entranceGlass constant

Glass channel of an entrance: resolved just short of the end, so the shape exists before the icon does.

Linear, like every channel here — Interval's own default. The native transition moves its glass at a near-constant rate, and both ways of departing from that were visible side by side: an ease-out starts at 3× and popped the surface in before drifting, while an ease-in is so flat off the line that the surface visibly started after the native one. A symmetric S-curve does both — it ran ahead through the middle and then idled at the top.