Ian Mallett wrote:
> Hello,
>
> I have an NVidia GeForce 8400M GS. I have recently implemented an
> application that uses FBOs extensively. The application is available
> here: http://www.mediafire.com/download.php?z2xkwyjmmzm. It works
> excellently for me. It should look like:
> http://img7.imageshack.us/img7/6495/image1gsh.png. My friend, on an
> ATI Mobility Radeon HD 2300, is getting the texture vertically
> flipped: http://img3.imageshack.us/img3/3637/image2sle.png. I have no
> idea why it is happening. As a check, I had him manually flip the
> texture, which visually fixed the problem:
> vec2 coords = coord.st/coord.q <http://coord.st/coord.q>;
> value =
> (coord.p/coord.q<=texture2D(shadtex,vec2(coords.x,1.0-coords.y)).r) ?
> 1.0:0.0;
> instead of:
> value = (coord.p/coord.q<=texture2DProj(shadtex,coord).r) ? 1.0:0.0;
> The issue is annoying me. How can it be "fixed" the real way--e.g.,
> not a hack?
To complicate your hack/workaround, I'm on a Mobility Radeon HD 3650
(Ubuntu Jaunty 9.04 AMD64 w/fglrx drivers) and the code renders
perfectly. That is, just checking for vendor string doesn't sound like
a solution.
Afraid I don't know of any reason the flip would occur, so I don't have
any real suggestions for how to fix it properly. You might be able to
hack it by rendering a black/white texture and reading off a pixel
result, but that seems... sub-optimal.
Good luck,
Mike
--
________________________________________________
Mike C. Fletcher
Designer, VR Plumber, Coder
http://www.vrplumber.com
http://blog.vrplumber.com
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