fpclass_t
fpclass(double x)
{
int sign, exp;
exp = EXPONENT(x);
sign = SIGNBIT(x);
if (exp == 0) { /* de-normal or zero */
if (HIFRACTION(x) || LOFRACTION(x)) /* de-normal */
return (sign ? FP_NDENORM : FP_PDENORM);
else
return (sign ? FP_NZERO : FP_PZERO);
}
if (exp == MAXEXP) { /* infinity or NaN */
if ((HIFRACTION(x) == 0) && (LOFRACTION(x) == 0)) /* infinity */
return (sign ? FP_NINF : FP_PINF);
else
if (QNANBIT(x))
/* hi-bit of mantissa set - quiet nan */
return (FP_QNAN);
else return (FP_SNAN);
}
/* if we reach here we have non-zero normalized number */
return (sign ? FP_NNORM : FP_PNORM);
}
int *iota(int start, int stop, int step){
if(stop == 0 && step == 0){
stop = start;
start = 0;
}
if(step == 0){
step = SIGNBIT(stop - start);
}
int count = (stop-start)/step;
int *ret = xmalloc(count*sizeof(int));
int i, x;
for(i = 0, x = start; i<count; i++, x += step){
ret[i] = x;
}
return ret;
}
int f_mult(int An, int SRn)
{
register int EXP;
register int WAnMANT;
int AnS, MAG, AnMANT;
AnS = SIGNBIT(An, 15);
MAG = AnS? (16384 - (An >> 2)) & 8191 : An >> 2;
/* {
register int mag = MAG << 1;
for (EXP = 0; mag >>= 1; EXP++)
;
} */
AnMANT = MAG ? LSHIFT(MAG, EXP - 6) : 1 << 5;
EXP += ((SRn >> 6) & 15);
WAnMANT = (((SRn & 63) * AnMANT) + 48) >> 4;
MAG = LSHIFT(WAnMANT, 19 - EXP) & 32767;
return ((SRn >> 10) ^ AnS ? (65536 - MAG) & 65535 : MAG);
}
REAL Vec2::angle() const
{
Vec2 n=this->normal();
REAL angle=ACOS(n.x);
return SETSIGN(angle,SIGNBIT(n.y));
}