o3de/Code/Editor/Util/Util.h

/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */


#ifndef CRYINCLUDE_CRYCOMMONTOOLS_UTIL_H
#define CRYINCLUDE_CRYCOMMONTOOLS_UTIL_H
#pragma once


#include <cstring>  // memset()

#ifndef BIT
#define BIT(x) (1 << (x))
#endif


union IntOrPtr
{
    int m_int;
    unsigned int m_uint;
    void* m_pVoid;
    char* m_pChar;

    void setZero()
    {
        memset(this, 0, sizeof(*this));
    }

    bool operator==(const IntOrPtr& a) const
    {
        return memcmp(this, &a, sizeof(*this)) == 0;
    }

    bool operator!=(const IntOrPtr& a) const
    {
        return memcmp(this, &a, sizeof(*this)) != 0;
    }
};


namespace Util
{
    // note: names 'getMin' and 'getMax' (instead of usual 'min' and 'max') are
    // used to avoid conflicts with global and/or user's #define of 'min' and 'max'

    template<class T>
    inline const T& getMin(const T& a, const T& b)
    {
        return (a < b) ? a : b;
    }

    template<class T>
    inline const T& getMax(const T& a, const T& b)
    {
        return (a < b) ? b : a;
    }

    template<class T>
    inline const T& getMin(const T& a, const T& b, const T& c)
    {
        return (a < b)
               ? ((a < c) ? a : c)
               : ((b < c) ? b : c);
    }

    template<class T>
    inline const T& getMax(const T& a, const T& b, const T& c)
    {
        return (a < b)
               ? ((b < c) ? c : b)
               : ((a < c) ? c : a);
    }


    template<class T>
    inline const T& getClamped(const T& a, const T& a_min, const T& a_max)
    {
        if (a < a_min)
        {
            return a_min;
        }
        if (a_max < a)
        {
            return a_max;
        }
        return a;
    }

    // note: name 'clampMinMax' (instead of usual 'clamp') is used
    // to avoid conflicts with global and/or user's #define of 'clamp'
    template<class T>
    inline void clampMinMax(T& a, const T& a_min, const T& a_max)
    {
        if (a < a_min)
        {
            a = a_min;
        }
        else if (a_max < a)
        {
            a = a_max;
        }
    }

    template<class T>
    inline void clampMin(T& a, const T& a_min)
    {
        if (a < a_min)
        {
            a = a_min;
        }
    }

    template<class T>
    inline void clampMax(T& a, const T& a_max)
    {
        if (a_max < a)
        {
            a = a_max;
        }
    }


    template <class TInteger>
    inline bool isPowerOfTwo(TInteger x)
    {
        return (x & (x - 1)) == 0;
    }


    template <class TInteger>
    inline TInteger getCeiledPowerOfTwo(TInteger x)
    {
        x = x - 1;

        if (sizeof(TInteger) > 0)
        {
            x |= x >> 1;
        }
        if (sizeof(TInteger) > 0)
        {
            x |= x >> 2;
        }
        if (sizeof(TInteger) > 0)
        {
            x |= x >> 4;
        }
        if (sizeof(TInteger) > 1)
        {
            x |= x >> 8;
        }
        if (sizeof(TInteger) > 2)
        {
            x |= x >> 16;
        }
        if (sizeof(TInteger) > 4)
        {
            x |= x >> 32;
        }

        return x + 1;
    }


    template <class TInteger>
    inline TInteger getFlooredPowerOfTwo(TInteger x)
    {
        if (!isPowerOfTwo(x))
        {
            x = getCeiledPowerOfTwo(x) >> 1;
        }

        return x;
    }


    template <class T>
    inline T square(T x)
    {
        return x * x;
    }


    template <class T>
    inline T cube(T x)
    {
        return x * x * x;
    }
} // namespace Util

#endif // CRYINCLUDE_CRYCOMMONTOOLS_UTIL_H