Memory references and integers in SSCI are both 16-bit numbers,
so game scripts frequently (incorrectly) use an IntArray instead
of an IDArray for holding references. Since references in ScummVM
are 32-bit reg_ts, IntArray entries must be large enough to hold
reg_ts in order to be compatible with game scripts that store
references in integer arrays.
The alternative solution is to find and patch all incorrect use of
IntArray across all games. This is possible, but a bit risky from
a save game stability perspective, since incorrect IntArray usage
is sometimes not apparent until well after the array is
instantiated (like GK1's global interview array).
This change invalidates existing SCI32 save games.
This change invalidates earlier SCI32 save games, which separated
arrays and strings in an incompatible manner. Old save games
contain invalid references to a string segment which no longer
exists, and contain incompatible array structures that lack
critical type information.
When new bitmaps are added and the underlying Common::Array needs
to move to expand, this invalidates all pointers to bitmaps, which
makes it basically impossible to use the bitmap segment since you
never know if a reference is going to be invalidated due to an
array move.
To solve this, BitmapTable is changed to hold pointers to
SciBitmaps that are allocated separately on the heap instead, so
when those bitmaps are looked up, the resulting pointers are valid
for the lifetime of the bitmap, instead of the lifetime of the
Common::Array used internally by BitmapTable.
No functionality change has been made with this commit. This avoids
setting and getting the reg_t members directly, and is the basis of any
future work on large SCI3 scripts (larger than 64KB)
find -name '*.h' -or -name '*.cpp' | xargs sed -r -i 's@\(([A-Za-z0-9]+)\*\)@(\1 *)@g'
This seems to have caught some params as well which is not undesirable IMO.
It also caught some strings containing this which is undesirable so I
excluded them manually. (engines/sci/engine/kernel_tables.h)
This tries to make our code a bit more compliant with our code formatting
conventions. For future use, this is the command I used:
git ls-files "*.cpp" "*.h" | xargs sed -i -e 's/[ \t]*$//'
SCI scripts can contain stale pointers, which are used later on. We now delete
the contents of hunk entries without invalidating the relevant pointers and let
the GC clear the references. Many thanks to waltervn and wjp for all their work
and help on this.
