pub type ZoomRegion = (Rect, Arc<dyn Fn(f32) + Send + Sync>);Expand description
A registered pinch-to-zoom region (InteractiveViewer, Phase 32) — the
callback receives the gesture’s delta (winit’s PinchGesture::delta:
positive = magnify, negative = shrink; NOT a multiplier, an increment —
callers typically do zoom *= 1.0 + delta).