1 files changed, 63 insertions, 0 deletions
diff --git a/src/synth/logic.rs b/src/synth/logic.rs
new file mode 100644
index 0000000..5071d95
--- /dev/null
+++ b/src/synth/logic.rs
@@ -0,0 +1,63 @@
+use std::{mem, cmp};
+use super::*;
+
+#[derive(Debug)]
+pub struct IfElse {
+    pub cond: GenBox,
+    pub iftrue: GenBox,
+    pub iffalse: GenBox,
+    pub buf: SampleBuffer,
+}
+
+impl Generator for IfElse {
+    fn eval<'a>(&'a mut self, params: &Parameters) -> &'a SampleBuffer {
+        let cond_buf = self.cond.eval(params);
+        let iftrue_buf = self.iftrue.eval(params);
+        let iffalse_buf = self.iffalse.eval(params);
+        
+        if (
+            cond_buf.rate == Rate::Control &&
+            iftrue_buf.rate == Rate::Control &&
+            iffalse_buf.rate == Rate::Control
+        ) {
+            self.buf.set(if cond_buf.first() >= 0.5 {
+                iftrue_buf.first()
+            } else {
+                iffalse_buf.first()
+            });
+            return &self.buf;
+        }
+
+        self.buf.rate = Rate::Sample;
+
+        let mut bound = self.buf.len();
+        if cond_buf.rate == Rate::Sample { bound = cmp::min(bound, cond_buf.len()); }
+        if iftrue_buf.rate == Rate::Sample { bound = cmp::min(bound, iftrue_buf.len()); }
+        if iffalse_buf.rate == Rate::Sample { bound = cmp::min(bound, iffalse_buf.len()); }
+
+        for i in 0..bound {
+            let tv = match iftrue_buf.rate {
+                Rate::Sample => iftrue_buf[i],
+                Rate::Control => iftrue_buf.first(),
+            };
+            let fv = match iffalse_buf.rate {
+                Rate::Sample => iffalse_buf[i],
+                Rate::Control => iffalse_buf.first(),
+            };
+            let cv = match cond_buf.rate {
+                Rate::Sample => cond_buf[i],
+                Rate::Control => cond_buf.first(),
+            };
+            self.buf[i] = if cv >= 0.5 {
+                tv
+            } else {
+                fv
+            };
+        }
+
+        &self.buf
+    }
+    fn set_buffer(&mut self, buf: SampleBuffer) -> SampleBuffer {
+        mem::replace(&mut self.buf, buf)
+    }
+}