1 files changed, 78 insertions, 0 deletions
diff --git a/src/synth/rel.rs b/src/synth/rel.rs
new file mode 100644
index 0000000..76b6c04
--- /dev/null
+++ b/src/synth/rel.rs
@@ -0,0 +1,78 @@
+use std::{cmp, mem};
+use super::*;
+
+#[derive(Debug)]
+pub enum RelOp {
+    Greater,
+    GreaterEqual,
+    Equal,
+    NotEqual,
+    LessEqual,
+    Less,
+}
+
+#[derive(Debug)]
+pub struct Rel {
+    pub left: GenBox,
+    pub right: GenBox,
+    pub op: RelOp,
+    pub buf: SampleBuffer,
+}
+
+impl Generator for Rel {
+    fn eval<'a>(&'a mut self, params: &Parameters) -> &'a SampleBuffer {
+        let left_buf = self.left.eval(params);
+        let right_buf = self.right.eval(params);
+
+        match left_buf.rate {
+            Rate::Sample => {
+                self.buf.rate = Rate::Sample;
+
+                let bound = match right_buf.rate {
+                    Rate::Sample => cmp::min(left_buf.len(), right_buf.len()),
+                    Rate::Control => left_buf.len(),
+                };
+                for i in 0..bound {
+                    let val = left_buf[i];
+                    let thres = match right_buf.rate {
+                        Rate::Sample => right_buf[i],
+                        Rate::Control => right_buf.first(),
+                    };
+                    self.buf[i] = if match self.op {
+                        RelOp::Greater => val > thres,
+                        RelOp::GreaterEqual => val >= thres,
+                        RelOp::Equal => val == thres,
+                        RelOp::NotEqual => val != thres,
+                        RelOp::LessEqual => val <= thres,
+                        RelOp::Less => val < thres,
+                    } {
+                        1.0
+                    } else {
+                        0.0
+                    };
+                }
+            },
+            Rate::Control => {
+                let val = left_buf.first();
+                let thres = right_buf.first();
+                self.buf.set(if match self.op {
+                    RelOp::Greater => val > thres,
+                    RelOp::GreaterEqual => val >= thres,
+                    RelOp::Equal => val == thres,
+                    RelOp::NotEqual => val != thres,
+                    RelOp::LessEqual => val <= thres,
+                    RelOp::Less => val < thres,
+                } {
+                    1.0
+                } else {
+                    0.0
+                });
+            },
+        }
+
+        &self.buf
+    }
+    fn set_buffer(&mut self, buf: SampleBuffer) -> SampleBuffer {
+        mem::replace(&mut self.buf, buf)
+    }
+}