[Insight-developers] Preconditions / Exceptions / Code values

[Miller, James V (CRD)]

I think you can still use the IsPointInside() method but it needs to take a parameter (the point).
The algorithm code would then look like

    if(  mapper->IsPointInside( myInterestPoint ) )
    {
      value = mapper->GetPixel( myInterestPoint );
      // inside the image, value is valid
    }
    else 
    {
      // outside the image,
      // do something else
    }

This would be my choice.  It would allow algorithms that "need-to-check" whether a given point is
inside or not to check while allowing algorithms that know they are always inside to avoid the check.

I am wary of using exceptions for things that can be handled without them. But this might just
because I don't have a lot of experience with exceptions.  My naive thinking is to limit their use to
"device" related problems (out of memory, out of disk space, etc.).

Jim


-----Original Message-----
From: Luis Ibanez [mailto:ibanez@cs.unc.edu]
Sent: Wednesday, December 20, 2000 4:26 PM
To: Paul Hughett
Cc: Insight-developers@public.kitware.com
Subject: Re: [Insight-developers] Preconditions / Exceptions / Code
values


On Wed, 20 Dec 2000, Paul Hughett wrote:
 
> A further point:  Unless you are being a lot trickier than appears on the
> surface, the local static values implied by 
> 
>  void  SetPoint(  const Point<dimension, double> & coordinates );
>  bool  IsPointInside( void ) const;
>  TPixelType  GetPixel( void ) const;
> 
> are not going to be thread-safe.  What happens if two different threads
> are using these methods at the same time on the same image?
> 
Oops!!
My mistake,
that sequence of three call will not survive a concurrent access.

I guess that the only option left is to use exceptions...


Thanks for pointing this out.


Luis




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