From bcb7ee0bdf4bf031846999ffc35b866ab4fb8990 Mon Sep 17 00:00:00 2001
From: Randy Jones <randy@madronalabs.com>
Date: Wed, 10 Jul 2024 14:57:04 -0700
Subject: [PATCH] add clear() for some DSP objects

---
 source/DSP/MLDSPFilters.h | 34 +++++++++++++++++++++
 source/DSP/MLDSPGens.h    | 62 ++++++++++++++++++++++++++++++++-------
 2 files changed, 85 insertions(+), 11 deletions(-)

diff --git a/source/DSP/MLDSPFilters.h b/source/DSP/MLDSPFilters.h
index a7d11b95..0f796fdc 100644
--- a/source/DSP/MLDSPFilters.h
+++ b/source/DSP/MLDSPFilters.h
@@ -481,6 +481,11 @@ struct OnePole
   {
     y1 = f;
   }
+
+  void clear()
+  {
+    y1 = 0.f;
+  }
 };
 
 // A one-pole, one-zero filter to attenuate DC.
@@ -1296,6 +1301,15 @@ class HalfBandFilter
     }
     return vy;
   }
+  
+  void clear()
+  {
+    apa0.clear();
+    apa1.clear();
+    apb0.clear();
+    apb1.clear();
+    b1 = 0;
+  }
 
  private:
   // order=4, rejection=70dB, transition band=0.1.
@@ -1386,6 +1400,16 @@ class Downsampler
   {
     return DSPVector(bufferPtr(_numBuffers - 1));
   }
+  
+  void clear()
+  {
+    for(auto& f : _filters)
+    {
+      f.clear();
+    }
+    _buffers.clear();
+    _counter = 0;
+  }
 };
 
 
@@ -1450,6 +1474,16 @@ struct Upsampler
     load(result, bufferPtr(readIdx_++));
     return result;
   }
+  
+  void clear()
+  {
+    for(auto& f : _filters)
+    {
+      f.clear();
+    }
+    _buffers.clear();
+    readIdx_ = 0;
+  }
 };
 
 
diff --git a/source/DSP/MLDSPGens.h b/source/DSP/MLDSPGens.h
index f75cfc36..156518b3 100644
--- a/source/DSP/MLDSPGens.h
+++ b/source/DSP/MLDSPGens.h
@@ -398,16 +398,34 @@ class SawGen
 };
 
 // ----------------------------------------------------------------
-// LinearGlide
+// Interpolator1
 
-// convert a scalar float input into a DSPVector with linear slew.
-// to allow optimization, glide time is quantized to DSPVectors.
-// Note that a onepole or other IIR filter is not used because we must reach
-// the actual value in a finite time.
+// linear interpolate over signal length to next value.
 
 constexpr float unityRampFn(int i) { return (i + 1) / static_cast<float>(kFloatsPerDSPVector); }
 ConstDSPVector kUnityRampVec{unityRampFn};
 
+struct Interpolator1
+{
+  float currentValue{0};
+  
+  DSPVector operator()(float f)
+  {
+    float dydt = f - currentValue;
+    DSPVector outputVec = DSPVector(currentValue) + kUnityRampVec*dydt;
+    currentValue = f;
+    return outputVec;
+  }
+};
+
+// TODO needs test
+
+// ----------------------------------------------------------------
+// LinearGlide
+
+// convert a scalar float input into a DSPVector with linear slew.
+// to allow optimization, glide time is quantized to DSPVectors.
+
 class LinearGlide
 {
   DSPVector mCurrVec{0.f};
@@ -415,7 +433,7 @@ class LinearGlide
   float mTargetValue{0};
   float mDyPerVector{1.f / 32};
   int mVectorsPerGlide{32};
-  int mVectorsRemaining{0};
+  int mVectorsRemaining{-1};
   
 public:
   void setGlideTimeInSamples(float t)
@@ -445,7 +463,11 @@ class LinearGlide
     }
     
     // process glide
-    if (mVectorsRemaining == 0)
+    if (mVectorsRemaining < 0)
+    {
+      // do nothing
+    }
+    else if (mVectorsRemaining == 0)
     {
       // end glide: write target value to output vector
       mCurrVec = DSPVector(mTargetValue);
@@ -462,7 +484,7 @@ class LinearGlide
       mStepVec = DSPVector(dydv);
       
       // setup current vector with first interpolation ramp.
-      mCurrVec = DSPVector(currentValue) + kUnityRampVec * DSPVector(dydv);
+      mCurrVec = DSPVector(currentValue) + kUnityRampVec * mStepVec;
       
       mVectorsRemaining--;
     }
@@ -478,6 +500,14 @@ class LinearGlide
     
     return mCurrVec;
   }
+  
+  void clear()
+  {
+    mCurrVec = 0.f;
+    mStepVec = 0.f;
+    mTargetValue = 0.f;
+    mVectorsRemaining = -1;
+  }
 };
 
 class SampleAccurateLinearGlide
@@ -487,7 +517,7 @@ class SampleAccurateLinearGlide
   float mTargetValue{0.f};
   int mSamplesPerGlide{32};
   float mDyPerSample{1.f/32};
-  int mSamplesRemaining{0};
+  int mSamplesRemaining{-1};
   
 public:
   void setGlideTimeInSamples(float t)
@@ -517,7 +547,11 @@ class SampleAccurateLinearGlide
     }
     
     // process glide
-    if (mSamplesRemaining == 0)
+    if (mSamplesRemaining < 0)
+    {
+      // do nothing
+    }
+    else if (mSamplesRemaining == 0)
     {
       // end glide: write target value to output vector
       mCurrValue = (mTargetValue);
@@ -528,7 +562,6 @@ class SampleAccurateLinearGlide
     {
       // start glide: get change in output value per sample
       mStepValue = (mTargetValue - mCurrValue) * mDyPerSample;
-      
       mSamplesRemaining--;
     }
     else
@@ -543,6 +576,13 @@ class SampleAccurateLinearGlide
     
     return mCurrValue;
   }
+  void clear()
+  {
+    mCurrValue = 0.f;
+    mStepValue = 0.f;
+    mTargetValue = 0.f;
+    mSamplesRemaining = -1;
+  }
 };
 
 }  // namespace ml