[1/2] d3dx9: Implemented non-equal declaration support in CloneMesh.

[Matteo Bruni]

2011/10/24 Michael Mc Donnell <michael at mcdonnell.dk>:
> On Mon, Oct 24, 2011 at 9:13 AM, Matteo Bruni <matteo.mystral at gmail.com> wrote:
>> Hi Michael,
>>
>> +    for (i = 0; declaration1[i].Stream != 0xff; i++)
>> +    {
>> +        if (memcmp(&declaration1[i], &declaration2[i], sizeof(*declaration1)))
>>
>> Doesn't that loop need to stop at the first end marker of either
>> declaration? I.e. may the first vertex declaration be longer than the
>> second one?
>
> The first vertex declaration may be longer than the second one, e.g.
> to make room for more vertex attributes. The loop actually still
> breaks if the second declaration is shorter because it will have an
> end marker and the first one doesn't.
>
> I must admit it is difficult to read. I guess It would be easier to
> read the code if it first finds the size of each declaration and does
> a full memcmp if they're equal:
>
> static BOOL declaration_equals(CONST D3DVERTEXELEMENT9 *declaration1,
> CONST D3DVERTEXELEMENT9 *declaration2)
> {
>    UINT size1, size2;
>
>    /* Find the size of each declaration */
>    for (size1 = 0; declaration1[size1].Stream != 0xff; size1++);
>
>    for (size2 = 0; declaration2[size2].Stream != 0xff; size2++);
>
>    /* If not same size then they are definately not equal */
>    if (size1 != size2)
>        return FALSE;
>
>    /* Check that all components are the same */
>    if (memcmp(declaration1, declaration2, size1*sizeof(*declaration1)) == 0)
>        return TRUE;
>
>    return FALSE;
> }
>
> I'll update the patch and send it again.
>

You're right, sorry for the noise. I see that you have already resent
the patches, that's fine anyway.