Physics library for use in Specs, using cgmath and collision-rs.

Example

```rust extern crate cgmath; extern crate rhusics; extern crate shrev; extern crate specs;

use cgmath::{Point2, Rad, Rotation2, Transform}; use shrev::EventChannel; use specs::{RunNow, World};

use rhusics::ecs::collide::prelude2d::{register_collision, BasicCollisionSystem2, BodyPose2, BroadBruteForce2, CollisionMode, CollisionShape2, CollisionStrategy, ContactEvent2, GJK2, Rectangle};

pub fn main() { let mut world = World::new(); register_collision::, ()>(&mut world);

let mut reader_1 = world
    .write_resource::<EventChannel<ContactEvent2<f32>>>()
    .register_reader();

world
    .create_entity()
    .with(CollisionShape2::<f32, BodyPose2<f32>, ()>::new_simple(
        CollisionStrategy::FullResolution,
        CollisionMode::Discrete,
        Rectangle::new(10., 10.).into(),
    ))
    .with(BodyPose2::<f32>::one());

world
    .create_entity()
    .with(CollisionShape2::<f32, BodyPose2<f32>, ()>::new_simple(
        CollisionStrategy::FullResolution,
        CollisionMode::Discrete,
        Rectangle::new(10., 10.).into(),
    ))
    .with(BodyPose2::new(
        Point2::new(3., 2.),
        Rotation2::from_angle(Rad(0.)),
    ));

let mut system = BasicCollisionSystem2::<f32, BodyPose2<f32>, ()>::new()
    .with_broad_phase(BroadBruteForce2::default())
    .with_narrow_phase(GJK2::new());
system.run_now(&world.res);
println!(
    "Contacts: {:?}",
    world
        .read_resource::<EventChannel<ContactEvent2<f32>>>()
        .read(&mut reader_1)
        .collect::<Vec<_>>()
);

} ```

Features:

• Has support for all primitives in collision-rs
• Has support for the following broad phase algorithms in collision-rs:
  • Brute force
  • Sweep and Prune
• Narrow phase collision detection using GJK, and optionally EPA for full contact information
• specs::System for collision detection working on user supplied transform, and shape components. Can optionally use broad and/or narrow phase detection. Library supplies a transform implementation for convenience.
• specs::System for spatial sorting on user supplied transform, and shape components.
• Has support for doing spatial sort/collision detection using the collision-rs DBVT.
• Support for doing broad phase using the collision-rs DBVT.
• Continuous collision detection, using GJK
• Simple rigid body implementation with single contact forward resolution

TODO:

• Impulse solver
• Integrator implementations (Euler, RK4, etc.)
• Parallel solver implementation