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author | Max Horn | 2009-07-14 23:03:25 +0000 |
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committer | Max Horn | 2009-07-14 23:03:25 +0000 |
commit | 99fc508609e0def31b9e5c7b59e28fada54c0e1e (patch) | |
tree | eb237d9920221e0dfaf92c3ce10862d3ec91530d | |
parent | 59b35ff5fbb00b47b473c8d0c5ff670bd500e347 (diff) | |
download | scummvm-rg350-99fc508609e0def31b9e5c7b59e28fada54c0e1e.tar.gz scummvm-rg350-99fc508609e0def31b9e5c7b59e28fada54c0e1e.tar.bz2 scummvm-rg350-99fc508609e0def31b9e5c7b59e28fada54c0e1e.zip |
AGOS: Some more cleanup and added some comments to the PN code
svn-id: r42494
-rw-r--r-- | engines/agos/pn.cpp | 10 | ||||
-rw-r--r-- | engines/agos/script_pn.cpp | 56 |
2 files changed, 42 insertions, 24 deletions
diff --git a/engines/agos/pn.cpp b/engines/agos/pn.cpp index fd88d63ec3..d92efa9077 100644 --- a/engines/agos/pn.cpp +++ b/engines/agos/pn.cpp @@ -269,16 +269,16 @@ void AGOSEngine_PN::processor() { _variableArray[16] = _quickshort[6]; _variableArray[17] = _quickshort[7]; _variableArray[19] = getptr(55L); + + // q indicates the process to run and is 0 the first time, + // but 1 later on (i.e., when we are "called" from badload()). setposition(q, 0); doline(0); } void AGOSEngine_PN::setqptrs() { - int a = 0; - - while (a < 11) { - _quickptr[a] = getlong(3L * a); - a++; + for (int i = 0; i < 11; ++i) { + _quickptr[i] = getlong(3 * i); } _quickptr[11] = getlong(58L); _quickptr[12] = getlong(61L); diff --git a/engines/agos/script_pn.cpp b/engines/agos/script_pn.cpp index 9fe05f7f6a..4f9aab2965 100644 --- a/engines/agos/script_pn.cpp +++ b/engines/agos/script_pn.cpp @@ -30,6 +30,10 @@ namespace AGOS { +enum { + kJmpClassNum = -1 +}; + #define OPCODE(x) _OPCODE(AGOSEngine_PN, x) void AGOSEngine_PN::setupOpcodes() { @@ -122,7 +126,7 @@ void AGOSEngine_PN::setupOpcodes() { void AGOSEngine_PN::executeOpcode(int opcode) { OpcodeProcPN op = _opcodesPN[opcode].proc; - (this->*op) (); + (this->*op)(); } int AGOSEngine_PN::readfromline() { @@ -303,11 +307,10 @@ void AGOSEngine_PN::opn_opcode21() { void AGOSEngine_PN::opn_opcode22() { int pf[8]; - int a; - a = varval(); - funcentry(pf, a); + int n = varval(); + funcentry(pf, n); funccpy(pf); - setposition(a, 0); + setposition(n, 0); setScriptReturn(true); } @@ -316,19 +319,27 @@ void AGOSEngine_PN::opn_opcode23() { } void AGOSEngine_PN::opn_opcode24() { - popstack(-1); + popstack(kJmpClassNum); + // Jump back to the last doline, which will return 2-1=1. + // That value then is returned to actCallD, which once again + // returns it. In the end, this amounts to a setScriptReturn(true) + // (but possibly in a different level than the current one). longjmp(*(_stackbase->savearea), 2); setScriptReturn(false); } void AGOSEngine_PN::opn_opcode25() { - popstack(-1); + popstack(kJmpClassNum); + // Jump back to the last doline, which will return 1-1=0. + // That value then is returned to actCallD, which once again + // returns it. In the end, this amounts to a setScriptReturn(false) + // (but possibly in a different level than the current one). longjmp(*(_stackbase->savearea), 1); setScriptReturn(false); } void AGOSEngine_PN::opn_opcode26() { - while ((_stackbase != NULL) && (_stackbase->classnum != -1)) + while ((_stackbase != NULL) && (_stackbase->classnum != kJmpClassNum)) junkstack(); dumpstack(); setScriptReturn(true); @@ -348,6 +359,8 @@ void AGOSEngine_PN::opn_opcode28() { void AGOSEngine_PN::opn_opcode29() { popstack(varval()); + // Jump back to the last doline indicated by the top stackfram. + // The -1 tells it to simply go on with its business. longjmp(*(_stackbase->savearea), -1); setScriptReturn(false); } @@ -837,7 +850,7 @@ void AGOSEngine_PN::setbitf(uint32 ptr, int offs, int val) { int AGOSEngine_PN::actCallD(int n) { int pf[8]; funcentry(pf, n); - addstack(-1); + addstack(kJmpClassNum); funccpy(pf); setposition(n, 0); return doline(1); @@ -862,7 +875,7 @@ int AGOSEngine_PN::doaction() { int AGOSEngine_PN::doline(int needsave) { int x; - jmp_buf *ljmpbuff = NULL; + jmp_buf *old_jmpbuf = NULL; jmp_buf *mybuf; mybuf = (jmp_buf *)malloc(sizeof(jmp_buf)); @@ -874,16 +887,25 @@ int AGOSEngine_PN::doline(int needsave) { // (and of course 0 when it returns directly, as always). if (x > 0) { dumpstack(); - _cjmpbuff = ljmpbuff; + // Restore the active jmpbuf to its previous value, + // then return the longjmp value (will be 2-1=1 or 1-1=0). + _cjmpbuff = old_jmpbuf; free((char *)mybuf); return (x - 1); } if (x == -1) { + // Make this doline instance the active one (again). + // This is used to "return" over possibly multiple + // layers of nested script invocations. + // Kind of like throwing an exception. _cjmpbuff = mybuf; goto carryon; } - ljmpbuff = _cjmpbuff; + + // Remember the previous active jmpbuf (gets restored + // above when a longjmp with a positive param occurs). + old_jmpbuf = _cjmpbuff; _cjmpbuff = mybuf; if (needsave) _stackbase->savearea = mybuf; @@ -963,13 +985,9 @@ void AGOSEngine_PN::funccpy(int *store) { } void AGOSEngine_PN::funcentry(int *store, int procn) { - int ct = 0; - int nprm; - - nprm = _dataBase[getlong(_quickptr[6] + 3L * procn)]; - while (ct < nprm) { + int numParams = _dataBase[getlong(_quickptr[6] + 3 * procn)]; + for (int i = 0; i < numParams; ++i) { *store++ = varval(); - ct++; } } @@ -1082,7 +1100,7 @@ void AGOSEngine_PN::junkstack() { error("junkstack: Stack underflow or unknown longjmp"); a = _stackbase->nextframe; - if (_stackbase->classnum == -1) + if (_stackbase->classnum == kJmpClassNum) free((char *)_stackbase->savearea); free((char *)_stackbase); _stackbase = a; |