visibleIndexRange method

(int, int) visibleIndexRange(
  1. int totalPoints
)

Range of data indices that map to the visible canvas area.

Useful for culling off-screen data points in bar/line charts where x = index.

Implementation

(int start, int end) visibleIndexRange(int totalPoints) {
  if (totalPoints == 0) return (0, 0);
  final startIdx = toDataX(left).floor().clamp(0, totalPoints - 1);
  final endIdx = toDataX(right).ceil().clamp(0, totalPoints - 1);
  return (startIdx, endIdx);
}