basicrange.hxx

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
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 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */
 
#pragma once
 
#include <sal/types.h>
#include <float.h>
#include <basegfx/numeric/ftools.hxx>
 
 
namespace basegfx
{
    template< typename T, typename Traits > class BasicRange
    {
    protected:
        T mnMinimum;
        T mnMaximum;
 
    public:
        typedef T       ValueType;
        typedef Traits  TraitsType;
 
        BasicRange() :
            mnMinimum(Traits::maxVal()),
            mnMaximum(Traits::minVal())
        {
        }
 
        explicit BasicRange( T nValue ) :
            mnMinimum(nValue),
            mnMaximum(nValue)
        {
        }
 
        void reset()
        {
            mnMinimum = Traits::maxVal();
            mnMaximum = Traits::minVal();
        }
 
        bool isEmpty() const
        {
            return Traits::maxVal() == mnMinimum;
        }
 
        T getMinimum() const { return mnMinimum; }
        T getMaximum() const { return mnMaximum; }
 
        double getCenter() const
        {
            if(isEmpty())
            {
                return 0.0;
            }
            else
            {
                return ((mnMaximum + mnMinimum) / 2.0);
            }
        }
 
        bool isInside(T nValue) const
        {
            if(isEmpty())
            {
                return false;
            }
            else
            {
                return (nValue >= mnMinimum) && (nValue <= mnMaximum);
            }
        }
 
        bool isInside(const BasicRange& rRange) const
        {
            if(isEmpty())
            {
                return false;
            }
            else
            {
                if(rRange.isEmpty())
                {
                    return false;
                }
                else
                {
                    return (rRange.mnMinimum >= mnMinimum) && (rRange.mnMaximum <= mnMaximum);
                }
            }
        }
 
        bool overlaps(const BasicRange& rRange) const
        {
            if(isEmpty())
            {
                return false;
            }
            else
            {
                if(rRange.isEmpty())
                {
                    return false;
                }
                else
                {
                    return (rRange.mnMaximum >= mnMinimum) && (rRange.mnMinimum <= mnMaximum);
                }
            }
        }
 
        bool overlapsMore(const BasicRange& rRange) const
        {
            if(isEmpty() || rRange.isEmpty())
                return false;
            // returns true if the overlap is more than just a touching at the limits
            return ((rRange.mnMaximum > mnMinimum) && (rRange.mnMinimum < mnMaximum));
        }
 
        bool operator==( const BasicRange& rRange ) const
        {
            return (mnMinimum == rRange.mnMinimum && mnMaximum == rRange.mnMaximum);
        }
 
        bool operator!=( const BasicRange& rRange ) const
        {
            return (mnMinimum != rRange.mnMinimum || mnMaximum != rRange.mnMaximum);
        }
 
        bool equal(const BasicRange& rRange) const
        {
            return (
                fTools::equal(mnMinimum, rRange.mnMinimum) &&
                fTools::equal(mnMaximum, rRange.mnMaximum));
        }
 
        void expand(T nValue)
        {
            if(isEmpty())
            {
                mnMinimum = mnMaximum = nValue;
            }
            else
            {
// Silence over-eager warning emitted at least by GCC 4.9.2 in certain
// instantiations:
#if defined __GNUC__ && !defined __clang__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstrict-overflow"
#endif
                if(nValue < mnMinimum)
#if defined __GNUC__ && !defined __clang__
#pragma GCC diagnostic pop
#endif
                {
                    mnMinimum = nValue;
                }
 
                if(nValue > mnMaximum)
                {
                    mnMaximum = nValue;
                }
            }
        }
 
        void expand(const BasicRange& rRange)
        {
            if(isEmpty())
            {
                mnMinimum = rRange.mnMinimum;
                mnMaximum = rRange.mnMaximum;
            }
            else
            {
                if(!rRange.isEmpty())
                {
                    if(rRange.mnMinimum < mnMinimum)
                    {
                        mnMinimum = rRange.mnMinimum;
                    }
 
                    if(rRange.mnMaximum > mnMaximum)
                    {
                        mnMaximum = rRange.mnMaximum;
                    }
                }
            }
        }
 
        void intersect(const BasicRange& rRange)
        {
            // here, overlaps also tests all isEmpty() conditions already.
            if( !overlaps( rRange ) )
            {
                reset();
            }
            else
            {
                if(rRange.mnMinimum > mnMinimum)
                {
                    mnMinimum = rRange.mnMinimum;
                }
 
                if(rRange.mnMaximum < mnMaximum)
                {
                    mnMaximum = rRange.mnMaximum;
                }
            }
        }
 
        void grow(T nValue)
        {
            if(isEmpty())
                return;
 
            bool bLessThanZero(nValue < 0);
 
            if(nValue > 0 || bLessThanZero)
            {
                mnMinimum -= nValue;
                mnMaximum += nValue;
 
                if(bLessThanZero)
                {
                    // test if range did collapse
                    if(mnMinimum > mnMaximum)
                    {
                        // if yes, collapse to center
                        mnMinimum = mnMaximum = (mnMinimum + mnMaximum) / 2;
                    }
                }
            }
        }
 
        T clamp(T nValue) const
        {
            if(isEmpty())
            {
                return nValue;
            }
            else
            {
                if(nValue < mnMinimum)
                {
                    return mnMinimum;
                }
 
                if(nValue > mnMaximum)
                {
                    return mnMaximum;
                }
 
                return nValue;
            }
        }
 
#if defined _MSC_VER && defined(_M_ARM64)
#pragma warning(push)
#pragma warning(disable: 4723) /* ignore: warning for C4723 on windows arm64 build */
#endif
        typename Traits::DifferenceType getRange() const
        {
            if(isEmpty())
            {
                return Traits::neutral();
            }
            else
            {
                return (mnMaximum - mnMinimum);
            }
        }
#if defined _MSC_VER && defined(_M_ARM64)
#pragma warning( pop )
#endif
    };
 
    // some pre-fabricated traits
    struct DoubleTraits
    {
        static constexpr double minVal() { return DBL_MIN; };
        static constexpr double maxVal() { return DBL_MAX; };
        static constexpr double neutral() { return 0.0; };
 
        typedef double DifferenceType;
    };
 
    struct Int32Traits
    {
        static constexpr sal_Int32 minVal() { return SAL_MIN_INT32; };
        static constexpr sal_Int32 maxVal() { return SAL_MAX_INT32; };
        static constexpr sal_Int32 neutral() { return 0; };
 
        typedef sal_Int64 DifferenceType;
    };
 
} // end of namespace basegfx
 
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