Fix serde feature errors

core/src/channel/event.rs

@@ -24,6 +24,7 @@ pub enum KeyNoteEvent {
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub enum ChannelConfigEvent {
     /// Sets the soundfonts for the channel
+    #[cfg_attr(feature = "serde", serde(skip))]
     SetSoundfonts(Vec<Arc<dyn SoundfontBase>>),
 
     /// Sets the layer count for the soundfont

core/src/channel/mod.rs

@@ -118,7 +118,11 @@ impl ControlEventData {
 
 /// Options for initializing a new VoiceChannel.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(default)
+)]
 pub struct ChannelInitOptions {
     /// If set to true, the voices killed due to the voice limit will fade out.
     /// If set to false, they will be killed immediately, usually causing clicking

core/src/channel_group/config.rs

@@ -44,7 +44,11 @@ pub enum ThreadCount {
 ///     render very small sample counts each time (e.g. sub 1 millisecond), not using per-key
 ///     multithreading becomes more efficient.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(default)
+)]
 pub struct ParallelismOptions {
     /// Render the MIDI channels parallel in a threadpool with the specified
     /// thread count.

core/src/soundfont/config.rs

@@ -29,7 +29,11 @@ pub enum EnvelopeCurveType {
 
 /// Options for the curves of a specific envelope.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(default)
+)]
 pub struct EnvelopeOptions {
     /// Controls the type of curve of the attack envelope stage. See the
     /// documentation of the `EnvelopeCurveType` enum for available options.
@@ -62,7 +66,11 @@ impl Default for EnvelopeOptions {
 
 /// Options for initializing/loading a new sample soundfont.
 #[derive(Clone, Copy, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(default)
+)]
 pub struct SoundfontInitOptions {
     /// The bank number (0-128) to extract and use from the soundfont.
     /// `None` means to use all available banks (bank 0 for SFZ).

realtime/src/config.rs

@@ -6,7 +6,11 @@ pub use xsynth_core::{
 
 /// Options for initializing a new RealtimeSynth.
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Deserialize, serde::Serialize),
+    serde(default)
+)]
 pub struct XSynthRealtimeConfig {
     /// Channel initialization options (same for all channels).
     /// See the `ChannelInitOptions` documentation for more information.