Rotated grids in Rust

🎨 For halftone dithering and more.

This crate provides a generator for enumerating grid coordinates at a specified frequency along a rotated grid. This can come in useful e.g. when you want to create halftone dithering grids for CMYK processing:

See e.g. my opencv-cartoon-effect repo for an almost-real-world usage example.

Usage example

```rust use rotated_grid::{Angle, GridPositionIterator, GridCoordinate};

const WIDTH: usize = 16; const HEIGHT: usize = 10;

fn main() { let halftone_grids = [ ("Cyan", 15.0), ("Magenta", 75.0), ("Yellow", 0.0), ("Black", 45.0), ];

for (name, angle) in halftone_grids {
    println!("{name} at {angle}°", name = name, angle = angle);

    let grid = GridPositionIterator::new(
        WIDTH as _,
        HEIGHT as _,
        7.0,
        7.0,
        0.0,
        0.0,
        Angle::<f64>::from_degrees(angle),
    );

    let (_, expected_max) = grid.size_hint();
    let mut count = 0;

    for GridCoordinate { x, y } in grid {
        println!("{x}, {y}", x = x, y = y);
        count += 1;
    }

    assert!(count <= expected_max.unwrap())
}

} ```

You can run the example application using

shell cargo run --package cmyk