Re: [Gnu3dkit-dev] G3DLine -intersectsLine:

[Philippe C . D . Robert]

On Tuesday, October 22, 2002, at 06:34  Uhr, Brent Gulanowski wrote:
> On Tuesday, October 22, 2002, at 12:03  PM, Philippe C.D. Robert wrote:
> > On Monday, October 21, 2002, at 08:08  Uhr, Brent Gulanowski wrote:
> >
> > > This method does a blanket failure if the direction vectors are 
> > > parallel. I am not a geometry math whiz, but as far as I can tell, 
> > > this ignores the case where the lines are coincident.
> >
> > I did not really look at it, but what part of the code do you think 
> > fails in this case? I will have a look at it ASAP.
>
>
>   G3DMultiplyVector3fv(_t_v1,d1,d2);
>   denom = G3DScalarProduct3fv(_t_v1,_t_v1);
>
>   // Parallel if equals 0
>   if (denom == 0.0f) {
>     return NO;
>   }
>
> it returns NO for all cases of parallel lines, but what about when two 
> lines lie on top of each other -- they technically intersect at every 
> point. Is that still a "NO" for some reason?

Fixed, more or less ... well, isEqualToLine: needs a fix to make it 
work correctly.

-Phil
--
Philippe C.D. Robert
http://www.nice.ch/~phip