Re: problem with output of the program on different OS

On May 13, 4:13 pm, Bart <b...@[EMAIL PROTECTED]
> wrote:


> But I've now changed a couple of things: < 0.0 to < (-EPSILON) and >
> 1.0 to > (1+EPSILON).
>
> *Now*, all my 4 compilers (5 including new Pelles) give the 7.08...
> result.
>
> (Whether that is right or not, I've still no idea.)

But, why should we change < 0.0 to < -EPSILON just to get consistent
results ?

Numerical accuracy is very im****tant in my program. <0.0 is a negative
number. For example I test t < 0.0 which means if the distance that
the ray has travelled is negative, then it means the intersection is
behind the ray's origin.  But taking < - EPSILON will allow a lot of
negative values of t to pass through as well.

I'm wondering if I'm doing a wrong thing by taking having a tolerance
value in my program for floating point checks. If accuracy is really
im****tant, perhaps I should do away with such checks and compare with
exact values or may have an extremely small tolerance like 10e-20 or
something.