49 lines
1.2 KiB
Rust
49 lines
1.2 KiB
Rust
use instant::Instant;
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use lyra_ecs::{Component, World};
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use lyra_reflect::Reflect;
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use crate::{plugin::Plugin, game::GameStages};
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#[derive(Clone, Copy, Component, Default, Reflect)]
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pub struct DeltaTime(f32, #[reflect(skip)] Option<Instant>);
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impl From<f32> for DeltaTime {
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fn from(value: f32) -> Self {
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DeltaTime(value, None)
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}
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}
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impl std::ops::Deref for DeltaTime {
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type Target = f32;
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fn deref(&self) -> &Self::Target {
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&self.0
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}
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}
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impl std::ops::DerefMut for DeltaTime {
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fn deref_mut(&mut self) -> &mut Self::Target {
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&mut self.0
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}
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}
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/// A system that updates the [`DeltaTime``] resource.
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///
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/// The resource is updated in the [`GameStages::First`] stage.
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pub fn delta_time_system(world: &mut World) -> anyhow::Result<()> {
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let now = Instant::now();
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let mut delta = world.get_resource_mut::<DeltaTime>();
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delta.0 = delta.1.unwrap_or(now).elapsed().as_secs_f32();
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delta.1 = Some(now);
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Ok(())
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}
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pub struct DeltaTimePlugin;
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impl Plugin for DeltaTimePlugin {
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fn setup(&self, game: &mut crate::game::Game) {
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game.world_mut().add_resource(DeltaTime(0.0, None));
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game.add_system_to_stage(GameStages::First, "delta_time", delta_time_system, &[]);
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}
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} |