Code review changes

CHANGELOG.md

@@ -12,10 +12,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - New test signal generator sources:
     - `TestSignal` source generates a sine, triangle, square wave or sawtooth
       of a given frequency and sample rate.
-    - `Chirp` source generates a sine wave with linearly period over a given
-      frequency range and duration.
+    - `Chirp` source generates a sine wave with a linearly-increasing 
+      frequency over a given frequency range and duration.
     - `white` and `pink` generate white or pink noise, respectively. These 
-      sources depend on the `rand` crate  and are guarded with the "noise" 
+      sources depend on the `rand` crate and are guarded with the "noise" 
       feature.
     - Documentation for the "noise" feature has been added to `lib.rs`.
 - New Fade and Crossfade sources:

examples/signal_generator.rs

@@ -1,4 +1,4 @@
-//! Noise generator example. Use the "noise" feature to enable the noise generator sources.
+//! Test signal generator example.
 
 fn main() {
     use rodio::source::{chirp, Function, Source, TestWaveform};
@@ -7,15 +7,15 @@ fn main() {
 
     let (_stream, stream_handle) = rodio::OutputStream::try_default().unwrap();
 
-    let noise_duration = Duration::from_millis(1000);
+    let test_signal_duration = Duration::from_millis(1000);
     let interval_duration = Duration::from_millis(1500);
 
     println!("Playing 1000 Hz tone");
     stream_handle
         .play_raw(
             TestWaveform::new(cpal::SampleRate(48000), 1000.0, Function::Sine)
                 .amplify(0.1)
-                .take_duration(noise_duration),
+                .take_duration(test_signal_duration),
         )
         .unwrap();
 
@@ -26,7 +26,7 @@ fn main() {
         .play_raw(
             TestWaveform::new(cpal::SampleRate(48000), 10000.0, Function::Sine)
                 .amplify(0.1)
-                .take_duration(noise_duration),
+                .take_duration(test_signal_duration),
         )
         .unwrap();
 
@@ -37,7 +37,7 @@ fn main() {
         .play_raw(
             TestWaveform::new(cpal::SampleRate(48000), 440.0, Function::Triangle)
                 .amplify(0.1)
-                .take_duration(noise_duration),
+                .take_duration(test_signal_duration),
         )
         .unwrap();
 
@@ -48,7 +48,7 @@ fn main() {
         .play_raw(
             TestWaveform::new(cpal::SampleRate(48000), 440.0, Function::Sawtooth)
                 .amplify(0.1)
-                .take_duration(noise_duration),
+                .take_duration(test_signal_duration),
         )
         .unwrap();
 
@@ -59,7 +59,7 @@ fn main() {
         .play_raw(
             TestWaveform::new(cpal::SampleRate(48000), 440.0, Function::Square)
                 .amplify(0.1)
-                .take_duration(noise_duration),
+                .take_duration(test_signal_duration),
         )
         .unwrap();
 
@@ -75,7 +75,7 @@ fn main() {
                 Duration::from_secs(1),
             )
             .amplify(0.1)
-            .take_duration(noise_duration),
+            .take_duration(test_signal_duration),
         )
         .unwrap();
 

src/source/sine.rs

@@ -5,8 +5,6 @@ use crate::Source;
 
 use super::SeekError;
 
-const SAMPLE_RATE: u32 = 48000;
-
 /// An infinite source that produces a sine.
 ///
 /// Always has a rate of 48kHz and one channel.
@@ -16,10 +14,12 @@ pub struct SineWave {
 }
 
 impl SineWave {
+    const SAMPLE_RATE: u32 = 48000;
+
     /// The frequency of the sine.
     #[inline]
     pub fn new(freq: f32) -> SineWave {
-        let sr = cpal::SampleRate(SAMPLE_RATE);
+        let sr = cpal::SampleRate(Self::SAMPLE_RATE);
         SineWave {
             test_sine: TestWaveform::new(sr, freq, Function::Sine),
         }
@@ -48,7 +48,7 @@ impl Source for SineWave {
 
     #[inline]
     fn sample_rate(&self) -> u32 {
-        SAMPLE_RATE
+        Self::SAMPLE_RATE
     }
 
     #[inline]

src/source/test_waveform.rs

@@ -34,19 +34,19 @@ impl Function {
     /// Create a single sample for the given waveform
     #[inline]
     fn render(&self, i: u64, period: f32) -> f32 {
-        let i_div_p: f32 = i as f32 / period;
+        let cycle_pos: f32 = i as f32 / period;
 
         match self {
-            Self::Sine => (TAU * i_div_p).sin(),
-            Self::Triangle => 4.0f32 * (i_div_p - (i_div_p + 0.5f32).floor()).abs() - 1f32,
+            Self::Sine => (TAU * cycle_pos).sin(),
+            Self::Triangle => 4.0f32 * (cycle_pos - (cycle_pos + 0.5f32).floor()).abs() - 1f32,
             Self::Square => {
-                if i_div_p % 1.0f32 < 0.5f32 {
+                if cycle_pos % 1.0f32 < 0.5f32 {
                     1.0f32
                 } else {
                     -1.0f32
                 }
             }
-            Self::Sawtooth => 2.0f32 * (i_div_p - (i_div_p + 0.5f32).floor()),
+            Self::Sawtooth => 2.0f32 * (cycle_pos - (cycle_pos + 0.5f32).floor()),
         }
     }
 }