Re: Question about ddraw implemtation

[Ralph Little]

Hi,
Further to my last post, I can confirm that the pixelformat structure is 
completely empty.
A quick dump of the DDPIXELFORMAT structure shows that:

=================================
trace:ddraw:PixelFormat_DD2WineD3D =========dwSize = 32, sizeof(32)
trace:ddraw:PixelFormat_DD2WineD3D =========dwFlags = 0
trace:ddraw:PixelFormat_DD2WineD3D =========dwFourCC = 0
trace:ddraw:PixelFormat_DD2WineD3D =========dwRGBBitCount = 0
trace:ddraw:PixelFormat_DD2WineD3D =========dwRBitMask = 0
trace:ddraw:PixelFormat_DD2WineD3D =========dwGBitMask = 0
trace:ddraw:PixelFormat_DD2WineD3D =========dwBBitMask = 0
trace:ddraw:PixelFormat_DD2WineD3D =========dwRGBAlphaBitMask = 0
=================================

I don't know if this is a bug in the Sims that either:

a) DDPIXELFORMAT is improperly filled in relying on some buggy behaviour 
in DirectDraw
b) DDPIXELFORMAT is properly filled in for some default behaviour.
c) DDSURFACEDESC2 is improperly defined with dwFlags & DDSD_PIXELFORMAT

If anyone can try this out in (real) DirectDraw and let me know what 
happens that would be really cool.

Cheers,
Ralph

Question about ddraw implemtation

[Stefan Dösinger]

On Friday 13 May 2011 01:36:09 Ralph Little wrote:
> Hi,
> Further to my last post, I can confirm that the pixelformat structure is
> completely empty.
> A quick dump of the DDPIXELFORMAT structure shows that:

Can you show us the entire DDSURFACEDESC2 structure?
> b) DDPIXELFORMAT is properly filled in for some default behaviour.

That's most likely, although there is no sensible default for this. We don't 
even know if the app wants a RGB surface, a Paletteindexed surface, a YUV 
surface etc. Probably Windows creates a surface with the format of the primary 
surface. I think this is what happens when the app doesn't specify 
DDSD_PIXELFORMAT in the DDSURFACEDESC2.
> If anyone can try this out in (real) DirectDraw and let me know what
> happens that would be really cool.

See dlls/ddraw/tests/dsurface.c. If you don't have a Windows machine to run 
tests yourself you can either use winetestbot or ask someone to run it for you 
on #winehackers. The latter is recommended because winetestbot uses VMs only. 
There is basic ddraw support in those VMs(VMware), but it may be different from 
real GPUs.

Question about ddraw implemtation

[Ralph Little]

Hi,

On 11-05-13 03:33 AM, Stefan Dösinger wrote:
> On Friday 13 May 2011 01:36:09 Ralph Little wrote:
> > Hi,
> > Further to my last post, I can confirm that the pixelformat structure is
> > completely empty.
> > A quick dump of the DDPIXELFORMAT structure shows that:
>
> Can you show us the entire DDSURFACEDESC2 structure

OK, here it is:

================================
trace:ddraw:CreateSurface DDSURF==== dwSize(124) sizeof 
DDSURFACEDESC(108) sizeof DDSURFACEDESC2(124)
trace:ddraw:CreateSurface DDSURF==== dwFlags(124)
trace:ddraw:CreateSurface DDSURF==== dwHeight(600)
trace:ddraw:CreateSurface DDSURF==== dwWidth(800)
trace:ddraw:CreateSurface DDSURF==== u1.lPitch(0)
trace:ddraw:CreateSurface DDSURF==== u1.dwLinearSize(0)
trace:ddraw:CreateSurface DDSURF==== dwBackBufferCount/dwDepth(0)
trace:ddraw:CreateSurface DDSURF==== 
u2.dwMipMapCount/dwRefreshRate/dwSrcVBHandle(0)
trace:ddraw:CreateSurface DDSURF==== dwAlphaBitDepth(0)
trace:ddraw:CreateSurface DDSURF==== dwReserved(0)
trace:ddraw:CreateSurface DDSURF==== lpSurface((nil))
trace:ddraw:CreateSurface DDSURF==== u3.dwEmptyFaceColor(0)
trace:ddraw:CreateSurface DDSURF==== 
u3.ddckCKDestOverlay.dwColorSpaceLowValue(0)
trace:ddraw:CreateSurface DDSURF==== 
u3.ddckCKDestOverlay.dwColorSpaceHighValue(0)
trace:ddraw:CreateSurface DDSURF==== ddckCKDestBlt.dwColorSpaceLowValue(0)
trace:ddraw:CreateSurface DDSURF==== ddckCKDestBlt.dwColorSpaceHighValue(0)
trace:ddraw:CreateSurface DDSURF==== 
ddckCKSrcOverlay.dwColorSpaceLowValue(0)
trace:ddraw:CreateSurface DDSURF==== 
ddckCKSrcOverlay.dwColorSpaceHighValue(0)
trace:ddraw:CreateSurface DDSURF==== ddckCKSrcBlt.dwColorSpaceLowValue(0)
trace:ddraw:CreateSurface DDSURF==== ddckCKSrcBlt.dwColorSpaceHighValue(0)
trace:ddraw:CreateSurface DDSURF==== u4.dwFVF(32)
trace:ddraw:CreateSurface DDSURF==== ddsCaps.dwCaps(133120)
trace:ddraw:CreateSurface DDSURF==== ddsCaps.dwCaps2(0)
trace:ddraw:CreateSurface DDSURF==== ddsCaps.dwCaps3(0)
trace:ddraw:CreateSurface DDSURF==== ddsCaps.dwCaps4(0)
trace:ddraw:CreateSurface DDSURF==== dwTextureStage(0)
===============================================

I notice that the Wine definition of DDSURFACEDESC2 does not include the 
second union shown here:

http://msdn.microsoft.com/en-us/library/ff550340%28VS.85%29.aspx

which is a union of dwBackBufferCount/dwDepth.

I think it likely that it is a whole-screen surface (800x600) so your 
assertion that it will use the default pixel format for the display is 
probably right.

Interestingly, the surface pointer is NULL.

Any ideas what this surface is trying to accomplish? Is it merely an 
attempt to blank the screen with no content?

Cheers,
Ralph

Question about ddraw implemtation

[Henri Verbeet]

On 13 May 2011 19:03, Ralph Little  wrote:
> trace:ddraw:CreateSurface DDSURF==== dwFlags(124)

Is that correct? It doesn't have DDSD_PIXELFORMAT set.

Question about ddraw implemtation

[Ralph Little]

Hi,
> On 13 May 2011 19:03, Ralph Little  wrote:
> > trace:ddraw:CreateSurface DDSURF==== dwFlags(124)
>
> Is that correct? It doesn't have DDSD_PIXELFORMAT set.

Wait, you're right. I misread what the code was doing.

/* No pixelformat given? Use the current screen format */
     if(!(desc2.dwFlags & DDSD_PIXELFORMAT))
     {
         WARN("No pixelformat given\n");
         desc2.dwFlags |= DDSD_PIXELFORMAT;
         desc2.u4.ddpfPixelFormat.dwSize=sizeof(DDPIXELFORMAT);

It sees that there is no pixelformat specified, then tries to fill one in.

Here:

else
         {
              WARN("pixformat=default\n");
            PixelFormat_WineD3DtoDD(&desc2.u4.ddpfPixelFormat, Mode.Format);
         }

it calls the function PixelFormat_WineD3DtoDD() to determine the format 
details, assuming that there is something in ddpfPixelFormat worth 
looking at.
In this case, it is wrong.

With the surface ptr. being NULL, I suspect that all talk of pixelformat 
is moot in this case. There are no pixels to render.
I really do wonder if this is a "trick" to blank the screen.

Cheers,
Ralph

Question about ddraw implemtation

[Ralph Little]

Hi,

On 11-05-13 10:15 AM, Henri Verbeet wrote:
> On 13 May 2011 19:03, Ralph Little  wrote:
> > trace:ddraw:CreateSurface DDSURF==== dwFlags(124)
>
> Is that correct? It doesn't have DDSD_PIXELFORMAT set.

No scrap that last message, my original trace was incorrect.
A typo meant I was outputting the size, not the flags :(

The flags are actually 4103 which includes DDSD_PIXELFORMAT.

Back to the original situation.

So, what is happening is that the caller is specifying DDSD_PIXELFORMAT 
but there is nothing in the DDPIXELFORMAT structure to indicate how to 
render.
However, the surface pointer is NULL so there is nothing to actually draw.

I added some code to test the PIXELFORMAT structure and if didn't like 
what it found, it inserted the default.
It gets a lot further but crashes later on. I will try and find out what 
is happening then.

Cheers,
Ralph