$#include "Vector3.h"

/// Three-dimensional vector.
class Vector3
{
public:
    /// Construct undefined.
    Vector3()
    {
    }
    
    /// Copy-construct from another vector.
    Vector3(const Vector3& vector) :
        x_(vector.x_),
        y_(vector.y_),
        z_(vector.z_)
    {
    }
    
    /// Construct from a two-dimensional vector and the Z coordinate.
    Vector3(const Vector2& vector, float z) :
        x_(vector.x_),
        y_(vector.y_),
        z_(z)
    {
    }
    
    /// Construct from coordinates.
    Vector3(float x, float y, float z) :
        x_(x),
        y_(y),
        z_(z)
    {
    }
    
    /// Test for equality with another vector without epsilon.
    bool operator == (const Vector3& rhs) const { return x_ == rhs.x_ && y_ == rhs.y_ && z_ == rhs.z_; }
    /// Add a vector.
    Vector3 operator + (const Vector3& rhs) const { return Vector3(x_ + rhs.x_, y_ + rhs.y_, z_ + rhs.z_); }
    /// Return negation.
    Vector3 operator - () const { return Vector3(-x_, -y_, -z_); }
    /// Subtract a vector.
    Vector3 operator - (const Vector3& rhs) const { return Vector3(x_ - rhs.x_, y_ - rhs.y_, z_ - rhs.z_); }
    /// Multiply with a scalar.
    Vector3 operator * (float rhs) const { return Vector3(x_ * rhs, y_ * rhs, z_ * rhs); }
    /// Multiply with a vector.
    Vector3 operator * (const Vector3& rhs) const { return Vector3(x_ * rhs.x_, y_ * rhs.y_, z_ * rhs.z_); }
    /// Divide by a scalar.
    Vector3 operator / (float rhs) const { return Vector3(x_ / rhs, y_ / rhs, z_ / rhs); }
    /// Divide by a vector.
    Vector3 operator / (const Vector3& rhs) const { return Vector3(x_ / rhs.x_, y_ / rhs.y_, z_ / rhs.z_); }
    Vector3 operator / (const Vector3& rhs) const;
    
    /// Normalize to unit length and return the previous length.
    float Normalize()
    {
        float len = Length();
        if (len >= M_EPSILON)
        {
            float invLen = 1.0f / len;
            x_ *= invLen;
            y_ *= invLen;
            z_ *= invLen;
        }
        
        return len;
    }
    
    /// Return length.
    float Length() const { return sqrtf(x_ * x_ + y_ * y_ + z_ * z_); }
    /// Return squared length.
    float LengthSquared() const { return x_ * x_ + y_ * y_ + z_ * z_; }
    /// Calculate dot product.
    float DotProduct(const Vector3& rhs) const { return x_ * rhs.x_ + y_ * rhs.y_ + z_ * rhs.z_; }
    /// Calculate absolute dot product.
    float AbsDotProduct(const Vector3& rhs) const { return Urho3D::Abs(x_ * rhs.x_) + Urho3D::Abs(y_ * rhs.y_) + Urho3D::Abs(z_ * rhs.z_); }
    
    /// Calculate cross product.
    Vector3 CrossProduct(const Vector3& rhs) const
    {
        return Vector3(
            y_ * rhs.z_ - z_ * rhs.y_,
            z_ * rhs.x_ - x_ * rhs.z_,
            x_ * rhs.y_ - y_ * rhs.x_
        );
    }
    
    /// Return absolute vector.
    Vector3 Abs() const { return Vector3(Urho3D::Abs(x_), Urho3D::Abs(y_), Urho3D::Abs(z_)); }
    /// Linear interpolation with another vector.
    Vector3 Lerp(const Vector3& rhs, float t) const { return *this * (1.0f - t) + rhs * t; }
    /// Test for equality with another vector with epsilon.
    bool Equals(const Vector3& rhs) const { return Urho3D::Equals(x_, rhs.x_) && Urho3D::Equals(y_, rhs.y_) && Urho3D::Equals(z_, rhs.z_); }
    
    /// Return normalized to unit length.
    Vector3 Normalized() const
    {
        float len = Length();
        if (len >= M_EPSILON)
            return *this * (1.0f / len);
        else
            return *this;
    }
    
    /// Return as string.
    String ToString() const;
    
    /// X coordinate.
    float x_ @ x;
    /// Y coordinate.
    float y_ @ y;
    /// Z coordinate.
    float z_ @ z;
    
    /// Zero vector.
    static const Vector3 ZERO;
    /// (-1,0,0) vector.
    static const Vector3 LEFT;
    /// (1,0,0) vector.
    static const Vector3 RIGHT;
    /// (0,1,0) vector.
    static const Vector3 UP;
    /// (0,-1,0) vector.
    static const Vector3 DOWN;
    /// (0,0,1) vector.
    static const Vector3 FORWARD;
    /// (0,0,-1) vector.
    static const Vector3 BACK;
    /// (1,1,1) vector.
    static const Vector3 ONE;
};