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

//

// 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,

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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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

#ifndef INCLUDED_IEXMATHFLOATEXC_H

#define INCLUDED_IEXMATHFLOATEXC_H

#ifndef IEXMATH_EXPORT_H

#define IEXMATH_EXPORT_H

#if defined(OPENEXR_DLL)

    #if defined(IEX_EXPORTS)

    #define IEXMATH_EXPORT __declspec(dllexport)

    #else

    #define IEXMATH_EXPORT __declspec(dllimport)

    #endif

    #define IEXMATH_EXPORT_CONST

#else

    #define IEXMATH_EXPORT

    #define IEXMATH_EXPORT_CONST const

#endif

#endif

#include "IexNamespace.h"

#include "IexMathExc.h"

//#include <IexBaseExc.h>

#include "IexMathIeeeExc.h"

IEX_INTERNAL_NAMESPACE_HEADER_ENTER

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

// Function mathExcOn() defines which floating point exceptions

// will be trapped and converted to C++ exceptions.

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

IEXMATH_EXPORT

void mathExcOn (int when = (IEEE_OVERFLOW | IEEE_DIVZERO | IEEE_INVALID));

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

// Function getMathExcOn() tells you for which floating point exceptions

// trapping and conversion to C++ exceptions is currently enabled.

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

IEXMATH_EXPORT

int getMathExcOn();

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

// A classs that temporarily sets floating point exception trapping

// and conversion, and later restores the previous settings.

//

// Example:

//

//	float

//	trickyComputation (float x)

//	{

//	    MathExcOn meo (0);		// temporarily disable floating

//	    				// point exception trapping

//

//	    float result = ...;		// computation which may cause

//	    				// floating point exceptions

//

//	    return result;		// destruction of meo restores

//	}				// the program's previous floating

//					// point exception settings

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

class IEXMATH_EXPORT MathExcOn

{

  public:

    MathExcOn (int when)

	:

	_changed (false)

    {

	_saved = getMathExcOn(); 

	if (_saved != when)

	{

	    _changed = true;

	    mathExcOn (when);

	}

    }

    ~MathExcOn ()

    {

	if (_changed)

	    mathExcOn (_saved);

    }

    // It is possible for functions to set the exception registers

    // yet not trigger a SIGFPE.  Specifically, the implementation

    // of pow(x, y) we're using can generates a NaN from a negative x

    // and fractional y but a SIGFPE is not generated.

    // This function examimes the exception registers and calls the

    // fpHandler if those registers modulo the exception mask are set.

    // It should be called wherever this class is commonly used where it has

    // been found that certain floating point exceptions are not being thrown.

    void handleOutstandingExceptions();

  private:

    bool                        _changed;

    int				_saved;

};

IEX_INTERNAL_NAMESPACE_HEADER_EXIT

#endif