reactos/media/doc/DdCreateDirectDrawObject.txt

DdCreateDirectDrawObject  

When IN HDC is not NULL
1. we need check the IN HDC is NULL or not
2. if it not null we need create a directdraw handler 
   and store it to pDirectDrawGlobal->hDD
3. if the directdraw handle is null return false
   we did fail to create directdraw HAL 
4. if the directdraw handle was not null we return true
   we did susses to create directdraw HAL 
 
When IN HDC is NULL   
Now we come to if IN HDC is null basic we need create
   a hdc and cashe some data
1. if internal cache of directdraw handle is not null (pDirectDrawGlobalInternal->hDD)
   we take it and fill to the public directdraw handler (pDirectDrawGlobal->hDD)
   and return susses.
 
2.  if no internal cache of directdraw handle is found we need create it
    by using CreateDC for tempary HDC that will be cache in the win32k later
 
3.  we need check see if we got a tempary HDC or not, if we fail getting tempary 
    HDC return FALSE
 
4. Now we trying create directdraw handler it being cache to (pDirectDrawGlobalInternal->hDD)
   and it also set same handler to the public (pDirectDrawGlobal->hDD)
5. if it fails to create directdraw handle return false
   we did fail to create directdraw HAL 
6. if it susses create directdraw handle return true
   we did susses to create directdraw HAL    
 
To create a directdraw handler you need call the NtGdiDdCreateDirectDrawObject with a hdc