Linearly interpolate between two table borders.
Source
static TableBorder lerp(TableBorder a, TableBorder b, double t) { if (a == null && b == null) return null; if (a == null) return b.scale(t); if (b == null) return a.scale(1.0 - t); return new TableBorder( top: BorderSide.lerp(a.top, b.top, t), right: BorderSide.lerp(a.right, b.right, t), bottom: BorderSide.lerp(a.bottom, b.bottom, t), left: BorderSide.lerp(a.left, b.left, t), horizontalInside: BorderSide.lerp(a.horizontalInside, b.horizontalInside, t), verticalInside: BorderSide.lerp(a.verticalInside, b.verticalInside, t) ); }