needs to know about Direct3D headers etc.

the Scene code still breaks Direct3D rendering.

class, so that the calling code does not need to know what the backend is.

issues that were introduced with the Direct3D changes.

retrieve the constant's register index in the description table. This also
allows us to use a single uniform handle for both the vertex and pixel
shaders in a PS3 Cg program.

support is still missing.

cannot used DirectX 10 because my video card only supports DX9, and there
is no compatibility layer. DX11 has feature levels for older hardware so
it would work with a DX9 card, but it's not available for WinXP.

tweak the triangle tutorial to make it shorter.

works on the Xbox.

link properly on the Xbox.

that are not explicitly real, even with namespace mistakes.

workaround for a Visual Studio compiler bug (Connect Id #730878).

the matrix code itself.

that x + y != x, and nextafter() which behaves like the C function.

functions are now about 20% faster.

bonus, multiplication or division by a power of two will be optimised as
a shift of the exponent.

add the corresponding unit test.