6 releases
0.3.1 | Oct 9, 2019 |
---|---|
0.3.0 | Oct 8, 2019 |
0.2.0 | Oct 7, 2019 |
0.1.2 | Jan 8, 2019 |
0.1.1 | Dec 26, 2018 |
#9 in #click
Used in 4 crates
(via sylasteven)
11KB
143 lines
Layer system
This is a simple system for managing programs with multiple different parts.
It's inspired by State
in Amethyst, but aims to be simpler, more flexible and more general.
Example Usage
enum Event {
Fixed, // generated at fixed times
Click(u16, u16), // generated by click
Quit, // genreated by try to close window
}
use self::Event::*;
struct State; // a global state
type LayerManager = layer_system::LayerManager<State, Event>; // the layer manager
use layer_system::{Change, Layer}; // other imports from layer System
struct World; // layer for the game world
impl Layer<State, Event> for World {
fn passive_update(&mut self, _state: &mut State, event: &Event) {
match event {
Fixed => { /* render here */ }
_ => (),
}
}
fn update(&mut self, _state: &mut State, event: &Event) -> Change<State, Event> {
match event {
Fixed => { /* world physics update */ }
_ => (),
}
Change::none()
}
}
struct Interface;
enum ClickEvent {
Action,
Pause,
Exit,
Nothing,
}
impl Interface {
fn click(&self, x: u16, y: u16) -> ClickEvent {
use self::ClickEvent::*;
if y < 16 {
if x < 64 {
Action
} else if x < 128 {
Pause
} else if x < 192 {
Exit
} else {
Nothing
}
} else {
Nothing
}
}
}
impl Layer<State, Event> for Interface {
fn passive_update(&mut self, _state: &mut State, event: &Event) {
match event {
Fixed => { /* render here */ }
_ => (),
}
}
fn update(&mut self, _state: &mut State, event: &Event) -> Change<State, Event> {
match event {
Click(x, y) => match self.click(*x, *y) {
// execute some action when clicking "Action"
ClickEvent::Action => {
/* execute action */
Change::none()
}
// pause when clicking "Pause"
ClickEvent::Pause => Change::add(vec![Box::new(Pause)]),
// remove all layers when clicking "Exit"
ClickEvent::Exit => Change::close(),
// nothing was clicked, so in case the world supports a click event, just defer it
ClickEvent::Nothing => Change::pass(),
},
// when trying to quit the game, pause it first
Quit => Change::add(vec![Box::new(Pause)]),
// Defer all other events, so World will handle everything else
_ => Change::pass(),
}
}
}
struct Pause;
impl Layer<State, Event> for Pause {
fn passive_update(&mut self, _state: &mut State, event: &Event) {
match event {
Fixed => { /* render here */ }
_ => (),
}
}
fn update(&mut self, _state: &mut State, event: &Event) -> Change<State, Event> {
match event {
// do not defer `Fixed`, so world physics won't be updated anymore
Fixed => Change::none(),
// end pause by clicking somewhere
Click(_, _) => Change::remove(),
// when trying to quit the game again, quit it
Quit => Change::close(),
}
}
}
fn main() {
let mut manager = LayerManager::new(vec![Box::new(World), Box::new(Interface)]);
let mut state = State;
while manager.is_active() {
manager.update(&mut state, Fixed);
/* handle other events in events loop */
// if click event:
manager.update(&mut state, Click(0, 0));
// if quit event:
manager.update(&mut state, Quit);
/* wait for a fixed time */
}
}