react-native-sortables/src/providers/layout/grid/utils/helpers.ts

Powerful Sortable Components for Flexible Content Reordering in React Native

export const getMainIndex = (index: number, numGroups: number): number => {
  'worklet';
  return +index % numGroups;
};

export const getCrossIndex = (index: number, numGroups: number): number => {
  'worklet';
  return Math.floor(+index / numGroups);
};