Witcher 2 Engine Fix 0.10.0

GOG support, softer door lighting and a memory guard

GOG is supported now. Besides the Steam version (3.5.0.26), this version also supports the GOG version of The Witcher 2: Assassins of Kings - Enhanced Edition (3.5.0.26g), with every feature and setting. The GOG game is a separately compiled build, so each fix had to be found in it again. The DLL tells the two builds apart at start and uses each one's own addresses.

DXVK is strongly recommended, and at 4K you need it. The game is a 32-bit program, so it has 4 GB of memory at most. With the game's own Direct3D 9 every texture also takes room there, and at 4K the game runs out of memory soon after loading a save in Flotsam, with or without this mod. DXVK keeps the textures on the graphics card: copy its x32\d3d9.dll into the game's bin folder. If the game hangs after a while with DXVK (a GPU reset, "device lost"), put the line dxvk.enableDescriptorHeap = False in bin\dxvk.conf.

• New: GOG 3.5.0.26g. Seamless interiors, draw distance presets and the Options rows, the save fixes, the Display mode, the Windows keys, the book markers, Continue, Quit, the medallion, the crash and quit guards and the interior maps all work on GOG. On GOG the save previews go next to the save in Documents\Witcher 2\gamesaves, and the save list has no leak to fix.
• Changed: the lighting at house doors blends over 1 second instead of jumping. Inns and houses have their own lighting (no sun, other colours, a shorter view), and the game used to switch it in one frame behind its fade. Without the fade you saw the street go flat as Geralt opened the door, and the inn's walls change colour on the way out. [loading] door_light_blend=0 switches at once again.
• Changed: no loading spinner in the corner on doors without a fade. [loading] door_spinner=1 shows it again.
• Fixed: a freeze on the first walk out after loading a save made inside a house. The street was not part of the load, so the first door loaded it in plain view (~0.4 s), and every later exit from that house blinked black. The street now loads with the save.
• New: memory guard for the seamless interiors. Preloaded interiors load only while at least 1280 MB of the game's memory is free; the rest load on their first visit, behind a short fade. A door that starts with less than 1024 MB free uses the game's own door. With DXVK there is room to spare and neither kicks in. [loading] preload_memory_mb and door_memory_mb.
• Fixed: two QuickSaves within 10 seconds could show the same picture.
• New: the log says how the game ended (exit: lines). On GOG the log ends with exit: CorExitProcess(0) instead of unloaded; that is a normal quit.

Upgrading

Extract the zip over the previous version (into the game folder, so that bin\dinput8.dll is replaced). The new ini replaces the old one; if you changed settings, note them first. bin\witcher2_enginefix.log should start with witcher2_enginefix 0.10.0 loaded, followed by a build: line naming Steam 3.5.0.26 or GOG 3.5.0.26g.

Tested on Steam 3.5.0.26 and GOG 3.5.0.26g (Enhanced Edition), Windows 11, with DXVK and with the game's own Direct3D 9. Not yet seen in game: on GOG, the preview fix writing a late preview (the game wrote its own every time) and the memory guard skipping a preloaded interior.