non-blocking audio example

examples/audio/.gitignore

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+target

examples/audio/Cargo.toml

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+[package]
+name = "psp-audio-example"
+version = "0.1.0"
+authors = ["Paul Sajna <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+psp = { path = "../../psp" }

examples/audio/src/main.rs

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+#![no_std]
+#![no_main]
+
+use psp::sys::{
+    sceAudioChReserve, sceAudioOutput, sceAudioOutputBlocking,
+    sceAudioSetChannelDataLen, sceAudioGetChannelRestLen,
+};
+
+psp::module!("sound_sample", 1, 1);
+
+// In a real scenario you would probably load this out of a file at runtime
+// I leave that as an exercise to the user ;)
+// 44.1KHz signed 16-bit PCM in RAW (no header) format 
+static AUDIO_CLIP: [u8; 718828] = *include_bytes!("../assets/showtime.rawpcm16"); 
+
+const MAX_VOL: i32 = 0x8000;
+const MAX_SAMPLES: usize = 65472;
+const CHANNEL: i32 = 0;
+
+fn psp_main() {
+    psp::enable_home_button();
+    unsafe { 
+        sceAudioChReserve(CHANNEL, MAX_SAMPLES as i32, psp::sys::AudioFormat::Stereo) 
+    };
+    let mut start_pos: usize = 0;
+    let mut restlen = 0;
+    while (start_pos+MAX_SAMPLES*4) < AUDIO_CLIP.len() {
+        if restlen > 0 {
+            psp::dprintln!("Check it out, I can do other stuff while audio plays!");
+        } else {
+            unsafe {
+                sceAudioOutput(
+                    CHANNEL,
+                    MAX_VOL,
+                    AUDIO_CLIP.as_ptr().add(start_pos) as *mut _
+                )
+            };
+            start_pos += MAX_SAMPLES*4;
+        }
+        restlen = unsafe { sceAudioGetChannelRestLen(CHANNEL) };
+    }
+    let remainder: i32 = (((AUDIO_CLIP.len() % (MAX_SAMPLES*4)/4)+63) & !63) as i32;
+    unsafe { sceAudioSetChannelDataLen(CHANNEL, remainder)};
+    unsafe {
+        // Blocking here so the program doesn't exit while we're finishing
+        // up outputting audio
+        sceAudioOutputBlocking(
+            CHANNEL,
+            MAX_VOL,
+            AUDIO_CLIP.as_ptr().add(start_pos) as *mut _)
+    };
+}