use DDRAW4 instead of DDRAW7

[Markus Stockhausen]

Hi,

as I did not find anything in the Wiki maybe a stupid question: If I
want an application to use DDRAW4 functions in Wine instead of DDRAW7,
how can I accomplish that?

Thanks in advance.

Markus

[Markus Stockhausen]

Am Sonntag, den 11.10.2009, 12:40 +0200 schrieb Markus Stockhausen:
> Hi,
>
> as I did not find anything in the Wiki maybe a stupid question: If I
> want an application to use DDRAW4 functions in Wine instead of DDRAW7,
> how can I accomplish that?
>
> Thanks in advance.
>
> Markus

Sorry, wrong forum.

[Stefan Dösinger]

Am 11.10.2009 um 12:40 schrieb Markus Stockhausen:
> Hi,
>
> as I did not find anything in the Wiki maybe a stupid question: If I
> want an application to use DDRAW4 functions in Wine instead of DDRAW7,
> how can I accomplish that?

You can't.

Except if you have the sourcecode. In that case you have to reprogram  
the app to use IDirectDraw4 and friends, rather than IDirectDraw7.  
Which ddraw version an app uses isn't a setting you can change - its  
hardcoded into the app, just like usually its hardcoded whether an app  
uses opengl or d3d.

[Markus Stockhausen]

Am Sonntag, den 11.10.2009, 12:47 +0200 schrieb Stefan Dösinger:
> Which ddraw version an app uses isn't a setting you can change - its  
> hardcoded into the app, just like usually its hardcoded whether an app  
> uses opengl or d3d.

Then I'm somehow in trouble. How can one explain the following 
error: Application calls IDirectDraw GetDeviceIdentifier of
DDRAW7 but only reserves memory with sizeof(DDEVICEIDENTIFIER) 
instead of sizeof(DDEVICEIDENTIFIER2) bytes. Wine returns the 
required structure but with the contents of dwWHQLLevel  
stack contents are overwritten.

Markus

ddraw.h structure alignment

[Markus Stockhausen]

Am Sonntag, den 11.10.2009, 13:18 +0200 schrieb Markus Stockhausen:
> Then I'm somehow in trouble. How can one explain the following 
> error: Application calls IDirectDraw GetDeviceIdentifier of
> DDRAW7 but only reserves memory with sizeof(DDEVICEIDENTIFIER) 
> instead of sizeof(DDEVICEIDENTIFIER2) bytes. Wine returns the 
> required structure but with the contents of dwWHQLLevel  
> stack contents are overwritten.
>
> Markus

Source of error was found. DDEVICEIDENTIFIER2 is aligned to 8 bytes and
therefore 4 bytes too large (at least on my 64 bit Linux). Should a
patch include a pragma pack handling in the ddraw.h file itself or is
there any other location where one can fix that?

Best regards.

Markus

ddraw.h structure alignment

[Stefan Dösinger]

Am 11.10.2009 um 14:42 schrieb Markus Stockhausen:
> Am Sonntag, den 11.10.2009, 13:18 +0200 schrieb Markus Stockhausen:
> > Then I'm somehow in trouble. How can one explain the following
> > error: Application calls IDirectDraw GetDeviceIdentifier of
> > DDRAW7 but only reserves memory with sizeof(DDEVICEIDENTIFIER)
> > instead of sizeof(DDEVICEIDENTIFIER2) bytes. Wine returns the
> > required structure but with the contents of dwWHQLLevel
> > stack contents are overwritten.
> >
> > Markus
>
> Source of error was found. DDEVICEIDENTIFIER2 is aligned to 8 bytes  
> and
> therefore 4 bytes too large (at least on my 64 bit Linux). Should a
> patch include a pragma pack handling in the ddraw.h file itself or is
> there any other location where one can fix that?

Does a pragma pack fix the issue? If yes, then that's probably the  
correct fix.

Its probably worth writing a test that allocates e.g. a char data[64],  
then passes this to GetDeviceIdentifier, fill it with non-zero data,  
and check how much is overwritten.

Otoh I find it strange that the struct is aligned to 8 bytes. Are you  
running wine in 64 bit? Or do you have some other compiler flags that  
make the compiler use 8 byte alignment?

ddraw.h structure alignment

[Markus Stockhausen]

Am Sonntag, den 11.10.2009, 17:15 +0200 schrieb Stefan Dösinger:
> Does a pragma pack fix the issue? If yes, then that's probably the  
> correct fix.
>
> Its probably worth writing a test that allocates e.g. a char data[64],  
> then passes this to GetDeviceIdentifier, fill it with non-zero data,  
> and check how much is overwritten.
>
> Otoh I find it strange that the struct is aligned to 8 bytes. Are you  
> running wine in 64 bit? Or do you have some other compiler flags that  
> make the compiler use 8 byte alignment?

You are right.

- I'm working on 64 bit (gcc 4.3.3)
- #pragma pack(push,4) / #pragma pack(pop) around DDDEVICEIDENTIFIER2
  fixes the behaviour
- a testcase fails without pragma:

ok(sizeof(DDDEVICEIDENTIFIER2)==0x42c, "DDDEVICEIDENTIFIER2 too large
(misaligned)\n");

I'll send a patch