/*******************************************************************************
* Copyright 2015-2020 Intel Corporation.
*
* This software and the related documents are Intel copyrighted  materials,  and
* your use of  them is  governed by the  express license  under which  they were
* provided to you (License).  Unless the License provides otherwise, you may not
* use, modify, copy, publish, distribute,  disclose or transmit this software or
* the related documents without Intel's prior written permission.
*
* This software and the related documents  are provided as  is,  with no express
* or implied  warranties,  other  than those  that are  expressly stated  in the
* License.
*******************************************************************************/

//    The code example below illustrates how the horizontal edges of an image can be detected.
// implemented with Intel(R) Integrated Primitives (Intel(R) IPP) functions:
//     ippiSet_32f_C1R
//     ippiAddC_32f_C1IR
//     ippiCopy_32f_C1R
//     ippiFFTGetSize_R_32f
//     ippiFFTInit_R_32f
//     ippiFFTFwd_RToPack_32f_C1R
//     ippiMulPack_32f_C1R
//     ippiFFTInv_PackToR_32f_C1R


#include <stdio.h>
#include "ipp.h"

/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine:                                  /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) IPP function returned status different from ippStsNoErr */

/* Results of ippMalloc() are not validated because Intel(R) IPP functions perform bad arguments check and will return an appropriate status  */

int main(void)
{
    IppStatus status = ippStsNoErr;
    IppiFFTSpec_R_32f *pSpec = NULL;             /* Pointer to FFT spec structure */

    Ipp32f pSrc[64],   pFlt[64],   pDst[64];     /* Pointers to source/filter/destination images */
    Ipp32f pSrcFr[64], pFltFr[64], pDstFr[64];   /* Pointers to source/filter/destination images into the frequency domain */

    Ipp8u *pMemInit = NULL, *pBuffer = NULL;     /* Pointer to the work buffers */
    int sizeSpec = 0, sizeInit = 0, sizeBuf = 0; /* size of FFT spec structure, Init and work buffers */

    const IppiSize roiSize8x8 = { 8, 8 }, roiSize3x3 = { 3, 3 }; /* image and filter roi sizes */
    const Ipp32f filter[3*3] = {-1,-1,-1, 0,0,0, 1,1,1};         /* filter data */

    /* set the image zero */
    check_sts( status = ippiSet_32f_C1R( 0, pSrc, 8*sizeof(Ipp32f), roiSize8x8 ) )

    /* create unit area in the image */
    check_sts( status = ippiAddC_32f_C1IR( 1, pSrc+8+1, 8*sizeof(Ipp32f), roiSize3x3 ) )

    /* set the filter zero */
    check_sts( status = ippiSet_32f_C1R( 0, pFlt, 8*sizeof(Ipp32f), roiSize8x8 ) )

    /* copy the filter coefficients */
    check_sts( status = ippiCopy_32f_C1R( filter, 3*sizeof(Ipp32f), pFlt, 8*sizeof(Ipp32f), roiSize3x3 ) )

    check_sts( status = ippiFFTGetSize_R_32f(3, 3, IPP_FFT_DIV_INV_BY_N, ippAlgHintAccurate,
                           &sizeSpec, &sizeInit, &sizeBuf) )

    /* memory allocation */
    pSpec    = (IppiFFTSpec_R_32f*) ippMalloc( sizeSpec );
    pBuffer  = (Ipp8u*) ippMalloc( sizeBuf );
    pMemInit = (Ipp8u*) ippMalloc( sizeInit );

    check_sts( status = ippiFFTInit_R_32f(3, 3, IPP_FFT_DIV_INV_BY_N, ippAlgHintAccurate, pSpec, pMemInit) )

    /* forward FFT transform : the source image is transformed into the frequency domain*/
    check_sts( status = ippiFFTFwd_RToPack_32f_C1R( pSrc, 8*sizeof(Ipp32f), pSrcFr, 8*sizeof(Ipp32f), pSpec, pBuffer ) )

    /* forward FFT transform: the filter is transformed into the frequency domain */
    check_sts( status = ippiFFTFwd_RToPack_32f_C1R( pFlt, 8*sizeof(Ipp32f), pFltFr, 8*sizeof(Ipp32f), pSpec, pBuffer ) )

    /* multiplying the packed data */
    check_sts( status = ippiMulPack_32f_C1R( pSrcFr, 8*sizeof(Ipp32f), pFltFr, 8*sizeof(Ipp32f), pDstFr, 8*4, roiSize8x8) )

    /* inverse FFT transform : the filtered data is transformed to the time domain */
    check_sts( status = ippiFFTInv_PackToR_32f_C1R( pDstFr, 8*sizeof(Ipp32f), pDst, 8*sizeof(Ipp32f), pSpec, pBuffer ) )

EXIT_MAIN
    ippFree( pMemInit );
    ippFree( pSpec );
    ippFree( pBuffer );
    printf("Exit status %d (%s)\n", (int)status, ippGetStatusString(status));
    return (int)status;
}