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 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 * 
 * Copyright 2008 by Sun Microsystems, Inc.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * $RCSfile: mcvmath.cxx,v $
 * $Revision: 1.5 $
 *
 * This file is part of OpenOffice.org.
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 * it under the terms of the GNU Lesser General Public License version 3
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
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 ************************************************************************/

// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_svtools.hxx"

#include <mcvmath.hxx>

// ---------------------------------------------------------------------
// die folgenden Tabellen enthalten     sin(phi) * 2**14
// fuer phi= 360Grad*2**-32 bis 360 Grad
// def. fuer x: phi=360Grad * 2**(x-16)
//           d.h. x =  16 -> 360 Grad
//                x = -16 -> (2**-16) * 360 Grad
//         x:         -16 ... 0 ... 15
//x=    0,     1,     2,     3,     4,     5,     6,      7,
//      8,     9,    10,    11,    12,    13,    14,     15

static const short CosTab[16] =
{
	16384, 16384, 16384, 16384, 16384, 16384, 16384,  16383,
	16379, 16364, 16305, 16069, 15137, 11585,     0, -16383
};
static const short SinTab[16]=
{
		2,     3,      6,    13,    25,     50,   101,  201,
	  402,   804,   1606,  3196,  6270,  11585, 16384,    0
};

/**************************************************************************
|*
|*    ImpMultBig2()
|*
|*    Beschreibung       Multiplikation fuer FixPoint-Berechnungen
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

//  first parameter should be the bigger one

Fix ImpMultBig2( const Fix& a, const Fix& b )
{
	Fix f;
	f.x = (((b.x+FIX_A2)>>FIX_P2)*a.x+FIX_A3)>>FIX_P3;
	return f;
}

/**************************************************************************
|*
|*    ImpMultBig2()
|*
|*    Beschreibung       Multiplikation fuer FixPoint-Berechnungen
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

//  first parameter should be the bigger one

FixCpx ImpMultBig2( const FixCpx& ra, const FixCpx& rb )
{
	Fix rr = ImpMultBig2(ra.r,rb.r)-ImpMultBig2(ra.i,rb.i);
	Fix ii = ImpMultBig2(ra.r,rb.i)+ImpMultBig2(ra.i,rb.r);
	return FixCpx( rr,ii );
}

/**************************************************************************
|*
|*    ImpSqrt()
|*
|*    Beschreibung       Wurzelfunktion fuer FixPoint-Berechnungen
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

USHORT ImpSqrt( ULONG nRadi )
{
	register ULONG  inf = 1;
	register ULONG  sup = nRadi;
	register ULONG sqr;

	if ( !nRadi )
		return 0;

	while ( (inf<<1) <= sup )
	{
		sup >>= 1;
		inf <<= 1;
	}
	sqr = (sup+inf) >> 1;               // Anfangswert der Iteration

	sqr = (nRadi/sqr + sqr) >> 1;       // 2 Newton-Iterationen reichen fuer
	sqr = (nRadi/sqr + sqr) >> 1;       // +- 1 Digit

	return sal::static_int_cast< USHORT >(sqr);
}

/**************************************************************************
|*
|*    ImpExPI()
|*
|*    Beschreibung       EXPI-Funktion fuer FixPoint-Berechnungen
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

// e**(i*nPhi), Einheit nPhi: 2**16 == 360 Grad

FixCpx ImpExPI( USHORT nPhi )
{
	short i;
	FixCpx aIter(1L);                   // e**(0*i)
	FixCpx Mul;
	const char Sft=14-FIX_POST;

	for ( i = 15; i >= 0; i-- )
	{
		if ( (1L<<i) & nPhi )
		{
			Mul.r.x = CosTab[i]>>Sft;   // e**(i(phi1+phi2)) =
			Mul.i.x = SinTab[i]>>Sft;   // e**(i*phi1)) * e**(i*phi2))
			aIter  *= Mul;
		}
	}

	return aIter;
}

/**************************************************************************
|*
|*    ImpATanx2()
|*
|*    Beschreibung       ATANX2-Funktion fuer FixPoint-Berechnungen
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

// use for x*x+y*y==1 only

static USHORT ImpATanx2( const Fix& rX, const Fix& rY )
{
	USHORT      phi0 = 0;           // result angel higher part
	USHORT      phi = 0;            // dito lower part
	long        x = rX.x;
	long        y = rY.x;
	long        z;
	const char  Sft=14-FIX_POST;
	short       i;
	FixCpx      aTry;
	FixCpx      aInc;
	FixCpx      aIter(1L);
	BOOL        Small = FALSE;

	if ( (x==0) && (y==0) )
		return 0;

	if ( y < 0)
	{
		// reduce 3. to 1. quadrant (0..90 Degree)
		phi0 += 180L * 65536L / 360L;
		// turn 180 degree
		y    *= -1;
		x    *= -1;
	}

	if ( x < 0)
	{
		// 2. to 1. q.
		phi0 += 90L * 65536L / 360L;
		// turn 90 degree clockwise
		z = y;
		y = -x;
		x = z;
	}

	for ( i = 13; i >= 0; i-- )
	{
		aInc.r.x = CosTab[i]>>Sft; // e**(i(phi1+phi2)) =
		aInc.i.x = SinTab[i]>>Sft; // e**(i*phi1)) * e**(i*phi2))
		aTry     = aIter*aInc;

		if ( Small )
		{
			// is try ok
		   if ( aTry.r.x >= x )
		   {
				aIter =  aTry;
				phi   += (1<<i);
			}
		}
		else
		{
			// is try ok
			if ( aTry.i.x <= y )
			{
				aIter = aTry;
				phi  += (1<<i);

				if ( i > 11 )
					Small=TRUE;
			}
		}
	}

	return phi0+phi;
}

/**************************************************************************
|*
|*    ImpATan2()
|*
|*    Beschreibung       ATAN-Funktion fuer FixPoint-Berechnungen
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

USHORT ImpATan2( const short x, const short y )
{
	Fix rRad = ImpSqrt(ULONG(long(x)*x+long(y)*y));

	if ( !rRad.x )
		return 0;
	Fix fx = x;
	fx.DivBig( rRad );            // Normiere auf Einheitskreis
	Fix fy = y;
	fy.DivBig( rRad );

	return ImpATanx2( fx, fy );
}

/**************************************************************************
|*
|*    ImpCartToPolar()
|*
|*    Beschreibung       Koordinaaten-Wandlung
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

void ImpCartToPolar( const short x, const short y, Fix& rRad, USHORT& rPhi )
{
	rRad = Fix( ImpSqrt( ULONG( long(x)*x+long(y)*y ) ) );

	if ( !rRad.x )
		rPhi=0;
	else
	{
		// Normiere auf Einheitskreis
		Fix fx = x;
		fx.DivBig(rRad);
		Fix fy = y;
		fy.DivBig(rRad);
		rPhi = ImpATanx2(fx, fy);
	}
}

/**************************************************************************
|*
|*    ImpPolarToCart()
|*
|*    Beschreibung       Koordinaaten-Wandlung
|*    Ersterstellung     SH 01.07.93
|*    Letzte Aenderung   SH 01.07.93
|*
**************************************************************************/

void ImpPolarToCart( const Fix& rR, const USHORT Phi, short& rX, short& rY )
{
	FixCpx fc = ImpExPI( Phi );  // calculate sin() & cos()
	fc.GetReal().MultBig( rR );
	rX = sal::static_int_cast< short >(long( fc.GetReal() ));
	fc.GetImag().MultBig( rR );
	rY = sal::static_int_cast< short >(long( fc.GetImag() ));
}

