vec3.h

#ifndef CVec3_h
#define CVec3_h

#include <cmath>

class CVec3
{
public:
    // Data
    float x, y, z;

    // Ctors
    CVec3( float InX, float InY, float InZ ) : x( InX ), y( InY ), z( InZ )
        {
        }
    CVec3( ) : x(0), y(0), z(0)
        {
        }

    // Operator Overloads
    inline bool operator== (const CVec3& V2) const
        {
        return (x == V2.x && y == V2.y && z == V2.z);
        }

    inline CVec3 operator+ (const CVec3& V2) const
        {
        return CVec3( x + V2.x,  y + V2.y,  z + V2.z);
        }
    inline CVec3 operator- (const CVec3& V2) const
        {
        return CVec3( x - V2.x,  y - V2.y,  z - V2.z);
        }
    inline CVec3 operator- ( ) const
        {
        return CVec3(-x, -y, -z);
        }

    inline CVec3 operator/ (float S ) const
        {
        float fInv = 1.0f / S;
        return CVec3 (x * fInv , y * fInv, z * fInv);
        }
    inline CVec3 operator/ (const CVec3& V2) const
        {
        return CVec3 (x / V2.x,  y / V2.y,  z / V2.z);
        }
    inline CVec3 operator* (const CVec3& V2) const
        {
        return CVec3 (x * V2.x,  y * V2.y,  z * V2.z);
        }
    inline CVec3 operator* (float S) const
        {
        return CVec3 (x * S,  y * S,  z * S);
        }

    inline void operator+= ( const CVec3& V2 )
        {
        x += V2.x;
        y += V2.y;
        z += V2.z;
        }
    inline void operator-= ( const CVec3& V2 )
        {
        x -= V2.x;
        y -= V2.y;
        z -= V2.z;
        }

    inline float operator[] ( int i )
        {
        if ( i == 0 ) return x;
        else if ( i == 1 ) return y;
        else return z;
        }

    // Functions
    inline float Dot( const CVec3 &V1 ) const
        {
        return V1.x*x + V1.y*y + V1.z*z;
        }

    inline CVec3 CrossProduct( const CVec3 &V2 ) const
        {
        return CVec3(
            y * V2.z  -  z * V2.y,
            z * V2.x  -  x * V2.z,
            x * V2.y  -  y * V2.x   );
        }

    // Return vector rotated by the 3x3 portion of matrix m
    // (provided because it's used by bbox.cpp in article 21)
    CVec3 RotByMatrix( const float m[16] ) const
    {
    return CVec3(
        x*m[0] + y*m[4] + z*m[8],
        x*m[1] + y*m[5] + z*m[9],
        x*m[2] + y*m[6] + z*m[10] );
    }

    // These require math.h for the sqrtf function
    float Magnitude( ) const
        {
        return sqrtf( x*x + y*y + z*z );
        }

    float Distance( const CVec3 &V1 ) const
        {
        return ( *this - V1 ).Magnitude();
        }

    inline void Normalize()
        {
        float fMag = ( x*x + y*y + z*z );
        if (fMag == 0) {return;}

        float fMult = 1.0f/sqrtf(fMag);
        x *= fMult;
        y *= fMult;
        z *= fMult;
        return;
        }
};
#endif