/*

-----------------------------------------------------------------------------

This source file is part of OGRE

    (Object-oriented Graphics Rendering Engine)

For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2014 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.

-----------------------------------------------------------------------------

*/

#include "OgreStableHeaders.h"

#include "OgrePlatformInformation.h"

/**

*

* |___2___|3|_________5__________|__6__|

* ^         ^

* 1         4

*

* 1 -> Pointer to start of the block allocated by new.

* 2 -> Gap used to get 4 aligned on given alignment

* 3 -> Byte offset between 1 and 4

* 4 -> Pointer to the start of data block.

* 5 -> Data block.

* 6 -> Wasted memory at rear of data block.

*/

namespace Ogre {

    /** Allocate memory with given alignment.

        @param

            size The size of memory need to allocate.

        @param

            alignment The alignment of result pointer, must be power of two

            and in range [1, 128].

        @return

            The allocated memory pointer.

        @par

            On failure, exception will be throw.

    */

    void* AlignedMemory::allocate(size_t size, size_t alignment)

    {

        assert(0 < alignment && alignment <= 128 && Bitwise::isPO2(alignment));

        unsigned char* p = new unsigned char[size + alignment];

        size_t offset = alignment - (size_t(p) & (alignment-1));

        unsigned char* result = p + offset;

        result[-1] = (unsigned char)offset;

        return result;

    }

    //---------------------------------------------------------------------

    void* AlignedMemory::allocate(size_t size)

    {

        return allocate(size, OGRE_SIMD_ALIGNMENT);

    }

    //---------------------------------------------------------------------

    void AlignedMemory::deallocate(void* p)

    {

        if (p)

        {

            unsigned char* mem = (unsigned char*)p;

            mem = mem - mem[-1];

            delete [] mem;

        }

    }

}