Re: [PATCH v2 3/3] d2d1: Implement d2d_effect_{Get,Set}Input{,Count}().

[Ziqing Hui]

On 8/3/21 11:53 PM, Henri Verbeet wrote:
> > static HRESULT STDMETHODCALLTYPE d2d_effect_SetInputCount(ID2D1Effect *iface, UINT32 count)
> >  {
> > - FIXME("iface %p, count %u stub!\n", iface, count);
> > - struct d2d_effect *effect = impl_from_ID2D1Effect(iface);
> > - unsigned int i;
> > - return E_NOTIMPL;
> > - TRACE("iface %p, count %u.\n", iface, count);
> > -
> > - if (count < effect->min_inputs || count > effect->max_inputs)
> > -
> >    return E_INVALIDARG;
> > -
> > - if (count != effect->inputs_count)
> > - {
> > -
> >    if (count < effect->inputs_count)
> > -
> >    {
> > -
> >        for (i = count; i < effect->inputs_count; ++i)
> > -
> >        {
> > -
> >            if (effect->inputs[i])
> > -
> >                ID2D1Image_Release(effect->inputs[i]);
> > -
> >        }
> > -
> >    }
> > -
> >    effect->inputs_count = count;
> > -
> >    HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, effect->inputs, sizeof(*effect->inputs) * count);
> > - }
> > -
> > - return S_OK;
> >
> > }
>
> That doesn't generally work; the memory returned by HeapReAlloc() may
> not be the same as what was originally passed in. More broadly, it's
> not clear to me that we gain much from avoiding d2d_array_reserve()
> here.

I need to use HeapReAlloc(HEAP_ZERO_MEMORY) to initialize the newly allocated memory to zero.

Which way is better? HeapReAlloc(HEAP_ZERO_MEMORY) or d2d_array_reserve() + memset(0)?