ImathInterval.h

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//
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#ifndef INCLUDED_IMATHINTERVAL_H
#define INCLUDED_IMATHINTERVAL_H


//-------------------------------------------------------------------
//
//  class Imath::Interval<class T>
//  --------------------------------
//
//  An Interval has a min and a max and some miscellaneous
//  functions. It is basically a Box<T> that allows T to be
//  a scalar.
//
//-------------------------------------------------------------------

#include "ImathVec.h"

namespace Imath {


template <class T>  
class Interval
{
  public:

    //-------------------------
    //  Data Members are public
    //-------------------------

    T               min;
    T               max;

    //-----------------------------------------------------
    //  Constructors - an "empty" Interval is created by default
    //-----------------------------------------------------

    Interval(); 
    Interval(const T& point);
    Interval(const T& minT, const T& maxT);

    //--------------------------------
    //  Operators:  we get != from STL
    //--------------------------------
    
    bool                        operator == (const Interval<T> &src) const;

    //------------------
    //  Interval manipulation
    //------------------

    void            makeEmpty();
    void            extendBy(const T& point);
    void            extendBy(const Interval<T>& interval);

    //---------------------------------------------------
    //  Query functions - these compute results each time
    //---------------------------------------------------

    T               size() const;
    T               center() const;
    bool            intersects(const T &point) const;
    bool            intersects(const Interval<T> &interval) const;

    //----------------
    //  Classification
    //----------------

    bool            hasVolume() const;
    bool            isEmpty() const;
};


//--------------------
// Convenient typedefs
//--------------------


typedef Interval <float>  Intervalf;
typedef Interval <double> Intervald;
typedef Interval <short>  Intervals;
typedef Interval <int>    Intervali;

//----------------
//  Implementation
//----------------


template <class T>
inline Interval<T>::Interval()
{
    makeEmpty();
}

template <class T>
inline Interval<T>::Interval(const T& point)
{
    min = point;
    max = point;
}

template <class T>
inline Interval<T>::Interval(const T& minV, const T& maxV)
{
    min = minV;
    max = maxV;
}

template <class T>
inline bool
Interval<T>::operator == (const Interval<T> &src) const
{
    return (min == src.min && max == src.max);
}

template <class T>
inline void
Interval<T>::makeEmpty()
{
    min = limits<T>::max();
    max = limits<T>::min();
}

template <class T>
inline void
Interval<T>::extendBy(const T& point)
{
    if ( point < min )
    min = point;
    
    if ( point > max )
    max = point;
}

template <class T>
inline void
Interval<T>::extendBy(const Interval<T>& interval)
{
    if ( interval.min < min )
    min = interval.min;

    if ( interval.max > max )
    max = interval.max;
}

template <class T>
inline bool
Interval<T>::intersects(const T& point) const
{
    return point >= min && point <= max;
}

template <class T>
inline bool
Interval<T>::intersects(const Interval<T>& interval) const
{
    return interval.max >= min && interval.min <= max;
}

template <class T> 
inline T
Interval<T>::size() const 
{ 
    return max-min;
}

template <class T> 
inline T
Interval<T>::center() const 
{ 
    return (max+min)/2;
}

template <class T>
inline bool
Interval<T>::isEmpty() const
{
    return max < min;
}

template <class T>
inline bool Interval<T>::hasVolume() const
{
    return max > min;
}

} // namespace Imath

#endif