Re: [PATCH 3/7] d3d11: Add ID3D11Texture3D interface stub.

[Henri Verbeet]

On 1 September 2015 at 00:27, Józef Kucia  wrote:
> - else if (IsEqualGUID(riid, &IID_ID3D10Texture3D)
> -
>        || IsEqualGUID(riid, &IID_ID3D10Resource)
> -
>        || IsEqualGUID(riid, &IID_ID3D10DeviceChild))
> - {
> -
>    IUnknown_AddRef(iface);
> -
>    *object = &texture->ID3D10Texture3D_iface;

For what it's worth, this works here because the d3d10 and d3d11
interfaces share the reference count, but in general you should
AddRef() the actual interface you're returning.

[PATCH 3/7] d3d11: Add ID3D11Texture3D interface stub.

[Józef Kucia]

On Tue, Sep 1, 2015 at 3:53 PM, Henri Verbeet  wrote:
> On 1 September 2015 at 00:27, Józef Kucia  wrote:
> > - else if (IsEqualGUID(riid, &IID_ID3D10Texture3D)
> > -
> >        || IsEqualGUID(riid, &IID_ID3D10Resource)
> > -
> >        || IsEqualGUID(riid, &IID_ID3D10DeviceChild))
> > - {
> > -
> >    IUnknown_AddRef(iface);
> > -
> >    *object = &texture->ID3D10Texture3D_iface;
>
> For what it's worth, this works here because the d3d10 and d3d11
> interfaces share the reference count, but in general you should
> AddRef() the actual interface you're returning.

IMHO, this is somehow clearer than IUnknown_AddRef((IUnknown
*)*object). On the other hand, it seems suspicious when AddRef() is
called on other interface than the one returned.

[PATCH 3/7] d3d11: Add ID3D11Texture3D interface stub.

[Henri Verbeet]

On 1 September 2015 at 18:56, Józef Kucia  wrote:
> IMHO, this is somehow clearer than IUnknown_AddRef((IUnknown
> *)*object). On the other hand, it seems suspicious when AddRef() is
> called on other interface than the one returned.

You're mixing styles a bit. One way is to first assign *out/*object
and then have a common IUnknown_AddRef() at the end of
QueryInterface(). The advantage is mostly that you're saving some code
duplication for the AddRef() and return, although at the cost of
introducing a cast. E.g. d3d10_device_inner_QueryInterface(). The
other style is to AddRef() with the correct interface and return
immediately, e.g. ddraw_surface7_QueryInterface(). I.e., in this case
you'd use "ID3D10Texture3D_AddRef(&texture->ID3D10Texture3D_iface);".
Note that the "else" is redundant if you return.