ba237a9d91
Files correlati : Ricompilazione Demo : [ ] Commento : Aggiunti i sorgenti per Greenleaf Math Library (gfm.dll) git-svn-id: svn://10.65.10.50/trunk@10079 c028cbd2-c16b-5b4b-a496-9718f37d4682
81 lines
1.5 KiB
C
Executable File
81 lines
1.5 KiB
C
Executable File
/* DEC *ArcCosineDecimal(pDst,pSrc)
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*
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* ARGUMENT
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* DEC *pDst;
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* DEC *pSrc;
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*
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* DESCRIPTION
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* Sets pDst = the arccosine (in radians) of pSrc,
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* which always lies between 0 and pi
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*
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* RETURNS
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* Returns pointer to pDst if successful, otherwise a GM_NULL.
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*
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* POSSIBLE ERROR CODES
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*
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* GM_NULLPOINTER
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* GM_IMAG if | pSrc | > 1
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*
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* AUTHOR
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* Jared Levy Aug 7, 1987
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* Copyright (C) 1987-1990 Greenleaf Software Inc. All rights reserved.
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*
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* MODIFICATIONS
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*
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*/
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#include <stdio.h>
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#include "gm.h"
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#include "gmsystem.h"
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DEC *ArcCosineDecimal(pDst,pSrc)
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DEC *pDst;
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DEC *pSrc;
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{
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int isn = 0;
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DEC *nsrc, dnsrc, *temp1, dtemp1, *temp2, dtemp2;
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DEC *temp3, dtemp3, *temp4, dtemp4;
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_MacStart(GM_DACOS);
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_MacInVar(pSrc,GM_NULL);
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_MacOutVar(pDst,GM_NULL);
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nsrc = &dnsrc;
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_MacDCopy(nsrc, pSrc);
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if (_MacIsDecN(nsrc)) {
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isn = 1;
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_MacDChgs(nsrc);
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}
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if ((CompareDecimal(nsrc,&decOne)) == 1) {
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_MacErr(GM_IMAG);
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_MacRet(GM_NULL);
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}
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if (_MacIsDecZ(pSrc)) {
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_MacDCopy(pDst,&decPiOver2);
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_MacRet(pDst);
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}
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(void) _MulDec80Bit(temp1= &dtemp1, nsrc, nsrc);
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(void) _SubDec80Bit(temp2= &dtemp2, &decOne, temp1);
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_SqrtDec80Bit(temp3=&dtemp3, temp2);
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if (_MacIsDecZ(temp3)) /* arcsin(1) = pi/2 */
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{_MacDZero(pDst);}
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else {
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(void) _DivDec80Bit(temp4=&dtemp4, temp3, nsrc);
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_ATanDec80Bit(pDst, temp4);
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}
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if (isn)
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(void) _SubDec80Bit(pDst, &decPi, pDst);
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/* reduce from 80-bit back to 64-bit */
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(void) _Sq5UnsTo4Uns(pDst);
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_MacRet(pDst);
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}
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