From 07de83c28ca6031bb0a9f1826ad9fc8508d93241 Mon Sep 17 00:00:00 2001
From: Paul <paul@pwjw.com>
Date: Mon, 1 Apr 2019 11:30:40 -0400
Subject: [PATCH] Initialize All Filters

In two places, filters were using uninitialized memory at
creation. In some cases, for some values, in some instances,
this would create a large "pop" as the filter went unstable
with crazy coefficients or history values.

In my headless simulator, without these initialization changes
we get a click and pop within the first 100 instances. With them
there is no unstable run within 20,000 instances.

In theory this
Closes #790
Closes #753
Closes #699
Closes #698
Closes #662
Closes #660
---
 src/common/SurgeSynthesizer.cpp      |  7 ++++++
 src/common/dsp/QuadFilterChain.h     | 33 ++++++++++++++++++++++++++++
 src/common/vt_dsp/halfratefilter.cpp |  5 +++++
 3 files changed, 45 insertions(+)

diff --git a/src/common/SurgeSynthesizer.cpp b/src/common/SurgeSynthesizer.cpp
index 77a2e93ba9d..a372f2d2d30 100644
--- a/src/common/SurgeSynthesizer.cpp
+++ b/src/common/SurgeSynthesizer.cpp
@@ -84,6 +84,13 @@ SurgeSynthesizer::SurgeSynthesizer(PluginLayer* parent)
    FBQ[1] =
        (QuadFilterChainState*)_aligned_malloc((MAX_VOICES >> 2) * sizeof(QuadFilterChainState), 16);
 
+   for(int i=0; i<(MAX_VOICES >> 2); ++i)
+   {
+       FBQ[0][i].initToZero();
+       FBQ[1][i].initToZero();
+   }
+
+
    SurgePatch& patch = storage.getPatch();
 
    patch.polylimit.val.i = 8;
diff --git a/src/common/dsp/QuadFilterChain.h b/src/common/dsp/QuadFilterChain.h
index 163b7fbf251..d107e859449 100644
--- a/src/common/dsp/QuadFilterChain.h
+++ b/src/common/dsp/QuadFilterChain.h
@@ -14,6 +14,39 @@ struct QuadFilterChainState
 
    __m128 OutL, OutR, dOutL, dOutR;
    __m128 Out2L, Out2R, dOut2L, dOut2R; // fb_stereo only
+
+   void initToZero()
+   {
+       Gain = _mm_setzero_ps();
+       FB = _mm_setzero_ps();
+       Mix1 = _mm_setzero_ps();
+       Mix2 = _mm_setzero_ps();
+       Drive = _mm_setzero_ps();
+       dGain = _mm_setzero_ps();
+       dFB = _mm_setzero_ps();
+       dMix1 = _mm_setzero_ps();
+       dMix2 = _mm_setzero_ps();
+       dDrive = _mm_setzero_ps();
+
+       wsLPF = _mm_setzero_ps();
+       FBlineL = _mm_setzero_ps();
+       FBlineR = _mm_setzero_ps();
+
+       for(auto i=0; i<BLOCK_SIZE_OS; ++i)
+       {
+           DL[i] = _mm_setzero_ps();
+           DR[i] = _mm_setzero_ps();
+       }
+
+       OutL = _mm_setzero_ps();
+       OutR = _mm_setzero_ps();
+       dOutL = _mm_setzero_ps();
+       dOutR = _mm_setzero_ps();
+       Out2L = _mm_setzero_ps();
+       Out2R = _mm_setzero_ps();
+       dOut2L = _mm_setzero_ps();
+       dOut2R = _mm_setzero_ps();
+   }
 };
 
 struct fbq_global
diff --git a/src/common/vt_dsp/halfratefilter.cpp b/src/common/vt_dsp/halfratefilter.cpp
index 81411010f6f..f428e2b9207 100644
--- a/src/common/vt_dsp/halfratefilter.cpp
+++ b/src/common/vt_dsp/halfratefilter.cpp
@@ -405,6 +405,11 @@ void HalfRateFilter::set_coefficients(float* cA, float* cB)
 
 void HalfRateFilter::load_coefficients()
 {
+   for (int i = 0; i < M; i++)
+   {
+     va[i] = _mm_setzero_ps();
+   }
+
    int order = M << 1;
    if (steep)
    {