[AD] [WIN] Page flipping code rewrite

["Eric Botcazou" <ebotcazou@xxxxxxxxxx>]

The attached patch contains a new implementation of the page flipping/triple
buffering code for the three DirectDraw drivers (fullscreen, windows,
overlay). It has been tested with the two first drivers only (the gfx card
of the system I use here doesn't apparently support overlays). But I don't
expect any serious problem for the third driver, given that it behaves the
same as the fullscreen one regarding page flipping/triple buffering.

DirectDraw requires the surfaces to be attached (forming a so-called
flipping chain) to perform page flipping or triple buffering on them. Early
3.9.3x WIP versions attach/detach the surfaces on the fly (for each flipping
operation). Later 3.9.3x and 4.0.x versions create a flipping chain (with 3
surfaces) at startup (when set_gfx_mode is called). This implementation
attaches each surface individually when it is created.

Hopefully this will solve the problems on Win2k/WinXP I previously talked
about.

- Eric

Attachment: win_flip.zip
Description: Zip compressed data