S-VIEW-10: velocity-curve editor UI — draggable spline box beside the Sample hero + in the Zone panel, all math through the pure velocity_curve module

src/vst/reasampler_editor.h

@@ -36,6 +36,7 @@
 #include "param_slider.h"     // ControlRow (the S12/S15/S16 control-surface geometry)
 #include "peaks.h"            // Envelope (the cached peak thumbnail)
 #include "sample_map.h"       // SampleChoice, BankChoice, PerformanceMap (the shell's snapshot)
+#include "velocity_curve.h"   // VelocityCurve (S-VIEW-10 transfer-curve editor state)
 
 #ifdef _WIN32
 #include <windows.h>
@@ -78,9 +79,10 @@ private:
     // 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_); kEnvNode is a
     // draggable envelope breakpoint on the Sample-view hero overlay (S-VIEW-3, which node in
-    // envNode_).
+    // envNode_); kCurveNode is a draggable velocity-curve control point in the S-VIEW-10
+    // transfer-curve editor (which point in curvePointIndex_).
     enum class DragKind { kNone, kRootMarker, kZoneLow, kZoneHigh, kZoneBody, kWaveMarker,
-                          kScrollThumb, kParamSlider, kEnvNode };
+                          kScrollThumb, kParamSlider, kEnvNode, kCurveNode };
 
     // The parameter controls on the setup surface (S12 AHDSR + the S15/S16 control surfaces).
     // The int value is the ControlDesc id the pure param_slider hit-test returns; the shell
@@ -133,6 +135,7 @@ private:
         kAddZone,         // the "+ Add Zone" button
         kDeleteZone,      // the "Delete" zone button
         kControl,         // a param-panel control row (index = ControlDesc id)
+        kCurveNode,       // a velocity-curve control point (index = point index, S-VIEW-10)
     };
     struct HoverTarget {
         HoverKind kind = HoverKind::kNone;
@@ -152,6 +155,17 @@ private:
     // `zone`'s play params, at the sample's wall-clock duration. Shared by the Sample hero band.
     void paintEnvelopeOverlay(LICE_IBitmap* bmp, const Rect& waveArea, const PerformanceZone& zone,
                               std::int64_t frames);
+    // S-VIEW-10: the velocity->amp transfer-curve editor — a bordered box (X = velocity 0-127,
+    // Y = amp 0-1), the monotone spline traced by eval, one draggable node handle per control
+    // point. Shared by the Sample face (beside the hero) and the Zone param panel; all mapping /
+    // hit-test / clamp math lives in the pure velocity_curve module. `r` empty -> draws nothing.
+    void paintVelocityCurve(LICE_IBitmap* bmp, const Rect& r, const PerformanceZone& zone);
+
+    // Route a mouse-down inside curve-editor box `r` editing map_.zones[zoneIndex]: a node grab
+    // starts a kCurveNode drag; Alt-click on an interior node deletes it (committed at once);
+    // an empty-space click ADDS a point at the cursor and grabs it for an immediate drag.
+    // `zoneIndex` must be a valid index into map_.zones (callers materialize first).
+    void handleCurveMouseDown(const Rect& r, int zoneIndex, int x, int y);
 
     void onMouseDown(int x, int y);
     void onMouseMove(int x, int y);
@@ -405,6 +419,15 @@ private:
     EnvNode envNode_ = EnvNode::Origin;
     AmpEnvelope dragStartEnv_{};
 
+    // S-VIEW-10 velocity-curve node drag: which point is grabbed, the curve snapshotted at grab
+    // (resolvePointDrag's absolute-delta contract), the box rect the grab happened in (the Sample
+    // and Zone views place the editor differently — the drag resolves against the grab-time box),
+    // and which zone the edit lands on. Mirror of the envelope-node drag state.
+    int curvePointIndex_ = -1;
+    VelocityCurve dragStartCurve_ = VelocityCurve::flat();
+    Rect dragCurveRect_{};
+    int dragCurveZone_ = -1;
+
     // --- 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.