Function lerp2 

pub fn lerp2<F>(a1: F, a2: F, x00: F, x10: F, x01: F, x11: F) -> F
where
    F: Copy + Mul<Output = F> + Add<Output = F> + Sub<Output = F>,

Bilinear interpolation.

Interpolates between 4 values in a 2D grid.

Java reference: Mth.lerp2(double, double, double, double, double, double)