1 files changed, 84 insertions, 0 deletions
diff --git a/src/synth/lut.rs b/src/synth/lut.rs
new file mode 100644
index 0000000..73b5efa
--- /dev/null
+++ b/src/synth/lut.rs
@@ -0,0 +1,84 @@
+use super::*;
+
+#[derive(Debug)]
+pub struct Lut {
+    pub freq: GenBox,
+    pub phase: f32,
+    pub lut: Vec<Sample>,
+    pub buf: SampleBuffer,
+}
+
+impl Generator for Lut {
+    fn eval<'a>(&'a mut self, params: &Parameters) -> &'a SampleBuffer {
+        self.buf.rate = Rate::Sample;
+
+        let pvel = self.freq.eval(params).first() / params.env.sample_rate;
+        for i in 0..self.buf.len() {
+            self.buf[i] = self.lut[(((self.phase + pvel * (i as f32)) % 1.0) * (self.lut.len() as f32)) as usize];
+        }
+
+        self.phase = (self.phase + pvel * (self.buf.len() as f32)) % 1.0;
+        &self.buf
+    }
+    fn buffer(&self) -> &SampleBuffer { &self.buf }
+    fn set_buffer(&mut self, buf: SampleBuffer) -> SampleBuffer {
+        mem::replace(&mut self.buf, buf)
+    }
+}
+
+pub struct LutDataFactory;
+
+impl GeneratorFactory for LutDataFactory {
+    fn new(&self, params: &mut FactoryParameters) -> Result<GenBox, GenFactoryError> {
+        Ok(Box::new(Lut {
+            freq: params.remove_param("freq", 0)?.into_gen()?,
+            phase: params.get_param("phase", 1, &mut ParamValue::Float(0.0)).as_f32()?,
+            buf: SampleBuffer::new(params.env.default_buffer_size),
+            lut: {
+                let mut lut: Vec<Sample> = Vec::new();
+                let mut i = 0;
+
+                while let Ok(samp) = params.get_req_param("_", 2 + i).and_then(|pv| pv.as_f32()) {
+                    lut.push(samp);
+                    i += 1;
+                }
+
+                if lut.is_empty() {
+                    return Err(GenFactoryError::MissingRequiredParam("samples".to_string(), 2));
+                }
+
+                lut
+            },
+        }))
+    }
+}
+
+pub static FactoryLutData: LutDataFactory = LutDataFactory;
+
+pub struct LutGenFactory;
+
+impl GeneratorFactory for LutGenFactory {
+    fn new(&self, params: &mut FactoryParameters) -> Result<GenBox, GenFactoryError> {
+        eprintln!("LutGenFactory::new({:?})", params);
+        Ok(Box::new(Lut {
+            freq: params.remove_param("freq", 2)?.into_gen()?,
+            phase: params.get_param("phase", 3, &mut ParamValue::Float(0.0)).as_f32()?,
+            buf: SampleBuffer::new(params.env.default_buffer_size),
+            lut: {
+                let mut gen = params.remove_param("gen", 0)?.into_gen()?;
+                let samps = params.get_req_param("samples", 1)?.as_f32()?;
+                let var = params.get_param("var", 4, &mut ParamValue::String("lut_freq".to_string())).as_string()?;
+                let mut genparams = Parameters { env: params.env.clone(), ..Default::default() };
+                genparams.env.sample_rate = samps;
+                genparams.vars.insert(var, 1.0);
+
+                gen.set_buffer(SampleBuffer::new(samps as usize));
+                gen.eval(&genparams);
+
+                gen.set_buffer(SampleBuffer::new(0)).samples
+            },
+        }))
+    }
+}
+
+pub static FactoryLutGen: LutGenFactory = LutGenFactory;