player_movement2.rs

use bevy::{prelude::*, window::WindowResolution};
use bevy_rapier2d::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins.set(WindowPlugin {
            primary_window: Some(Window {
                resolution: WindowResolution::new(1000., 1000.),
                title: "Player Movement Example".to_string(),
                ..default()
            }),
            ..default()
        }))
        .add_startup_system(spawn_player)
        .add_system(player_movement)
        .add_plugin(RapierPhysicsPlugin::<NoUserData>::pixels_per_meter(100.0))
        .add_plugin(RapierDebugRenderPlugin::default())
        .run();
}

// The float value is the player movement speed in 'pixels/second'.
#[derive(Component)]
struct Player(f32);

fn spawn_player(mut commands: Commands, mut rapier_config: ResMut<RapierConfiguration>) {
    // Set gravity to 0.0 and spawn camera.
    rapier_config.gravity = Vec2::ZERO;
    commands.spawn(Camera2dBundle::default());

    let sprite_size = 100.0;

    // Spawn entity with `Player` struct as a component for access in movement query.
    commands.spawn((
        SpriteBundle {
            sprite: Sprite {
                color: Color::rgb(0.0, 0.0, 0.0),
                custom_size: Some(Vec2::new(sprite_size, sprite_size)),
                ..Default::default()
            },
            ..Default::default()
        },
        RigidBody::Dynamic,
        Velocity::zero(),
        Collider::ball(sprite_size / 2.0),
        Player(100.0),
    ));
}

fn player_movement(
    keyboard_input: Res<Input<KeyCode>>,
    mut player_info: Query<(&Player, &mut Velocity)>,
) {
    for (player, mut rb_vels) in &mut player_info {
        let up = keyboard_input.any_pressed([KeyCode::W, KeyCode::Up]);
        let down = keyboard_input.any_pressed([KeyCode::S, KeyCode::Down]);
        let left = keyboard_input.any_pressed([KeyCode::A, KeyCode::Left]);
        let right = keyboard_input.any_pressed([KeyCode::D, KeyCode::Right]);

        let x_axis = -(left as i8) + right as i8;
        let y_axis = -(down as i8) + up as i8;

        let mut move_delta = Vec2::new(x_axis as f32, y_axis as f32);
        if move_delta != Vec2::ZERO {
            move_delta /= move_delta.length();
        }

        // Update the velocity on the rigid_body_component,
        // the bevy_rapier plugin will update the Sprite transform.
        rb_vels.linvel = move_delta * player.0;
    }
}