Glass cards scrolled out of view still ran their full effect path, and
the rainbow border always used a segment count derived from a fixed
per-pixel budget, so wide cards drew far more line segments than their
slowly changing gradient needed.
- A glass panel whose rectangle lies wholly outside the draw list's clip
rect now returns early, so a scrolled-out card draws nothing (its
border and ember passes are skipped along with the fill).
- The rainbow border is split into segments by perimeter arc length:
straight edges get one segment per ~32 dp, corner arcs get a few
chords each to stay round, and a fully transparent border is skipped
outright. A wide card now draws tens of segments instead of a couple
hundred, with no visible change.
Tests: the segment fractions are ascending and bounded, each corner arc
keeps at least three chords, and the rect-cull margin test.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
