/*
** initialize the global tolerance
** should be called only once at the beginning of the program
*/
void
T_initdefault()
{
static int called_before = 0;
if (called_before)
{
Z_fatal("T_initdefault called more than once\n");
}
/*
** if the default tolerance was set somewhere else
** don't set it here
*/
if (T_isnull(_T_gtol))
{
T_defatol(_T_ADEF);
T_defrtol(_T_RDEF);
}
called_before = 1;
}
/*
** compare two F_floats using a tolerance
*/
static int
_X_floatdiff(F_float p1,F_float p2,T_tol the_tol)
{
F_float diff, float_tmp;
T_tol tol_tmp;
/*
** check for null tolerance list
*/
if (T_isnull(the_tol))
{
Z_fatal("_X_floatdiff called with a null tolerance");
}
/*
** look for an easy answer. i.e -- check
** to see if any of the tolerances are of type T_IGNORE
** or if the numbers are too small to exceed an absolute
** tolerance.
** if so, return immediately
*/
for(tol_tmp=the_tol; !(T_isnull(tol_tmp)) ;tol_tmp=T_getnext(tol_tmp))
{
if ((T_IGNORE == T_gettype(tol_tmp)) ||
/*
** take a look at the exponents before you bother
** with the mantissas
*/
((T_ABSOLUTE == T_gettype(tol_tmp))
&& !F_zerofloat(T_getfloat(tol_tmp))
&& (F_getexp(p1) <
F_getexp(T_getfloat(tol_tmp))-1)
&& (F_getexp(p2) <
F_getexp(T_getfloat(tol_tmp))-1)))
{
return(0);
}
}
/*
** ok, we're going to have to do some arithmetic, so
** first find the magnitude of the difference
*/
if (F_getsign(p1) != F_getsign(p2))
{
diff = F_floatmagadd(p1,p2);
}
else
{
diff = F_floatsub(p1,p2);
}
/*
** now check to see if the difference exceeds any tolerance
*/
for(tol_tmp=the_tol; !(T_isnull(tol_tmp)) ;tol_tmp=T_getnext(tol_tmp))
{
float_tmp = T_getfloat(tol_tmp);
if (T_gettype(tol_tmp) == T_ABSOLUTE)
{
/* do nothing */
}
else if (T_gettype(tol_tmp) == T_RELATIVE)
{
if (F_floatcmp(p1,p2) > 0)
{
float_tmp = F_floatmul(p1, float_tmp);
}
else
{
float_tmp = F_floatmul(p2, float_tmp);
}
}
else
{
Z_fatal("bad value for type of tolerance in floatdiff");
}
/*
** if we pass this tolerance, then we're done
*/
if (F_floatcmp(diff,float_tmp) <= 0)
{
return(0);
}
}
/*
** all of the tolerances were exceeded
*/
return(1);
}
