use crate::{
assets::{
font::FontAssetSubsystem, shader::ShaderAssetSubsystem, sound::SoundAssetSubsystem,
texture::TextureAssetSubsystem,
},
audio::Audio,
context::GameContext,
};
#[cfg(not(target_arch = "wasm32"))]
use glutin::{event::Event, window::Window};
#[cfg(target_arch = "wasm32")]
use instant::Instant;
use keket::database::AssetDatabase;
use spitfire_draw::{
context::DrawContext,
utils::{ShaderRef, Vertex},
};
use spitfire_glow::{app::AppState, graphics::Graphics, renderer::GlowBlending};
use spitfire_gui::context::GuiContext;
use spitfire_input::InputContext;
#[cfg(not(target_arch = "wasm32"))]
use std::time::Instant;
use std::{
any::{Any, TypeId},
cell::{Ref, RefCell, RefMut},
collections::HashMap,
};
#[cfg(target_arch = "wasm32")]
use winit::{event::Event, window::Window};
pub trait GameObject {
#[allow(unused_variables)]
fn activate(&mut self, context: &mut GameContext) {}
#[allow(unused_variables)]
fn deactivate(&mut self, context: &mut GameContext) {}
#[allow(unused_variables)]
fn process(&mut self, context: &mut GameContext, delta_time: f32) {}
#[allow(unused_variables)]
fn draw(&mut self, context: &mut GameContext) {}
}
#[derive(Default)]
pub enum GameStateChange {
#[default]
Continue,
Swap(Box<dyn GameState>),
Push(Box<dyn GameState>),
Pop,
}
#[allow(unused_variables)]
pub trait GameState {
fn enter(&mut self, context: GameContext) {}
fn exit(&mut self, context: GameContext) {}
fn update(&mut self, context: GameContext, delta_time: f32) {}
fn fixed_update(&mut self, context: GameContext, delta_time: f32) {}
fn draw(&mut self, context: GameContext) {}
fn draw_gui(&mut self, context: GameContext) {}
}
pub trait GameSubsystem {
fn run(&mut self, context: GameContext, delta_time: f32);
}
#[derive(Default)]
pub struct GameGlobals {
globals: HashMap<TypeId, RefCell<Box<dyn Any>>>,
}
impl GameGlobals {
pub fn set<T: 'static>(&mut self, value: T) {
self.globals
.insert(TypeId::of::<T>(), RefCell::new(Box::new(value)));
}
pub fn unset<T: 'static>(&mut self) {
self.globals.remove(&TypeId::of::<T>());
}
pub fn read<T: 'static>(&self) -> Option<Ref<T>> {
self.globals
.get(&TypeId::of::<T>())
.and_then(|v| v.try_borrow().ok())
.map(|v| Ref::map(v, |v| v.downcast_ref::<T>().unwrap()))
}
pub fn write<T: 'static>(&self) -> Option<RefMut<T>> {
self.globals
.get(&TypeId::of::<T>())
.and_then(|v| v.try_borrow_mut().ok())
.map(|v| RefMut::map(v, |v| v.downcast_mut::<T>().unwrap()))
}
}
pub struct GameInstance {
pub fixed_delta_time: f32,
pub color_shader: &'static str,
pub image_shader: &'static str,
pub text_shader: &'static str,
pub input_maintain_on_fixed_step: bool,
draw: DrawContext,
gui: GuiContext,
input: InputContext,
assets: AssetDatabase,
audio: Audio,
timer: Instant,
fixed_timer: Instant,
states: Vec<Box<dyn GameState>>,
state_change: GameStateChange,
subsystems: Vec<Box<dyn GameSubsystem>>,
globals: GameGlobals,
}
impl Default for GameInstance {
fn default() -> Self {
Self {
fixed_delta_time: 1.0 / 60.0,
color_shader: "color",
image_shader: "image",
text_shader: "text",
input_maintain_on_fixed_step: true,
draw: Default::default(),
gui: Default::default(),
input: Default::default(),
assets: Default::default(),
audio: Default::default(),
timer: Instant::now(),
fixed_timer: Instant::now(),
states: Default::default(),
state_change: Default::default(),
subsystems: vec![
Box::new(ShaderAssetSubsystem),
Box::new(TextureAssetSubsystem),
Box::new(FontAssetSubsystem),
Box::new(SoundAssetSubsystem),
],
globals: Default::default(),
}
}
}
impl GameInstance {
pub fn new(state: impl GameState + 'static) -> Self {
Self {
state_change: GameStateChange::Push(Box::new(state)),
..Default::default()
}
}
pub fn with_fixed_time_step(mut self, value: f32) -> Self {
self.fixed_delta_time = value;
self
}
pub fn with_fps(mut self, frames_per_second: usize) -> Self {
self.set_fps(frames_per_second);
self
}
pub fn with_color_shader(mut self, name: &'static str) -> Self {
self.color_shader = name;
self
}
pub fn with_image_shader(mut self, name: &'static str) -> Self {
self.image_shader = name;
self
}
pub fn with_text_shader(mut self, name: &'static str) -> Self {
self.text_shader = name;
self
}
pub fn with_input_maintain_on_fixed_step(mut self, value: bool) -> Self {
self.input_maintain_on_fixed_step = value;
self
}
pub fn with_subsystem(mut self, subsystem: impl GameSubsystem + 'static) -> Self {
self.subsystems.push(Box::new(subsystem));
self
}
pub fn with_globals<T: 'static>(mut self, value: T) -> Self {
self.globals.set(value);
self
}
pub fn setup_assets(mut self, f: impl FnOnce(&mut AssetDatabase)) -> Self {
f(&mut self.assets);
self
}
pub fn fps(&self) -> usize {
(1.0 / self.fixed_delta_time).ceil() as usize
}
pub fn set_fps(&mut self, frames_per_second: usize) {
self.fixed_delta_time = 1.0 / frames_per_second as f32;
}
pub fn process_frame(&mut self, graphics: &mut Graphics<Vertex>) {
let delta_time = self.timer.elapsed().as_secs_f32();
for subsystem in &mut self.subsystems {
subsystem.run(
GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
},
delta_time,
);
}
self.assets.maintain().unwrap();
if let Some(state) = self.states.last_mut() {
self.timer = Instant::now();
state.update(
GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
},
delta_time,
);
}
let fixed_delta_time = self.fixed_timer.elapsed().as_secs_f32();
let fixed_step = if fixed_delta_time > self.fixed_delta_time {
self.fixed_timer = Instant::now();
if let Some(state) = self.states.last_mut() {
state.fixed_update(
GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
},
fixed_delta_time,
);
}
true
} else {
false
};
self.draw.begin_frame(graphics);
self.draw.push_shader(&ShaderRef::name(self.image_shader));
self.draw.push_blending(GlowBlending::Alpha);
if let Some(state) = self.states.last_mut() {
state.draw(GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
});
}
self.gui.begin_frame();
if let Some(state) = self.states.last_mut() {
state.draw_gui(GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
});
}
self.gui.end_frame(
&mut self.draw,
graphics,
&ShaderRef::name(self.color_shader),
&ShaderRef::name(self.image_shader),
&ShaderRef::name(self.text_shader),
);
self.draw.end_frame();
if !self.input_maintain_on_fixed_step || fixed_step {
self.input.maintain();
}
match std::mem::take(&mut self.state_change) {
GameStateChange::Continue => {}
GameStateChange::Swap(mut state) => {
if let Some(mut state) = self.states.pop() {
state.exit(GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
});
}
state.enter(GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
});
self.states.push(state);
self.timer = Instant::now();
}
GameStateChange::Push(mut state) => {
state.enter(GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
});
self.states.push(state);
self.timer = Instant::now();
}
GameStateChange::Pop => {
if let Some(mut state) = self.states.pop() {
state.exit(GameContext {
graphics,
draw: &mut self.draw,
gui: &mut self.gui,
input: &mut self.input,
state_change: &mut self.state_change,
assets: &mut self.assets,
audio: &mut self.audio,
globals: &mut self.globals,
});
}
self.timer = Instant::now();
}
}
}
pub fn process_event(&mut self, event: &Event<()>) -> bool {
if let Event::WindowEvent { event, .. } = event {
self.input.on_event(event);
}
!self.states.is_empty() || !matches!(self.state_change, GameStateChange::Continue)
}
}
impl AppState<Vertex> for GameInstance {
fn on_redraw(&mut self, graphics: &mut Graphics<Vertex>) {
self.process_frame(graphics);
}
fn on_event(&mut self, event: Event<()>, _: &mut Window) -> bool {
self.process_event(&event)
}
}