Propagate state changes that occur inside of an active pass to the device before rendering.
This method has no parameters.
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be one of the following: D3DERR_INVALIDCALL, D3DXERR_INVALIDDATA.
If the application changes any effect state using any of the ID3DXEffect::Setx methods inside of an ID3DXEffect::BeginPass/ID3DXEffect::EndPass matching pair, the application must call ID3DXEffect::CommitChanges before any DrawxPrimitive call to propagate state changes to the device before rendering. If no state changes occur within a ID3DXEffect::BeginPass and ID3DXEffect::EndPass matching pair, it is not necessary to call ID3DXEffect::CommitChanges.
This is slightly different for any shared parameters in a cloned effect. When a technique is active on a cloned effect (that is, when ID3DXEffect::Begin has been called but and ID3DXEffect::End has not been called), ID3DXEffect::CommitChanges updates parameters that are not shared as expected. To update a shared parameter (only for a cloned effect whose technique is active), call ID3DXEffect::End to deactivate the technique and ID3DXEffect::Begin to reactivate the technique before calling ID3DXEffect::CommitChanges.