fix(velcurve-ui): caption overlap, add-in-ring data corruption, drag-off warn affordance

src/vst/reasampler_editor.cpp

@@ -700,7 +700,7 @@ constexpr int kPad = 8;
 // border so an endpoint at amp 0/1 stays grabbable.
 constexpr int kVelCurveBoxW = 168;    // the curve box width (incl. border)
 constexpr int kVelCurveMinHeroW = 240;  // hero must keep at least this much width beside the box
-constexpr int kVelCurveInset = 6;     // border -> mapping-box inset (>= node half-size + 3)
+constexpr int kVelCurveInset = 14;    // border -> mapping-box inset: caption band (~12px) + 2px gap
 constexpr int kCurveDragOffMargin = 24;  // release beyond box+margin -> drag-off delete
 
 struct SampleBands {
@@ -1157,17 +1157,28 @@ void ReaSamplerEditor::paintVelocityCurve(LICE_IBitmap* bmp, const Rect& r,
     }
 
     // Draggable node handles (mirror of the envelope overlay's): accent-primary squares lifted
-    // to accent-hot when grabbed or hovered.
+    // to accent-hot when grabbed or hovered, or warn when a drag-off delete is armed (cursor
+    // has passed kCurveDragOffMargin outside the box — release will delete the node).
     const LICE_pixel handle = toLice(roleColor(Role::AccentPrimary));
     const LICE_pixel handleHot = toLice(roleColor(Role::AccentHot));
+    const LICE_pixel handleWarn = toLice(roleColor(Role::Warn));
+    // Drag-off check: during a kCurveNode drag on THIS box, is the live cursor beyond the margin?
+    const bool dragOffArmed = (drag_ == DragKind::kCurveNode && dragCurveRect_.left == r.left &&
+                               dragCurveRect_.top == r.top) &&
+                              (dragCurX_ < r.left - kCurveDragOffMargin ||
+                               dragCurX_ > r.right + kCurveDragOffMargin ||
+                               dragCurY_ < r.top - kCurveDragOffMargin ||
+                               dragCurY_ > r.bottom + kCurveDragOffMargin);
     for (std::size_t i = 0; i < curve.points().size(); ++i) {
         const auto np = VelocityCurve::pixelFromPoint(box, curve.points()[i]);
         const bool grabbed = (drag_ == DragKind::kCurveNode &&
                               curvePointIndex_ == static_cast<int>(i));
         const bool hot = grabbed || isHovered(HoverKind::kCurveNode, static_cast<int>(i));
+        // A grabbed node in drag-off territory draws warn to signal "release will delete."
+        const LICE_pixel col = (grabbed && dragOffArmed) ? handleWarn
+                                                         : (hot ? handleHot : handle);
         const int nr = 3;
-        LICE_FillRect(bmp, np.x - nr, np.y - nr, 2 * nr, 2 * nr, hot ? handleHot : handle,
+        LICE_FillRect(bmp, np.x - nr, np.y - nr, 2 * nr, 2 * nr, col, 1.0f, 0);
-                      1.0f, 0);
     }
 }
 
@@ -1193,12 +1204,23 @@ void ReaSamplerEditor::handleCurveMouseDown(const Rect& r, int zoneIndex, int x,
     // ADD (mirror of the other map-editing drags' dragStartMap_ contract).
     dragStartMap_ = map_;
 
-    // Empty-space click: add a control point at the cursor via the pure inverse map, then grab
+    // Empty-space click inside the MAPPING BOX: add a control point at the cursor via the pure
-    // it — the click flows straight into a placing drag.
+    // inverse map, then grab it — the click flows straight into a placing drag.  Guard: the caller
+    // gates on contains(r, x, y) (the full border rect), but the 6+px inset ring — including the
+    // caption band — must not add a point; a click there would clamp to velocity 0/127 and
+    // produce an undeletable duplicate stacked on an endpoint.  Clicks in the ring may still grab
+    // an existing node (pointAtPixel's pick radius legitimately extends into the ring), which is
+    // handled above; only the add path is box-gated here.
     if (idx < 0) {
+        const bool inBox = (x >= box.left && x < box.left + box.width &&
+                            y >= box.top  && y < box.top  + box.height);
+        if (inBox) {
             const VelocityPoint p = VelocityCurve::pointFromPixel(box, x, y);
             idx = static_cast<int>(z.velocityCurve.addPoint(p.velocity, p.amp));
         }
+    }
+
+    if (idx < 0) return;  // ring click with no node hit — nothing to grab
 
     drag_ = DragKind::kCurveNode;
     curvePointIndex_ = idx;
@@ -2056,6 +2078,8 @@ bool ReaSamplerEditor::handleControlClick(int zoneIndex, const Rect& panel, int
 
 void ReaSamplerEditor::onMouseMove(int x, int y) {
     if (drag_ == DragKind::kNone) return;
+    dragCurX_ = x;  // keep the live cursor position for drag-state draw cues (e.g. drag-off warn)
+    dragCurY_ = y;
     RECT cr{};
     GetClientRect(childHwnd_, &cr);
     const int w = cr.right - cr.left;
@@ -2276,6 +2300,7 @@ void ReaSamplerEditor::onMouseUp(int x, int y) {
         if (off) {
             map_.zones[static_cast<std::size_t>(curveZone)].velocityCurve.deletePoint(
                 static_cast<std::size_t>(curveIdx));
+            hover_ = HoverTarget{};  // stale kCurveNode index would light a shifted node on next paint
         }
     }
     commitAndReload();

src/vst/reasampler_editor.h

@@ -392,6 +392,8 @@ private:
     DragKind drag_ = DragKind::kNone;
     int dragStartX_ = 0;                  // grab x (px), for the pixel-delta resolver
     int dragStartY_ = 0;                  // grab y (px), for the vertical scrollbar-thumb drag
+    int dragCurX_ = 0;                    // live cursor x (px) during a drag — updated in onMouseMove
+    int dragCurY_ = 0;                    // live cursor y (px) during a drag — updated in onMouseMove
     int dragStartLow_ = 0;                // the grabbed field's note at grab time
     int dragStartHigh_ = 0;
     int dragStartRoot_ = 60;