Set up a main animation loop

Cargo.lock

@@ -921,6 +921,7 @@ dependencies = [
 name = "cyberpunk-slideshow"
 version = "0.1.0"
 dependencies = [
+ "async-std",
  "cairo-rs",
  "cyberpunk",
  "gio 0.18.4",

cyberpunk-slideshow/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+async-std = "1.13.0"
 cairo-rs    = "0.18"
 cyberpunk   = { path = "../cyberpunk" }
 gio         = "0.18"

cyberpunk-slideshow/script.yml

@@ -1,11 +1,18 @@
 - text: The distinguishing thing about magic is that it includes some kind of personal element. The person who is performing the magic is relevant to the magic. -- Ted Chang, Marie Brennan
   position: top
-  transition: !Fade
+  transition:
+    secs: 2
+    nanos: 0
+
 - text: Any sufficiently advanced technology is indistinguishable from magic. -- Arthur C. Clark.
   position: middle
-  transition: !Fade
+  transition:
+    secs: 2
+    nanos: 0
 
 - text: Electricity is the closest we get to Magic in this world.
   position: middle
-  transition: !Fade
+  transition:
+    secs: 2
+    nanos: 0
 

cyberpunk-slideshow/src/main.rs

@@ -1,5 +1,14 @@
-use std::{cell::RefCell, fs::File, io::Read, ops::Index, path::Path, rc::Rc, time::Duration};
+use std::{
+    cell::RefCell,
+    fs::File,
+    io::Read,
+    ops::Index,
+    path::Path,
+    rc::Rc,
+    time::{Duration, Instant},
+};
 
+use cairo::Context;
 use cyberpunk::{AsymLine, AsymLineCutout, GlowPen, Pen, Text};
 use glib::{GString, Object};
 use gtk::{
@@ -10,6 +19,7 @@ use gtk::{
 };
 use serde::{Deserialize, Serialize};
 
+const FPS: u64 = 60;
 const PURPLE: (f64, f64, f64) = (0.7, 0., 1.);
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
@@ -20,24 +30,11 @@ enum Position {
     Bottom,
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
-enum TransitionName {
-    Fade,
-    CrossFade,
-}
-
-struct Fade(Step);
-
-enum Transition {
-    Fade(Fade),
-    CrossFade(Step, Step),
-}
-
 #[derive(Serialize, Deserialize, Debug, Clone)]
 struct Step {
     text: String,
     position: Position,
-    transition: TransitionName,
+    transition: Duration,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
@@ -75,6 +72,59 @@ impl Index<usize> for Script {
     }
 }
 
+struct Fade {
+    text: String,
+    position: Position,
+    duration: Duration,
+
+    start_time: Instant,
+}
+
+/*
+impl Fade {
+    fn render(&self, context: &Context) {
+        let start = Instant::now();
+    }
+}
+*/
+
+/*
+impl Transition {
+    fn render(&self, context: &Context) {
+        match self {
+            Transition::Fade(fade) => fade.render(context),
+            Transition::CrossFade(start, end) => {}
+        }
+    }
+}
+*/
+
+trait Animation {
+    fn position(&self) -> Position;
+
+    fn tick(&self, now: Instant, context: &Context) -> bool;
+}
+
+impl Animation for Fade {
+    fn position(&self) -> Position {
+        self.position.clone()
+    }
+
+    fn tick(&self, now: Instant, context: &Context) -> bool {
+        let total_frames = self.duration.as_secs() * FPS;
+        let alpha_rate: f64 = 1. / total_frames as f64;
+
+        let frames = (now - self.start_time).as_secs_f64() * FPS as f64;
+        let alpha = alpha_rate * frames as f64;
+
+        let _ = context.set_source_rgba(PURPLE.0, PURPLE.1, PURPLE.2, alpha);
+        let text_display = Text::new(self.text.clone(), context, 32.);
+        text_display.draw();
+
+        false
+    }
+}
+
 #[derive(Debug)]
 pub struct CyberScreenState {
     script: Script,
@@ -103,13 +153,15 @@ impl CyberScreenState {
         s
     }
 
-    fn next_page(&mut self) -> Transition {
+    fn next_page(&mut self) -> impl Animation {
         let idx = match self.idx {
             None => 0,
-            Some(idx) => if idx < self.script.len() {
+            Some(idx) => {
-                idx + 1
+                if idx < self.script.len() {
-            } else {
+                    idx + 1
-                idx
+                } else {
+                    idx
+                }
             }
         };
         self.idx = Some(idx);
@@ -117,40 +169,28 @@ impl CyberScreenState {
 
         match step.position {
             Position::Top => {
-                let transition = if let Some(old_step) = self.top.take() {
+                self.top = Some(step.clone());
-                    Transition::CrossFade(old_step, step.clone())
-                } else {
-                    Transition::Fade(Fade(step.clone()))
-                };
-                self.top = Some(step);
-                transition
             }
             Position::Middle => {
-                let transition = if let Some(old_step) = self.middle.take() {
+                self.middle = Some(step.clone());
-                    Transition::CrossFade(old_step, step.clone())
-                } else {
-                    Transition::Fade(Fade(step.clone()))
-                };
-                self.middle = Some(step);
-                transition
             }
             Position::Bottom => {
-                let transition = if let Some(old_step) = self.bottom.take() {
+                self.bottom = Some(step.clone());
-                    Transition::CrossFade(old_step, step.clone())
-                } else {
-                    Transition::Fade(Fade(step.clone()))
-                };
-                self.bottom = Some(step);
-                transition
             }
         }
+        Fade {
+            text: step.text.clone(),
+            position: step.position,
+            duration: step.transition,
+            start_time: Instant::now(),
+        }
     }
 }
 
 #[derive(Default)]
 pub struct CyberScreenPrivate {
     state: Rc<RefCell<CyberScreenState>>,
-    transition_queue: Rc<RefCell<Vec<Transition>>>,
+    animations: Rc<RefCell<Vec<Box<dyn Animation>>>>,
 }
 
 #[glib::object_subclass]
@@ -171,7 +211,7 @@ impl CyberScreenPrivate {
 
     fn next_page(&self) {
         let transition = self.state.borrow_mut().next_page();
-        self.transition_queue.borrow_mut().push(transition);
+        self.animations.borrow_mut().push(Box::new(transition));
     }
 }
 
@@ -187,6 +227,7 @@ impl CyberScreen {
         s.set_draw_func({
             let s = s.clone();
             move |_, context, width, height| {
+                let now = Instant::now();
                 let _ = context.set_source_rgb(0., 0., 0.);
                 let _ = context.paint();
 
@@ -198,40 +239,27 @@ impl CyberScreen {
                 }
                 pen.stroke();
                 */
-
-
-
                 let tracery = pen.finish();
                 let _ = context.set_source(tracery);
                 let _ = context.paint();
 
-                for transition in s.imp().transition_queue.borrow().iter() {
+                let mut animations = s.imp().animations.borrow_mut();
-                    if let Some(ref text) = s.imp().state.borrow().top {
+                let mut to_remove = vec![];
-                        let text_display = Text::new(text.text.clone(), context, 32.);
+                for (idx, animation) in animations.iter().enumerate() {
-                        let y = height as f64 * 1. / 5. + text_display.extents().height();
+                    let y = match animation.position() {
+                        Position::Top => height as f64 * 1. / 5.,
+                        Position::Middle => height as f64 * 2. / 5.,
+                        Position::Bottom => height as f64 * 3. / 5.,
+                    };
+                    context.move_to(20., y);
+                    let done = animation.tick(now, context);
+                    if done {
+                        to_remove.push(idx)
+                    };
+                }
 
-                        context.move_to(20., y);
+                for idx in to_remove.into_iter() {
-                        let _ = context.set_source_rgb(PURPLE.0, PURPLE.1, PURPLE.2);
+                    animations.remove(idx);
-                        text_display.draw();
-                    }
-
-                    if let Some(ref text) = s.imp().state.borrow().middle {
-                        let text_display = Text::new(text.text.clone(), context, 32.);
-                        let y = height as f64 * 2. / 5. + text_display.extents().height();
-
-                        context.move_to(20., y);
-                        let _ = context.set_source_rgb(PURPLE.0, PURPLE.1, PURPLE.2);
-                        text_display.draw();
-                    }
-
-                    if let Some(ref text) = s.imp().state.borrow().bottom {
-                        let text_display = Text::new(text.text.clone(), context, 32.);
-                        let y = height as f64 * 3. / 5. + text_display.extents().height();
-
-                        context.move_to(20., y);
-                        let _ = context.set_source_rgb(PURPLE.0, PURPLE.1, PURPLE.2);
-                        text_display.draw();
-                    }
                 }
             }
         });
@@ -247,6 +275,14 @@ impl CyberScreen {
 }
 
 fn main() {
+    let script = Script(vec![Step {
+        text: "The distinguishing thing".to_owned(),
+        position: Position::Top,
+        transition: Duration::from_secs(2),
+    }]);
+
+    println!("{}", serde_yml::to_string(&script).unwrap());
+
     let script = Script::from_file(Path::new("./script.yml")).unwrap();
     for element in script.iter() {
         println!("{:?}", element);
@@ -277,6 +313,14 @@ fn main() {
         window.set_width_request(800);
         window.set_height_request(600);
         window.present();
+
+        let _ = glib::spawn_future_local({
+            let screen = screen.clone();
+            async move { loop {
+                screen.queue_draw();
+                async_std::task::sleep(Duration::from_millis(1000 / FPS)).await;
+            }}
+        });
     });
 
     app.run();