$#include "NavigationMesh.h"

/// Description of a navigation mesh geometry component, with transform and bounds information.
struct NavigationGeometryInfo
{
    /// Component.
    Component* component_;
    /// Geometry LOD level if applicable.
    unsigned lodLevel_;
    /// Transform relative to the navigation mesh root node.
    Matrix3x4 transform_;
    /// Bounding box relative to the navigation mesh root node.
    BoundingBox boundingBox_;
};

/// Navigation mesh component. Collects the navigation geometry from child nodes with the Navigable component and responds to path queries.
class NavigationMesh : public Component
{
public:
    /// Set tile size.
    void SetTileSize(int size);
    /// Set cell size.
    void SetCellSize(float size);
    /// Set cell height.
    void SetCellHeight(float height);
    /// Set navigation agent height.
    void SetAgentHeight(float height);
    /// Set navigation agent radius.
    void SetAgentRadius(float radius);
    /// Set navigation agent max vertical climb.
    void SetAgentMaxClimb(float maxClimb);
    /// Set navigation agent max slope.
    void SetAgentMaxSlope(float maxSlope);
    /// Set region minimum size.
    void SetRegionMinSize(float size);
    /// Set region merge size.
    void SetRegionMergeSize(float size);
    /// Set edge max length.
    void SetEdgeMaxLength(float length);
    /// Set edge max error.
    void SetEdgeMaxError(float error);
    /// Set detail sampling distance.
    void SetDetailSampleDistance(float distance);
    /// Set detail sampling maximum error.
    void SetDetailSampleMaxError(float error);
    /// Set padding of the navigation mesh bounding box. Having enough padding allows to add geometry on the extremities of the navigation mesh when doing partial rebuilds.
    void SetPadding(const Vector3& padding);
    /// Rebuild the navigation mesh. Return true if successful.
    bool Build();
    /// Rebuild part of the navigation mesh contained by the world-space bounding box. Return true if successful.
    bool Build(const BoundingBox& boundingBox);
    /// Find a path between world space points. Return non-empty list of points if successful. Extents specifies how far off the navigation mesh the points can be.
    void FindPath(PODVector<Vector3>& dest, const Vector3& start, const Vector3& end, const Vector3& extents = Vector3::ONE);
    /// Return a random point on the navigation mesh.
    Vector3 GetRandomPoint();
    /// Return a random point on the navigation mesh within a circle. The circle radius is only a guideline and in practice the returned point may be further away.
    Vector3 GetRandomPointInCircle(const Vector3& center, float radius, const Vector3& extents = Vector3::ONE);
    /// Return distance to wall from a point. Maximum search radius must be specified.
    float GetDistanceToWall(const Vector3& point, float radius, const Vector3& extents = Vector3::ONE);
    /// Perform a walkability raycast on the navigation mesh between start and end and return the point where a wall was hit, or the end point if no walls.
    Vector3 Raycast(const Vector3& start, const Vector3& end, const Vector3& extents = Vector3::ONE);

    /// Return tile size.
    int GetTileSize() const;
    /// Return cell size.
    float GetCellSize() const;
    /// Return cell height.
    float GetCellHeight() const;
    /// Return navigation agent height.
    float GetAgentHeight() const;
    /// Return navigation agent radius.
    float GetAgentRadius() const;
    /// Return navigation agent max vertical climb.
    float GetAgentMaxClimb() const;
    /// Return navigation agent max slope.
    float GetAgentMaxSlope() const;
    /// Return region minimum size.
    float GetRegionMinSize() const;
    /// Return region merge size.
    float GetRegionMergeSize() const;
    /// Return edge max length.
    float GetEdgeMaxLength() const;
    /// Return edge max error.
    float GetEdgeMaxError() const;
    /// Return detail sampling distance.
    float GetDetailSampleDistance() const;
    /// Return detail sampling maximum error.
    float GetDetailSampleMaxError() const;
    /// Return navigation mesh bounding box padding.
    const Vector3& GetPadding() const;
    /// Return whether has been initialized with valid navigation data.
    bool IsInitialized() const;
    /// Return local space bounding box of the navigation mesh.
    const BoundingBox& GetBoundingBox() const;
    /// Return world space bounding box of the navigation mesh.
    BoundingBox GetWorldBoundingBox() const;
    /// Return number of tiles.
    IntVector2 GetNumTiles() const;    
};