clayHighlightAlphaFor function

int clayHighlightAlphaFor(
  1. int face,
  2. int highlight
)

The highlight alpha the renderer actually paints on face (and the guardrail checks): the Palette.highlight alpha × 1.0 (face L ≥ 0.80), 0.75 (≥ 0.62), 0.55 (≥ 0.40) or 0.35 (darker, e.g. a night pillow).

Implementation

int clayHighlightAlphaFor(int face, int highlight) {
  final l = _lightness(face);
  final permille = l >= 0.80
      ? 1000
      : l >= 0.62
      ? 750
      : l >= 0.40
      ? 550
      : 350;
  final a = (highlight >>> 24) & 0xFF;
  return (a * permille + 500) ~/ 1000;
}