Techwiki:NtGdiD3dContextCreate

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BOOL 
STDCALL
NtGdiD3dContextCreate(
    HANDLE hDirectDrawLocal,
    HANDLE hSurfColor,
    HANDLE hSurfZ,
    D3DNTHAL_CONTEXTCREATEDATA* pdcci)

The Function NtGdiD3dContextCreate checks if you can create a context for Directx. It redirects to dxg.sys in Windows XP/2003, dxkrnl.sys in Vista and is fully implemented in win32k.sys in Windows 2000 and below.

Parameters

  • HANDLE hDirectDrawLocal
The handle we receive from NtGdiDdCreateDirectDrawObject
  • HANDLE hSurfColor
Handle to DD_SURFACE_LOCAL to be used for the rendering target
  • HANDLE hSurfZ
Handle to a DD_SURFACE_LOCAL. It is the Z deep buffer.
According MSDN if it is set to NULL nothing should happen.
  • LPD3DNTHAL_CONTEXTCREATEDATA pdcci
The buffer to create the context data

Return

  • DDHAL_DRIVER_HANDLED or DDHAL_DRIVER_NOTHANDLED if the driver supports this function.
  • A full check is done by checking if the return value is DDHAL_DRIVER_HANDLED

To check if the function has been successful, do a full check by seeing if the return value is DDHAL_DRIVER_HANDLED and pdcci->ddRVal is set to DD_OK.

Remarks

dxg.sys NtGdiD3dContextCreate calls are redirected to the same function in the dxg.sys. As such they all work the same way.

Before calling this function set the pdcci->ddRVal to an error value such as DDERR_NOTSUPORTED, or the ddRVal will otherwise be unchanged, even if an error occurs inside the driver.

  • pdcci->lpDDLcl is a pointer to DDRAWI_DIRECTDRAW_LCL, not DD_DIRECTDRAW_LOCAL as MSDN claims.
  • pdcci->lpDDSLcl is a pointer to DDRAWI_DDRAWSURFACE_LCL, not DD_DDDRAWSURFACE_LOCAL as MSDN claims.
  • pdcci->lpDDSZLcl is a pointer to DDRAWI_DDRAWSURFACE_LCL, not DD_DDRAWSURFACE_LOCAL as MSDN claims.
  • pdcci->dwhContext also needs to be filled with the handle we receive from NtGdiDdCreateDirectDrawObject.
  • pdcci->dwPID is the ProcessId it belongs to, that you need to fill in.

Do not forget that LPD3DNTHAL_CONTEXTCREATEDATA is typecasted to LPD3DHAL_CONTEXTCREATEDATA and those two structs are of different size. The correct struct is LPD3DHAL_CONTEXTCREATEDATA.