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

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of the License "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:

 //

 // Description:

 // e32\euser\maths\um_sin.cpp

 // Floating point sine and cosine functions

 // 

 //

 #include "um_std.h"

 #if defined(__USE_VFP_MATH) && !defined(__CPU_HAS_VFP)

 #error	__USE_VFP_MATH was defined but not __CPU_HAS_VFP - impossible combination, check variant.mmh 

 #endif

 #ifndef __USE_VFP_MATH

 LOCAL_D const TUint32 SinCoeffs[] =

 	{

 	0x2168C235,0xC90FDAA2,0x80000000,	// polynomial approximation to sin(pi*x)

 	0x2DF200BF,0xA55DE731,0x80010001,	// for |x| <= 0.25

 	0xAC273AA1,0xA335E33B,0x80000000,

 	0x5AB23F44,0x99696671,0x7FFE0001,

 	0xD585EAFE,0xA83C17D9,0x7FFB0000,

 	0xA30DE7AD,0xF1802BAC,0x7FF70001,

 	0xF57FD821,0xF1F6A1C9,0x7FF30000

 	};

 LOCAL_D const TUint32 CosCoeffs[] =

 	{

 	0x00000000,0x80000000,0x7FFF0000,	// polynomial approximation to cos(pi*x)

 	0xF22EF286,0x9DE9E64D,0x80010001,	// for |x| <= 0.25

 	0xDAD59F90,0x81E0F840,0x80010000,

 	0xE4E45144,0xAAE9E3F1,0x7FFF0001,

 	0x3232D733,0xF0FA8342,0x7FFC0000,

 	0x03E16BB8,0xD368F6A3,0x7FF90001,

 	0x712FD084,0xFCE66DE2,0x7FF50000,

 	0x9E5353EE,0xD94951B0,0x7FF10001

 	};

 LOCAL_D const TUint32 PiInvdata[] = {0x4E44152A,0xA2F9836E,0x7FFD0000};			// 1/pi

 LOCAL_D const TUint32 Halfdata[] = {0x00000000,0x80000000,0x7FFE0000};			// 0.5

 LOCAL_D const TUint32 Onedata[] = {0x00000000,0x80000000,0x7FFF0000};			// 1.0

 LOCAL_C TInt CalcSinCos(TReal& aTrg, TRealX& aSrc, TBool aCos)

 	{

 	// Calculate sin(aSrc) if aCos=false or cos(aSrc) if aCos=true

 	// and write result to aTrg.

 	// Algorithm:

 	//		Divide aSrc by pi and throw away integer part, but change sign

 	//			of result if integer part odd. Replace aSrc with remainder.

 	//			( use identities	sin(x+n*pi)=(-1)^n*sin(x)

 	//								cos(x+n*pi)=(-1)^n*cos(x) )

 	//		If aSrc>=0.5 replace aSrc with 1-aSrc, and change sign of result

 	//			if cos required.

 	//			( use identities sin(pi-x)=sin(x), cos(pi-x)=-cos(x) )

 	//		If aSrc>=0.25 replace aSrc with 0.5-aSrc and swap sin and cos

 	//			( use identities sin(pi/2-x)=cos(x), cos(pi/2-x)=sin(x) )

 	//		Use polynomial approximation to evaluate sin(pi*x) or cos(pi*x)

 	//		for |x|<=0.25

 	const TRealX& One = *(const TRealX*)Onedata;

 	const TRealX& Half = *(const TRealX*)Halfdata;

 	const TRealX& PiInv = *(const TRealX*)PiInvdata;

 	TRealX y;

 	aSrc*=PiInv;

 	TInt n=(TInt)aSrc;

 	if (n<KMaxTInt && n>KMinTInt)

 		{

 		aSrc-=TRealX(n);

 		TInt sign=0;

 		if (!aCos)

 			sign=aSrc.iSign & 1;

 		sign^=n;

 		aSrc.iSign=0;

 		if (aSrc.iExp>=0x7FFE)			// if remainder>=pi/2

 			{

 			aSrc=One-aSrc;

 			if (aCos)

 				sign^=1;

 			}

 		if (aSrc.iExp>=0x7FFD)			// if remainder>=pi/4

 			{

 			aSrc=Half-aSrc;				// take complementary angle

 			aCos=!aCos;					// and swap sin and cos

 			}

 		if (aCos)

 			Math::PolyX(y,aSrc*aSrc,7,(const TRealX*)CosCoeffs);

 		else

 			{

 			Math::PolyX(y,aSrc*aSrc,6,(const TRealX*)SinCoeffs);

 			y*=aSrc;

 			}

 		if (sign & 1)

 			y=-y;

 		return y.GetTReal(aTrg);

 		}

 	return KErrArgument;

 	}

 EXPORT_C TInt Math::Sin(TReal& aTrg, const TReal& aSrc)

 /**

 Calculates the sine of a number.

 @param aTrg A reference containing the result. 

 @param aSrc The argument of the sin function in radians.

 @return KErrNone if successful, otherwise another of

         the system-wide error codes.

 */

 	{

 	TRealX x;

 	TInt r=x.Set(aSrc);

 	if (r==KErrNone)

 		r=CalcSinCos(aTrg,x,EFalse);

 	if (r==KErrNone)

 		return r;

 	SetNaN(aTrg);

 	return KErrArgument;

 	}

 EXPORT_C TInt Math::Cos(TReal& aTrg, const TReal& aSrc)

 /**

 Calculates the cosine of a number.

 @param aTrg A reference containing the result. 

 @param aSrc The argument of the cos function in radians

 @return KErrNone if successful, otherwise another of

         the system-wide error codes.

 */

 	{

 	TRealX x;

 	TInt r=x.Set(aSrc);

 	if (r==KErrNone)

 		r=CalcSinCos(aTrg,x,ETrue);

 	if (r==KErrNone)

 		return r;

 	SetNaN(aTrg);

 	return KErrArgument;

 	}

 #else // __USE_VFP_MATH

 // definitions come from RVCT math library

 extern "C" TReal sin(TReal);

 extern "C" TReal cos(TReal);

 EXPORT_C TInt Math::Sin(TReal& aTrg, const TReal& aSrc)

 	{

 	if (aSrc<KMaxTInt && aSrc>KMinTInt)

 		{

 		aTrg = sin(aSrc);

 		if (Math::IsFinite(aTrg))

 			return KErrNone;

 		}

 	SetNaN(aTrg);

 	return KErrArgument;

 	}

 EXPORT_C TInt Math::Cos(TReal& aTrg, const TReal& aSrc)

 	{

 	if (aSrc<KMaxTInt && aSrc>KMinTInt)

 		{

 		aTrg = cos(aSrc);

 		if (Math::IsFinite(aTrg))

 			return KErrNone;

 		}

 	SetNaN(aTrg);

 	return KErrArgument;

 	}

 #endif