/*
 *
 *  Copyright (C) 1996-2017, OFFIS e.V.
 *  All rights reserved.  See COPYRIGHT file for details.
 *
 *  This software and supporting documentation were developed by
 *
 *    OFFIS e.V.
 *    R&D Division Health
 *    Escherweg 2
 *    D-26121 Oldenburg, Germany
 *
 *
 *  Module:  dcmimgle
 *
 *  Author:  Joerg Riesmeier
 *
 *  Purpose: DicomMonochromeInputPixelTemplate (Header)
 *
 */


#ifndef DIMOIPXT_H
#define DIMOIPXT_H

#include "dcmtk/config/osconfig.h"

#include "dcmtk/ofstd/ofbmanip.h"
#include "dcmtk/ofstd/ofcast.h"

#include "dcmtk/dcmimgle/dimopxt.h"
#include "dcmtk/dcmimgle/diinpx.h"


/*---------------------*
 *  class declaration  *
 *---------------------*/

/** Template class to convert monochrome pixel data to intermediate representation
 */
template<class T1, class T2, class T3>
class DiMonoInputPixelTemplate
  : public DiMonoPixelTemplate<T3>
{

 public:

    /** constructor
     *
     ** @param  pixel     pointer to input pixel representation
     *  @param  modality  pointer to modality transform object
     */
    DiMonoInputPixelTemplate(DiInputPixel *pixel,
                             DiMonoModality *modality)
      : DiMonoPixelTemplate<T3>(pixel, modality)
    {
        if ((pixel != NULL) && (this->Count > 0))
        {
            // check whether to apply any modality transform
            if ((this->Modality != NULL) && this->Modality->hasLookupTable() && (bitsof(T1) <= MAX_TABLE_ENTRY_SIZE))
            {
                modlut(pixel);
                // ignore modality LUT min/max values since the image does not necessarily have to use all LUT entries
                this->determineMinMax();
            }
            else if ((this->Modality != NULL) && this->Modality->hasRescaling())
            {
                rescale(pixel, this->Modality->getRescaleSlope(), this->Modality->getRescaleIntercept());
                this->determineMinMax(OFstatic_cast(T3, this->Modality->getMinValue()), OFstatic_cast(T3, this->Modality->getMaxValue()));
            } else {
                rescale(pixel);                     // "copy" or reference pixel data
                this->determineMinMax(OFstatic_cast(T3, this->Modality->getMinValue()), OFstatic_cast(T3, this->Modality->getMaxValue()));
            }
            /* erase empty part of the buffer (= blacken the background) */
            if ((this->Data != NULL) && (this->InputCount < this->Count))
                OFBitmanipTemplate<T3>::zeroMem(this->Data + this->InputCount, this->Count - this->InputCount);
        }
    }

    /** destructor
     */
    virtual ~DiMonoInputPixelTemplate()
    {
    }


 private:

    /** initialize optimization LUT
     *
     ** @param  lut   reference to storage area for lookup table
     *  @param  ocnt  number of LUT entries (will be check as optimization criteria)
     *
     ** @return status, true if successful (LUT has been created), false otherwise
     */
    inline int initOptimizationLUT(T3 *&lut,
                                   const unsigned long ocnt)
    {
        int result = 0;
        if ((sizeof(T1) <= 2) && (this->InputCount > 3 * ocnt))               // optimization criteria
        {                                                                     // use LUT for optimization
            lut = new T3[ocnt];
            if (lut != NULL)
            {
                DCMIMGLE_DEBUG("using optimized routine with additional LUT");
                result = 1;
            }
        }
        return result;
    }

    /** perform modality LUT transform
     *
     ** @param  input  pointer to input pixel representation
     */
    void modlut(DiInputPixel *input)
    {
        const T1 *pixel = OFstatic_cast(const T1 *, input->getData());
        if ((pixel != NULL) && (this->Modality != NULL))
        {
            const DiLookupTable *mlut = this->Modality->getTableData();
            if (mlut != NULL)
            {
                const int useInputBuffer = (sizeof(T1) == sizeof(T3)) && (this->Count <= input->getCount());
                if (useInputBuffer)                            // do not copy pixel data, reference them!
                {
                    DCMIMGLE_DEBUG("re-using input buffer, do not copy pixel data");
                    this->Data = OFstatic_cast(T3 *, input->getDataPtr());
                    input->removeDataReference();              // avoid double deletion
                } else
                    this->Data = new T3[this->Count];
                if (this->Data != NULL)
                {
                    DCMIMGLE_DEBUG("applying modality transformation with LUT (" << mlut->getCount() << " entries)");
                    T2 value = 0;
                    const T2 firstentry = mlut->getFirstEntry(value);                     // choose signed/unsigned method
                    const T2 lastentry = mlut->getLastEntry(value);
                    const T3 firstvalue = OFstatic_cast(T3, mlut->getFirstValue());
                    const T3 lastvalue = OFstatic_cast(T3, mlut->getLastValue());
                    const T1 *p = pixel + input->getPixelStart();
                    T3 *q = this->Data;
                    unsigned long i;
                    T3 *lut = NULL;
                    const unsigned long ocnt = OFstatic_cast(unsigned long, input->getAbsMaxRange());  // number of LUT entries
                    if (initOptimizationLUT(lut, ocnt))
                    {                                                                     // use LUT for optimization
                        const T2 absmin = OFstatic_cast(T2, input->getAbsMinimum());
                        q = lut;
                        for (i = 0; i < ocnt; ++i)                                        // calculating LUT entries
                        {
                            value = OFstatic_cast(T2, i) + absmin;
                            if (value <= firstentry)
                                *(q++) = firstvalue;
                            else if (value >= lastentry)
                                *(q++) = lastvalue;
                            else
                                *(q++) = OFstatic_cast(T3, mlut->getValue(value));
                        }
                        const T3 *lut0 = lut - OFstatic_cast(T2, absmin);                 // points to 'zero' entry
                        q = this->Data;
                        for (i = this->InputCount; i != 0; --i)                           // apply LUT
                            *(q++) = *(lut0 + (*(p++)));
                    }
                    if (lut == NULL)                                                      // use "normal" transformation
                    {
                        for (i = this->InputCount; i != 0; --i)
                        {
                            value = OFstatic_cast(T2, *(p++));
                            if (value <= firstentry)
                                *(q++) = firstvalue;
                            else if (value >= lastentry)
                                *(q++) = lastvalue;
                            else
                                *(q++) = OFstatic_cast(T3, mlut->getValue(value));
                        }
                    }
                    delete[] lut;
                }
            }
        }
    }

    /** perform rescale slope/intercept transform
     *
     ** @param  input      pointer to input pixel representation
     *  @param  slope      rescale slope value (optional)
     *  @param  intercept  rescale intercept value (optional)
     */
    void rescale(DiInputPixel *input,
                 const double slope = 1.0,
                 const double intercept = 0.0)
    {
        const T1 *pixel = OFstatic_cast(const T1 *, input->getData());
        if (pixel != NULL)
        {
            const int useInputBuffer = (sizeof(T1) == sizeof(T3)) && (this->Count <= input->getCount()) && (input->getPixelStart() == 0);
            if (useInputBuffer)
            {                                              // do not copy pixel data, reference them!
                DCMIMGLE_DEBUG("re-using input buffer, do not copy pixel data");
                this->Data = OFstatic_cast(T3 *, input->getDataPtr());
                input->removeDataReference();              // avoid double deletion
            } else
                this->Data = new T3[this->Count];
            if (this->Data != NULL)
            {
                T3 *q = this->Data;
                unsigned long i;
                if ((slope == 1.0) && (intercept == 0.0))
                {
                    if (!useInputBuffer)
                    {
                        DCMIMGLE_DEBUG("copying pixel data from input buffer");
                        const T1 *p = pixel + input->getPixelStart();
                        for (i = this->InputCount; i != 0; --i)   // copy pixel data: can't use copyMem because T1 isn't always equal to T3
                            *(q++) = OFstatic_cast(T3, *(p++));
                    }
                } else {
                    DCMIMGLE_DEBUG("applying modality transformation with rescale slope = " << slope << ", intercept = " << intercept);
                    T3 *lut = NULL;
                    const T1 *p = pixel + input->getPixelStart();
                    const unsigned long ocnt = OFstatic_cast(unsigned long, input->getAbsMaxRange());  // number of LUT entries
                    if (initOptimizationLUT(lut, ocnt))
                    {                                                                     // use LUT for optimization
                        const double absmin = input->getAbsMinimum();
                        q = lut;
                        if (slope == 1.0)
                        {
                            for (i = 0; i < ocnt; ++i)                                    // calculating LUT entries
                                *(q++) = OFstatic_cast(T3, OFstatic_cast(double, i) + absmin + intercept);
                        } else {
                            if (intercept == 0.0)
                            {
                                for (i = 0; i < ocnt; ++i)
                                    *(q++) = OFstatic_cast(T3, (OFstatic_cast(double, i) + absmin) * slope);
                            } else {
                                for (i = 0; i < ocnt; ++i)
                                    *(q++) = OFstatic_cast(T3, (OFstatic_cast(double, i) + absmin) * slope + intercept);
                            }
                        }
                        const T3 *lut0 = lut - OFstatic_cast(T2, absmin);                 // points to 'zero' entry
                        q = this->Data;
                        for (i = this->InputCount; i != 0; --i)                           // apply LUT
                            *(q++) = *(lut0 + (*(p++)));
                    }
                    if (lut == NULL)                                                      // use "normal" transformation
                    {
                        if (slope == 1.0)
                        {
                            for (i = this->InputCount; i != 0; --i)
                                *(q++) = OFstatic_cast(T3, OFstatic_cast(double, *(p++)) + intercept);
                        } else {
                            if (intercept == 0.0)
                            {
                                for (i = this->InputCount; i != 0; --i)
                                    *(q++) = OFstatic_cast(T3, OFstatic_cast(double, *(p++)) * slope);
                            } else {
                                for (i = this->InputCount; i != 0; --i)
                                    *(q++) = OFstatic_cast(T3, OFstatic_cast(double, *(p++)) * slope + intercept);
                            }
                        }
                    }
                    delete[] lut;
                }
            }
        }
    }
};


#endif
