/*

* Simd Library (http://ermig1979.github.io/Simd).

*

* Copyright (c) 2011-2017 Yermalayeu Ihar.

*

* 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 "Simd/SimdMemory.h"

#include "Simd/SimdMath.h"

namespace Simd

{

    namespace Base

    {

        void ReduceGray2x2(const uint8_t *src, size_t srcWidth, size_t srcHeight, size_t srcStride,

            uint8_t *dst, size_t dstWidth, size_t dstHeight, size_t dstStride)

        {

            assert((srcWidth + 1) / 2 == dstWidth && (srcHeight + 1) / 2 == dstHeight);

            size_t evenWidth = AlignLo(srcWidth, 2);

            for (size_t srcRow = 0; srcRow < srcHeight; srcRow += 2)

            {

                const uint8_t *s0 = src;

                const uint8_t *s1 = (srcRow == srcHeight - 1 ? src : src + srcStride);

                const uint8_t *end = src + evenWidth;

                uint8_t *d = dst;

                for (; s0 < end; s0 += 2, s1 += 2, d += 1)

                {

                    d[0] = Average(s0[0], s0[1], s1[0], s1[1]);

                }

                if (evenWidth != srcWidth)

                {

                    d[0] = Average(s0[0], s1[0]);

                }

                src += 2 * srcStride;

                dst += dstStride;

            }

        }

    }

}