Fixed a bug in modops processing when no edge was assigned

src/dsp/mod.rs

@@ -171,6 +171,9 @@ impl ProcBuf {
         }
     }
 
+    #[inline]
+    pub fn is_null(&self) -> bool { self.0.is_null() }
+
     pub fn free(&self) {
         if !self.0.is_null() {
             drop(unsafe { Box::from_raw(self.0) });

src/nodes/node_prog.rs

@@ -51,7 +51,9 @@ impl ModOp {
         let inbuf  = &mut self.inbuf;
         let outbuf = &mut self.outbuf;
 
-        println!("PROCMA {}", self.amount);
+        if inbuf.is_null() {
+            return;
+        }
 
         for frame in 0..nframes {
             modbuf.write(frame,

tests/modamt.rs

@@ -0,0 +1,46 @@
+mod common;
+use common::*;
+
+#[test]
+fn check_param_mod_amt_no_input() {
+    let (node_conf, mut node_exec) = new_node_engine();
+    let mut matrix = Matrix::new(node_conf, 3, 3);
+
+    let sin = NodeId::Sin(0);
+    let out = NodeId::Out(0);
+    matrix.place(0, 0, Cell::empty(sin)
+                       .out(None, None, sin.out("sig")));
+    matrix.place(0, 1, Cell::empty(out)
+                       .input(out.inp("ch1"), None, None));
+    matrix.sync().unwrap();
+
+    matrix.set_param_modamt(
+        sin.inp_param("freq").unwrap(), Some(0.2)).unwrap();
+
+    let rms = run_and_get_first_rms_mimax(&mut node_exec, 50.0);
+    assert_rmsmima!(rms, (0.4999, -1.0, 1.0));
+}
+
+#[test]
+fn check_param_mod_amt_with_input() {
+    let (node_conf, mut node_exec) = new_node_engine();
+    let mut matrix = Matrix::new(node_conf, 3, 3);
+
+    let sin  = NodeId::Sin(0);
+    let sin2 = NodeId::Sin(1);
+    let out  = NodeId::Out(0);
+    matrix.place(0, 0, Cell::empty(sin2)
+                       .out(None, None, sin2.out("sig")));
+    matrix.place(0, 1, Cell::empty(sin)
+                       .input(sin.inp("freq"), None, None)
+                       .out(None, None, sin.out("sig")));
+    matrix.place(0, 2, Cell::empty(out)
+                       .input(out.inp("ch1"), None, None));
+    matrix.sync().unwrap();
+
+    matrix.set_param_modamt(
+        sin.inp_param("freq").unwrap(), Some(0.2)).unwrap();
+
+    let rms = run_and_get_first_rms_mimax(&mut node_exec, 50.0);
+    assert_rmsmima!(rms, (0.4992, -1.0, 1.0));
+}