Is wine reporting the right value for MaxVertexBlendMatrices ?

[Julio Fernandez]

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 http://bugs.winehq.org/show_bug.cgi?id=8357

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 d3dx9_30.dll

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' vertex are apparently Blended ones on a Mesh setup.

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 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

pCaps->MaxVertexBlendMatrices=0x4;

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