From c878777e16148e792af13505aaf924225d21a5b3 Mon Sep 17 00:00:00 2001
From: Blu3train <frtempra@gmail.com>
Date: Tue, 24 Oct 2023 18:22:07 +0200
Subject: [PATCH] IMS script (Jellyfish) engine hooks

---
 texthook/engine/engine.cc  | 125 +++++++++++++++++++++++++++++++++++++
 texthook/engine/engine.h   |   1 +
 texthook/engine/match32.cc |   4 ++
 3 files changed, 130 insertions(+)

diff --git a/texthook/engine/engine.cc b/texthook/engine/engine.cc
index c2c7abc..2326b51 100644
--- a/texthook/engine/engine.cc
+++ b/texthook/engine/engine.cc
@@ -21728,6 +21728,131 @@ bool InsertNamcoPS2Hook()
 }
 #endif // 0
 
+bool ISMscriptFilter(LPVOID data, DWORD *size, HookParam *, BYTE)
+{
+  auto text = reinterpret_cast<LPWSTR>(data);
+  auto len = reinterpret_cast<size_t *>(size);
+  
+  // Remove flashing cursor
+  if ( *text == L'\x4081' || *text == L'\xa481'  || *text == L'\xa581' || *text == L'\x9e81'  ||
+       *text == L'\xe681' || *text == L'\xe781'  || *text == L'\xe881')
+    return false;
+
+  return true;
+}
+
+bool InsertISMscript1Hook() {
+	//by Blu3train
+	/*
+	* Sample games:
+	* https://vndb.org/v973
+	*/
+	const BYTE bytes[] = {
+		0xCC,                    // int 3 
+		0x55,                    // push ebp        <- hook here
+		0x56,                    // push esi
+		0x8B, 0xF1,              // mov esi,ecx
+		0x8B, 0xAE, XX4,         // mov ebp,[esi+0000025C]
+		0x39, 0x2D, XX4          // cmp [ism.dll+BE2C4],ebp
+	};
+
+	HMODULE module = GetModuleHandleW(L"ism.dll");
+	auto [minAddress, maxAddress] = Util::QueryModuleLimits(module);
+	ULONG addr = MemDbg::findBytes(bytes, sizeof(bytes), minAddress, maxAddress);
+	if (!addr)
+		return false;
+
+	HookParam hp = {};
+	hp.address = addr + 1;
+	hp.offset = pusha_eax_off -4;
+    hp.index = 0;
+	hp.length_offset = 1;
+	hp.type = BIG_ENDIAN | NO_CONTEXT;
+	hp.filter_fun = ISMscriptFilter;
+
+	ConsoleOutput("vnreng: INSERT ISM-script1");
+	NewHook(hp, "ISM-script1");
+
+	return true;
+}
+
+bool InsertISMscript2Hook() {
+	//by Blu3train
+	/*
+	* Sample games:
+	* https://vndb.org/v3896
+	*/
+	const BYTE bytes[] = {
+		0x0B, 0xC1,                      // or eax,ecx
+		0x52,                            // push edx
+		0x50,                            // push eax
+		0x8B, 0xCE                       // mov ecx,esi        <- hook here
+	};
+	enum { addr_offset = sizeof(bytes) - 2 };
+
+	HMODULE module = GetModuleHandleW(L"ism.dll");
+	auto [minAddress, maxAddress] = Util::QueryModuleLimits(module);
+	ULONG addr = MemDbg::findBytes(bytes, sizeof(bytes), minAddress, maxAddress);
+	if (!addr)
+		return false;
+
+	HookParam hp = {};
+	hp.address = addr + addr_offset;
+	hp.offset = pusha_eax_off -4;
+    hp.index = 0;
+	hp.length_offset = 1;
+	hp.split = 0x14 * 4; //arg 14
+	hp.split_index = 0;
+	hp.type = BIG_ENDIAN | NO_CONTEXT | USING_SPLIT;
+	hp.filter_fun = ISMscriptFilter;
+
+	ConsoleOutput("vnreng: INSERT ISM-script2");
+	NewHook(hp, "ISM-script2");
+
+	return true;
+}
+
+bool InsertISMscript3Hook() {
+	//by Blu3train
+	/*
+	* Sample games:
+	* https://vndb.org/r1135
+	*/
+	const BYTE bytes[] = {
+		0xCC,                    // int 3 
+		0xA1, XX4,               // mov eax,[ISM.DLL+BDAD4]        <- hook here
+		0x57,                    // push edi
+		0x8B, 0x3D, XX4          // mov edi,[ISM.DLL+E8658]
+	};
+
+	HMODULE module = GetModuleHandleW(L"ism.dll");
+	auto [minAddress, maxAddress] = Util::QueryModuleLimits(module);
+	ULONG addr = MemDbg::findBytes(bytes, sizeof(bytes), minAddress, maxAddress);
+	if (!addr)
+		return false;
+
+	HookParam hp = {};
+	hp.address = addr + 1;
+	hp.offset = pusha_eax_off -4;
+    hp.index = 0;
+	hp.length_offset = 1;
+	hp.type = BIG_ENDIAN | NO_CONTEXT;
+	hp.filter_fun = ISMscriptFilter;
+
+	ConsoleOutput("vnreng: INSERT ISM-script3");
+	NewHook(hp, "ISM-script3");
+
+	return true;
+}
+
+bool InsertISMscriptHooks()
+{ 
+  bool ok = InsertISMscript1Hook();
+  ok = InsertISMscript2Hook() || ok;
+  ok = InsertISMscript3Hook() || ok;
+  return ok;
+}
+
 } // namespace Engine
 
 // EOF
diff --git a/texthook/engine/engine.h b/texthook/engine/engine.h
index 5e167b2..0e18009 100644
--- a/texthook/engine/engine.h
+++ b/texthook/engine/engine.h
@@ -156,6 +156,7 @@ bool InsertWillPlusHook();      // WillPlus: Rio.arc
 bool InsertWolfHook();          // Wolf: Data.wolf
 bool InsertYukaSystem2Hook();   // YukaSystem2: *.ykc
 bool InsertYurisHook();         // YU-RIS: *.ypf
+bool InsertISMscriptHooks();    // ISM script Engine: ism.dll
 
 void InsertBrunsHook();         // Bruns: bruns.exe
 void InsertIronGameSystemHook();// IroneGameSystem: igs_sample.exe
diff --git a/texthook/engine/match32.cc b/texthook/engine/match32.cc
index fffc4c7..54ba95f 100644
--- a/texthook/engine/match32.cc
+++ b/texthook/engine/match32.cc
@@ -370,6 +370,10 @@ bool DetermineEngineByFile3()
 
 bool DetermineEngineByFile4()
 {
+  if (Util::CheckFile(L"ism.dll")) {
+    if (InsertISMscriptHooks())
+      return true;
+  }
   if (Util::CheckFile(L"EAGLS.dll")) { // jichi 3/24/2014: E.A.G.L.S
     //ConsoleOutput("vnreng: IGNORE EAGLS");
     InsertEaglsHook();