Bug report & fix: interpolation qualifier mismatch error in ReShade 6.7.x

[umaniweb]

Bug report & fix: interpolation qualifier mismatch error in ReShade 6.7.x

Hi, I ran into a compilation error with qUINT_lightroom.fx under ReShade 6.7.3 (D3D12). The shader was failing with the following errors:

qUINT_lightroom.fx(851, 1): error X4568: 'PS_ProcessLUT': input parameter 'huefactors' interpolation qualifiers do not match vertex shader ones
qUINT_lightroom.fx(857, 1): error X4568: 'PS_ApplyLUT': input parameter 'huefactors' interpolation qualifiers do not match vertex shader ones
qUINT_lightroom.fx(871, 1): error X4568: 'PS_DisplayStatistics': input parameter 'huefactors' interpolation qualifiers do not match vertex shader ones

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Root cause

The HLSL compiler in recent ReShade versions is stricter about how interpolants are declared across shader stages. Passing a raw float[7] array tagged as nointerpolation on a single semantic (TEXCOORD1) is ambiguous - the compiler can no longer resolve how to map 7 floats onto a single 4-component register.

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Fix

Replaced the loose array parameter with a dedicated VStoPS struct that packs the 7 hue factors into:

• nointerpolation float4 huefactors0 : TEXCOORD1 (indices 0-3)
• nointerpolation float3 huefactors1 : TEXCOORD2 (indices 4-6)

Each semantic maps cleanly onto one register. The local float huefactors[7] array is then reconstructed at the top of each pixel shader before being passed to palette(), so the function itself required no changes.

Before:

void VS_Lightroom(in uint id : SV_VertexID, out float4 position : SV_Position, out float2 uv : TEXCOORD0, out nointerpolation float huefactors[7] : TEXCOORD1)

After:

struct VStoPS
{
    float4 position    : SV_Position;
    float2 uv          : TEXCOORD0;
    nointerpolation float4 huefactors0 : TEXCOORD1; // hf[0..3]
    nointerpolation float3 huefactors1 : TEXCOORD2; // hf[4..6]
};

VStoPS VS_Lightroom(in uint id : SV_VertexID)

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The fix was produced by [Claude](https://claude.ai) (Anthropic's AI assistant) - I just tested and confirmed it works. Happy to submit a pull request with the corrected file if that would be useful.