Fixed animation frame-skip by only using the time since the last rere…

…nder request

Also cleaned up a few things

src/app.rs

@@ -420,7 +420,7 @@ impl<T: Send + 'static, V: View<T> + 'static> App<T, V> {
 
         let main_loop_tracing_span = tracing::debug_span!("main loop");
         let mut time_of_last_render = Instant::now();
-        let mut time_since_last_render = Duration::ZERO;
+        let mut time_since_last_render_request = Duration::ZERO;
         while let Some(event) = self.event_chan.blocking_recv() {
             let mut events = vec![event];
             // batch events
@@ -439,7 +439,7 @@ impl<T: Send + 'static, V: View<T> + 'static> App<T, V> {
             }
 
             if let Some(root_pod) = self.root_pod.as_mut() {
-                let cx_state = &mut CxState::new(&mut self.events, time_since_last_render);
+                let cx_state = &mut CxState::new(&mut self.events, time_since_last_render_request);
 
                 let mut cx = EventCx {
                     is_handled: false,
@@ -453,12 +453,17 @@ impl<T: Send + 'static, V: View<T> + 'static> App<T, V> {
             }
             self.send_events();
 
-            let rerender_requested = self.render(time_since_last_render)?;
+            let rerender_requested = self.render(time_since_last_render_request)?;
+            // TODO this is a workaround (I consider this at least as that) for getting animations right
+            // There's likely a cleaner solution
             if rerender_requested {
                 self.request_render_notifier.notify_one();
+                time_since_last_render_request = time_of_last_render.elapsed();
+            } else {
+                time_since_last_render_request = Duration::ZERO;
             }
-            time_since_last_render = time_of_last_render.elapsed();
             time_of_last_render = Instant::now();
+
             if quit {
                 break;
             }

src/view/animatables.rs

@@ -9,10 +9,10 @@ use crate::{
 
 // This is basically a View trait without <T, A> (but this may be subject to change, to allow animations based on the AppState (via e.g. event callbacks))
 pub trait Animatable<V>: Send + Sync {
-    /// Associated state for the view.
+    /// Associated state for the animatable.
     type State: Send;
 
-    /// Associated state for the view.
+    /// Associated state for the animatable.
     type Element: AnimatableElement<V>;
 
     /// Build the associated widget and initialize state.
@@ -33,7 +33,7 @@ pub trait Animatable<V>: Send + Sync {
     /// Propagate a message.
     ///
     /// Handle a message, propagating to children if needed. Here, `id_path` is a slice
-    /// of ids beginning at a child of this view.
+    /// of ids beginning at a child of this animatable.
     fn message(
         &self,
         id_path: &[Id],
@@ -58,16 +58,15 @@ impl<V, T: Tweenable<V>, R: Animatable<f64>> Animatable<V> for Lerp<T, R> {
     type Element = widget::animatables::Lerp<T::Element, R::Element>;
 
     fn build(&self, cx: &mut Cx) -> (Id, Self::State, Self::Element) {
-        let (id, (state, el)) = cx.with_new_id(|cx| {
+        let (id, (state, element)) = cx.with_new_id(|cx| {
             let (ratio_id, ratio_state, ratio_element) = self.ratio.build(cx);
             let (tweenable_id, tweenable_state, tweenable_element) = self.tweenable.build(cx);
-            let element = widget::animatables::Lerp::new(tweenable_element, ratio_element);
             (
                 (tweenable_id, tweenable_state, ratio_id, ratio_state),
-                element,
+                widget::animatables::Lerp::new(tweenable_element, ratio_element),
             )
         });
-        (id, state, el)
+        (id, state, element)
     }
 
     fn rebuild(
@@ -236,7 +235,7 @@ pub trait Tweenable<V>: Send + Sync {
     /// Build the associated widget and initialize state.
     fn build(&self, cx: &mut Cx) -> (Id, Self::State, Self::Element);
 
-    /// Update the associated value.
+    /// Update the associated element.
     ///
     /// Returns an indication of what, if anything, has changed.
     fn rebuild(
@@ -245,7 +244,7 @@ pub trait Tweenable<V>: Send + Sync {
         prev: &Self,
         id: &mut Id,
         state: &mut Self::State,
-        value: &mut Self::Element,
+        element: &mut Self::Element,
     ) -> ChangeFlags;
 
     /// Propagate a message.

src/widget/animatables.rs

@@ -45,8 +45,6 @@ macro_rules! impl_animatable_for_primitive {
 }
 
 // All builtin number types
-impl_animatable_for_primitive!(f64);
-impl_animatable_for_primitive!(f32);
 impl_animatable_for_primitive!(i8);
 impl_animatable_for_primitive!(u8);
 impl_animatable_for_primitive!(i16);
@@ -60,6 +58,9 @@ impl_animatable_for_primitive!(u128);
 impl_animatable_for_primitive!(isize);
 impl_animatable_for_primitive!(usize);
 
+impl_animatable_for_primitive!(f32);
+impl_animatable_for_primitive!(f64);
+
 #[derive(Clone, Debug)]
 pub struct LowPassIIR<AT, V> {
     pub(crate) target: AT,
@@ -91,7 +92,7 @@ impl<AT: AnimatableElement<f64>> AnimatableElement<f64> for LowPassIIR<AT, f64>
         let target_value = self.target.animate(cx);
         if let Some(value) = &mut self.value {
             if (*target_value - *value).abs() > 0.0001 {
-                let delta_time = cx.time_since_last_render().as_secs_f64() * 100.0; // could be a different factor, and maybe more precisely a frequency based cutoff or something like that
+                let delta_time = cx.time_since_last_render_request().as_secs_f64() * 100.0; // could be a different factor, and maybe more precisely a frequency based cutoff or something like that
                 let time_adjusted_decay =
                     1.0 - ((1.0 - self.decay.clamp(0.0, 1.0)).powf(delta_time));
                 *value += time_adjusted_decay * (*target_value - *value);
@@ -154,7 +155,7 @@ impl<V: 'static, PS: AnimatableElement<f64>, TW: TweenableElement<V>> Animatable
         let duration_as_secs = self.duration.as_secs_f64();
         let current_time_as_secs = self.current_time.as_secs_f64();
         let new_time = (current_time_as_secs
-            + *play_speed * cx.time_since_last_render().as_secs_f64())
+            + *play_speed * cx.time_since_last_render_request().as_secs_f64())
         .clamp(0.0, duration_as_secs);
         // avoid division by zero
         let ratio = if duration_as_secs == 0.0 {

src/widget/core.rs

@@ -20,14 +20,14 @@ message!(Send);
 /// Static state that is shared between most contexts.
 pub struct CxState<'a> {
     messages: &'a mut Vec<Message>,
-    pub(crate) time_since_last_render: Duration, // in seconds TODO Duration instead of f64?
+    pub(crate) time_since_last_render_request: Duration, // in seconds TODO Duration instead of f64?
 }
 
 impl<'a> CxState<'a> {
-    pub fn new(messages: &'a mut Vec<Message>, time_since_last_render: Duration) -> Self {
+    pub fn new(messages: &'a mut Vec<Message>, time_since_last_render_request: Duration) -> Self {
         Self {
             messages,
-            time_since_last_render,
+            time_since_last_render_request,
         }
     }
 }
@@ -144,8 +144,8 @@ impl_context_method!(
             self.widget_state.flags |= PodFlags::REQUEST_ANIMATION;
         }
 
-        pub fn time_since_last_render(&self) -> Duration {
-            self.cx_state.time_since_last_render
+        pub fn time_since_last_render_request(&self) -> Duration {
+            self.cx_state.time_since_last_render_request
         }
 
         /// Notify Trui that this widgets view context changed.