[Plib-devel] ssgVtxArray bug(s) ?

[Steve B. <sjb...@ai...>]

I was looking in the ssgVtxTable class code and spotted a bug in the 'transform'
member function. (It was translating the surface normals as well as rotating them!!)

I wondered whether the same bug might be in ssgVtxArray also - which it was - but
that's neither here nor there... but in the process of looking around in that code,
I noticed that in several places there is code like this:

  for ( i = 0 ; i < getNumIndices() ; i++ )
  {
    int ii = *( indices->get(i) );

    ...do something to vertices->get(ii)...
  }

...I'm not entirely up to speed on the ssgVtxArray code - but doesn't that
mean that there is a potential for some vertices to get operated on more
than once?

For example, I might have an index array like this:

   0 1 2 3 3 2 1 0

...if I was drawing two back-to-back quads using GL_QUADS or something.

In some cases (eg computing a bounding sphere), this is just inefficient,
but in the case of the 'transform' function (for example) - it means that
some vertices will get transformed twice just because they are referenced
twice.

I *think* that the code should (in each case) just use the underlying
ssgVtxTable code - which will work fine.

I'm suprised that this wouldn't have shown up MUCH earlier.

Do I have a crossed wire here - or is this really a bug?

Is anyone actually using ssgVtxArray?
                                                                          
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