SCI/SCI32 Mac Support Status
This page is an attempt to track the state of ScummVM support for SCI32 Mac games. They are not supported yet but we're making good progress. Many are now playable and all of them can at least boot to the title screen. Gabriel Knight 1 has even been moved to ADGF_TESTING and has been completed by a tester. GK1 is floppy-only and unaffected by the issues that need addressing to support CD and later games.
Working with data files from SCI32 Macintosh CDs is difficult. Some of these difficulties are for users while others are problems for us that we haven't solved yet. It's not just one thing, it's the combination:
- Resource forks: Game data files use Macintosh resource forks while individual resource files use data forks.
- Hidden files: Most data files and directories are flagged Hidden. This is an extraction obstacle for software that respects this flag, such as classic Finder.
- Thousands of files: Each speech audio resource is stored as an individual file. Some games have up to 10,000 files. Our SCI resource loader is not designed for this large amount. On startup it performs work on each file and this creates delays that can last minutes.
- Folder structure: Data files are scattered across folders, some hidden and some not, with duplicates. Some of these duplicates appear to contain no resources. The idea was to present a folder that users would copy to their hard drive with the executable and one or two data files, leaving the others on disc and invisible.
- Many data files: Games have many small Data## files instead of a few large volume files. Our Advanced Detector only supports 13 files.
- Multi-disc: The structure of multi-disc games is at odds with our detection model. Each disc has many small Data## files with the same filenames as those on other discs. They can't all be placed in the same directory with those names, but there are also far too many to require manual renaming. It seems like some kind of subdirectory scheme will be required. As mentioned above, the Advanced Detector doesn't have support enough entries for even one disc of these games, let alone six. Given that setting up these files properly could be error prone, not being able to detect missing files would be a problem.
I (sluicebox) have decompiled the scripts of every SCI32 Mac game and compared them to the PC versions. Aside from one joke in Phantasmagoria and an updated birthday in Space Quest 6, the Mac versions don't seem to offer interesting differences beyond native (worse) cursors and some different audio formats. It's fun to add support for them where possible, but it's probably not worth significantly complicating the codebase just to for these rare versions that are more difficult to setup and often more limited than the PC versions. For example, Space Quest 6 Mac stores music in a unique way (regular MIDI files!) that breaks core assumptions in our audio code. No other game does this. If that requires a major audio refactor, it would be hard to justify. So far, I've been able to fix Mac incompatibilities and add Mac features with low impact changes. What's left is the hard stuff.
Later SCI32 games were mostly distributed on CDs with both PC and Macintosh partitions so these discs already have the working PC files anyway. This reduces the practical benefits of Mac support for these games even further.
- Determine how to handle multi-disc data files and implement it. (Current blocker for Phant1 and GK2)
- Improve load times when faced with thousands of patch files. (This would help PC fan-patches too: [Bug #11353] )
- Add engine support for a library of standard MIDI files (SQ6 only)
- Implement kPlatform Mac subops for saving and restoring in Lighthouse.
- Document game file extraction for users
SCI32 Mac Games
kPlatform supports a handful of miscellaneous Mac-specific sub operations. The SCI32 ones are different than SCI16, and some changed between SCI32 versions. I have decompiled and audited all kPlatform calls in all SCI32 Mac scripts. I have implemented these for every game except Lighthouse since it's not playable enough to test this yet. I'm leaving all of these kPlatform notes here until Lighthouse's subops are done:
- KQ7 does custom saving and restoring with subops 3, 4, and 5 to initiate, save, and restore files. Initiate is called when starting a new game. Initiate and Restore would display a native Mac save or open dialog with a hard-coded and misspelled prompt such as "Who's game?". The interpreter would remember the current save file, not the game scripts. These subops take no parameters.
- Shivers also does custom saving and restoring with subops 3, 4, and 5 but they take parameters similar to the normal kSave and kRestore functions. It appears the interpreter is no longer in charge of tracking the current save file.
- Lighthouse also does custom saving and restoring but just for fun it only uses subop 3 but adds a sub-subop parameter for the three operations. It appears that -1 initializes, 1 saves, and 0 restores.
- Mother Goose uses subops 6, 7, 8, 9, 10, and 11 for saving and restoring. These subops take parameters similar to kSave and kRestore.
- Phantasmagoria sets the music volume from the control panel with subop 12 and passes a volume parameter between 0 and 15.
There is a Mac floppy version of HOYLE5 with a separate executable for each card game. No attempt has been made to support this. I don't know anything else about it.