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#include "convolutionTexture_common.h"

////////////////////////////////////////////////////////////////////////////////
// Reference row convolution filter
////////////////////////////////////////////////////////////////////////////////
extern "C" void convolutionRowsCPU(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 = 0;

        if (d >= imageW) d = imageW - 1;

        sum += h_Src[y * imageW + d] * h_Kernel[kernelR - k];
      }

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

////////////////////////////////////////////////////////////////////////////////
// Reference column convolution filter
////////////////////////////////////////////////////////////////////////////////
extern "C" void convolutionColumnsCPU(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 = 0;

        if (d >= imageH) d = imageH - 1;

        sum += h_Src[d * imageW + x] * h_Kernel[kernelR - k];
      }

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