/* Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of NVIDIA CORPORATION nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "convolutionSeparable_common.h"

////////////////////////////////////////////////////////////////////////////////
// Reference row convolution filter
////////////////////////////////////////////////////////////////////////////////
extern "C" void convolutionRowCPU(float *h_Dst, float *h_Src, float *h_Kernel,
                                  int imageW, int imageH, int kernelR) {
  for (int y = 0; y < imageH; y++)
    for (int x = 0; x < imageW; x++) {
      float sum = 0;

      for (int k = -kernelR; k <= kernelR; k++) {
        int d = x + k;

        if (d >= 0 && d < imageW)
          sum += h_Src[y * imageW + d] * h_Kernel[kernelR - k];
      }

      h_Dst[y * imageW + x] = sum;
    }
}

////////////////////////////////////////////////////////////////////////////////
// Reference column convolution filter
////////////////////////////////////////////////////////////////////////////////
extern "C" void convolutionColumnCPU(float *h_Dst, float *h_Src,
                                     float *h_Kernel, int imageW, int imageH,
                                     int kernelR) {
  for (int y = 0; y < imageH; y++)
    for (int x = 0; x < imageW; x++) {
      float sum = 0;

      for (int k = -kernelR; k <= kernelR; k++) {
        int d = y + k;

        if (d >= 0 && d < imageH)
          sum += h_Src[d * imageW + x] * h_Kernel[kernelR - k];
      }

      h_Dst[y * imageW + x] = sum;
    }
}