Mobile Scroll Physics: Rubber-Band Overscroll & Momentum (2D)

Touch interfaces feel fluid because the scroll view underneath is running a small, precise physics model, not just moving pixels. This simulator renders a 2D mobile card list on a flat canvas that you can drag and flick directly: release your finger and the list coasts under exponential friction decay, and once it runs past the top or bottom it switches into rubber-band mode — the classic UIScrollView compression function that resists pulling harder the further you go — before a spring-damper term pulls it back to rest exactly at the edge. Live readouts track velocity, overscroll distance and scroll state (Idle / Dragging / Flinging / Bouncing) while sliders let you tune the rubber-band stiffness, the deceleration rate and the spring stiffness, and a toggle swaps the elastic edge for a rigid hard stop so the two feel-models can be compared directly.