$#include "PhysicsWorld.h"

/// Physics raycast hit.
struct PhysicsRaycastResult
{
    PhysicsRaycastResult();
	
    /// Hit position.
    Vector3 position_ @ position;
    /// Hit normal.
    Vector3 normal_ @ normal;
    /// Hit distance from ray origin.
    float distance_ @ distance;
    /// Rigid body that was hit.
    RigidBody* body_ @ body;
};

/// Delayed world transform assignment for parented rigidbodies.
struct DelayedWorldTransform
{
    /// Rigid body.
    RigidBody* rigidBody_ @ rigidBody;
    /// Parent rigid body.
    RigidBody* parentRigidBody_ @ parentRigidBody;
    /// New world position.
    Vector3 worldPosition_ @ worldPosition;
    /// New world rotation.
    Quaternion worldRotation_ @ worldRotation;
};


/// Physics simulation world component. Should be added only to the root scene node.
class PhysicsWorld : public Component
{
public:
    /// Step the simulation forward.
    void Update(float timeStep);
    /// Refresh collisions only without updating dynamics.
    void UpdateCollisions();
    /// Set simulation steps per second.
    void SetFps(int fps);
    /// Set gravity.
    void SetGravity(Vector3 gravity);
    /// Set number of constraint solver iterations.
    void SetNumIterations(int num);
    /// Set whether to interpolate between simulation steps.
    void SetInterpolation(bool enable);
    /// Set whether to use Bullet's internal edge utility for trimesh collisions. Disabled by default.
    void SetInternalEdge(bool enable);
    /// Set split impulse collision mode. This is more accurate, but slower. Disabled by default.
    void SetSplitImpulse(bool enable);
    /// Set maximum angular velocity for network replication.
    void SetMaxNetworkAngularVelocity(float velocity);
    /// Perform a physics world raycast and return all hits.
    /// Perform a physics world raycast and return the closest hit.
    void RaycastSingle(PhysicsRaycastResult& result, const Ray& ray, float maxDistance, unsigned collisionMask = M_MAX_UNSIGNED);
    /// Perform a physics world swept sphere test and return the closest hit.
    void SphereCast(PhysicsRaycastResult& result, const Ray& ray, float radius, float maxDistance, unsigned collisionMask = M_MAX_UNSIGNED);
    
    /// Return gravity.
    Vector3 GetGravity() const;
    /// Return number of constraint solver iterations.
    int GetNumIterations() const;
    /// Return whether interpolation between simulation steps is enabled.
    bool GetInterpolation() const { return interpolation_; }
    /// Return whether Bullet's internal edge utility for trimesh collisions is enabled.
    bool GetInternalEdge() const { return internalEdge_; }
    /// Return whether split impulse collision mode is enabled.
    bool GetSplitImpulse() const;
    /// Return simulation steps per second.
    int GetFps() const { return fps_; }
    /// Return maximum angular velocity for network replication.
    float GetMaxNetworkAngularVelocity() const { return maxNetworkAngularVelocity_; }

    /// Add a rigid body to keep track of. Called by RigidBody.
    void AddRigidBody(RigidBody* body);
    /// Remove a rigid body. Called by RigidBody.
    void RemoveRigidBody(RigidBody* body);
    /// Add a collision shape to keep track of. Called by CollisionShape.
    void AddCollisionShape(CollisionShape* shape);
    /// Remove a collision shape. Called by CollisionShape.
    void RemoveCollisionShape(CollisionShape* shape);
    /// Add a constraint to keep track of. Called by Constraint.
    void AddConstraint(Constraint* joint);
    /// Remove a constraint. Called by Constraint.
    void RemoveConstraint(Constraint* joint);
    /// Add a delayed world transform assignment. Called by RigidBody.
    void AddDelayedWorldTransform(const DelayedWorldTransform& transform);
    /// Add debug geometry to the debug renderer.
    void DrawDebugGeometry(bool depthTest);
    /// Set debug renderer to use. Called both by PhysicsWorld itself and physics components.
    void SetDebugRenderer(DebugRenderer* debug);
    /// Set debug geometry depth test mode. Called both by PhysicsWorld itself and physics components.
    void SetDebugDepthTest(bool enable);

    /// Clean up the geometry cache.
    void CleanupGeometryCache();
    /// Set node dirtying to be disregarded.
    void SetApplyingTransforms(bool enable);
    /// Return whether node dirtying should be disregarded.
    bool IsApplyingTransforms() const;
};