waveform VST

plugin/CMakeLists.txt

@@ -62,6 +62,7 @@ function(add_prism_scope TARGET PRODUCT PLUGIN_CODE SCOPE_DEFINE)
         ${PRISM_NATIVE_DIR}/vectorscope.cpp
         ${PRISM_NATIVE_DIR}/multiband.cpp
         ${PRISM_NATIVE_DIR}/spectrogram.cpp
+        ${PRISM_NATIVE_DIR}/waveform.cpp
         ${PRISM_NATIVE_DIR}/dsp_utils.cpp)
 
     target_include_directories(${TARGET} PRIVATE Source ${PRISM_NATIVE_DIR})
@@ -103,3 +104,4 @@ add_prism_scope(PrismVUMeter      "Prism VU Meter"     Pvum "PRISM_SCOPE_VUMETER
 add_prism_scope(PrismLUFSMeter    "Prism Loudness Meter" Pluf "PRISM_SCOPE_LUFSMETER=1")
 add_prism_scope(PrismVectorscope  "Prism Vectorscope"  Pvct "PRISM_SCOPE_VECTORSCOPE=1")
 add_prism_scope(PrismSpectrogram  "Prism Spectrogram"  Pspg "PRISM_SCOPE_SPECTROGRAM=1")
+add_prism_scope(PrismWaveform     "Prism Waveform"     Pwav "PRISM_SCOPE_WAVEFORM=1")

plugin/Source/PluginEditor.cpp

@@ -5,6 +5,7 @@
 #include "LUFSMeterEngine.h"
 #include "VectorscopeEngine.h"
 #include "SpectrogramEngine.h"
+#include "WaveformEngine.h"
 #include <cstring>
 
 #if ! PRISM_USE_DEV_SERVER
@@ -22,7 +23,9 @@ namespace
 
     std::unique_ptr<ScopeEngine> makeEngine()
     {
-#if defined(PRISM_SCOPE_SPECTROGRAM) && PRISM_SCOPE_SPECTROGRAM
+#if defined(PRISM_SCOPE_WAVEFORM) && PRISM_SCOPE_WAVEFORM
+        return std::make_unique<WaveformEngine>();
+#elif defined(PRISM_SCOPE_SPECTROGRAM) && PRISM_SCOPE_SPECTROGRAM
         return std::make_unique<SpectrogramEngine>();
 #elif defined(PRISM_SCOPE_VECTORSCOPE) && PRISM_SCOPE_VECTORSCOPE
         return std::make_unique<VectorscopeEngine>();

plugin/Source/WaveformEngine.h

@@ -0,0 +1,97 @@
+#pragma once
+
+#include "ScopeEngine.h"
+#include "waveform.h"   // reused, unmodified, from native/src
+#include <vector>
+#include <cmath>
+#include <algorithm>
+
+/**
+ * Waveform engine. Runs the reused Visualizer::WaveformMultibandAnalyzer, which
+ * summarizes audio into per-column min/max + 3-band RMS. Unlike the spectrogram, the
+ * column width (samplesPerColumn) is a pure function of sampleRate and scrollSpeed —
+ * sampleRate / (128 * scrollSpeed), the same formula the renderer uses — so the engine
+ * derives it itself; no canvas round-trip. mode ('stereo' vs 'mono') selects
+ * processStereo (stride 10) vs processMono (stride 5), flagged in the frame. multiband
+ * is render-only (the analyzer always emits the band RMS columns use for coloring).
+ */
+class WaveformEngine : public ScopeEngine
+{
+public:
+    WaveformEngine() { reconfigure(); }
+
+    const char* scopeId() const override { return "waveform"; }
+    juce::Identifier frameEventId() const override { return frameId; }
+
+    void setSampleRate(double sr) override
+    {
+        if (sr > 0.0 && (float) sr != sampleRate)
+        {
+            sampleRate = (float) sr;
+            reconfigure();
+        }
+    }
+
+    void configure(const juce::var& settings) override
+    {
+        stereo = settings.getProperty("mode", "mono").toString() == "stereo";
+        const auto speed = (float) settings.getProperty("scrollSpeed", (double) scrollSpeed);
+        if (speed > 0.0f)
+            scrollSpeed = speed;
+        reconfigure();
+    }
+
+    void process(const float* left, const float* right, int numSamples) override
+    {
+        if (numSamples <= 0)
+            return;
+
+        if (stereo)
+        {
+            const auto& cols = wave.processStereo(left, right, (size_t) numSamples);
+            pending.insert(pending.end(), cols.begin(), cols.end());
+        }
+        else
+        {
+            if ((int) mono.size() < numSamples)
+                mono.resize((size_t) numSamples);
+            for (int i = 0; i < numSamples; ++i)
+                mono[(size_t) i] = 0.5f * (left[i] + right[i]);
+            const auto& cols = wave.processMono(mono.data(), (size_t) numSamples);
+            pending.insert(pending.end(), cols.begin(), cols.end());
+        }
+    }
+
+    juce::var buildFrame(double sr) override
+    {
+        const size_t stride = stereo ? Visualizer::WAVEFORM_STEREO_SUMMARY_STRIDE
+                                     : Visualizer::WAVEFORM_MONO_SUMMARY_STRIDE;
+        auto* obj = new juce::DynamicObject();
+        obj->setProperty("sampleRate", sr);
+        obj->setProperty("stereo", stereo);
+        obj->setProperty("columnCount", (int) (pending.size() / stride));
+        if (! pending.empty())
+            obj->setProperty("summaries", juce::Base64::toBase64(pending.data(), pending.size() * sizeof(float)));
+        else
+            obj->setProperty("summaries", juce::String());
+        pending.clear();
+        return juce::var(obj);
+    }
+
+private:
+    void reconfigure()
+    {
+        const float pps = 128.0f * std::max(0.01f, scrollSpeed);
+        samplesPerColumn = (size_t) std::max(1L, std::lround(sampleRate / pps));
+        wave.configure(sampleRate, samplesPerColumn);
+        pending.clear();
+    }
+
+    const juce::Identifier frameId { "waveformFrame" };
+    Visualizer::WaveformMultibandAnalyzer wave;
+    std::vector<float> mono, pending;
+    float sampleRate = 48000.0f;
+    float scrollSpeed = 1.0f;
+    size_t samplesPerColumn = 1;
+    bool stereo = false;
+};