From 1821eeba14106a6e6eb0125d687a58f0eb3bc925 Mon Sep 17 00:00:00 2001
From: Rob Watson <rob@netflux.io>
Date: Wed, 9 Sep 2020 17:41:40 +0200
Subject: [PATCH] Add cpal player framework

---
 Cargo.toml      |   7 ++-
 Makefile        |   3 --
 src/controls.rs |   2 +
 src/lib.rs      |   3 ++
 src/player.rs   | 114 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 125 insertions(+), 4 deletions(-)
 create mode 100644 src/player.rs

diff --git a/Cargo.toml b/Cargo.toml
index 5b046eb..23d486b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,9 +12,9 @@ yew = "0.17"
 #yew = { path = "/home/rob/dev/yew/yew" }
 yewtil = "0.3.1"
 wasm-bindgen = "0.2"
-gloo-events = "0.1.0"
 js-sys = "0.3.44"
 futures = "0.3.5"
+cpal = { version = "0.12.1", features = ["wasm-bindgen"] }
 wasm-bindgen-futures = "0.4"
 console_error_panic_hook = "0.1.6"
 
@@ -27,3 +27,8 @@ features = [
   "HtmlCanvasElement",
   "CanvasRenderingContext2d",
 ]
+
+[profile.release]
+lto = true
+
+# TODO: add wee_alloc
diff --git a/Makefile b/Makefile
index fb16d85..96d9ed5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,5 @@
 # Based on https://raw.githubusercontent.com/saschagrunert/webapp.rs/master/Makefile
 
-GENERAL_ARGS = --release
-FRONTEND_ARGS = $(GENERAL_ARGS)
-
 .PHONY: \
         build \
         run
diff --git a/src/controls.rs b/src/controls.rs
index d493d70..9f684f7 100644
--- a/src/controls.rs
+++ b/src/controls.rs
@@ -1,3 +1,4 @@
+use super::player::Player;
 use crate::agents::audio_agent::{self, AudioAgent};
 use web_sys::HtmlInputElement;
 use yew::agent::Dispatched;
@@ -52,6 +53,7 @@ impl Component for Controls {
                     <input ref=self.file_input.clone() type="file"/>
                 </label>
                 <button onclick=self.link.callback(move |_| Msg::SubmitForm)>{"Open file"}</button>
+                <Player/>
             </section>
         }
     }
diff --git a/src/lib.rs b/src/lib.rs
index a2d70af..829180d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,10 +10,13 @@ mod app;
 mod canvas;
 mod controls;
 mod home;
+mod player;
 mod utils;
 
 #[wasm_bindgen(start)]
 pub fn run_app() {
+    #[cfg(debug_assertions)]
     panic::set_hook(Box::new(console_error_panic_hook::hook));
+
     App::<app::App>::new().mount_to_body();
 }
diff --git a/src/player.rs b/src/player.rs
new file mode 100644
index 0000000..a0a405e
--- /dev/null
+++ b/src/player.rs
@@ -0,0 +1,114 @@
+use crate::agents::audio_agent::{self, AudioAgent};
+use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
+use cpal::{Device, SampleFormat, SampleRate, Stream, StreamConfig};
+use yew::agent::Dispatcher;
+use yew::prelude::*;
+use yew::services::ConsoleService;
+
+pub enum Status {
+    Stopped,
+    Playing,
+}
+
+pub struct Player {
+    link: ComponentLink<Self>,
+    status: Status,
+    stream: Option<Stream>,
+    audio_agent: Dispatcher<AudioAgent>,
+}
+
+pub enum Msg {
+    Play,
+}
+
+impl Component for Player {
+    type Message = Msg;
+    type Properties = ();
+
+    fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
+        Self {
+            link,
+            status: Status::Stopped,
+            stream: None,
+            audio_agent: AudioAgent::dispatcher(),
+        }
+    }
+
+    fn rendered(&mut self, first_render: bool) {}
+
+    fn update(&mut self, msg: Self::Message) -> ShouldRender {
+        match msg {
+            Msg::Play => self.handle_play_button_clicked(),
+        }
+    }
+
+    fn change(&mut self, _: Self::Properties) -> ShouldRender {
+        false
+    }
+
+    fn view(&self) -> Html {
+        html! {
+            <div>
+                <button onclick=self.link.callback(move |_| Msg::Play)>{self.button_text()}</button>
+            </div>
+        }
+    }
+}
+
+impl Player {
+    fn play(&mut self) {
+        let host = cpal::default_host();
+        let device = host.default_output_device().unwrap();
+
+        // TODO: improve
+        let config = device
+            .supported_output_configs()
+            .unwrap()
+            .nth(1)
+            .unwrap()
+            .with_sample_rate(SampleRate(44100));
+
+        ConsoleService::log(&format!("Using output config: {:?}", config));
+
+        let stream = match config.sample_format() {
+            SampleFormat::F32 => Player::run::<f32>(&device, &config.into()),
+            SampleFormat::I16 => Player::run::<i16>(&device, &config.into()),
+            SampleFormat::U16 => Player::run::<u16>(&device, &config.into()),
+        };
+
+        self.stream = Some(stream);
+    }
+
+    fn run<T>(device: &Device, config: &StreamConfig) -> Stream
+    where
+        T: cpal::Sample,
+    {
+        let err_fn = |err| ConsoleService::warn(&format!("an error occurred on stream: {}", err));
+
+        let stream = device
+            .build_output_stream(config, move |data: &mut [T], _| {}, err_fn)
+            .unwrap();
+
+        stream.play().unwrap();
+        stream
+    }
+
+    fn handle_play_button_clicked(&mut self) -> ShouldRender {
+        match self.status {
+            Status::Stopped => {
+                self.status = Status::Playing;
+                self.play();
+            }
+            Status::Playing => self.status = Status::Stopped,
+        }
+        true
+    }
+
+    fn button_text(&self) -> &str {
+        if let Status::Stopped = self.status {
+            "Play"
+        } else {
+            "Pause"
+        }
+    }
+}