}
fn is_event_from_result(&self, event: Event) -> bool {
self.are_from_result[left_event_to_position(self.to_left_event(event))]
}
fn is_left_event_from_first_operand(&self, event: Event) -> bool {
self.left_event_to_segment_id(event) < self.first_segments_count
}
fn is_left_event_outside(&self, event: Event) -> bool {
let event_position = left_event_to_position(event);
!self.other_have_interior_to_left[event_position]
&& !self.have_overlap[event_position]
}
fn left_event_to_segment_id(&self, event: Event) -> usize {
self.segments_ids[left_event_to_position(event)]
}
fn to_events_queue_key(&self, event: Event) -> EventsQueueKey<Point> {
EventsQueueKey::new(
event,
self.is_event_from_first_operand(event),
self.get_endpoints(),
self.get_opposites(),
)
}
fn to_left_event(&self, event: Event) -> Event {
if is_event_left(event) {
event
} else {
self.to_opposite_event(event)
}
}
fn to_sweep_line_key(&self, event: Event) -> SweepLineKey<Point> {
SweepLineKey::new(
event,
self.is_left_event_from_first_operand(event),
&self.endpoints,
&self.opposites,
)
}
}
impl<
Point: Clone + PartialOrd,
const FIRST_IS_LINEAR: bool,
const KIND: u8,
> Operation<Point, FIRST_IS_LINEAR, KIND>
where
Self: EventsQueue<Event = Event> + SweepLine<Event = Event>,
for<'a> &'a Point: IntersectCrossingSegments<Output = Point> + Orient,
{
fn detect_intersection(
&mut self,
below_event: Event,
event: Event,
) -> bool {
debug_assert_ne!(below_event, event);
let event_start = self.get_event_start(event);
let event_end = self.get_event_end(event);
let below_event_start = self.get_event_start(below_event);
let below_event_end = self.get_event_end(below_event);
let event_start_orientation =
below_event_end.orient(below_event_start, event_start);
let event_end_orientation =
below_event_end.orient(below_event_start, event_end);
if event_start_orientation == event_end_orientation {
if event_start_orientation == Orientation::Collinear {
debug_assert_ne!(
self.is_left_event_from_first_operand(below_event),
self.is_left_event_from_first_operand(event)
);
if event_start == below_event_start {
if event_end != below_event_end {
let (max_end_event, min_end_event) =
if event_end < below_event_end {
(below_event, event)
} else {
(event, below_event)
};
let min_end =
self.get_event_end(min_end_event).clone();
let (min_end_to_start_event, min_end_to_max_end_event) =
self.divide(max_end_event, min_end);
self.push(min_end_to_start_event);
self.push(min_end_to_max_end_event);
}
self.have_overlap[left_event_to_position(below_event)] =
true;
self.have_overlap[left_event_to_position(event)] = true;
return true;
} else if event_end == below_event_end {
let (max_start_event, min_start_event) =
if event_start < below_event_start {
(below_event, event)
} else {
(event, below_event)
};
let max_start =
self.get_event_start(max_start_event).clone();
let (max_start_to_min_start_event, max_start_to_end_event) =
self.divide(min_start_event, max_start);
self.push(max_start_to_min_start_event);
self.push(max_start_to_end_event);
} else if below_event_start < event_start
&& event_start < below_event_end
{
if event_end < below_event_end {
let event_start = event_start.clone();
let event_end = event_end.clone();
self.divide_event_by_mid_segment_event_endpoints(
below_event,
event,
event_start,
event_end,
);
} else {
let (max_start, min_end) =
(event_start.clone(), below_event_end.clone());
self.divide_overlapping_events(
below_event,
event,
max_start,
min_end,
);
}
} else if event_start < below_event_start
&& below_event_start < event_end
{
if below_event_end < event_end {
let below_event_start = below_event_start.clone();
let below_event_end = below_event_end.clone();
self.divide_event_by_mid_segment_event_endpoints(
event,
below_event,
below_event_start,
below_event_end,
);
} else {
let (max_start, min_end) =
(below_event_start.clone(), event_end.clone());
self.divide_overlapping_events(
event,
below_event,
max_start,
min_end,
);
}
}
}
} else if event_start_orientation == Orientation::Collinear {
if below_event_start < event_start && event_start < below_event_end
{
let point = event_start.clone();
self.divide_event_by_midpoint(below_event, point);
}
} else if event_end_orientation == Orientation::Collinear {
if below_event_start < event_end && event_end < below_event_end {
let point = event_end.clone();
self.divide_event_by_midpoint(below_event, point);
}
} else {
let below_event_start_orientation =
event_start.orient(event_end, below_event_start);
let below_event_end_orientation =
event_start.orient(event_end, below_event_end);
if below_event_start_orientation == Orientation::Collinear {
debug_assert_ne!(
below_event_end_orientation,
Orientation::Collinear
);
if event_start < below_event_start
&& below_event_start < event_end
{
let point = below_event_start.clone();
self.divide_event_by_midpoint(event, point);
}
} else if below_event_end_orientation == Orientation::Collinear {
if event_start < below_event_end && below_event_end < event_end
{
let point = below_event_end.clone();
self.divide_event_by_midpoint(event, point);
}
} else if below_event_start_orientation
!= below_event_end_orientation
{
let cross_point =
IntersectCrossingSegments::intersect_crossing_segments(
event_start,
event_end,
below_event_start,
below_event_end,
);
self.divide_event_by_midpoint(
below_event,
cross_point.clone(),
);
self.divide_event_by_midpoint(event, cross_point);
}
}
false
}
fn divide_overlapping_events(
&mut self,
min_start_event: Event,
max_start_event: Event,
max_start: Point,
min_end: Point,
) {
self.divide_event_by_midpoint(max_start_event, min_end);
self.divide_event_by_midpoint(min_start_event, max_start);
}
fn divide_event_by_mid_segment_event_endpoints(
&mut self,
event: Event,
mid_segment_event: Event,
mid_segment_event_start: Point,
mid_segment_event_end: Point,
) where
Point: PartialEq,
{
debug_assert!(mid_segment_event_start
.eq(self.get_event_start(mid_segment_event)));
debug_assert!(
mid_segment_event_end.eq(self.get_event_end(mid_segment_event))
);
debug_assert!(mid_segment_event_start.ne(self.get_event_start(event)));
debug_assert!(mid_segment_event_end.ne(self.get_event_end(event)));
self.divide_event_by_midpoint(event, mid_segment_event_end);
self.divide_event_by_midpoint(event, mid_segment_event_start);
}
fn divide_event_by_midpoint(&mut self, event: Event, point: Point) {
let (point_to_event_start_event, point_to_event_end_event) =
self.divide(event, point);
self.push(point_to_event_start_event);
self.push(point_to_event_end_event);
}
}
impl<Point: Clone, const FIRST_IS_LINEAR: bool, const KIND: u8>
Operation<Point, FIRST_IS_LINEAR, KIND>
{
fn divide(&mut self, event: Event, mid_point: Point) -> (Event, Event) {
debug_assert!(is_event_left(event));
let opposite_event = self.to_opposite_event(event);
let mid_point_to_event_end_event: Event = self.endpoints.len();
self.segments_ids.push(self.left_event_to_segment_id(event));
self.endpoints.push(mid_point.clone());
self.opposites.push(opposite_event);
self.opposites[opposite_event] = mid_point_to_event_end_event;
self.other_have_interior_to_left.push(false);
self.are_from_result.push(false);
self.have_overlap.push(false);
self.starts_ids.push(UNDEFINED_INDEX);
let mid_point_to_event_start_event: Event = self.endpoints.len();
self.endpoints.push(mid_point);
self.opposites.push(event);
self.opposites[event] = mid_point_to_event_start_event;
self.starts_ids.push(UNDEFINED_INDEX);
debug_assert_eq!(
self.is_left_event_from_first_operand(event),
self.is_event_from_first_operand(mid_point_to_event_start_event)
);
debug_assert_eq!(
self.is_left_event_from_first_operand(event),
self.is_left_event_from_first_operand(
mid_point_to_event_end_event
)
);
(mid_point_to_event_start_event, mid_point_to_event_end_event)
}
}
impl<Point: Ord, const FIRST_IS_LINEAR: bool, const KIND: u8> EventsQueue
for Operation<Point, FIRST_IS_LINEAR, KIND>
where
for<'a> &'a Point: Orient,
{
type Event = Event;
fn peek(&mut self) -> Option<Self::Event> {
self.events_queue_data.peek().map(|key| key.0.event)
}
fn pop(&mut self) -> Option<Self::Event> {
self.events_queue_data.pop().map(|key| key.0.event)
}
fn push(&mut self, event: Self::Event) {
self.events_queue_data
.push(Reverse(self.to_events_queue_key(event)));
}
}
impl<Point, const FIRST_IS_LINEAR: bool, const KIND: u8> SweepLine
for Operation<Point, FIRST_IS_LINEAR, KIND>
where
SweepLineKey<Point>: Ord,
{
type Event = Event;
fn above(&self, event: Self::Event) -> Option<Self::Event> {
self.sweep_line_data
.range((Excluded(&self.to_sweep_line_key(event)), Unbounded))
.next()
.map(|key| key.event)
}
fn below(&self, event: Self::Event) -> Option<Self::Event> {
self.sweep_line_data
.range((Unbounded, Excluded(&self.to_sweep_line_key(event))))
.last()
.map(|key| key.event)
}
fn find(&self, event: Self::Event) -> Option<Self::Event> {
self.sweep_line_data
.get(&self.to_sweep_line_key(event))
.map(|key| key.event)
}
fn insert(&mut self, event: Self::Event) -> bool {
self.sweep_line_data.insert(self.to_sweep_line_key(event))
}
fn remove(&mut self, event: Self::Event) -> bool {
self.sweep_line_data.remove(&self.to_sweep_line_key(event))
}
}
impl<Point: Ord, const FIRST_IS_LINEAR: bool, const KIND: u8>
Operation<Point, FIRST_IS_LINEAR, KIND>
where
for<'a> &'a Point: Orient,
{
fn extend<Segment>(&mut self, segments: impl Iterator<Item = Segment>)
where
Segment: Segmental<Endpoint = Point>,
{
let segment_id_offset = self.endpoints.len() / 2;
for (segment_index, segment) in segments.enumerate() {
let (mut start, mut end) = segment.endpoints();
debug_assert!(start != end);
let segment_id = segment_id_offset + segment_index;
let is_sorted_segment = start < end;
if !is_sorted_segment {
(start, end) = (end, start);
self.have_interior_to_left[segment_id] = false;
}
let left_event = segment_id_to_left_event(segment_id);
let right_event = segment_id_to_right_event(segment_id);
self.endpoints.push(start);
self.endpoints.push(end);
self.opposites.push(right_event);
self.opposites.push(left_event);
self.push(left_event);
self.push(right_event);
}
}
fn with_capacity(
first_segments_count: usize,
second_segments_count: usize,
) -> Self {
let segments_count = first_segments_count + second_segments_count;
let initial_events_count = 2 * segments_count;
Self {
first_segments_count,
are_from_result: vec![false; segments_count],
endpoints: Box::new(Vec::with_capacity(initial_events_count)),
events_queue_data: BinaryHeap::with_capacity(initial_events_count),
have_interior_to_left: vec![true; segments_count],
have_overlap: vec![false; segments_count],
opposites: Box::new(Vec::with_capacity(initial_events_count)),
other_have_interior_to_left: vec![false; segments_count],
segments_ids: (0..segments_count).collect(),
starts_ids: vec![UNDEFINED_INDEX; initial_events_count],
sweep_line_data: BTreeSet::new(),
}
}
}