1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134

use crate::physics::*;
use crate::{EmeraldError, Vector2};

use hecs::Entity;
use rapier2d::prelude::*;

pub struct PhysicsHandler<'a> {
    physics_engine: &'a mut PhysicsEngine,
    world: &'a mut hecs::World,
}
impl<'a> PhysicsHandler<'a> {
    pub fn new(physics_engine: &'a mut PhysicsEngine, world: &'a mut hecs::World) -> Self {
        PhysicsHandler {
            world,
            physics_engine,
        }
    }

    pub fn build_body(
        &mut self,
        entity: Entity,
        desc: RigidBodyBuilder,
    ) -> Result<RigidBodyHandle, EmeraldError> {
        self.physics_engine
            .build_body(entity, desc, &mut self.world)
    }

    pub fn build_collider(
        &mut self,
        body_handle: RigidBodyHandle,
        desc: ColliderBuilder,
    ) -> ColliderHandle {
        self.physics_engine.build_collider(body_handle, desc)
    }

    /// Retrieves the entities with bodies that are touching the body of this entity.
    /// This includes:
    /// Collider <- Contact -> Collider
    /// Collider <- Contact -> Sensor
    /// Sensor <- Contact -> Sensor
    pub fn get_colliding_entities(&self, entity: Entity) -> Vec<Entity> {
        self.physics_engine.get_colliding_entities(entity)
    }

    #[deprecated(note = "use `world.physics().get_colliding_bodies()` instead")]
    /// Retrieves the entities with bodies that are touching the rigid body of this entity.
    pub fn get_colliding_bodies(&self, entity: Entity) -> Vec<Entity> {
        self.physics_engine.get_colliding_entities(entity)
    }

    #[deprecated(note = "use `world.physics().get_colliding_bodies()` instead")]
    /// Retrieves the entities with sensors that are touching this entity.
    pub fn get_colliding_areas(&self, entity: Entity) -> Vec<Entity> {
        self.physics_engine.get_colliding_entities(entity)
    }

    pub fn get_colliders(&self, entity: Entity) -> Vec<ColliderHandle> {
        self.physics_engine.get_colliders(entity)
    }

    pub fn get_collider_desc(&self, collider_handle: ColliderHandle) -> Option<Collider> {
        if let Some(collider) = self.physics_engine.colliders.get(collider_handle) {
            return Some(collider.clone());
        }

        None
    }

    /// Remove physics body attached to this entity.
    pub fn remove_body(&mut self, entity: Entity) -> Option<RigidBody> {
        if let Some(body) = self.physics_engine.remove_body(entity) {
            if self.world.remove_one::<RigidBodyHandle>(entity).is_ok() {
                return Some(body);
            }
        }

        None
    }

    pub fn remove_collider(&mut self, collider_handle: ColliderHandle) -> Option<Collider> {
        self.physics_engine.remove_collider(collider_handle)
    }

    pub fn rigid_body(&mut self, body_handle: RigidBodyHandle) -> Option<&RigidBody> {
        self.physics_engine.bodies.get(body_handle)
    }

    pub fn rigid_body_mut(&mut self, body_handle: RigidBodyHandle) -> Option<&mut RigidBody> {
        self.physics_engine.bodies.get_mut(body_handle)
    }

    pub fn body_count(&self) -> usize {
        self.physics_engine.bodies.len()
    }

    /// Returns the first entity the ray hits if one exists.
    pub fn cast_ray(&mut self, ray_cast_query: RayCastQuery<'_>) -> Option<Entity> {
        self.physics_engine.cast_ray(ray_cast_query)
    }

    /// Returns the first entity the shape collides with if one exists.
    pub fn cast_shape(
        &mut self,
        shape: &dyn Shape,
        shape_cast_query: ShapeCastQuery<'_>,
    ) -> Option<Entity> {
        self.physics_engine.cast_shape(shape, shape_cast_query)
    }

    /// Steps the physics at 1/60 timestep
    pub fn step(&mut self, delta: f32) {
        self.step_n(1, delta);
    }

    /// Steps the physics n-times at 1/60 timestep
    pub fn step_n(&mut self, n: u32, delta: f32) {
        self.physics_engine
            .sync_physics_world_to_game_world(&mut self.world);

        for _ in 0..n {
            self.physics_engine.step(delta);
        }

        self.physics_engine
            .sync_game_world_to_physics_world(&mut self.world);

        self.physics_engine.consume_contacts();
        self.physics_engine.update_query_pipeline();
    }

    pub fn set_gravity(&mut self, gravity: Vector2<f32>) {
        self.physics_engine.gravity = gravity;
    }
}