media/doc/DdCreateDirectDrawObject.txt

   1 DdCreateDirectDrawObject
   2
   3 When IN HDC is not NULL
   4 1. we need check the IN HDC is NULL or not
   5 2. if it not null we need create a directdraw handler
   6    and store it to pDirectDrawGlobal->hDD
   7 3. if the directdraw handle is null return false
   8    we did fail to create directdraw HAL
   9 4. if the directdraw handle was not null we return true
  10    we did susses to create directdraw HAL
  11
  12 When IN HDC is NULL
  13 Now we come to if IN HDC is null basic we need create
  14    a hdc and cashe some data
  15 1. if internal cache of directdraw handle is not null (pDirectDrawGlobalInternal->hDD)
  16    we take it and fill to the public directdraw handler (pDirectDrawGlobal->hDD)
  17    and return susses.
  18
  19 2.  if no internal cache of directdraw handle is found we need create it
  20     by using CreateDC for tempary HDC that will be cache in the win32k later
  21
  22 3.  we need check see if we got a tempary HDC or not, if we fail getting tempary
  23     HDC return FALSE
  24
  25 4. Now we trying create directdraw handler it being cache to (pDirectDrawGlobalInternal->hDD)
  26    and it also set same handler to the public (pDirectDrawGlobal->hDD)
  27 5. if it fails to create directdraw handle return false
  28    we did fail to create directdraw HAL
  29 6. if it susses create directdraw handle return true
  30    we did susses to create directdraw HAL
  31
  32 To create a directdraw handler you need call the NtGdiDdCreateDirectDrawObject with a hdc