Add neoplay and snake.

Taken from Neotron-Apps.

Cargo.toml

@@ -1,7 +1,7 @@
 [workspace]
 members = [
     "neotron-os",
-    "utilities/flames",
+    "utilities/*",
 ]
 resolver = "2"
 exclude = [

nbuild/src/main.rs

@@ -42,20 +42,37 @@ pub struct NBuildApp {
 
 fn packages() -> Vec<nbuild::Package> {
     vec![
+        // *** build system ***
         nbuild::Package {
             name: "nbuild",
             path: std::path::Path::new("./nbuild/Cargo.toml"),
             output_template: None,
             kind: nbuild::PackageKind::NBuild,
             testable: nbuild::Testable::All,
         },
+        // *** utilities ***
         nbuild::Package {
             name: "flames",
             path: std::path::Path::new("./utilities/flames/Cargo.toml"),
             output_template: Some("./target/{target}/{profile}/flames"),
             kind: nbuild::PackageKind::Utility,
             testable: nbuild::Testable::No,
         },
+        nbuild::Package {
+            name: "neoplay",
+            path: std::path::Path::new("./utilities/neoplay/Cargo.toml"),
+            output_template: Some("./target/{target}/{profile}/neoplay"),
+            kind: nbuild::PackageKind::Utility,
+            testable: nbuild::Testable::No,
+        },
+        nbuild::Package {
+            name: "snake",
+            path: std::path::Path::new("./utilities/snake/Cargo.toml"),
+            output_template: Some("./target/{target}/{profile}/snake"),
+            kind: nbuild::PackageKind::Utility,
+            testable: nbuild::Testable::No,
+        },
+        // *** OS ***
         nbuild::Package {
             name: "Neotron OS",
             path: std::path::Path::new("./neotron-os/Cargo.toml"),

utilities/neoplay/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "neoplay"
+version = "0.1.0"
+edition = "2021"
+license = "MIT OR Apache-2.0"
+authors = ["Jonathan 'theJPster' Pallant <[email protected]>"]
+description = "4-channel ProTracker player for Neotro"
+
+[dependencies]
+grounded = { version = "0.2.0", features = ["critical-section", "cas"] }
+neotracker = { git = "https://github.com/thejpster/neotracker.git", rev = "2ee7a85006a9461b876bdf47e45b6105437a38f6" }
+neotron-sdk = { workspace = true }
+
+# See workspace for profile settings

utilities/neoplay/README.md

@@ -0,0 +1,27 @@
+# Neoplay
+
+A ProTracker MOD player for the Neotron Pico.
+
+Runs at 11,025 Hz, quadrupling samples for the audio codec which runs at 44,100 Hz.
+
+```console
+$ cargo build --release --target=thumbv6m-none-eabi
+$ cp ../target/thumbv6m-none-eabi/release/neoplay /media/USER/SDCARD/NEOPLAY.ELF
+
+```
+
+```console
+> load neoplay.elf
+> run airwolf.mod
+Loading "airwolf.mod"
+audio 44100, SixteenBitStereo
+Playing "airwolf.mod"
+
+000 000000 12 00fe 0f04|-- ---- ----|-- ---- ----|-- ---- ----|
+000 000001 -- ---- ----|-- ---- ----|-- ---- ----|-- ---- ----|
+000 000002 -- ---- ----|-- ---- ----|-- ---- ----|-- ---- ----|
+000 000003 -- ---- ----|-- ---- ----|-- ---- ----|-- ---- ----|
+etc
+```
+
+Here's a video of it in action: https://youtu.be/ONZhDrZsmDU

utilities/neoplay/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rustc-link-arg-bin=neoplay=-Tneotron-cortex-m.ld");
+}

utilities/neoplay/src/main.rs

@@ -0,0 +1,88 @@
+#![cfg_attr(target_os = "none", no_std)]
+#![cfg_attr(target_os = "none", no_main)]
+
+use core::{fmt::Write, ptr::addr_of_mut};
+
+const FILE_BUFFER_LEN: usize = 192 * 1024;
+static mut FILE_BUFFER: [u8; FILE_BUFFER_LEN] = [0u8; FILE_BUFFER_LEN];
+
+mod player;
+
+#[cfg(not(target_os = "none"))]
+fn main() {
+    neotron_sdk::init();
+}
+
+#[no_mangle]
+extern "C" fn neotron_main() -> i32 {
+    if let Err(e) = real_main() {
+        let mut stdout = neotron_sdk::stdout();
+        let _ = writeln!(stdout, "Error: {:?}", e);
+        1
+    } else {
+        0
+    }
+}
+
+fn real_main() -> Result<(), neotron_sdk::Error> {
+    let mut stdout = neotron_sdk::stdout();
+    let stdin = neotron_sdk::stdin();
+    let Some(filename) = neotron_sdk::arg(0) else {
+        return Err(neotron_sdk::Error::InvalidArg);
+    };
+    let _ = writeln!(stdout, "Loading {:?}...", filename);
+    let path = neotron_sdk::path::Path::new(&filename)?;
+    let f = neotron_sdk::File::open(path, neotron_sdk::Flags::empty())?;
+    let file_buffer = unsafe {
+        let file_buffer = &mut *addr_of_mut!(FILE_BUFFER);
+        let n = f.read(file_buffer)?;
+        &file_buffer[0..n]
+    };
+    drop(f);
+    // Set 16-bit stereo, 44.1 kHz
+    let dsp_path = neotron_sdk::path::Path::new("AUDIO:")?;
+    let dsp = neotron_sdk::File::open(dsp_path, neotron_sdk::Flags::empty())?;
+    if dsp.ioctl(1, 3 << 60 | 44100).is_err() {
+        let _ = writeln!(stdout, "Failed to configure audio");
+        return neotron_sdk::Result::Err(neotron_sdk::Error::DeviceSpecific);
+    }
+
+    let mut player = match player::Player::new(file_buffer, 44100) {
+        Ok(player) => player,
+        Err(e) => {
+            let _ = writeln!(stdout, "Failed to create player: {:?}", e);
+            return Err(neotron_sdk::Error::InvalidArg);
+        }
+    };
+
+    let _ = writeln!(stdout, "Playing {:?}...", filename);
+    let mut sample_buffer = [0u8; 1024];
+    // loop some some silence to give us a head-start
+    for _i in 0..11 {
+        let _ = dsp.write(&sample_buffer);
+    }
+
+    loop {
+        for chunk in sample_buffer.chunks_exact_mut(4) {
+            let (left, right) = player.next_sample(&mut stdout);
+            let left_bytes = left.to_le_bytes();
+            let right_bytes = right.to_le_bytes();
+            chunk[0] = left_bytes[0];
+            chunk[1] = left_bytes[1];
+            chunk[2] = right_bytes[0];
+            chunk[3] = right_bytes[1];
+        }
+        let _ = dsp.write(&sample_buffer);
+        let mut in_buf = [0u8; 1];
+        if player.is_finished() {
+            break;
+        }
+        if stdin.read(&mut in_buf).is_ok() && in_buf[0].to_ascii_lowercase() == b'q' {
+            break;
+        }
+    }
+
+    let _ = writeln!(stdout, "Bye!");
+
+    Ok(())
+}