#[inline]
pub fn wrap(x: f32, max: f32) -> f32 {
    x - max * ((x > max) as i32 as f32 - (x < 0.0_f32) as i32 as f32)
}

// Truncate x and y and return a corresponding index into the data slice.
#[inline]
pub const fn index(width: usize, height: usize, x: f32, y: f32) -> usize {
    // x/y can come in negative, hence we shift them by width/height.
    let i = (x + width as f32) as usize & (width - 1);
    let j = (y + height as f32) as usize & (height - 1);
    j * width + i
}