make faust allocate on the heap instead of the stack

Cargo.toml

@@ -9,6 +9,8 @@ description = "A lookahead compressor/limiter that's soft as a lamb"
 
 [features]
 faust-rebuild = ["dep:faust-build"]
+default = ["default-boxed"]
+default-boxed = ["dep:default-boxed"]
 
 [workspace]
 members = ["xtask"]
@@ -27,6 +29,7 @@ nih_plug = { git = "https://github.com/robbert-vdh/nih-plug.git", features = ["a
 faust-types = { git = "https://github.com/Frando/rust-faust" }
 nih_plug_vizia = { git = "https://github.com/robbert-vdh/nih-plug.git" }
 atomic_float = "0.1"
+default-boxed = { version = "0.2.0", optional=true }
 
 [profile.release]
 lto = "thin"
@@ -42,3 +45,4 @@ strip = "none"
 # faust-build = { path = "../rust-faust/faust-build", optional = true }
 faust-build = { git = "https://github.com/Frando/rust-faust", optional = true }
 faust-types = { git = "https://github.com/Frando/rust-faust" }
+default-boxed = { version = "0.2.0", optional=true }

src/lib.rs

@@ -6,6 +6,8 @@ mod buffer;
 mod dsp;
 use buffer::*;
 
+use default_boxed::DefaultBoxed;
+
 // this seems to be the number JUCE is using
 // TODO: does this need to be set at runtime?
 const MAX_SOUNDCARD_BUFFER_SIZE: usize = 32768;
@@ -17,7 +19,7 @@ const PEAK_METER_DECAY_MS: f64 = 150.0;
 
 pub struct Lamb {
     params: Arc<LambParams>,
-    dsp: dsp::LambRs,
+    dsp: Box<dsp::LambRs>,
     accum_buffer: TempBuffer,
     temp_output_buffer_l: [f64; MAX_SOUNDCARD_BUFFER_SIZE],
     temp_output_buffer_r: [f64; MAX_SOUNDCARD_BUFFER_SIZE],
@@ -45,7 +47,7 @@ impl Default for Lamb {
             gain_reduction_left: Arc::new(AtomicF32::new(0.0)),
             gain_reduction_right: Arc::new(AtomicF32::new(0.0)),
 
-            dsp: dsp::LambRs::new(),
+            dsp: dsp::LambRs::default_boxed(),
 
             accum_buffer: TempBuffer::default(),
             temp_output_buffer_l: [0.0_f64; MAX_SOUNDCARD_BUFFER_SIZE],