Some kernel calls need to be able to call back into game script
code, which requires a valid stack pointer for use with
invokeSelector.
An example of this is the guest additions code that syncs audio
volumes from ScummVM: it needs to be able to call into the game
scripts responsible for managing the in-game audio volume UI.
SCI3 includes four new opcodes:
* op_info[0x26][0] puts -info- flag in accumulator
* op_infoSP[0x26][1] pushes -info- flag to stack
* op_superP[0x27][0] puts -super- reference in accumulator
* op_superPSP[0x27][1] pushes -super- reference to stack
The implementation of these opcodes was correct already, but the
opcode names given were a bit misleading (the value is not always
stored to accumulator), and magic numbers were used for these
opcodes in places.
A review of the opcode table in Phant2 indicates that there are
no other new opcodes for SCI3.
1. pushi opcode now displays decimal value and selector value (if
one exists) in-line
2. lofsa, lofss, and super opcodes now display resolved
object/class names
3. Opcode arguments are visually aligned
Silently returning zero values can cause games to break. e.g.
Shivers 1 room 35170 has a script bug where vJoystick::handleEvent
makes a super call which causes doVerb to be called a second time
with no arguments. In the original game this happened to work
because the value already on the stack happened to be 1. In ScummVM
this silently (unless VM debug messages were enabled) failed
because the uninitialised read value was forced to 0.
Revert "SCI32: Fix KQ7 1.51 video background"
This reverts commit c8affb54cc.
Revert "SCI32: Fix crash when kShowMovie is called but the video cannot be found"
This reverts commit 93b06f4a9e.
Revert "SCI32: Fix KQ7 1.51 basic video playback"
This reverts commit cdab24aa07.
Revert "SCI32: Additional Video32 documentation"
This reverts commit 4ff0924e57.
Revert "SCI32: Implement kShowMovie"
This reverts commit 13297c1929.
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.
This is needed for future support of large SCI3 scripts. The program
counter is isolated and does not interfere with other parts of the VM,
plus it does not get stored in saved games, so it's pretty straightforward
to convert
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)
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]*$//'