getRect<E> function

Iterable<E> getRect<E>(Rect bounds, E get(Pos))

Returns each element within bounds, exclusive of the bottom-right edge.

The get function is called with each position within the bounds, and the return value is lazily yielded.

It is the caller's responsibility to ensure that the bounds are valid or the behavior is undefined. This function is intended as a low-level utility for grid-like structures; consider asserting or clamping the bounds if necessary before calling this function.

The result is in row-major order.

Example

For the below examples, we use a simple 2-dimensional list as the grid-like structure.

Consider package:sector for a complete implementation.

All elements in a grid

final grid = [
  [1, 2, 3],
  [4, 5, 6],
];

final allElemennts = getRect(
  Rect.fromWH(3, 2),
  (pos) => grid[pos.y][pos.x],
);
print(allElemennts); // => [1, 2, 3, 4, 5, 6]

Sub-elements in a grid

final subElements = getRect(
  Rect.fromLTWH(1, 0, 2, 1),
  (pos) => grid[pos.y][pos.x],
);
print(subElements); // => [2, 3]

Implementation

Iterable<E> getRect<E>(Rect bounds, E Function(Pos) get) {
  return bounds.positions.map(get);
}