From a217938275e02349efd47db178cfc067e62e8f1d Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Fri, 2 Aug 2024 01:35:44 -0700
Subject: [PATCH] Pass a span to Compressor::process

---
 alc/alu.cpp        |  2 +-
 core/mastering.cpp | 15 +++++----------
 core/mastering.h   |  4 +---
 3 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/alc/alu.cpp b/alc/alu.cpp
index 7f8503dce8..644974da41 100644
--- a/alc/alu.cpp
+++ b/alc/alu.cpp
@@ -2207,7 +2207,7 @@ uint DeviceBase::renderSamples(const uint numSamples)
     postProcess(samplesToDo);
 
     /* Apply compression, limiting sample amplitude if needed or desired. */
-    if(Limiter) Limiter->process(samplesToDo, RealOut.Buffer.data());
+    if(Limiter) Limiter->process(samplesToDo, RealOut.Buffer);
 
     /* Apply delays and attenuation for mismatched speaker distances. */
     if(ChannelDelays)
diff --git a/core/mastering.cpp b/core/mastering.cpp
index 67fa1c91c2..e31c3e9207 100644
--- a/core/mastering.cpp
+++ b/core/mastering.cpp
@@ -334,7 +334,6 @@ std::unique_ptr<Compressor> Compressor::Create(const size_t NumChans, const floa
         BufferLineSize-1.0f));
 
     auto Comp = CompressorPtr{new Compressor{}};
-    Comp->mNumChans = NumChans;
     Comp->mAuto.Knee = AutoKnee;
     Comp->mAuto.Attack = AutoAttack;
     Comp->mAuto.Release = AutoRelease;
@@ -382,15 +381,11 @@ std::unique_ptr<Compressor> Compressor::Create(const size_t NumChans, const floa
 Compressor::~Compressor() = default;
 
 
-void Compressor::process(const uint SamplesToDo, FloatBufferLine *OutBuffer)
+void Compressor::process(const uint SamplesToDo, const al::span<FloatBufferLine> InOut)
 {
-    const size_t numChans{mNumChans};
-
     ASSUME(SamplesToDo > 0);
     ASSUME(SamplesToDo <= BufferLineSize);
-    ASSUME(numChans > 0);
 
-    const auto output = al::span{OutBuffer, numChans};
     const float preGain{mPreGain};
     if(preGain != 1.0f)
     {
@@ -400,10 +395,10 @@ void Compressor::process(const uint SamplesToDo, FloatBufferLine *OutBuffer)
             std::transform(buffer.cbegin(), buffer.cend(), buffer.begin(),
                 [preGain](const float s) noexcept { return s * preGain; });
         };
-        std::for_each(output.begin(), output.end(), apply_gain);
+        std::for_each(InOut.begin(), InOut.end(), apply_gain);
     }
 
-    linkChannels(SamplesToDo, output);
+    linkChannels(SamplesToDo, InOut);
 
     if(mAuto.Attack || mAuto.Release)
         crestDetector(SamplesToDo);
@@ -416,7 +411,7 @@ void Compressor::process(const uint SamplesToDo, FloatBufferLine *OutBuffer)
     gainCompressor(SamplesToDo);
 
     if(!mDelay.empty())
-        signalDelay(SamplesToDo, output);
+        signalDelay(SamplesToDo, InOut);
 
     const auto gains = assume_aligned_span<16>(al::span{mSideChain}.first(SamplesToDo));
     auto apply_comp = [gains](const FloatBufferSpan inout) noexcept -> void
@@ -425,7 +420,7 @@ void Compressor::process(const uint SamplesToDo, FloatBufferLine *OutBuffer)
         std::transform(gains.cbegin(), gains.cend(), buffer.cbegin(), buffer.begin(),
             std::multiplies{});
     };
-    for(const FloatBufferSpan inout : output)
+    for(const FloatBufferSpan inout : InOut)
         apply_comp(inout);
 
     const auto delayedGains = al::span{mSideChain}.subspan(SamplesToDo, mLookAhead);
diff --git a/core/mastering.h b/core/mastering.h
index 0fafff91e2..0af9a3da67 100644
--- a/core/mastering.h
+++ b/core/mastering.h
@@ -26,8 +26,6 @@ using uint = unsigned int;
  *   http://c4dm.eecs.qmul.ac.uk/audioengineering/compressors/
  */
 class SIMDALIGN Compressor {
-    size_t mNumChans{0u};
-
     struct AutoFlags {
         bool Knee : 1;
         bool Attack : 1;
@@ -76,7 +74,7 @@ class SIMDALIGN Compressor {
 
 public:
     ~Compressor();
-    void process(const uint SamplesToDo, FloatBufferLine *OutBuffer);
+    void process(const uint SamplesToDo, al::span<FloatBufferLine> InOut);
     [[nodiscard]] auto getLookAhead() const noexcept -> uint { return mLookAhead; }
 
     /**