// Tencent is pleased to support the open source community by making ncnn available.
//
// Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
//
// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// https://opensource.org/licenses/BSD-3-Clause
//
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.

#include "flatten.h"
#include <string.h>

namespace ncnn {

DEFINE_LAYER_CREATOR(Flatten)

Flatten::Flatten()
{
    one_blob_only = true;
    support_inplace = false;
}

int Flatten::forward(const Mat& bottom_blob, Mat& top_blob, const Option& opt) const
{
    int w = bottom_blob.w;
    int h = bottom_blob.h;
    int channels = bottom_blob.c;
    size_t elemsize = bottom_blob.elemsize;
    int size = w * h;

    top_blob.create(size * channels, elemsize, opt.blob_allocator);
    if (top_blob.empty())
        return -100;

    #pragma omp parallel for num_threads(opt.num_threads)
    for (int q=0; q<channels; q++)
    {
        const unsigned char* ptr = bottom_blob.channel(q);
        unsigned char* outptr = (unsigned char*)top_blob + size * elemsize * q;

        memcpy(outptr, ptr, size * elemsize);
    }

    return 0;
}

} // namespace ncnn