Re: [PATCH 0/5] MR53: vkd3d-shader/hlsl: transpose(), smoothstep(), and properly convert args of element-wise intrinsics.

[Zebediah Figura (＠zfigura)]

Zebediah Figura (@zfigura) commented about libs/vkd3d-shader/hlsl.y:
> return !!add_unary_arithmetic_expr(ctx, params->instrs, HLSL_OP1_SAT, arg, loc);
>  }
>
> +/* smoothstep(a, b, x) = saturate(p^2 (3 - 2p)), where p = (x - a)/(b - a) */
> +static bool intrinsic_smoothstep(struct hlsl_ctx *ctx,
> +        const struct parse_initializer *params, const struct vkd3d_shader_location *loc)

What you have here is instead "p^2 (3 - 2p), where p = saturate((x - a)/(b - a))". I haven't checked the math, but the discrepancy should probably be fixed.

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https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/53#note_17584