[PATCH vkd3d 3/4] vkd3d-shader: Introduce HLSL compilation flags.

[Henri Verbeet]

On Fri, 25 Sep 2020 at 19:26, Zebediah Figura <zfigura at codeweavers.com> wrote:
> On 9/25/20 8:00 AM, Henri Verbeet wrote:
> > On Fri, 25 Sep 2020 at 03:00, Zebediah Figura <zfigura at codeweavers.com> wrote:
> >> +enum vkd3d_shader_hlsl_compatibility_mode
> >> +{
> >> +    VKD3D_SHADER_HLSL_COMPATIBILITY_DEFAULT = 0,
> >> +    VKD3D_SHADER_HLSL_COMPATIBILITY_BACKWARDS_COMPATIBLE = 1,
> >> +    VKD3D_SHADER_HLSL_COMPATIBILITY_STRICT = 2,
> >> +
> >> +    VKD3D_FORCE_32_BIT_ENUM(VKD3D_SHADER_HLSL_COMPATIBILITY),
> >> +};
> >> +
> > Hexadecimal, please. These seem poorly defined, I'd prefer for these
> > to refer to some kind of version/standard, similar to the way that
> > e.g. gcc has "-std=gnu99". As far as I'm concerned it would be fine
> > for that to be something like VKD3D_SHADER_HLSL_COMPATIBILITY_HLSL24
> > to refer to the version of HLSL in d3dx9_24, if that makes sense for
> > HLSL.
>
> Sadly, they are poorly defined :-/
>
> As I'm sure you've guessed, they correspond to the D3DCompile() flags
> D3DCOMPILE_ENABLE_STRICTNESS and
> D3DCOMPILE_ENABLE_BACKWARDS_COMPATIBILITY. The latter essentially allows
> SM1-3 operations [tex2D(), but I don't know any others offhand] to be
> mapped to analogical SM4-5 operations (instead of producing an error). I
> don't actually know what ENABLE_STRICTNESS does.
>
Sure, and I wouldn't be surprised at all if
D3DCOMPILE_ENABLE_BACKWARDS_COMPATIBILITY enables different behaviour
in different versions of d3dcompiler. But presumably the behaviour we
would actually implement would be more specific than that.