After browsing the net a bit, I found the code that can be used for rounding a number up to the next power of two. While I am banking on D3DXCreateTexture to do it for me, it can be helpful in other situations, so I thought I would post it.

I converted it into a simple routine:



it requires the inclusion of math.h

and the basic idea of how it works, is you use frexp to get the exponent of the incomming number, then you do 2 to the e'th (exponent) and it gives you back the proper pow2 number, quite handy =)

you put in 255, it gives you 256
you put in 257, it gives you 512
you put in 256, it gives you 256

int NextPowerOfTwo(int i)
{
    int iReturn = 1;

    while(iReturn < i)
    {
        iReturn <<= 1;
    }

    return iReturn;
}

unsigned int NextPowerOfTwo(unsigned int v)
{
  v--;
  v |= v >> 1;
  v |= v >> 2;
  v |= v >> 4;
  v |= v >> 8;
  v |= v >> 16;
  v++;
  return v;
}