Merge ps-w8-t2-waveform: S11 waveform view + draggable loop points

src/vst/reasampler_editor.h

@@ -68,8 +68,14 @@ private:
 
     // What a mouse drag is currently editing (the drag-state machine). kNone = no drag in
     // flight. The zone-edit grabs mirror keyboard_strip::ZoneGrab; kRootMarker is the
-    // single-capture root drag on the setup strip.
-    enum class DragKind { kNone, kRootMarker, kZoneLow, kZoneHigh, kZoneBody };
+    // single-capture root drag on the setup strip; kWaveMarker is a draggable start/loop
+    // marker on the S11 waveform surface (which marker is in waveMarker_).
+    enum class DragKind { kNone, kRootMarker, kZoneLow, kZoneHigh, kZoneBody, kWaveMarker };
+
+    // The waveform markers on the single-capture setup surface (S11). Order is the draw + hit
+    // order (start first). Named generically per the spec so S15 can repurpose the surface with
+    // a different marker set; here it is start-point + the sustain loop's two ends.
+    enum class WaveMarker { kStart = 0, kLoopStart = 1, kLoopEnd = 2, kCount = 3 };
 
 #ifdef _WIN32
     void paint(HDC hdc);
@@ -105,6 +111,35 @@ private:
     // an empty envelope when the WAV can't be resolved/decoded. UI thread only (file I/O).
     const Envelope& thumbnailFor(const std::string& sampleId, int binCount);
 
+    // The decoded MONO PCM for a bank sample id, decoded once from the WAV and cached by id.
+    // Feeds the S11 waveform surface: the full-res envelope binned at view width AND the
+    // zero-crossing snap (both need the raw frames, not the binned thumbnail). Returns an empty
+    // vector when the WAV can't be resolved/decoded. UI thread only (file I/O). Reuses the same
+    // decode path as thumbnailFor (no new WAV reader), keyed by id (not width — snap is width-
+    // independent). Cleared with the thumbnail cache on refresh.
+    const std::vector<AudioSample>& monoPcmFor(const std::string& sampleId);
+
+    // The effective loop + start markers for the picked single capture (S11): the per-zone
+    // OVERRIDE for the picked id when one exists in map_, else the bank's S2 loop intrinsic
+    // (loop) / frame 0 (start). Absent loop -> loopStart==loopEnd==0 (the "no loop" state).
+    // frames is the decoded length (for defaulting loopEnd when the bank left the loop empty).
+    struct SetupMarkers {
+        std::int64_t start = 0;
+        std::int64_t loopStart = 0;
+        std::int64_t loopEnd = 0;
+        bool hasLoop = false;  // whether a sustain loop is set (drives the "no loop" affordance)
+    };
+    SetupMarkers pickedMarkers(std::int64_t frames) const;
+
+    // Commit an edited marker set for the picked capture as a per-zone loop/start override
+    // (upsert on the picked id — mirror of the root-marker path), then reload off-thread.
+    void commitPickedMarkers(const SetupMarkers& m);
+
+    // Write `m` as a loop/start override upsert into map_ for selectedId_ (find-or-append).
+    // Does NOT call commitAndReload — callers decide whether this is a live-drag update or a
+    // final commit. selectedId_ must be non-empty before calling.
+    void upsertPickedOverride(const SetupMarkers& m);
+
     ReaSamplerProcessor* processor_ = nullptr;
 
     // --- Snapshot of the live bank (drawn each paint; refreshed off the audio thread) ---
@@ -126,11 +161,25 @@ private:
     int dragStartLow_ = 0;                // the grabbed field's note at grab time
     int dragStartHigh_ = 0;
     int dragStartRoot_ = 60;
+    PerformanceMap dragStartMap_;         // map_ snapshotted at grab; restored on capture-loss
+
+    // S11 waveform-marker drag: which marker + the marker set snapshotted at grab time (so the
+    // pixel-delta resolver shifts the grabbed frame from its grab-time value, and inter-marker
+    // clamps use the sibling markers).
+    WaveMarker waveMarker_ = WaveMarker::kStart;
+    SetupMarkers dragStartMarkers_;
+    std::int64_t dragSampleFrames_ = 0;   // decoded length of the sample under the drag
 
     // --- Peak-thumbnail cache (mirror of bank_panel; id -> envelope at a bin width) ------
     // Keyed by "id|binCount" so a resize recomputes at the new width. Cleared on refresh so
     // a bank edit (a re-captured or deleted sample) does not show a stale thumbnail.
     std::unordered_map<std::string, Envelope> thumbCache_;
+
+    // --- Decoded mono-PCM cache (S11; id -> full-res frames) ------------------------------
+    // Keyed by id (width-independent, unlike thumbCache_). Feeds the waveform envelope binning
+    // + the zero-crossing snap. Cleared alongside thumbCache_ on refresh so a re-captured or
+    // deleted sample does not show/snap against stale PCM.
+    std::unordered_map<std::string, std::vector<AudioSample>> pcmCache_;
 };
 
 }  // namespace reasampler::vst