fix(waveform): 4x-oversampled min/max envelope, columnMinMax homed in peaks, panel routed through shared drawWaveform — one gap-free algorithm on all surfaces

src/vst/reasampler_editor.cpp

@@ -121,10 +121,12 @@ std::string sampleLabel(const std::vector<SampleChoice>& samples, const std::str
     return "?";
 }
 
-// The bin count a card's thumbnail is computed at: the card thumbnail width, so one bin
-// per horizontal pixel.
+// The bin count a card's thumbnail is computed at: kWaveformOversample bins per drawn
+// thumbnail pixel column (FA3 anti-alias) — drawWaveform collapses them per column via
+// peaks::columnMinMax. thumbnailFor clamps the request to the decoded frame count.
 int thumbBins(const BrowserLayout& layout) {
-    return (std::max)(1, cardThumbnailRect(layout, 0).width());
+    return (std::max)(1, kWaveformOversample *
+                             waveformColumnCount(toKitBox(cardThumbnailRect(layout, 0))));
 }
 #endif
 }  // namespace
@@ -570,8 +572,12 @@ const Envelope& ReaSamplerEditor::thumbnailFor(const std::string& sampleId, int
     const std::vector<AudioSample>& mono = monoPcmFor(sampleId);
     Envelope env;
     if (!mono.empty()) {
-        env = computeEnvelope(mono, 1, mono.size(),
-                              static_cast<std::size_t>((std::max)(1, binCount)));
+        // Clamp bins to the frame count: computeEnvelope pads binCount > frameCount with
+        // trailing empty {0,0} bins, which would render a very short sample as a comb of
+        // spikes over flat gaps.
+        const std::size_t bins =
+            (std::min)(static_cast<std::size_t>((std::max)(1, binCount)), mono.size());
+        env = computeEnvelope(mono, 1, mono.size(), bins);
     }
     auto ins = thumbCache_.emplace(key, std::move(env));
     return ins.first->second;
@@ -1005,8 +1011,15 @@ void ReaSamplerEditor::paintSample(LICE_IBitmap* bmp, int w, int h) {
     const Rect waveArea = bands.hero;
     fillSurface(bmp, toKitBox(waveArea), Role::BgBase, InteractionState::Rest);
     if (frames > 0 && waveArea.width() > 0) {
-        const int bins = (std::max)(1, waveArea.width());
-        const Envelope env = computeEnvelope(pcm, 1, pcm.size(), static_cast<std::size_t>(bins));
+        // FA3 anti-alias: request kWaveformOversample bins per drawn pixel column (clamped
+        // to the frame count) — drawWaveform collapses them per column via
+        // peaks::columnMinMax into a gap-free true min/max envelope.
+        const std::int64_t wantBins =
+            static_cast<std::int64_t>((std::max)(1, waveformColumnCount(toKitBox(waveArea)))) *
+            kWaveformOversample;
+        const std::size_t bins =
+            static_cast<std::size_t>(wantBins < frames ? wantBins : frames);
+        const Envelope env = computeEnvelope(pcm, 1, pcm.size(), bins);
         drawEnvelope(bmp, waveArea, env);
 
         const SetupMarkers m = pickedMarkers(frames);