From 5034888ba6791a3aa99bffeb5f7846b4d17783de Mon Sep 17 00:00:00 2001
From: Blu3train <frtempra@gmail.com>
Date: Tue, 7 Nov 2023 02:25:11 +0100
Subject: [PATCH] Sysd engine hook

---
 texthook/engine/engine.cc  | 55 ++++++++++++++++++++++++++++++++++++++
 texthook/engine/engine.h   |  1 +
 texthook/engine/match32.cc |  4 +++
 3 files changed, 60 insertions(+)

diff --git a/texthook/engine/engine.cc b/texthook/engine/engine.cc
index c2c7abc..2976715 100644
--- a/texthook/engine/engine.cc
+++ b/texthook/engine/engine.cc
@@ -21728,6 +21728,61 @@ bool InsertNamcoPS2Hook()
 }
 #endif // 0
 
+bool SysdFilter(LPVOID data, DWORD *size, HookParam *, BYTE)
+{
+  auto text = reinterpret_cast<LPSTR>(data);
+  auto len = reinterpret_cast<size_t *>(size);
+
+  if (text[0] == '\x81' && text[1] == '\x40') {
+    *len -= 2;
+    ::memmove(text, text + 2, *len);
+  }
+  while (text[*len-1] == '\n') {
+    (*len)--;
+    text[*len] = '\0';
+  }
+
+  return true;
+}
+
+bool InsertSysdHook() {
+	//by Blu3train
+	/*
+	* Sample games:
+	* https://vndb.org/v2069
+	*/
+	const BYTE bytes[] = {
+		0xC1, 0xE9, 0x02,              // shr ecx,02      <- hook here
+		0xF3, 0xA5,                    // repe movsd 
+		0x8B, 0xCA,                    // mov ecx,edx
+		0x83, 0xE1, 0x03,              // and ecx,03
+		0xF3, 0xA4,                    // repe movsb 
+		0x5F,                          // pop edi
+		0xB8, 0x01, 0x00, 0x00, 0x00   // mov eax,00000001
+	};
+
+	ULONG range = min(processStopAddress - processStartAddress, MAX_REL_ADDR);
+	ULONG addr = MemDbg::findBytes(bytes, sizeof(bytes), processStartAddress, processStartAddress + range);
+	if (!addr) {
+		ConsoleOutput("vnreng:Sysd: pattern not found");
+		return false;
+	}
+
+	HookParam hp = {};
+	hp.address = addr;
+	hp.offset = pusha_esi_off -4;
+    hp.index = 0;
+    hp.padding = 0x12;
+	hp.split = 0x2 * 4; //arg 2
+	hp.split_index = 0;
+	hp.type = USING_STRING | NO_CONTEXT | USING_SPLIT;
+	hp.filter_fun = SysdFilter;
+	ConsoleOutput("vnreng: INSERT Sysd");
+	NewHook(hp, "Sysd");
+
+	return true;
+}
+
 } // namespace Engine
 
 // EOF
diff --git a/texthook/engine/engine.h b/texthook/engine/engine.h
index 5e167b2..7d725fa 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 InsertSysdHook();          // Sysd: sysd.ini
 
 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..fd3abf3 100644
--- a/texthook/engine/match32.cc
+++ b/texthook/engine/match32.cc
@@ -370,6 +370,10 @@ bool DetermineEngineByFile3()
 
 bool DetermineEngineByFile4()
 {
+  if (Util::CheckFile(L"sysd.ini")) {
+    if (InsertSysdHook())
+      return true;
+  }
   if (Util::CheckFile(L"EAGLS.dll")) { // jichi 3/24/2014: E.A.G.L.S
     //ConsoleOutput("vnreng: IGNORE EAGLS");
     InsertEaglsHook();