#ifndef __RESAMPLER_CLIP_H__

#define __RESAMPLER_CLIP_H__

/*

* Copyright (c) 2010 Ixonos Plc.

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - Initial contribution

*

* Contributors:

* Ixonos Plc

*

* Description:

*

*/

#include "resampler_common_defs.h"

#include "resampler_data_types.h"

#include <stdlib.h>

#ifdef __cplusplus

extern "C" {

#endif

/** @file 

  @ingroup common_dsp

  Helper functions to limit output to different numerical ranges.

  The header file 'resampler_clip.h' contains helper (inline) functions for 

  limiting the input to a specified numerical range, or more specifically,

  to a specified number of bits. These functions are especially useful in 

  fixed point DSP units for limiting the output range.

*/

/** Clip function for signed 16-bit integer range.

  This function limits its input to the range -32768 <= output <= 32767.

  The implementation uses the traditional conditionals to check for 

  overflows..

*/

static FORCEINLINE int32 RESAMPLER_Clip16(int32 input)

{

    input = input < (-32768) ? (-32768) : input;

    input = input > 32767 ?  32767 : input;

    return input;

}

/** Shift-and-Clip function for signed 16-bit integer range.

  This function limits its input to the range -32768 <= output <= 32767

  after first shifting the input to the right by the given number of bits.

*/

static FORCEINLINE int32 RESAMPLER_RightShiftAndClip16(int32 input, int rightShift)

{

    input = input >> rightShift;

    return RESAMPLER_Clip16(input);

}

/** Shift-round-and-clip function for signed 16-bit integer range.

  This function limits its input to the range -32768 <= output <= 32767

  after first shifting the input to the right by the given number of bits

  with rounding.

*/

static FORCEINLINE int32 RESAMPLER_RightShiftRoundAndClip16(int32 input, int rightShift)

{

    if (rightShift > 0)

    {

        input += (int32)1 << (rightShift - 1);

    }

    input = input >> rightShift;

    return RESAMPLER_Clip16(input);

}

/** Saturated 16-bit absolute value.

  This function calculates a saturated 16-bit output value from a 16-bit 

  input RESAMPLER_AbsAndClip16(0x8000) => 0x7FFF.

*/

static FORCEINLINE int16 RESAMPLER_AbsSaturate16(int16 input)

{

    return (int16)RESAMPLER_Clip16(labs((long)input));

}

/** Saturated addition of two 16-bit values.

*/

static FORCEINLINE int16 RESAMPLER_AddSaturate16(int16 input1, int16 input2)

{

    return (int16)RESAMPLER_Clip16((int32)input1 + input2);

}

/** Saturated subtraction of two 16-bit values.

*/

static FORCEINLINE int16 RESAMPLER_SubSaturate16(int16 input1, int16 input2)

{

    return (int16)RESAMPLER_Clip16((int32)input1 - input2);

}

/** Saturated addition of two 32-bit values.

*/

static FORCEINLINE int32 RESAMPLER_AddSaturate32(int32 input1, int32 input2)

{

    /* int40 is the shortest "long long" available on all 

     * the current platforms 

     */

    int40 res = input1;

    res += input2;

    if (res > (int40)(2147483647L))

    {

        res = (int40)(2147483647L);

    }

    if (res < (int40)(-2147483647L - 1))

    {

        res = (int40)(-2147483647L - 1);

    }

    return (int32)res;

}

/** Saturated subtraction of two 32-bit values.

*/

static FORCEINLINE int32 RESAMPLER_SubSaturate32(int32 input1, int32 input2)

{

    int40 res = input1;

    res -= input2;

    if (res > (int40)(2147483647L))

    {

        res = (int40)(2147483647L);

    }

    if (res < (int40)(-2147483647L - 1))

    {

        res = (int40)(-2147483647L - 1);

    }

    return (int32)res;

}

#ifdef __cplusplus

}

#endif

#endif  /* __RESAMPLER_CLIP_H__ */