90ms+90ms Confirmation & Spring Physics

Click feedback must reconcile spatial certainty with high-speed execution. TuffEx formalizes the confirmation rhythm and continuous spring dynamics.

Why Instant Menu Dismissal Harms Usability

In many native operating systems, selecting an item from a context menu closes the panel within 0ms. Users frequently freeze for a fraction of a second: "Did I actually click that option, or did my pointer slip outside?" Missing feedback breaks the cognitive feedback loop.

The Two-Beat Confirmation Rhythm (90ms + 90ms)

TuffEx items (TxDropdownItem, TxContextMenuItem) employ an immutable 180ms two-beat confirmation rhythm:

[User triggers menu item selection]
  │
  ├─ [Beat 1: 90ms] Clears hover/focus highlights to dissolve pointer residue.
  │
  ├─ [Beat 2: 90ms] Pulses the active token fill to register visual confirmation.
  │
  └─ [Resolution] Emits the select event and closes the parent menu panel.

The entire cycle executes in 180ms, delivering confirmation without lagging the user. Under reduced motion, it degrades to 0ms instant execution.

Cubic Bezier Limitations Under Gesture Interruption

Standard CSS cubic bezier transitions are fixed-duration time interpolation curves. When user gestures interrupt an ongoing animation (such as catching a drawer mid-flight and reversing direction):

• Bezier curves cannot absorb initial velocity $\vec{v}_0$; they forcibly reset velocity to zero and restart.
• The visual motion stutters mechanically, violating physical intuition.

The TuffEx Second-Order Damped Spring Engine

TuffEx motion models rely on the second-order damped harmonic oscillator equation: $$m \frac{d^2x}{dt^2} + c \frac{dx}{dt} + k x = 0$$

• Stiffness ($k$): Governs restorative spring force.
• Damping ($c$): Dissipates oscillation energy, eliminating unwanted wobble.
• Mass ($m$): Imparts physical inertia.

When interrupted, the spring system inherits the instantaneous velocity vector naturally, maintaining physical continuity.