47 lines
1.1 KiB
Dart
47 lines
1.1 KiB
Dart
const int notePositionScale = 10;
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const int notePositionStep = 1000 * notePositionScale;
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const int notePositionRebalanceThreshold = 1;
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int toStoredNotePosition(double position) {
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return (position * notePositionScale).round();
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}
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double fromStoredNotePosition(int storedPosition) {
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return storedPosition / notePositionScale;
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}
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int nextTopNotePosition(Iterable<int> storedPositions) {
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int? highestPosition;
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for (final int position in storedPositions) {
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if (highestPosition == null || position > highestPosition) {
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highestPosition = position;
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}
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}
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if (highestPosition == null) {
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return 0;
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}
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return highestPosition + notePositionStep;
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}
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int? midpointNotePosition({
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required int higherPosition,
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required int lowerPosition,
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}) {
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final int gap = higherPosition - lowerPosition;
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if (gap <= notePositionRebalanceThreshold) {
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return null;
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}
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return lowerPosition + (gap ~/ 2);
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}
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List<int> rebalanceNotePositions(int itemCount) {
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return List<int>.generate(
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itemCount,
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(int index) => (itemCount - 1 - index) * notePositionStep,
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);
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}
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