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ReC98/th02/hardware/snd_kaja_func.asm

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NASM
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Use TASM calling convention syntax for previously identified ZUN functions With TH03 changing the calling convention for most of the code from __cdecl to __pascal, I've been getting more and more confused about this myself. So, let's settle on the following consistent syntax for function calls: * C where the calling convention is actually __cdecl and where TASM's emitted __cdecl code matches the original binary * PASCAL where the calling convention is actually __pascal * STDCALL where the calling convention is actually __cdecl, but where the caller either defers stack cleanup (summing up the stack size of multiple functions, then cleaning it all in a single "add sp" instruction) or where the stack is cleared in a different way (e.g. "pop cx"). Unfortunately though, when using the ARG directive to automatically generate an appropriate RET instruction for the given calling convention, TASM always emits ENTER and LEAVE instructions even when no local variables are declared, which greatly limits the number of functions where we can use that syntax. -.-
2014-12-16 04:53:56 +00:00
; int DEFCONV snd_kaja_func(int ax)
[Reverse-engineering] PMD and MMD function call wrapper Well, the naming. Even though only TH02 actually uses MIDI (and thus, the MMD driver), every game since then contains interrupt instructions for both functions. We could just name it "pmd", since it seems like that's what came first - the AH numbers of the 6 functions that make up MMD's interrupt API are identical to those of the equivalent functions in PMD, even including gaps in the numbering for PMD functions that don't have an equivalent in MIDI. However, except for the FM sound effect handling and the key display in TH05's Music Room, these 6 functions are all the games actually use. Also, we already distinguish between PMD and MMD in the driver check functions, and it might be confusing to only imply PMD from now on? So, "kaja" it is, collectively referring to the shared aspects of both drivers.
2014-11-26 19:03:58 +00:00
snd_kaja_func proc
@@ax = word ptr (cPtrSize + 2)
push bp
mov bp, sp
[Reverse-engineering] Sound mode determination Note how it's only one *mode* in TH02/TH03, but two *modes* in TH04/TH05, since you can't select between FM and Beep sound effect modes in TH02/TH03 (or even disable sounds altogether). Might be a bit confusing, but it seemed appropriate enough to distinguish the two functions.
2014-11-28 23:56:26 +00:00
cmp snd_active, 0
[Reverse-engineering] PMD and MMD function call wrapper Well, the naming. Even though only TH02 actually uses MIDI (and thus, the MMD driver), every game since then contains interrupt instructions for both functions. We could just name it "pmd", since it seems like that's what came first - the AH numbers of the 6 functions that make up MMD's interrupt API are identical to those of the equivalent functions in PMD, even including gaps in the numbering for PMD functions that don't have an equivalent in MIDI. However, except for the FM sound effect handling and the key display in TH05's Music Room, these 6 functions are all the games actually use. Also, we already distinguish between PMD and MMD in the driver check functions, and it might be confusing to only imply PMD from now on? So, "kaja" it is, collectively referring to the shared aspects of both drivers.
2014-11-26 19:03:58 +00:00
jz short @@ret
mov ax, [bp+@@ax]
cmp snd_midi_active, 1
jz short @@midi
int 60h
jmp short @@ret
@@midi:
int 61h
@@ret:
pop bp
if GAME ge 3
ret 2
else
ret
endif
snd_kaja_func endp