Re: [Raypp-general] CVS updates

[Andreas K. <and...@we...>]

Hi!

> - I would love to remove the configure test for endianness and replace it
with
>    a class like you did, but unfortunately this breaks the binary stream
classes
>    (kernel/bstream.h) in the respect that you can no longer write
>      bistream<file_is_lsb> inputfile("foo.bin");
>    This only works if "file_is_lsb" is a compile-time constant, and this
can only
>    be done as long as we use a configure mechanism.

Ah, didn't think of that :-(
I'll change it back. I have to do some changes for MSVC++ anyway.

>    If we could do it via expression templates (like we do with the
datatypes) that
>    would work, but I don't know how to do that.

The expression template code you introduced for compile time selection of
types is really cool. But I have no idea how to use something like this for
a
endianess test either.

First I wanted to do something like

const byte swap_test[2] = { 0, 1};
const bool big_endian = (*(uint2*)swap_test) != 1;

But this cannot be done either because the order the constants are getting
initailized is not defined. But I guess it wouldn't work for the bistream
class
anyway...

Another option would be to change the bistream class to not use templates.
Would be a bit less elegant and performance would be a bit worse, but the
class is not really a central point of ray++. So I think it would be worth
to
chnage it if we get rid of the configure problems.
Other opinions?

> - In trianglemesh.cxx a function filelength() is called, which does not
exist
>    on Linux. We will have to find something more portable.

Yeah, I thought that might be a problem, but didn't change it yet.

> - TRIANGLE_MESH::All_Intersections() appears to return only the first
intersection
>    with the mesh.

I'll have a look.
The class is far from being finished so there might be a few more problems
(apart
from the fact that it is still veeeery sloooow). But I was able to render my
first
teapot already!

> TRIANGLE_MESH::Load3DS() might be a good candidate for using the bistream
class.
> (I expect that the 3DS files are always little-endian, so they have to be
swapped
> on a big-endian machine).

Yes, I guess so as well.

Thanks for the code review,
Andreas