Fix bug where particle velocity was not correctly calculated based on…

… time (#8) * Fix bug where particle velocity was not correctly calculated based on time * Formatting
abnormalbrain · Jun 16, 2022 · 4394532 · 4394532
1 parent 2b11b88
commit 4394532
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Showing 2 changed files with 11 additions and 2 deletions.
diff --git a/examples/basic.rs b/examples/basic.rs
@@ -1,6 +1,8 @@
 use bevy::{
     core_pipeline::ClearColor,
+    diagnostic::{FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
     prelude::{App, AssetServer, Color, Commands, OrthographicCameraBundle, Res},
+    window::{PresentMode, WindowDescriptor},
     DefaultPlugins,
 };
 use bevy_particle_systems::{
@@ -11,6 +13,12 @@ use bevy_particle_systems::{
 fn main() {
     App::new()
         .insert_resource(ClearColor(Color::BLACK))
+        .insert_resource(WindowDescriptor {
+            present_mode: PresentMode::Immediate,
+            ..WindowDescriptor::default()
+        })
+        .add_plugin(FrameTimeDiagnosticsPlugin::default())
+        .add_plugin(LogDiagnosticsPlugin::default())
         .add_plugins(DefaultPlugins)
         .add_plugin(ParticleSystemPlugin::default()) // <-- Add the plugin
         .add_startup_system(startup_system)
@@ -28,7 +36,7 @@ fn startup_system(mut commands: Commands, asset_server: Res<AssetServer>) {
                 spawn_rate_per_second: 500.0.into(),
                 initial_velocity: JitteredValue::jittered(3.0, -1.0..1.0),
                 acceleration: ValueOverTime::Sin(SinWave {
-                    amplitude: 5.0,
+                    amplitude: 150.0,
                     period: 5.0,
                     ..SinWave::default()
                 }),

diff --git a/src/systems.rs b/src/systems.rs
@@ -268,7 +268,8 @@ pub(crate) fn particle_transform(
                     }
                 }
                 let lifetime_pct = lifetime.0 / particle.max_lifetime;
-                velocity.0 += particle_system.acceleration.at_lifetime_pct(lifetime_pct);
+                velocity.0 += particle_system.acceleration.at_lifetime_pct(lifetime_pct)
+                    * time.delta_seconds();
                 let initial_position = transform.translation;
 
                 transform.translation +=