fyrox_animation/machine/
event.rs

1// Copyright (c) 2019-present Dmitry Stepanov and Fyrox Engine contributors.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a copy
4// of this software and associated documentation files (the "Software"), to deal
5// in the Software without restriction, including without limitation the rights
6// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7// copies of the Software, and to permit persons to whom the Software is
8// furnished to do so, subject to the following conditions:
9//
10// The above copyright notice and this permission notice shall be included in all
11// copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
19// SOFTWARE.
20
21//! State machine could produces a fixed set of events during its work, this module contains all the stuff
22//! needed to works with such events.
23
24use crate::{
25    core::pool::Handle,
26    machine::{State, Transition},
27    EntityId,
28};
29use std::collections::VecDeque;
30
31/// Specific state machine event.
32#[derive(Debug, Clone, PartialEq, Eq)]
33pub enum Event<T: EntityId> {
34    /// Occurs when enter some state. See module docs for example.
35    StateEnter(Handle<State<T>>),
36
37    /// Occurs when leaving some state. See module docs for example.
38    StateLeave(Handle<State<T>>),
39
40    /// Occurs when a transition is done and a new active state was set.
41    ActiveStateChanged {
42        /// Previously active state.
43        prev: Handle<State<T>>,
44
45        /// New active state.
46        new: Handle<State<T>>,
47    },
48
49    /// Occurs when active transition was changed.
50    ActiveTransitionChanged(Handle<Transition<T>>),
51}
52
53/// A simple event queue with fixed capacity. It is used to store a fixed amount of events and discard any
54/// events when the queue is full.
55#[derive(Debug, Clone, PartialEq, Eq)]
56pub struct FixedEventQueue<T: EntityId> {
57    queue: VecDeque<Event<T>>,
58    limit: u32,
59}
60
61impl<T: EntityId> Default for FixedEventQueue<T> {
62    fn default() -> Self {
63        Self {
64            queue: Default::default(),
65            limit: u32::MAX,
66        }
67    }
68}
69
70impl<T: EntityId> FixedEventQueue<T> {
71    /// Creates a new queue with given limit.
72    pub fn new(limit: u32) -> Self {
73        Self {
74            queue: VecDeque::with_capacity(limit as usize),
75            limit,
76        }
77    }
78
79    /// Pushes an event to the queue.
80    pub fn push(&mut self, event: Event<T>) {
81        if self.queue.len() < (self.limit as usize) {
82            self.queue.push_back(event);
83        }
84    }
85
86    /// Pops an event from the queue.
87    pub fn pop(&mut self) -> Option<Event<T>> {
88        self.queue.pop_front()
89    }
90}
fyrox_animation/machine/event.rs

fyrox_animation/machine/
event.rs
