ref: 8fa6f230775bf0c036441bf7d5d941e2312709dc
dir: /LEAF/Externals/trigtbl.h/
/*
** Please only distribute this with it's associated FHT routine.
** This algorithm is apparently patented(!) and the code copyrighted.
** See the comment with the fht routine for more info.
** -Thanks,
** Ron Mayer
*/
#ifdef __cplusplus
extern "C" {
#endif
#ifdef REAL
#else
#define REAL double
#endif
#ifdef GOOD_TRIG
#else
#define FAST_TRIG
#endif
#if defined(GOOD_TRIG)
#define FHT_SWAP(a,b,t) {(t)=(a);(a)=(b);(b)=(t);}
#define TRIG_VARS \
int t_lam=0;
#define TRIG_INIT(k,c,s) \
{ \
int i; \
for (i=2 ; i<=k ; i++) \
{coswrk[i]=costab[i];sinwrk[i]=sintab[i];} \
t_lam = 0; \
c = 1; \
s = 0; \
}
#define TRIG_NEXT(k,c,s) \
{ \
int i,j; \
(t_lam)++; \
for (i=0 ; !((1<<i)&t_lam) ; i++); \
i = k-i; \
s = sinwrk[i]; \
c = coswrk[i]; \
if (i>1) \
{ \
for (j=k-i+2 ; (1<<j)&t_lam ; j++); \
j = k - j; \
sinwrk[i] = halsec[i] * (sinwrk[i-1] + sinwrk[j]); \
coswrk[i] = halsec[i] * (coswrk[i-1] + coswrk[j]); \
} \
}
#define TRIG_RESET(k,c,s)
#endif
#if defined(FAST_TRIG)
#define TRIG_VARS \
REAL t_c,t_s;
#define TRIG_INIT(k,c,s) \
{ \
t_c = costab[k]; \
t_s = sintab[k]; \
c = 1; \
s = 0; \
}
#define TRIG_NEXT(k,c,s) \
{ \
REAL t = c; \
c = t*t_c - s*t_s; \
s = t*t_s + s*t_c; \
}
#define TRIG_RESET(k,c,s)
#endif
static REAL halsec[20]=
{
0,
0,
.54119610014619698439972320536638942006107206337801,
.50979557910415916894193980398784391368261849190893,
.50241928618815570551167011928012092247859337193963,
.50060299823519630134550410676638239611758632599591,
.50015063602065098821477101271097658495974913010340,
.50003765191554772296778139077905492847503165398345,
.50000941253588775676512870469186533538523133757983,
.50000235310628608051401267171204408939326297376426,
.50000058827484117879868526730916804925780637276181,
.50000014706860214875463798283871198206179118093251,
.50000003676714377807315864400643020315103490883972,
.50000000919178552207366560348853455333939112569380,
.50000000229794635411562887767906868558991922348920,
.50000000057448658687873302235147272458812263401372
};
static REAL costab[20]=
{
.00000000000000000000000000000000000000000000000000,
.70710678118654752440084436210484903928483593768847,
.92387953251128675612818318939678828682241662586364,
.98078528040323044912618223613423903697393373089333,
.99518472667219688624483695310947992157547486872985,
.99879545620517239271477160475910069444320361470461,
.99969881869620422011576564966617219685006108125772,
.99992470183914454092164649119638322435060646880221,
.99998117528260114265699043772856771617391725094433,
.99999529380957617151158012570011989955298763362218,
.99999882345170190992902571017152601904826792288976,
.99999970586288221916022821773876567711626389934930,
.99999992646571785114473148070738785694820115568892,
.99999998161642929380834691540290971450507605124278,
.99999999540410731289097193313960614895889430318945,
.99999999885102682756267330779455410840053741619428
};
static REAL sintab[20]=
{
1.0000000000000000000000000000000000000000000000000,
.70710678118654752440084436210484903928483593768846,
.38268343236508977172845998403039886676134456248561,
.19509032201612826784828486847702224092769161775195,
.09801714032956060199419556388864184586113667316749,
.04906767432741801425495497694268265831474536302574,
.02454122852291228803173452945928292506546611923944,
.01227153828571992607940826195100321214037231959176,
.00613588464915447535964023459037258091705788631738,
.00306795676296597627014536549091984251894461021344,
.00153398018628476561230369715026407907995486457522,
.00076699031874270452693856835794857664314091945205,
.00038349518757139558907246168118138126339502603495,
.00019174759731070330743990956198900093346887403385,
.00009587379909597734587051721097647635118706561284,
.00004793689960306688454900399049465887274686668768
};
static REAL coswrk[20]=
{
.00000000000000000000000000000000000000000000000000,
.70710678118654752440084436210484903928483593768847,
.92387953251128675612818318939678828682241662586364,
.98078528040323044912618223613423903697393373089333,
.99518472667219688624483695310947992157547486872985,
.99879545620517239271477160475910069444320361470461,
.99969881869620422011576564966617219685006108125772,
.99992470183914454092164649119638322435060646880221,
.99998117528260114265699043772856771617391725094433,
.99999529380957617151158012570011989955298763362218,
.99999882345170190992902571017152601904826792288976,
.99999970586288221916022821773876567711626389934930,
.99999992646571785114473148070738785694820115568892,
.99999998161642929380834691540290971450507605124278,
.99999999540410731289097193313960614895889430318945,
.99999999885102682756267330779455410840053741619428
};
static REAL sinwrk[20]=
{
1.0000000000000000000000000000000000000000000000000,
.70710678118654752440084436210484903928483593768846,
.38268343236508977172845998403039886676134456248561,
.19509032201612826784828486847702224092769161775195,
.09801714032956060199419556388864184586113667316749,
.04906767432741801425495497694268265831474536302574,
.02454122852291228803173452945928292506546611923944,
.01227153828571992607940826195100321214037231959176,
.00613588464915447535964023459037258091705788631738,
.00306795676296597627014536549091984251894461021344,
.00153398018628476561230369715026407907995486457522,
.00076699031874270452693856835794857664314091945205,
.00038349518757139558907246168118138126339502603495,
.00019174759731070330743990956198900093346887403385,
.00009587379909597734587051721097647635118706561284,
.00004793689960306688454900399049465887274686668768
};
#ifdef __cplusplus
}
#endif