I picked FreeSCI’s file handling as an initial target because it looked like it would be fairly straightforward: replace anything in the FreeSCI code that used file IO with invocations of the ScummVM file and savegame classes. In the process, it would be possible to get used to the ScummVM and FreeSCI source code, making future tasks easier.
This gets complicated when one adds the additional goal of keeping the source code as close to the FreeSCI main branch as possible. Simply going through and replacing anything with a FILE* near it results in a lot of changed source code. This means that incorporating any future changes to the FreeSCI main branch into our code will be a bit of a pain.
One option is to build an abstraction layer into FreeSCI; this layer would encapsulate both the FILE* implementation and the use of ScummVM classes, so that one could choose between them. This is similar to the approach that FreeSCI’s graphics code uses to allow for different means of outputting graphics. An alternative is to keep copies of the relevant files and pick which one we want at compile time, depending on whether we’re compiling as a standalone copy of FreeSCI or a ScummVM engine.
Either way it involves a change to the FreeSCI base, so we’ve been getting feedback from other developers. Until it gets sorted out, I’m devoting some attention to the sound output.