SCI: Split the new script patch code in a separate file

svn-id: r51810

4 files changed, 249 insertions, 214 deletions

diff --git a/engines/sci/engine/script.cpp b/engines/sci/engine/script.cpp
index 07e0982076..3ba550adf9 100644
--- a/engines/sci/engine/script.cpp
+++ b/engines/sci/engine/script.cpp
@@ -113,211 +113,6 @@ 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
-
-
-// this here gets called on entry and when going out of game windows
-//  uEvt::port will not get changed after kDisposeWindow but a bit later, so
-//  we would get an invalid port handle to a kSetPort call. We just patch in
-//  resetting of the port selector. We destroy the stop/fade code in there,
-//  it seems it isn't used at all in the game.
-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]
-	+5, 43,            // [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
-	0x38, 0xa7, 0x00,  // pushi 00a7
-	0x76,              // push0
-	0x80, 0x29, 0x01,  // lag 0129
-	0x4a, 0x04,        // send 04 (song::stop)
-	0x39, 0x27,        // pushi 27
-	0x78,              // push1
-	0x8f, 0x01,        // lsp 01
-	0x51, 0x54,        // class 54
-	0x4a, 0x06,        // send 06 (PlaySong::play)
-	0x33, 0x09,        // jmp 09 -> end of routine
-	0x38, 0xaa, 0x00,  // pushi 00aa
-	0x76,              // push0
-	0x80, 0x29, 0x01,  // lag 0129
-	0x4a, 0x04,        // send 04
-	0x48,              // ret
-	0
-};
-
-#define PATCH_END             0xFFFF
-#define PATCH_ADDTOOFFSET     0x8000
-#define PATCH_GETORIGINALBYTE 0x4000
-
-const uint16 hoyle4PatchPortFix[] = {
-	PATCH_ADDTOOFFSET | +33,
-	0x38, 0x31, 0x01,  // pushi 0131 (selector curEvent)
-	0x76,              // push0
-	0x80, 0x50, 0x00,  // lag 0050 (global var 80h, "User")
-	0x4a, 0x04,        // send 04 (read User::curEvent)
-
-	0x38, 0x93, 0x00,  // pushi 0093 (selector port)
-	0x78,              // push1
-	0x76,              // push0
-	0x4a, 0x06,        // send 06 (write 0 to that object::port)
-	0x48,              // ret
-	PATCH_END
-};
-
-//    script, description,                                   magic DWORD,                adjust
-const SciScriptSignature hoyle4Signatures[] = {
-    {      0, "port fix when disposing windows",             CONSTANT_LE_32(0x00C83864),    -5, hoyle4SignaturePortFix,   hoyle4PatchPortFix },
-    {      0, NULL,                                          0,                              0, NULL,                     NULL }
-};
-
-
-// this is called on every death dialog. Problem is at least the german
-//  version of lsl6 gets title text that is far too long for the
-//  available temp space resulting in temp space corruption
-//  This patch moves the title text around, so this overflow
-//  doesn't happen anymore. We would otherwise get a crash
-//  calling for invalid views (this happens of course also
-//  in sierra sci)
-const byte larry6SignatureDeathDialog[] = {
-	7,
-	0x3e, 0x33, 0x01,             // link 0133 (offset 0x20)
-	0x35, 0xff,                   // ldi ff
-	0xa3, 0x00,                   // sal 00
-	+255, 0,
-	+255, 0,
-	+170, 12,                     // [skip 680 bytes]
-	0x8f, 0x01,                   // lsp 01 (offset 0x2cf)
-	0x7a,                         // push2
-	0x5a, 0x04, 0x00, 0x0e, 0x01, // lea 0004 010e
-	0x36,                         // push
-	0x43, 0x7c, 0x0e,             // kMessage[7c] 0e
-	+90, 10,                      // [skip 90 bytes]
-	0x38, 0xd6, 0x00,             // pushi 00d6 (offset 0x335)
-	0x78,                         // push1
-	0x5a, 0x04, 0x00, 0x0e, 0x01, // lea 0004 010e
-	0x36,                         // push
-	+76, 11,                      // [skip 76 bytes]
-	0x38, 0xcd, 0x00,             // pushi 00cd (offset 0x38b)
-	0x39, 0x03,                   // pushi 03
-	0x5a, 0x04, 0x00, 0x0e, 0x01, // lea 0004 010e
-	0x36,
-	0
-};
-
-const uint16 larry6PatchDeathDialog[] = {
-	0x3e, 0x00, 0x02,             // link 0200
-	PATCH_ADDTOOFFSET | +687,
-	0x5a, 0x04, 0x00, 0x40, 0x01, // lea 0004 0140
-	PATCH_ADDTOOFFSET | +98,
-	0x5a, 0x04, 0x00, 0x40, 0x01, // lea 0004 0140
-	PATCH_ADDTOOFFSET | +82,
-	0x5a, 0x04, 0x00, 0x40, 0x01, // lea 0004 0140
-	PATCH_END
-};
-
-//    script, description,                                   magic DWORD,                adjust
-const SciScriptSignature larry6Signatures[] = {
-    {     82, "death dialog memory corruption",              CONSTANT_LE_32(0x3501333e),     0, larry6SignatureDeathDialog, larry6PatchDeathDialog },
-    {      0, NULL,                                          0,                              0, NULL,                       NULL }
-};
-
-// will actually patch previously found signature area
-void Script::applyPatch(const uint16 *patch, byte *scriptData, const uint32 scriptSize, int32 signatureOffset) {
-	int32 offset = signatureOffset;
-	uint16 patchWord = *patch;
-
-	while (patchWord != PATCH_END) {
-		if (patchWord & PATCH_ADDTOOFFSET) {
-			offset += patchWord & ~PATCH_ADDTOOFFSET;
-		} else if (patchWord & PATCH_GETORIGINALBYTE) {
-			// TODO: implement this
-		} else {
-			scriptData[offset] = patchWord & 0xFF;
-			offset++;
-		}
-		patch++;
-		patchWord = *patch;
-	}	
-}
-
-// 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 == *(const 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 matchAdjust = 1;
-			while (matchAdjust) {
-				byte matchBytesCount = *signatureData++;
-				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 offset...
-				matchAdjust = *signatureData++;
-				byteOffset += matchAdjust;
-			}
-			if (!matchAdjust) // all matches worked?
-				return offset;
-		}
-		DWordOffset++;
-	}
-	// nothing found
-	return -1;
-}
-
-void Script::matchSignatureAndPatch(uint16 scriptNr, byte *scriptData, const uint32 scriptSize) {
-	const SciScriptSignature *signatureTable = NULL;
-	if (g_sci->getGameId() == GID_HOYLE4)
-		signatureTable = hoyle4Signatures;
-	if (g_sci->getGameId() == GID_LSL6)
-		signatureTable = larry6Signatures;
-
-	if (signatureTable) {
-		while (signatureTable->data) {
-			if (scriptNr == signatureTable->scriptNr) {
-				int32 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);
-					applyPatch(signatureTable->patch, scriptData, scriptSize, foundOffset);
-				}
-			}
-			signatureTable++;
-		}
-	}
-}
-
 void Script::load(ResourceManager *resMan) {
 	Resource *script = resMan->findResource(ResourceId(kResourceTypeScript, _nr), 0);
 	assert(script != 0);
diff --git a/engines/sci/engine/script.h b/engines/sci/engine/script.h
index 35daf20191..c60cc4b19f 100644
--- a/engines/sci/engine/script.h
+++ b/engines/sci/engine/script.h
@@ -31,17 +31,9 @@
 
 namespace Sci {
 
-struct SciScriptSignature {
-	uint16 scriptNr;
-	const char *description;
-	uint32 magicDWord;
-	int magicOffset;
-	const byte *data;
-	const uint16 *patch;
-};
-
 struct EngineState;
 class ResourceManager;
+struct SciScriptSignature;
 
 enum ScriptObjectTypes {
 	SCI_OBJ_TERMINATOR,
diff --git a/engines/sci/engine/script_patches.cpp b/engines/sci/engine/script_patches.cpp
new file mode 100644
index 0000000000..228bf39e7d
--- /dev/null
+++ b/engines/sci/engine/script_patches.cpp
@@ -0,0 +1,247 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#include "sci/sci.h"
+#include "sci/engine/script.h"
+
+#include "common/util.h"
+
+namespace Sci {
+
+struct SciScriptSignature {
+	uint16 scriptNr;
+	const char *description;
+	uint32 magicDWord;
+	int magicOffset;
+	const byte *data;
+	const uint16 *patch;
+};
+
+// 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
+
+
+// this here gets called on entry and when going out of game windows
+//  uEvt::port will not get changed after kDisposeWindow but a bit later, so
+//  we would get an invalid port handle to a kSetPort call. We just patch in
+//  resetting of the port selector. We destroy the stop/fade code in there,
+//  it seems it isn't used at all in the game.
+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]
+	+5, 43,            // [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
+	0x38, 0xa7, 0x00,  // pushi 00a7
+	0x76,              // push0
+	0x80, 0x29, 0x01,  // lag 0129
+	0x4a, 0x04,        // send 04 (song::stop)
+	0x39, 0x27,        // pushi 27
+	0x78,              // push1
+	0x8f, 0x01,        // lsp 01
+	0x51, 0x54,        // class 54
+	0x4a, 0x06,        // send 06 (PlaySong::play)
+	0x33, 0x09,        // jmp 09 -> end of routine
+	0x38, 0xaa, 0x00,  // pushi 00aa
+	0x76,              // push0
+	0x80, 0x29, 0x01,  // lag 0129
+	0x4a, 0x04,        // send 04
+	0x48,              // ret
+	0
+};
+
+#define PATCH_END             0xFFFF
+#define PATCH_ADDTOOFFSET     0x8000
+#define PATCH_GETORIGINALBYTE 0x4000
+
+const uint16 hoyle4PatchPortFix[] = {
+	PATCH_ADDTOOFFSET | +33,
+	0x38, 0x31, 0x01,  // pushi 0131 (selector curEvent)
+	0x76,              // push0
+	0x80, 0x50, 0x00,  // lag 0050 (global var 80h, "User")
+	0x4a, 0x04,        // send 04 (read User::curEvent)
+
+	0x38, 0x93, 0x00,  // pushi 0093 (selector port)
+	0x78,              // push1
+	0x76,              // push0
+	0x4a, 0x06,        // send 06 (write 0 to that object::port)
+	0x48,              // ret
+	PATCH_END
+};
+
+//    script, description,                                   magic DWORD,                adjust
+const SciScriptSignature hoyle4Signatures[] = {
+    {      0, "port fix when disposing windows",             CONSTANT_LE_32(0x00C83864),    -5, hoyle4SignaturePortFix,   hoyle4PatchPortFix },
+    {      0, NULL,                                          0,                              0, NULL,                     NULL }
+};
+
+
+// this is called on every death dialog. Problem is at least the german
+//  version of lsl6 gets title text that is far too long for the
+//  available temp space resulting in temp space corruption
+//  This patch moves the title text around, so this overflow
+//  doesn't happen anymore. We would otherwise get a crash
+//  calling for invalid views (this happens of course also
+//  in sierra sci)
+const byte larry6SignatureDeathDialog[] = {
+	7,
+	0x3e, 0x33, 0x01,             // link 0133 (offset 0x20)
+	0x35, 0xff,                   // ldi ff
+	0xa3, 0x00,                   // sal 00
+	+255, 0,
+	+255, 0,
+	+170, 12,                     // [skip 680 bytes]
+	0x8f, 0x01,                   // lsp 01 (offset 0x2cf)
+	0x7a,                         // push2
+	0x5a, 0x04, 0x00, 0x0e, 0x01, // lea 0004 010e
+	0x36,                         // push
+	0x43, 0x7c, 0x0e,             // kMessage[7c] 0e
+	+90, 10,                      // [skip 90 bytes]
+	0x38, 0xd6, 0x00,             // pushi 00d6 (offset 0x335)
+	0x78,                         // push1
+	0x5a, 0x04, 0x00, 0x0e, 0x01, // lea 0004 010e
+	0x36,                         // push
+	+76, 11,                      // [skip 76 bytes]
+	0x38, 0xcd, 0x00,             // pushi 00cd (offset 0x38b)
+	0x39, 0x03,                   // pushi 03
+	0x5a, 0x04, 0x00, 0x0e, 0x01, // lea 0004 010e
+	0x36,
+	0
+};
+
+const uint16 larry6PatchDeathDialog[] = {
+	0x3e, 0x00, 0x02,             // link 0200
+	PATCH_ADDTOOFFSET | +687,
+	0x5a, 0x04, 0x00, 0x40, 0x01, // lea 0004 0140
+	PATCH_ADDTOOFFSET | +98,
+	0x5a, 0x04, 0x00, 0x40, 0x01, // lea 0004 0140
+	PATCH_ADDTOOFFSET | +82,
+	0x5a, 0x04, 0x00, 0x40, 0x01, // lea 0004 0140
+	PATCH_END
+};
+
+//    script, description,                                   magic DWORD,                adjust
+const SciScriptSignature larry6Signatures[] = {
+    {     82, "death dialog memory corruption",              CONSTANT_LE_32(0x3501333e),     0, larry6SignatureDeathDialog, larry6PatchDeathDialog },
+    {      0, NULL,                                          0,                              0, NULL,                       NULL }
+};
+
+// will actually patch previously found signature area
+void Script::applyPatch(const uint16 *patch, byte *scriptData, const uint32 scriptSize, int32 signatureOffset) {
+	int32 offset = signatureOffset;
+	uint16 patchWord = *patch;
+
+	while (patchWord != PATCH_END) {
+		if (patchWord & PATCH_ADDTOOFFSET) {
+			offset += patchWord & ~PATCH_ADDTOOFFSET;
+		} else if (patchWord & PATCH_GETORIGINALBYTE) {
+			// TODO: implement this
+		} else {
+			scriptData[offset] = patchWord & 0xFF;
+			offset++;
+		}
+		patch++;
+		patchWord = *patch;
+	}	
+}
+
+// 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 == *(const 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 matchAdjust = 1;
+			while (matchAdjust) {
+				byte matchBytesCount = *signatureData++;
+				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 offset...
+				matchAdjust = *signatureData++;
+				byteOffset += matchAdjust;
+			}
+			if (!matchAdjust) // all matches worked?
+				return offset;
+		}
+		DWordOffset++;
+	}
+	// nothing found
+	return -1;
+}
+
+void Script::matchSignatureAndPatch(uint16 scriptNr, byte *scriptData, const uint32 scriptSize) {
+	const SciScriptSignature *signatureTable = NULL;
+	if (g_sci->getGameId() == GID_HOYLE4)
+		signatureTable = hoyle4Signatures;
+	if (g_sci->getGameId() == GID_LSL6)
+		signatureTable = larry6Signatures;
+
+	if (signatureTable) {
+		while (signatureTable->data) {
+			if (scriptNr == signatureTable->scriptNr) {
+				int32 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);
+					applyPatch(signatureTable->patch, scriptData, scriptSize, foundOffset);
+				}
+			}
+			signatureTable++;
+		}
+	}
+}
+
+} // End of namespace Sci
diff --git a/engines/sci/module.mk b/engines/sci/module.mk
index dae2807cc2..7107b722f9 100644
--- a/engines/sci/module.mk
+++ b/engines/sci/module.mk
@@ -30,6 +30,7 @@ MODULE_OBJS := \
 	engine/savegame.o \
 	engine/script.o \
 	engine/scriptdebug.o \
+	engine/script_patches.o \
 	engine/selector.o \
 	engine/seg_manager.o \
 	engine/segment.o \