Is wine reporting the right value for MaxVertexBlendMatrices?

Julio Fernandez ucldb at
Sat Feb 9 08:31:14 CST 2008

Hi, I don't know if this is the right place to post this, but sorry if 
not, and I'd like to be pointed to the right one

I have been working last weeks on making the game Everquest to work 
under wine, since 0.9.49 it was working flawlesly, but most models were 
not shown properly. This corresponds with bug

These are my findings:

The main executable is eqgame.exe it typically accesses D3D through a 
custom dll eqgraphicsdx9 which interacts with D3D itself or through 

Using channels and adding some extra messages into certain source files 
I got to track a possible reason:

The game was declaring vertex lists with a vertex of type '0xfe' and 
+189 offset

Sadly, I could not get any extra information tracking just from source 
code, so I had to run the game under Windows on a computer and using 
windbg to debug it, while running the same time on another computer the 
game under Debian etch using winedbg to debug, and so tracing both 
programs in assambler (I burnt my eyelashes there!), the fact that I 
could have d3d dll symbols availables on the windows box was the key 
here, I really missed winedbg to be able to read pdb files :(

After many hours I was able to track down the reason, and to my surprise 
it seems its not wine's fault (for the most of it)

The 'troublesome' vertexes are apparently blended ones in mesh declarations.

When d3dx9_30 calls ConvertToIndexedBlendedMesh, it calls GetDeviceInfo 
to get the device capabilites, in the end wine returns the capabilites 
through IWineD3DImpl_GetDeviceCaps in wine/dlls/wined3d/directx.c

Here comes the fun thing, the attribute MaxVertexBlendMatrices in 
D3DCAPS9, from (MSDN):

"Maximum number of matrices that this device can apply when performing 
multimatrix vertex blending. For a given physical device, this 
capability may vary across Direct3D devices depending on the parameters 
supplied to IDirect3D9::CreateDevice."

At the moment is set in wine as *pCaps->MaxVertexBlendMatrices = 
GL_LIMITS(blends) which results in a value of 0 (at least in my Linux 
computer/build), while under Windows (XPSP2 DX9c) results in a value of 4

d3dx9_30 has a check right after the capabilites are returned comparing 
that value with 2, resulting in different code paths for the remaining 
of MaxVertexBlendMatrices function, when the value was 0 both Linux and 
Windows (hacking the returned value to be 0) make those odd '0xfe' 
vertexes to be inserted (in Linux that makes the models to not be shown, 
in Windows it makes eqgame.exe to crash)

I proceeded then to try to 'hack' wine to return a value of 4, adding 
the line


Before returning from function 
IDirect3DDevice9Impl_GetDeviceCaps(LPDIRECT3DDEVICE9 iface, D3DCAPS9* 
pCaps) at wine/dlls/d3d9/directx.c

The result: MaxVertexBlendMatrices runs the same path as Windows does, 
the odd '0xfe' vertexes are not generated and the models work are now 
shown as expected

My apologies for the long post, but I thought it would be handy to tell 
the full story to justify calling your atention on this

- d3dx9_30 ConvertToIndexedBlendedMesh shows an 'odd' behavior when 
MaxVertexBlendMatrices capabilites in D3DCAPS9 is 0

- Is wine reporting the right value for MaxVertexBlendMatrices ??? As it 
seems the game works flawlesly in wine when it's hacked to be 4 (I don't 
know if this 'hack' would affect other programs in any other way

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