[PATCH 1/4] d2d1: Add a properties list for builtin effects.

[Giovanni Mascellani]

Hi Ziqing,

Il 29/07/21 03:30, Ziqing Hui ha scritto:
> Thanks for your reply. My plan is to add something like " struct
> d2d_effect_ops", which is a vtable. And each effect class needs to
> implement this vtable. It may look like this:
I think this strategy makes the code less idiomatic, therefore harder to 
read and maintain, and it requires a double virtual dispatching, for 
which I see no use. The COM virtual dispatching mechanism is already 
good enough to implement all the dynamic behavior you need, so I would 
use that one, putting each effect in its own class.

This would mean something like:

struct d2d_affine_effect
{
     ID2D1Effect ID2D1Effect_iface;
     ...
};

static const ID2D1EffectVtbl d2d_affine_effect_vtbl =
{
     d2d_affine_effect_QueryInterface,
     d2d_affine_effect_AddRef,
     d2d_affine_effect_Release,
     d2d_affine_effect_GetPropertyCount,
     ...
};

void d2d_effect_init(ID2D1Effect **effect, ID2D1Factory *factory, const 
CLSID *effect_id)
{
     if (IsEqualGUID(effect_id, &CLSID_D2D12DAffineTransform))
     {
         struct d2d_affine_effect *object = 
heap_alloc_zero(sizeof(*object));
         object->ID2D1Effect_iface.lpVtbl = &d2d_affine_effect;
         ...
         *effect = object->ID2D1Effect_iface.lpVtbl;
         return S_OK;
     }
     else if (IsEqualGUID(effect_id, &CLSID_D2D12DPerspectiveTransform))
     ...

     FIXME("Effect not implemented: %p\n", wine_dbgstr_guid(effect_id));
     return D2DERR_EFFECT_IS_NOT_REGISTERED;
}

(coding out of my mind, might require some tweaks, of course)

The implementations of the methods in the three different classes can 
very well share code by mean of helper functions, if that's useful.

Again, just my 2 cents.

Giovanni.