Function get_height 

pub fn get_height(
    world: &Arc<World>,
    pos: BlockPos,
    fluid_state: FluidState,
) -> f32

Returns the effective fluid height at a position, accounting for fluid above. If the same fluid type occupies the block directly above (hasSameAbove), the height is 1.0 (full block). Otherwise it is get_own_height(fluid_state).