implement speeding up and slowing down

3 files changed, 30 insertions, 2 deletions

diff --git a/src/bin/ttyplay/event.rs b/src/bin/ttyplay/event.rs
index f3bbc62..38dcb8a 100644
--- a/src/bin/ttyplay/event.rs
+++ b/src/bin/ttyplay/event.rs
@@ -13,6 +13,8 @@ pub enum TimerAction {
     LastFrame,
     NextFrame,
     PreviousFrame,
+    SpeedUp,
+    SlowDown,
     Quit,
 }
 
diff --git a/src/bin/ttyplay/input.rs b/src/bin/ttyplay/input.rs
index d8c8e92..8c45b69 100644
--- a/src/bin/ttyplay/input.rs
+++ b/src/bin/ttyplay/input.rs
@@ -30,6 +30,16 @@ pub fn spawn_task(
                     crate::event::TimerAction::Pause,
                 ),
                 textmode::Key::Ctrl(b'i') => crate::event::Event::ToggleUi,
+                textmode::Key::Char('=' | '+') => {
+                    crate::event::Event::TimerAction(
+                        crate::event::TimerAction::SpeedUp,
+                    )
+                }
+                textmode::Key::Char('_' | '-') => {
+                    crate::event::Event::TimerAction(
+                        crate::event::TimerAction::SlowDown,
+                    )
+                }
                 _ => continue,
             };
             event_w.send(event).await.unwrap();
diff --git a/src/bin/ttyplay/timer.rs b/src/bin/ttyplay/timer.rs
index 7be5245..db85001 100644
--- a/src/bin/ttyplay/timer.rs
+++ b/src/bin/ttyplay/timer.rs
@@ -17,6 +17,7 @@ pub fn spawn_task(
             None
         };
         let mut force_update_time = false;
+        let mut playback_ratio = 16;
         loop {
             enum Res {
                 Wait(Option<vt100::Screen>),
@@ -34,7 +35,7 @@ pub fn spawn_task(
                         frames.lock_arc().await.get(idx).unwrap().clone();
                     if force_update_time {
                         let now = std::time::Instant::now();
-                        start_time = now - frame.delay()
+                        start_time = now - frame.delay() * playback_ratio / 16
                             // give a bit of extra time before moving to the
                             // next frame, otherwise backing up behind two
                             // frames that are extremely close together
@@ -48,7 +49,8 @@ pub fn spawn_task(
                         std::future::pending::<()>().await;
                     } else {
                         async_std::task::sleep(
-                            (start_time + frame.delay())
+                            (start_time
+                                + frame.delay() * playback_ratio / 16)
                                 .saturating_duration_since(
                                     std::time::Instant::now(),
                                 ),
@@ -111,6 +113,20 @@ pub fn spawn_task(
                         idx = idx.saturating_sub(2);
                         force_update_time = true;
                     }
+                    crate::event::TimerAction::SpeedUp => {
+                        if playback_ratio > 1 {
+                            playback_ratio /= 2;
+                            let now = std::time::Instant::now();
+                            start_time = now - (now - start_time) / 2;
+                        }
+                    }
+                    crate::event::TimerAction::SlowDown => {
+                        if playback_ratio < 256 {
+                            playback_ratio *= 2;
+                            let now = std::time::Instant::now();
+                            start_time = now - (now - start_time) * 2;
+                        }
+                    }
                     crate::event::TimerAction::Quit => break,
                 },
                 Res::TimerAction(Err(e)) => panic!("{}", e),