OgreVector2.h

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/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2012 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
-----------------------------------------------------------------------------
*/
#ifndef __Vector2_H__
#define __Vector2_H__


#include "OgrePrerequisites.h"
#include "OgreMath.h"

namespace Ogre
{

    class _OgreExport Vector2
    {
    public:
        Real x, y;

    public:
        inline Vector2()
        {
        }

        inline Vector2(const Real fX, const Real fY )
            : x( fX ), y( fY )
        {
        }

        inline explicit Vector2( const Real scaler )
            : x( scaler), y( scaler )
        {
        }

        inline explicit Vector2( const Real afCoordinate[2] )
            : x( afCoordinate[0] ),
              y( afCoordinate[1] )
        {
        }

        inline explicit Vector2( const int afCoordinate[2] )
        {
            x = (Real)afCoordinate[0];
            y = (Real)afCoordinate[1];
        }

        inline explicit Vector2( Real* const r )
            : x( r[0] ), y( r[1] )
        {
        }

        inline void swap(Vector2& other)
        {
            std::swap(x, other.x);
            std::swap(y, other.y);
        }

        inline Real operator [] ( const size_t i ) const
        {
            assert( i < 2 );

            return *(&x+i);
        }

        inline Real& operator [] ( const size_t i )
        {
            assert( i < 2 );

            return *(&x+i);
        }

        inline Real* ptr()
        {
            return &x;
        }
        inline const Real* ptr() const
        {
            return &x;
        }

        inline Vector2& operator = ( const Vector2& rkVector )
        {
            x = rkVector.x;
            y = rkVector.y;

            return *this;
        }

        inline Vector2& operator = ( const Real fScalar)
        {
            x = fScalar;
            y = fScalar;

            return *this;
        }

        inline bool operator == ( const Vector2& rkVector ) const
        {
            return ( x == rkVector.x && y == rkVector.y );
        }

        inline bool operator != ( const Vector2& rkVector ) const
        {
            return ( x != rkVector.x || y != rkVector.y  );
        }

        // arithmetic operations
        inline Vector2 operator + ( const Vector2& rkVector ) const
        {
            return Vector2(
                x + rkVector.x,
                y + rkVector.y);
        }

        inline Vector2 operator - ( const Vector2& rkVector ) const
        {
            return Vector2(
                x - rkVector.x,
                y - rkVector.y);
        }

        inline Vector2 operator * ( const Real fScalar ) const
        {
            return Vector2(
                x * fScalar,
                y * fScalar);
        }

        inline Vector2 operator * ( const Vector2& rhs) const
        {
            return Vector2(
                x * rhs.x,
                y * rhs.y);
        }

        inline Vector2 operator / ( const Real fScalar ) const
        {
            assert( fScalar != 0.0 );

            Real fInv = 1.0f / fScalar;

            return Vector2(
                x * fInv,
                y * fInv);
        }

        inline Vector2 operator / ( const Vector2& rhs) const
        {
            return Vector2(
                x / rhs.x,
                y / rhs.y);
        }

        inline const Vector2& operator + () const
        {
            return *this;
        }

        inline Vector2 operator - () const
        {
            return Vector2(-x, -y);
        }

        // overloaded operators to help Vector2
        inline friend Vector2 operator * ( const Real fScalar, const Vector2& rkVector )
        {
            return Vector2(
                fScalar * rkVector.x,
                fScalar * rkVector.y);
        }

        inline friend Vector2 operator / ( const Real fScalar, const Vector2& rkVector )
        {
            return Vector2(
                fScalar / rkVector.x,
                fScalar / rkVector.y);
        }

        inline friend Vector2 operator + (const Vector2& lhs, const Real rhs)
        {
            return Vector2(
                lhs.x + rhs,
                lhs.y + rhs);
        }

        inline friend Vector2 operator + (const Real lhs, const Vector2& rhs)
        {
            return Vector2(
                lhs + rhs.x,
                lhs + rhs.y);
        }

        inline friend Vector2 operator - (const Vector2& lhs, const Real rhs)
        {
            return Vector2(
                lhs.x - rhs,
                lhs.y - rhs);
        }

        inline friend Vector2 operator - (const Real lhs, const Vector2& rhs)
        {
            return Vector2(
                lhs - rhs.x,
                lhs - rhs.y);
        }

        // arithmetic updates
        inline Vector2& operator += ( const Vector2& rkVector )
        {
            x += rkVector.x;
            y += rkVector.y;

            return *this;
        }

        inline Vector2& operator += ( const Real fScaler )
        {
            x += fScaler;
            y += fScaler;

            return *this;
        }

        inline Vector2& operator -= ( const Vector2& rkVector )
        {
            x -= rkVector.x;
            y -= rkVector.y;

            return *this;
        }

        inline Vector2& operator -= ( const Real fScaler )
        {
            x -= fScaler;
            y -= fScaler;

            return *this;
        }

        inline Vector2& operator *= ( const Real fScalar )
        {
            x *= fScalar;
            y *= fScalar;

            return *this;
        }

        inline Vector2& operator *= ( const Vector2& rkVector )
        {
            x *= rkVector.x;
            y *= rkVector.y;

            return *this;
        }

        inline Vector2& operator /= ( const Real fScalar )
        {
            assert( fScalar != 0.0 );

            Real fInv = 1.0f / fScalar;

            x *= fInv;
            y *= fInv;

            return *this;
        }

        inline Vector2& operator /= ( const Vector2& rkVector )
        {
            x /= rkVector.x;
            y /= rkVector.y;

            return *this;
        }

        inline Real length () const
        {
            return Math::Sqrt( x * x + y * y );
        }

        inline Real squaredLength () const
        {
            return x * x + y * y;
        }

        inline Real distance(const Vector2& rhs) const
        {
            return (*this - rhs).length();
        }

        inline Real squaredDistance(const Vector2& rhs) const
        {
            return (*this - rhs).squaredLength();
        }

        inline Real dotProduct(const Vector2& vec) const
        {
            return x * vec.x + y * vec.y;
        }

        inline Real normalise()
        {
            Real fLength = Math::Sqrt( x * x + y * y);

            // Will also work for zero-sized vectors, but will change nothing
            // We're not using epsilons because we don't need to.
            // Read http://www.ogre3d.org/forums/viewtopic.php?f=4&t=61259
            if ( fLength > Real(0.0f) )
            {
                Real fInvLength = 1.0f / fLength;
                x *= fInvLength;
                y *= fInvLength;
            }

            return fLength;
        }

        inline Vector2 midPoint( const Vector2& vec ) const
        {
            return Vector2(
                ( x + vec.x ) * 0.5f,
                ( y + vec.y ) * 0.5f );
        }

        inline bool operator < ( const Vector2& rhs ) const
        {
            if( x < rhs.x && y < rhs.y )
                return true;
            return false;
        }

        inline bool operator > ( const Vector2& rhs ) const
        {
            if( x > rhs.x && y > rhs.y )
                return true;
            return false;
        }

        inline void makeFloor( const Vector2& cmp )
        {
            if( cmp.x < x ) x = cmp.x;
            if( cmp.y < y ) y = cmp.y;
        }

        inline void makeCeil( const Vector2& cmp )
        {
            if( cmp.x > x ) x = cmp.x;
            if( cmp.y > y ) y = cmp.y;
        }

        inline Vector2 perpendicular(void) const
        {
            return Vector2 (-y, x);
        }

        inline Real crossProduct( const Vector2& rkVector ) const
        {
            return x * rkVector.y - y * rkVector.x;
        }

        inline Vector2 randomDeviant(Real angle) const
        {

            angle *=  Math::UnitRandom() * Math::TWO_PI;
            Real cosa = cos(angle);
            Real sina = sin(angle);
            return  Vector2(cosa * x - sina * y,
                            sina * x + cosa * y);
        }

        inline bool isZeroLength(void) const
        {
            Real sqlen = (x * x) + (y * y);
            return (sqlen < (1e-06 * 1e-06));

        }

        inline Vector2 normalisedCopy(void) const
        {
            Vector2 ret = *this;
            ret.normalise();
            return ret;
        }

        inline Vector2 reflect(const Vector2& normal) const
        {
            return Vector2( *this - ( 2 * this->dotProduct(normal) * normal ) );
        }

        inline bool isNaN() const
        {
            return Math::isNaN(x) || Math::isNaN(y);
        }

        inline Ogre::Radian angleBetween(const Ogre::Vector2& other) const
        {       
            Ogre::Real lenProduct = length() * other.length();
            // Divide by zero check
            if(lenProduct < 1e-6f)
                lenProduct = 1e-6f;
        
            Ogre::Real f = dotProduct(other) / lenProduct;
    
            f = Ogre::Math::Clamp(f, (Ogre::Real)-1.0, (Ogre::Real)1.0);
            return Ogre::Math::ACos(f);
        }

        inline Ogre::Radian angleTo(const Ogre::Vector2& other) const
        {
            Ogre::Radian angle = angleBetween(other);
        
            if (crossProduct(other)<0)          
                angle = (Ogre::Radian)Ogre::Math::TWO_PI - angle;       

            return angle;
        }

        // special points
        static const Vector2 ZERO;
        static const Vector2 UNIT_X;
        static const Vector2 UNIT_Y;
        static const Vector2 NEGATIVE_UNIT_X;
        static const Vector2 NEGATIVE_UNIT_Y;
        static const Vector2 UNIT_SCALE;

        inline _OgreExport friend std::ostream& operator <<
            ( std::ostream& o, const Vector2& v )
        {
            o << "Vector2(" << v.x << ", " << v.y <<  ")";
            return o;
        }
    };
}
#endif