diff options
| -rw-r--r-- | engines/sci/engine/script.cpp | 100 | ||||
| -rw-r--r-- | engines/sci/engine/script.h | 12 |
2 files changed, 112 insertions, 0 deletions
diff --git a/engines/sci/engine/script.cpp b/engines/sci/engine/script.cpp index 645094d9ec..845f5b92e3 100644 --- a/engines/sci/engine/script.cpp +++ b/engines/sci/engine/script.cpp @@ -113,6 +113,103 @@ void Script::init(int script_nr, ResourceManager *resMan) { } } +// signatures are built like this: +// - first a counter of the bytes that follow +// - then the actual bytes that need to get matched +// - then another counter of bytes (0 for EOS) +// - if not EOS, an adjust offset and the actual bytes +// - rinse and repeat +const byte hoyle4SignaturePortFix[] = { + 28, + 0x39, 0x09, // pushi 09 + 0x89, 0x0b, // lsg 0b + 0x39, 0x64, // pushi 64 + 0x38, 0xc8, 0x00, // pushi 00c8 + 0x38, 0x2c, 0x01, // pushi 012c + 0x38, 0x90, 0x01, // pushi 0190 + 0x38, 0xf4, 0x01, // pushi 01f4 + 0x38, 0x58, 0x02, // pushi 0258 + 0x38, 0xbc, 0x02, // pushi 02bc + 0x38, 0x20, 0x03, // pushi 0320 + 0x46, // calle [xxxx] [xxxx] [xx] + 13, +5, // [skip 5 bytes] + 0x30, 0x27, 0x00, // bnt 0027 -> end of routine + 0x87, 0x00, // lap 00 + 0x30, 0x19, 0x00, // bnt 0019 -> fade out + 0x87, 0x01, // lap 01 + 0x30, 0x14, 0x00, // bnt 0014 -> fade out + // [...] + 10, +20, // [skip 20 bytes] + 0x38, 0xaa, 0x00, // pushi 00aa + 0x76, // push0 + 0x80, 0x29, 0x01, // lag 0129 + 0x4a, 0x04, // send 04 + 0x48, // ret + 0 +}; + +const int16 hoyle4PatchPortFix[] = { + 0 +}; + +// script, description, magic DWORD, adjust +const SciScriptSignature hoyle4Signatures[] = { + { 0, "port fix when disponsing windows", CONSTANT_LE_32(0x00C83864), -5, hoyle4SignaturePortFix, hoyle4PatchPortFix }, + { 0, NULL, 0, 0, NULL, NULL } +}; + +// will return -1 if no match was found, otherwise an offset to the start of the signature match +int32 Script::findSignature(const SciScriptSignature *signature, const byte *scriptData, const uint32 scriptSize) { + if (scriptSize < 4) // we need to find a DWORD, so less than 4 bytes is not okay + return -1; + + const uint32 magicDWord = signature->magicDWord; // is platform-specific BE/LE form, so that the later match will work + const uint32 searchLimit = scriptSize - 3; + uint32 DWordOffset = 0; + // first search for the magic DWORD + while (DWordOffset < searchLimit) { + if (magicDWord == *(uint32 *)(scriptData + DWordOffset)) { + // magic DWORD found, check if actual signature matches + uint32 offset = DWordOffset + signature->magicOffset; + uint32 byteOffset = offset; + const byte *signatureData = signature->data; + byte matchBytesCount = *signatureData++; + while (matchBytesCount) { + if ((byteOffset + matchBytesCount) > scriptSize) // Out-Of-Bounds? + break; + if (memcmp(signatureData, &scriptData[byteOffset], matchBytesCount)) // Byte-Mismatch? + break; + // those bytes matched, adjust offsets accordingly + signatureData += matchBytesCount; + byteOffset += matchBytesCount; + // get next byte count and offset + matchBytesCount = *signatureData++; + if (matchBytesCount) + byteOffset += *signatureData++; + } + if (!matchBytesCount) // all matches worked? + return offset; + } + DWordOffset++; + } + // nothing found + return -1; +} + +void Script::matchSignatureAndPatch(uint16 scriptNr, const byte *scriptData, const uint32 scriptSize) { + if (g_sci->getGameId() == GID_HOYLE4) { + const SciScriptSignature *signatureTable = hoyle4Signatures; + while (signatureTable->data) { + uint32 foundOffset = findSignature(signatureTable, scriptData, scriptSize); + if (foundOffset != -1) { + // found, so apply the patch + warning("matched %s on script %d offset %d", signatureTable->description, scriptNr, foundOffset); + } + signatureTable++; + } + } +} + void Script::load(ResourceManager *resMan) { Resource *script = resMan->findResource(ResourceId(kResourceTypeScript, _nr), 0); assert(script != 0); @@ -123,6 +220,9 @@ void Script::load(ResourceManager *resMan) { assert(_bufSize >= script->size); memcpy(_buf, script->data, script->size); + // Check scripts for matching signatures and patch those, if found + matchSignatureAndPatch(_nr, _buf, script->size); + if (getSciVersion() >= SCI_VERSION_1_1) { Resource *heap = resMan->findResource(ResourceId(kResourceTypeHeap, _nr), 0); assert(heap != 0); diff --git a/engines/sci/engine/script.h b/engines/sci/engine/script.h index 3817f8aae1..8334cc838c 100644 --- a/engines/sci/engine/script.h +++ b/engines/sci/engine/script.h @@ -31,6 +31,15 @@ namespace Sci { +struct SciScriptSignature { + uint16 scriptNr; + const char *description; + uint32 magicDWord; + int magicOffset; + const byte *data; + const int16 *patch; +}; + struct EngineState; class ResourceManager; @@ -100,6 +109,9 @@ public: void init(int script_nr, ResourceManager *resMan); void load(ResourceManager *resMan); + void matchSignatureAndPatch(uint16 scriptNr, const byte *scriptData, const uint32 scriptSize); + int32 findSignature(const SciScriptSignature *signature, const byte *scriptData, const uint32 scriptSize); + virtual bool isValidOffset(uint16 offset) const; virtual SegmentRef dereference(reg_t pointer); virtual reg_t findCanonicAddress(SegManager *segMan, reg_t sub_addr) const; |