Game fixes
The Witcher 3: Wild Hunt

The Witcher 3: Wild Hunt

Refuses the stream-output pipeline that crashes D3DMetal's shader converter, and lets the game offer DLSS.

GPL-3.0-or-laterOriginal idea: tholtman1-del Reimplemented in MacGameFix

What you see

A black window at full CPU on every launch; once past it, DLSS listed as not supported

Why it happens

One stream-output pipeline crashes D3DMetal's shader converter; the game switches NVIDIA Streamline off when it finds Wine

What the fix changes

Refuse that pipeline; tell the one Streamline check that there is no Wine

The code

tholtman1-del's rule: a geometry-shader pipeline that streams out, or has no pixel shader, is refused.

fixes/w3-streamout-fix.c · refuse, lines 101–112

static BOOL refuse(BOOL gs, BOOL ps, UINT so_entries)
{
#ifdef W3_RTPROBE
    if (allow_gs_without_ps && gs && !so_entries && !ps)
    {
        logline("let through geometry-shader pipeline %ld with no pixel shader and no stream output",
                InterlockedIncrement(&let_through));
        return FALSE;
    }
#endif
    return gs && (so_entries || !ps);
}

The refusal: E_INVALIDARG before the pipeline reaches Apple's shader converter, which crashed on it and left the game deadlocked on a black screen.

fixes/w3-streamout-fix.c · my_gfx, lines 119–139

static HRESULT WINAPI my_gfx(void *dev, const void *desc, REFIID iid, void **out)
{
    const char *d = desc;
    InterlockedIncrement(&seen_gfx);
    if (d && refuse(has_shader(d + 72), has_shader(d + 24), *(const UINT *)(d + 96)))
    {
        LONG n = InterlockedIncrement(&refused);
        logline("refused stream-output pipeline %ld (graphics desc, %u entries)", n, *(const UINT *)(d + 96));
        if (out) *out = NULL;
        return E_INVALIDARG;
    }
#ifdef W3_RTPROBE
    {
        HRESULT hr = real_gfx(dev, desc, iid, out);
        if (FAILED(hr)) logline("CreateGraphicsPipelineState failed: %08lx", (unsigned long)hr);
        return hr;
    }
#else
    return real_gfx(dev, desc, iid, out);
#endif
}

Thanks to

tholtman1-delThe diagnosis of the black screen and the rule that refuses the pipeline (MIT).

Details

Needs: D3DMetal, D3D12, Metal 4 on
Installer: install-w3-fix.sh
Executable: witcher3.exe
Built from: w3-streamout-fix.c
Verified on: Stable 26.3 with Game Porting Toolkit 4.0b2 (2026-09-30)

The full story, with the measurements and the wrong turns