From 466a034c4cd18df4e4933a6b48dc1be38b2e7557 Mon Sep 17 00:00:00 2001
From: Hailey Somerville <hailey@hailey.lol>
Date: Sat, 4 Apr 2020 00:51:10 +1100
Subject: [PATCH] add mono line type

---
 frontend/src/workspace.rs |  3 ++-
 protocol/src/lib.rs       |  1 +
 src/module/amplifier.rs   | 10 +++++++---
 src/module/trigger.rs     |  2 +-
 4 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/frontend/src/workspace.rs b/frontend/src/workspace.rs
index efec7f1..5c38589 100644
--- a/frontend/src/workspace.rs
+++ b/frontend/src/workspace.rs
@@ -750,9 +750,10 @@ impl Component for Terminal {
             >
                 <svg width="16" height="16">
                     { match self.props.terminal.line_type {
+                        LineType::Mono => html! {},
                         LineType::Stereo => html! {
                             <polygon points="0,16 16,16 16,0" fill={ if self.hover { "#f0b5b3" } else { "#e0a5a3" } } />
-                        }
+                        },
                     } }
                 </svg>
             </div>
diff --git a/protocol/src/lib.rs b/protocol/src/lib.rs
index b895715..d4f26d9 100644
--- a/protocol/src/lib.rs
+++ b/protocol/src/lib.rs
@@ -93,6 +93,7 @@ impl OutputId {
 
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
 pub enum LineType {
+    Mono,
     Stereo,
 }
 
diff --git a/src/module/amplifier.rs b/src/module/amplifier.rs
index 345556f..acf732f 100644
--- a/src/module/amplifier.rs
+++ b/src/module/amplifier.rs
@@ -27,21 +27,25 @@ impl Module for Amplifier {
 
     fn run_tick(&mut self, _t: u64, inputs: &[Option<&[Sample]>], outputs: &mut [&mut [Sample]]) -> Option<Self::Indication> {
         let AmplifierParams {mod_depth, amplitude} = self.params;
-        let len = outputs[0].len();
 
         let input = &inputs[0].unwrap_or(&ZERO_BUFFER);
         let mod_input = &inputs[1].unwrap_or(&ONE_BUFFER);
         let output = &mut outputs[0];
 
+        let len = input.len();
+
         for i in 0..len {
-            output[i] = input[i] * depth(mod_input[i], mod_depth) * amplitude;
+            // mod input is a mono channel and so half the length:
+            let mod_value = mod_input[i / 2];
+
+            output[i] = input[i] * depth(mod_value, mod_depth) * amplitude;
         }
 
         None
     }
 
     fn inputs(&self) -> &[LineType] {
-        &[LineType::Stereo, LineType::Stereo]
+        &[LineType::Stereo, LineType::Mono]
     }
 
     fn outputs(&self) -> &[LineType] {
diff --git a/src/module/trigger.rs b/src/module/trigger.rs
index 66aa558..d0a0d18 100644
--- a/src/module/trigger.rs
+++ b/src/module/trigger.rs
@@ -45,6 +45,6 @@ impl Module for Trigger {
     }
 
     fn outputs(&self) -> &[LineType] {
-        &[LineType::Stereo]
+        &[LineType::Mono]
     }
 }