Fixed small issues in the example

ctru-rs/examples/audio_filters.rs

@@ -110,27 +110,18 @@ fn main() {
             break;
         } // break in order to return to hbmenu
 
-        if keys_down.contains(KeyPad::KEY_DOWN) {
+        if keys_down.intersects(KeyPad::KEY_DOWN) {
             note = note.saturating_sub(1);
-
+        } else if keys_down.intersects(KeyPad::KEY_UP) {
-            println!("\x1b[6;1Hnote = {} Hz        ", NOTEFREQ[note]);
-        } else if keys_down.contains(KeyPad::KEY_UP) {
             note += 1;
-            if note >= NOTEFREQ.len() {
-                note = 0;
-            }
-            println!("\x1b[6;1Hnote = {} Hz        ", NOTEFREQ[note]);
         }
 
-        // Check for upper limit
-        note = std::cmp::max(note, NOTEFREQ.len() - 1);
-
         let mut update_params = false;
-        if keys_down.contains(KeyPad::KEY_LEFT) {
+        if keys_down.intersects(KeyPad::KEY_LEFT) {
             filter = filter.saturating_sub(1);
 
             update_params = true;
-        } else if keys_down.contains(KeyPad::KEY_LEFT) {
+        } else if keys_down.intersects(KeyPad::KEY_RIGHT) {
             filter += 1;
             if filter >= filter_names.len() {
                 filter = 0;
@@ -138,8 +129,14 @@ fn main() {
             update_params = true;
         }
 
+		// Check for upper limit
+		note = std::cmp::min(note, NOTEFREQ.len() - 1);
+		filter = std::cmp::min(filter, filter_names.len() - 1);
+
+		println!("\x1b[6;1Hnote = {} Hz        ", NOTEFREQ[note]);
+		println!("\x1b[7;1Hfilter = {}         ", filter_names[filter]);
+
         if update_params {
-            println!("\x1b[7;1Hfilter = {}         ", filter_names[filter]);
             match filter {
                 1 => channel_zero.iir_biquad_set_params_low_pass_filter(1760., 0.707),
                 2 => channel_zero.iir_biquad_set_params_high_pass_filter(1760., 0.707),
@@ -175,4 +172,9 @@ fn main() {
         //Wait for VBlank
         gfx.wait_for_vblank();
     }
+	
+	// Ndsp *has* to be dropped before the WaveInfos,
+	// otherwise the status won't be flagged properly and the program will crash.
+	// TODO: find a way to get away with this using implicit functionality (rather than an explict `drop`).
+	drop(ndsp);
 }

ctru-rs/src/services/ndsp/mod.rs

@@ -188,6 +188,10 @@ impl Channel {
 
 impl Drop for Ndsp {
     fn drop(&mut self) {
+        for i in 0..24 {
+            self.channel(i).unwrap().clear_queue();
+        }
+
         unsafe {
             ctru_sys::ndspExit();
         }

ctru-rs/src/services/ndsp/wave.rs

@@ -1,5 +1,4 @@
 use super::AudioFormat;
-use crate::error::ResultCode;
 use crate::linear::LinearAllocator;
 
 /// Base struct to represent audio wave data. This requires audio format information.
@@ -50,10 +49,10 @@ impl WaveBuffer {
         let nsamples: usize = data.len() / (audio_format.sample_size() as usize);
 
         unsafe {
-            ResultCode(ctru_sys::DSP_FlushDataCache(
+            let _r = ctru_sys::DSP_FlushDataCache(
                 data.as_ptr().cast(),
                 data.len().try_into().unwrap(),
-            ))?;
+            );
         }
 
         Ok(WaveBuffer {