use fpnum::*;

#[derive(PartialEq, Eq, Clone, Copy, Debug)]

pub struct PhysicsProcessor {

    position_updates: PositionUpdates,

}

pub struct PositionUpdates {

    pub gear_ids: Vec<GearId>,

    pub shifts: Vec<(FPPoint, FPPoint)>,

}

impl PositionUpdates {

    pub fn new(capacity: usize) -> Self {

        Self {

            gear_ids: Vec::with_capacity(capacity),

            shifts: Vec::with_capacity(capacity),

        }

    }

    pub fn push(&mut self, gear_id: GearId, old_position: &FPPoint, new_position: &FPPoint) {

        self.gear_ids.push(gear_id);

        self.shifts.push((*old_position, *new_position));

    }

    pub fn iter(&self) -> impl Iterator<Item = (GearId, &FPPoint, &FPPoint)> {

        self.gear_ids

            .iter()

            .cloned()

            .zip(self.shifts.iter())

            .map(|(id, (from, to))| (id, from, to))

    }

    pub fn clear(&mut self) {

        self.gear_ids.clear();

        self.shifts.clear();

    }

}

impl PhysicsProcessor {

    pub fn new() -> Self {

        Self {

        }

    }

        let fp_step = time_step.to_fixed();

        self.position_updates.clear();

        &self.position_updates

    }

}