///////////////////////////////////////////////////////////////////////////

//

// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas

// Digital Ltd. LLC

// 

// 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 Industrial Light & Magic 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 AND CONTRIBUTORS

// "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.

//

///////////////////////////////////////////////////////////////////////////

//-----------------------------------------------------------------------------

//

//	Routines for converting between pixel data types,

//	with well-defined behavior for exceptional cases.

//

//-----------------------------------------------------------------------------

#include "ImfConvert.h"

#include "ImfNamespace.h"

#include <limits.h>

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_ENTER

namespace {

inline bool

isNegative (float f)

{

    union {float f; int i;} u;

    u.f = f;

    return (u.i & 0x80000000) != 0;

}

inline bool

isNan (float f)

{

    union {float f; int i;} u;

    u.f = f;

    return (u.i & 0x7fffffff) > 0x7f800000;

}

inline bool

isInfinity (float f)

{

    union {float f; int i;} u;

    u.f = f;

    return (u.i & 0x7fffffff) == 0x7f800000;

}

inline bool

isFinite (float f)

{

    union {float f; int i;} u;

    u.f = f;

    return (u.i & 0x7f800000) != 0x7f800000;

}

} // namespace

unsigned int

halfToUint (half h)

{

    if (h.isNegative() || h.isNan())

	return 0;

    if (h.isInfinity())

	return UINT_MAX;

    return (unsigned int) h;

}

unsigned int

floatToUint (float f)

{

    if (isNegative (f) || isNan (f))

	return 0;

    if (isInfinity (f) || f > UINT_MAX)

	return UINT_MAX;

    return (unsigned int) f;

}

half	

uintToHalf (unsigned int ui)

{

    if (ui >  HALF_MAX)

	return half::posInf();

    return half ((float) ui);

}

half	

floatToHalf (float f)

{

    if (isFinite (f))

    {

	if (f >  HALF_MAX)

	    return half::posInf();

	if (f < -HALF_MAX)

	    return half::negInf();

    }

    return half (f);

}

OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_EXIT