feat: legible ReaSampler 9000 editor — bigger knobs, ms time constants, per-ring double-click reset, and an antialiased draw pass

src/core/instrument/ui/knob_deck.cpp

@@ -190,4 +190,28 @@ DeckHit hitTestDeck(const DeckLayout& layout, int x, int y) {
     return {};
 }
 
+namespace {
+// Squared distance from a rect's centre, in the rect's own pixel units.
+double distSqFromCentre(const Rect& r, int x, int y) {
+    const double dx = x - (r.x + r.width / 2.0);
+    const double dy = y - (r.y + r.height / 2.0);
+    return dx * dx + dy * dy;
+}
+}  // namespace
+
+DeckFaceHit hitTestKnobFace(const DeckLayout& layout, int x, int y) {
+    for (const DeckGroupLayout& g : layout.groups) {
+        if (!contains(g.box, x, y)) continue;
+        for (const DeckCellLayout& c : g.cells) {
+            const double rOuter = c.knob.width / 2.0;
+            if (distSqFromCentre(c.knob, x, y) >= rOuter * rOuter) continue;
+            const double rInner = c.inner.width / 2.0;
+            const bool inner = distSqFromCentre(c.inner, x, y) < rInner * rInner;
+            return {c.id, inner};
+        }
+        return {};  // inside the group but off every dial
+    }
+    return {};
+}
+
 }  // namespace reasampler::instrument::ui