Controls that manage their own event loops and call frameOut
directly generally need to sleep in order to avoid 100% CPU,
just like the main VM event loop.
Modifying a value above the stack pointer doesn't seem to make much
sense. This was added in FreeSCI back in 2002 in a pair of commits that
did not make clear what the purpose of this was. My guess is that it
attempted to adjust argc, but failed. This wouldn't have been noticed
since argc was always set correctly by make_exec_stack_entry (which is
now the ExecStack constructor).
ExecStack now stores the kernel call number as well as the subfunction.
This allows kStub and backtraces to log the actual subfunction called.
The kernel call number in ExecStack used to be stored in the
debugSelector field. It now has its own field, to avoid confusion.
The way dimensions of scaled screen items are calculated changed
over the lifetime of SSCI. In early low-resolution and
mixed-resolution games, scaled drawing needed to use at a global
cadence across the entire screen to ensure proper alignment, but
in later games (like Torin), local scaling of individual screen
items seems to be the way scaling is performed.
Using the one from SCI2.1mid makes fades very slow because SDL has
a larger audio buffer than SSCI DOS. This new algorithm is based on
wall time so will always fade at the correct speed, although the
larger buffers will have a coarser granularity so the fades may
not be as smooth as in the original engine. If anyone cares, the
fade volume could be mixed into individual samples in `readBuffer`
instead of applying just once per complete buffer. SSCI did not
do this, however, so this implementation should be pretty accurate.
Overlays are shown with _currentShakePos offset too, so no need to
compensate the mousepointer position for overlays. This compensation
was done inconsistently in draw/undraw mouse causing the mouse trails.
Remap would crash SCI2.1early games with 19 remap slots, and
did not actually work in most cases in SCI2.1mid+ games.
1. Avoid accidental corruption of values from the VM that may be
valid when signed or larger than 8 bits
2. Fix bad `matchColor` function.
3. Remove unnecessary initialisation of SingleRemaps
4. Update architecture to more closely mirror how SSCI worked
5. Split large `apply` function into smaller units
6. Fix buffer overrun when loading a SCI2.1early game with remap
7. Warn instead of crashing with an error on invalid input (to
match SSCI more closely)
8. Add save/load function
