// Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// which accompanies this distribution, and is available

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// e32\euser\maths\um_rand.cpp

// 

//

#include "um_std.h"

EXPORT_C TInt Math::Rand(TInt64 &aSeed)

/**

Generates a stream of uniformly distributed pseudo-random integers

in the range, 0 to KMaxTInt.

For each stream of pseudo-random numbers you wish to generate, you should

pass the reference to the same 64-bit seed on each call to this function.

You should not change the seed between calls.

@param aSeed A reference to a 64-bit seed, which is updated

             as a result of the call.

@return The next pseudo-random number in the sequence. 

*/

	{

	aSeed*=214013;

    aSeed+=2531011;

    return(((TInt)(aSeed>>16))&0x7fffffff);

	}

EXPORT_C TReal Math::FRand(TInt64& aSeed) __SOFTFP

/**

Generates a stream of uniformly distributed pseudo-random real numbers

in the range, 0 to 1.

@param aSeed A reference to a 64-bit seed, which is updated

             as a result of the call.

@return The next pseudo-random number in the sequence. 

*/

	{

	TUint low = (TUint)Math::Rand(aSeed);

	TUint high = (TUint)Math::Rand(aSeed)&0x7FFFFFFF;	// make sure TInt64 is positive

	TRealX f((static_cast<TInt64>(high) << 32) | low);	// construct TRealX 0<=f<2^63

	if (f.iExp)

		f.iExp-=63;						// Scale f to range 0<=f<1

    return(TReal(f));

	}