Re: problem with output of the program on different OS

On May 12, 6:35 am, Richard Heathfield <r...@[EMAIL PROTECTED]
> wrote:


> Well, I don't hold out a lot of hope for this review, judging by the
OP's
> reply to the first part thereof ("I think this is not the problem", for
> instance, shows a remarkable talent for disregarding general-principle
> comments simply because they don't appear to explain the immediate cause
> of the immediate segfault - if ever there were a short-sighted approach
to
> debugging, this has to be it).

well, i did include the assert(index >= 0) statement in the code but
while executing the assertion fails. What I'm trying to say is that
this is natural because index is bound to have value -1 for cases
where ray does not intersect the triangle. Also res.hit = FALSE for
such situations.


> Nevertheless, let's press on for now.
>
> I fixed the scanfs in initialize_radar(), checking the return values and
> returning FAILURE if they were incorrect. (As mentioned in my earlier
> article, I also C90ified and re-indented the code, purely for my own
> convenience.) The function now looks like this:
>
> int initialize_radar(bbox b,
>                      radar_detector * radar)
> {
>   int rc = SUCCESS;
>   vector *pointinarray = NULL;
>   int i;
>   unsigned long int ray_count;
>
>   radar->maxP = b.maxB;
>   radar->minP = b.minB;
>   radar->maxP.z = radar->minP.z = b.minB.z - 1000;
>
>   printf
>     ("Enter the frequency of the electromagnetic rays to be fired\n");
>   if(scanf("%le", &radar->frequency) != 1)
>   {
>     rc = FAILURE;
>   }
>   else
>   {
>     radar->wavenumber = 2 * M_PI * radar->frequency / VELOCITY;
>
>     printf("Enter the amplitude of electric field\n");
>     if(scanf("%le", &radar->E0) != 1)
>     {
>       rc = FAILURE;
>     }
>   }
>
>   if(rc == SUCCESS)
>   {
>     printf("Enter the number of electromagnetic rays to be fired\n");
>     if(scanf("%lu", &radar->numberofrays) != 1)
>     {
>       rc = FAILURE;
>     }
>   }
>
>   if(rc == SUCCESS)
>   {
>     real(radar->E_incident) = 0;
>     imag(radar->E_scattered) = 0;
>
>     i =
>       gen_grid_points(&pointinarray, &radar->numberofrays, b.maxB.x,
>                       b.minB.x, b.maxB.y, b.minB.y, b.minB.z - 1000);
>     if(i == FAILURE)
>     {
>       rc = FAILURE;
>     }
>   }
>   if(rc == SUCCESS)
>   {
>     ray_count = radar->numberofrays;
>     radar->raylist = malloc(ray_count * sizeof (ray));
>     if(radar->raylist == NULL)
>     {
>       perror("malloc has failed");
>       rc = FAILURE;
>     }
>   }
>
>   if(rc == SUCCESS)
>   {
>     for(ray_count = 0; ray_count < radar->numberofrays; ray_count++)
>     {
>       radar->raylist[ray_count].origin = pointinarray[ray_count];
>       radar->raylist[ray_count].direction.x = 0;
>       radar->raylist[ray_count].direction.y = 0;
>       radar->raylist[ray_count].direction.z = 1;
>       radar->raylist[ray_count].depth = 0;
>       radar->raylist[ray_count].pathlength = DBL_MAX;
>       radar->raylist[ray_count].child = NULL;
>       real(radar->raylist[ray_count].efield) = radar->E0;
>       imag(radar->raylist[ray_count].efield) = 0;
>     }
>   }
>
>   free(pointinarray);
>
>   return rc;
>
> }
>
> This source file (radar.c) now gives just two diagnostic messages, both
to
> do with passing an unsigned long int to sqrt. (Yes, I killed my
insertion
> of assert(*numpoints >= 0, now that I realise *numpoints has unsigned
> integer type.
>
> Continuing on my quest to get the diagnostic count down a bit, I moved
on
> to reader.c. Simply moving the definitions of tem****ary vectors up to
the
> top of the function, I made the code C90-compatible. The remaining
> warnings are:
>
> reader.c:68: warning: passing arg 2 of `calloc' as unsigned due to
> prototype
> reader.c:69: warning: passing arg 2 of `calloc' as unsigned due to
> prototype
> reader.c:109: warning: enumeration value `LAST_LINE' not handled in
switch
>
> Although I don't like the first two, I can live with them if you can -
the
> alternative (i.e. to use unsigned types for nvert and ntri) may be more
> painful to fix than is practical (I haven't delved).
>
> The last one, I leave in your hands. I'm not making any huge attempt to
> understand the program here - I'm just looking at the C.
>
> I needed to C90ify the test.c file, changing a comment to /* style */
and
> moving a definition up a bit. The reflection.c file also needed some
> comment-fixing.
>
> Now it compiles. It doesn't /link/, but that's my makefile's problem,
not
> yours. So let's run it:
>
> $ ./raytrace
> Enter the frequency of the electromagnetic rays to be fired
>
> Well, I have no idea what to type here, so I just entered 0 for
everything,
> and lo and behold, I got an assertion failure:
>
> raytrace: radar.c:49: gen_grid_points: Assertion `numpointsx > 1'
failed.
>
> I added this assertion because your code assumed that numpointsx could
not
> be 1 or lower. That assumption is clearly wrong.
>
> I suggest you fix this (by validating your data before passing it to the
> function that needs it to be > 1). If the code continues to give
problems
> after that's fixed, show us the fixed code so that we know that this
> particular problem is known not to be a candidate any longer.
>

thanks i will try to incor****ate the changes you have suggested