Add Balance parameter on CostelloReverb

Author: wtholliday

Sources/CSoundpipeAudioKit/Effects/CostelloReverbDSP.mm

@@ -7,18 +7,21 @@
 enum CostelloReverbParameter : AUParameterAddress {
     CostelloReverbParameterFeedback,
     CostelloReverbParameterCutoffFrequency,
+    CostelloReverbParameterBalance,
 };
 
 class CostelloReverbDSP : public SoundpipeDSPBase {
 private:
     sp_revsc *revsc;
     ParameterRamper feedbackRamp;
     ParameterRamper cutoffFrequencyRamp;
+    ParameterRamper balanceRamp{1.0};
 
 public:
     CostelloReverbDSP() {
         parameters[CostelloReverbParameterFeedback] = &feedbackRamp;
         parameters[CostelloReverbParameterCutoffFrequency] = &cutoffFrequencyRamp;
+        parameters[CostelloReverbParameterBalance] = &balanceRamp;
     }
 
     void init(int channelCount, double sampleRate) override {
@@ -47,14 +50,20 @@ void process(FrameRange range) override {
             float leftIn = inputSample(0, i);
             float rightIn = inputSample(1, i);
 
-            float &leftOut = outputSample(0, i);
-            float &rightOut = outputSample(1, i);
+            float leftWet;
+            float rightWet;
 
-            sp_revsc_compute(sp, revsc, &leftIn, &rightIn, &leftOut, &rightOut);
+            sp_revsc_compute(sp, revsc, &leftIn, &rightIn, &leftWet, &rightWet);
+
+            float bal = balanceRamp.getAndStep();
+
+            outputSample(0, i) = bal * leftWet + (1-bal) * leftIn;
+            outputSample(1, i) = bal * rightWet + (1-bal) * rightIn;
         }
     }
 };
 
 AK_REGISTER_DSP(CostelloReverbDSP, "rvsc")
 AK_REGISTER_PARAMETER(CostelloReverbParameterFeedback)
 AK_REGISTER_PARAMETER(CostelloReverbParameterCutoffFrequency)
+AK_REGISTER_PARAMETER(CostelloReverbParameterBalance)

Sources/SoundpipeAudioKit/Effects/CostelloReverb.swift

@@ -46,6 +46,19 @@ public class CostelloReverb: Node {
     /// Low-pass cutoff frequency.
     @Parameter(cutoffFrequencyDef) public var cutoffFrequency: AUValue
 
+    /// Dry/wet mix.
+    public static let balanceDef = NodeParameterDef(
+        identifier: "balance",
+        name: "Balance",
+        address: akGetParameterAddress("CostelloReverbParameterBalance"),
+        defaultValue: 1,
+        range: 0 ... 1,
+        unit: .percent
+    )
+
+    /// Dry/wet mix. Should be a value between 0-1.
+    @Parameter(balanceDef) public var balance: AUValue
+
     // MARK: - Initialization
 
     /// Initialize this reverb node

Tests/SoundpipeAudioKitTests/GenericNodeTests.swift

@@ -121,7 +121,7 @@ class GenericNodeTests: XCTestCase {
         nodeParameterTest(md5: "ffd48f502e2a5b2a7027d42b917a6667", factory: { ChowningReverb(input) })
         nodeParameterTest(md5: "56e76b5bd1d59d77ad4bd670f605f191", factory: { Clipper(input) })
         nodeParameterTest(md5: "c9ab35b7818db6a9af4edfbe2cb83927", factory: { CombFilterReverb(input) })
-        nodeParameterTest(md5: "1d47a6a4a24667064b747cd6571d0874", factory: { CostelloReverb(input) })
+        nodeParameterTest(md5: "bfdb04ada04582bac1c59626207726c2", factory: { CostelloReverb(input) })
         nodeParameterTest(md5: "6d17509eee0059105454f3cad4499586", factory: { DCBlock(input) })
         nodeParameterTest(md5: "fd4e315defe463bd643dd0c797cfd1f2", factory: { Decimator(input) })
         nodeParameterTest(md5: "4e240310041e20bdc886dd5eb285e89c", factory: { Distortion(input) })