[1/3] WineD3D: Separate Tx tempregs from Tx varyings in ARB

[Henri Verbeet]

2009/5/12 Stefan Dösinger <stefan at codeweavers.com>:
> ps_1_3 uses Tx to pass in texture coordinates, but also as temporary
> registers. ps_1_4 and ps_2_0 only use them for texture coordinates. This patch
> gets rid of the Tx = fragment.texcoord[x] assign in all shader versions, and
> doesn't even declare Tx in ps_1_4 and ps_2_0.
>
> The <=ps_1_3 instructions know which kind of input they expect from the Tx
> register, so the instruction handlers now know if they have to read the
> tempreg Tx or the varying fragment.texcoord[x]
I'm probably missing something obvious, but with pre-1.4 texcoord
registers being read-write, what happens when you write to the
register before using it to sample a texture?

> I've put it in the backend and not the frontend because a hypothetical nvts
> shader backend would be confused by this.
>
Completely off-topic of course, but isn't it somewhat questionable to
anthropomorphize source code?