Add compressor plugin source with build files

Source/Compressor.cpp

@@ -0,0 +1,80 @@
+#include "Compressor.h"
+
+namespace pascal
+{
+
+void GlueCompressor::prepare (const juce::dsp::ProcessSpec& spec)
+{
+    sampleRate = spec.sampleRate > 0.0 ? spec.sampleRate : 44100.0;
+    reset();
+}
+
+void GlueCompressor::reset()
+{
+    detectorLevel = 0.0f;
+}
+
+void GlueCompressor::processBlock (juce::AudioBuffer<float>& buffer)
+{
+    const auto numChannels = buffer.getNumChannels();
+    const auto numSamples = buffer.getNumSamples();
+
+    if (numChannels == 0 || numSamples == 0)
+        return;
+
+    const float inputGain = juce::Decibels::decibelsToGain (juce::jlimit (-60.0f, 60.0f, inputDb));
+    const float makeupGain = juce::Decibels::decibelsToGain (juce::jlimit (-60.0f, 60.0f, makeupDb));
+    const float fs = static_cast<float> (sampleRate);
+    const float attackCoef = std::exp (-1.0f / (juce::jmax (0.2f, attackMs) * 0.001f * fs));
+    const float releaseCoef = std::exp (-1.0f / (juce::jmax (10.0f, releaseMs) * 0.001f * fs));
+    const float wet = juce::jlimit (0.0f, 1.0f, dryWet);
+    const float dry = 1.0f - wet;
+    const float knee = 6.0f;
+    const float ratioV = juce::jmax (1.0f, ratio);
+
+    juce::AudioBuffer<float> input;
+    input.makeCopyOf (buffer, true);
+
+    const auto* inChannels = input.getArrayOfReadPointers();
+    auto* outChannels = buffer.getArrayOfWritePointers();
+
+    for (int n = 0; n < numSamples; ++n)
+    {
+        float detect = 0.0f;
+        for (int c = 0; c < numChannels; ++c)
+            detect += inChannels[c][n];
+        detect = std::fabs (detect / static_cast<float> (numChannels)) * inputGain;
+
+        const float coeff = detect > detectorLevel ? (1.0f - attackCoef)
+                                                   : (1.0f - releaseCoef);
+        detectorLevel += coeff * (detect - detectorLevel);
+
+        const float overDb = juce::Decibels::gainToDecibels (detectorLevel + 1.0e-9f) - thresholdDb;
+
+        float grDb;
+        if (overDb <= -knee * 0.5f)
+        {
+            grDb = 0.0f;
+        }
+        else if (overDb >= knee * 0.5f)
+        {
+            grDb = -overDb * (1.0f - 1.0f / ratioV);
+        }
+        else
+        {
+            const float q = overDb + knee * 0.5f;
+            grDb = -(q * q / (2.0f * knee)) * (1.0f - 1.0f / ratioV);
+        }
+
+        const float gain = juce::Decibels::decibelsToGain (juce::jlimit (-80.0f, 24.0f, grDb)) * makeupGain;
+
+        for (int c = 0; c < numChannels; ++c)
+        {
+            const float in = inChannels[c][n] * inputGain;
+            const float wetSample = in * gain;
+            outChannels[c][n] = c < 2 ? in * dry + wetSample * wet : wetSample;
+        }
+    }
+}
+
+}