space-crush/space-crush-app/src/debug/ships.rs

use glc::vector::Vector4f;
use space_crush_common::{
    components::{Position, Ship, ShipObstacle, Velocity},
    continue_if_none,
};
use specs::{prelude::*, ReadStorage, System, World, WriteExpect};

use crate::resources::Geometry;

#[derive(Default)]
pub struct Ships;

#[derive(SystemData)]
pub struct ShipsData<'a> {
    geometry: WriteExpect<'a, Geometry>,
    positions: ReadStorage<'a, Position>,
    velocities: ReadStorage<'a, Velocity>,
    ships: ReadStorage<'a, Ship>,
}

impl<'a> System<'a> for Ships {
    type SystemData = ShipsData<'a>;

    fn run(&mut self, data: Self::SystemData) {
        let ShipsData {
            mut geometry,
            positions,
            velocities,
            ships,
        } = data;

        gl::enable(gl::BLEND);
        gl::blend_func(gl::SRC_ALPHA, gl::ONE);

        for (position, velocity, ship) in (&positions, &velocities, &ships).join() {
            let ship_pos = position.pos;

            geometry.render_lines(
                Vector4f::new(0.0, 0.0, 1.0, 0.2),
                &[ship_pos, ship_pos + velocity.dir * velocity.speed],
            );
            geometry.render_lines(
                Vector4f::new(1.0, 0.0, 0.0, 0.2),
                &[ship_pos, ship_pos + ship.target_dir * 100.0],
            );
            geometry.render_lines(
                Vector4f::new(1.0, 1.0, 1.0, 0.2),
                &[ship_pos, ship.target_pos],
            );

            if let ShipObstacle::Known(obstacle) = ship.obstacle {
                let obstacle_pos = continue_if_none!(positions.get(obstacle)).pos;

                geometry.render_lines(Vector4f::new(0.0, 1.0, 0.0, 0.2), &[ship_pos, obstacle_pos]);
            }
        }

        gl::disable(gl::BLEND);
    }
}