Loops

README.md

@@ -47,6 +47,7 @@ fn main() {
 * Optionally use [Symphonia](https://github.com/pdeljanov/Symphonia) to support most audio formats
 * Feature to disable audio playback support, if you want to use kittyaudio purely as an audio library
 * Commands to change volume, playback rate and position in the sound with easings
+* Loops, and commands to change them with easings
 
 # Roadmap
 

examples/loops.rs

@@ -0,0 +1,35 @@
+use kittyaudio::{include_sound, Change, Command, Easing, Mixer, PlaybackRate};
+
+fn main() {
+    let sound = include_sound!("../assets/drozerix_-_crush.ogg").unwrap();
+
+    let mut mixer = Mixer::new();
+    mixer.init();
+
+    let sound = mixer.play(sound);
+
+    // set the loop points to be from 2 to 4 seconds
+    sound.set_loop_enabled(true);
+    sound.set_loop(2.0..=4.0);
+
+    // after 6 seconds (the loop has ran 1 time), change the loop region to
+    // 4.0..=4.1 seconds in the span on 5 seconds
+    let command = Command::new(Change::LoopSeconds(4.0..=4.1), Easing::Linear, 6.0, 5.0);
+    sound.add_command(command);
+
+    // reverse the sound gradually after 11 seconds upto 16 seconds (11+5)
+    let command = Command::new(
+        Change::PlaybackRate(PlaybackRate::Factor(-1.0)),
+        Easing::Linear,
+        11.0,
+        5.0,
+    );
+    sound.add_command(command);
+
+    // change the loop to be 4-5 seconds from 13 secons in the span of 5 seconds
+    // (the playback rate change command is applied simultaneously)
+    let command = Command::new(Change::LoopSeconds(4.0..=6.0), Easing::Linear, 13.0, 5.0);
+    sound.add_command(command);
+
+    mixer.wait();
+}

src/command.rs

@@ -1,6 +1,5 @@
-use std::f32::consts::PI;
-
 use crate::PlaybackRate;
+use std::{f32::consts::PI, ops::RangeInclusive};
 
 /// https://github.com/Michaelangel007/easing#the-magic-of-170158
 const C1: f32 = 1.70158;
@@ -433,7 +432,7 @@ impl Easing {
 }
 
 /// Specifies what change to make to a [`crate::Sound`]. Used with [`Command`].
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum Change {
     /// Change volume value.
@@ -447,11 +446,15 @@ pub enum Change {
     Index(usize),
     /// Change the position in seconds.
     Position(f64),
+    /// Change the loop points in seconds.
+    LoopSeconds(RangeInclusive<f64>),
+    /// Change the loop points in samples.
+    LoopIndex(RangeInclusive<usize>),
 }
 
 /// A command that specifies an action that is applied on a [`crate::Sound`]
 /// with an optional tween.
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct Command {
     /// What variable to change.

src/lib.rs

@@ -37,6 +37,7 @@
 //! * Optionally use [Symphonia](https://github.com/pdeljanov/Symphonia) to support most audio formats
 //! * Feature to disable audio playback support, if you want to use kittyaudio purely as an audio library
 //! * Commands to change volume, playback rate and position in the sound with easings
+//! * Loops, and commands to change them with easings
 //!
 //! # Roadmap
 //!