patch: move transition animation patch to C++

lib/dllmain.cpp

@@ -177,26 +177,13 @@ __declspec(dllexport) DWORD WINAPI Patch()
   SearchReplacePattern(dllBase, mq_pattern, mq_replace, 8);
 
   // Transition Animation
-  std::string animation_type = config.GetString("TransitionType");
+  LPCVOID start_transition_offset = SearchPattern(dllBase, "\x89\x46\x2C\x8A\x44\x24\x14\x32\xC1\x24\x01\x32\xC1", 13);
-  int anim_val = 3;
+  
-  if (animation_type == "No Animation") {
+  MxResult (MxTransitionManager::* pFunc)(TransitionType, int, byte, bool) = &MxTransitionManager::InterceptStartTransition;
-    anim_val = 1;
+  OverwriteAllCalls(dllBase, (char*)start_transition_offset - 40, (void*&) pFunc);
-  } else if (animation_type == "Dissolve") {
+  
-    anim_val = 2;
+  startTransitionOriginal = PointerToMemberFunction<startTransitionFunction>((char*)start_transition_offset - 40);
-  } else if (animation_type == "Pixelation") {
+
-    anim_val = 3;
-  } else if (animation_type == "Vertical Wipe") {
-    anim_val = 4;
-  } else if (animation_type == "Window") {
-    anim_val = 5;
-  }
-  const char *at_pattern = "\x89\x46\x2C\x8A\x44\x24\x14\x32\xC1\x24\x01\x32\xC1";
-  char at_replace[13];
-  memcpy(at_replace, at_pattern, 13);
-  memcpy(at_replace, "\xC7", 1);
-  memcpy(at_replace+3, &anim_val, sizeof(anim_val));
-  memcpy(at_replace+11, "\xB0\x00", 2);
-  SearchReplacePattern(dllBase, at_pattern, at_replace, 13);
 
   // Field of view
   const char *fov_pattern = "\x00\x00\x00\x3F\x17\x6C\xC1\x16\x6C\xC1\x76\x3F";

lib/hooks.cpp

@@ -736,3 +736,23 @@ _CRTIMP size_t __cdecl InterceptFread(void *buffer, size_t size, size_t count, F
 
   return freadOriginal(buffer, size, count, stream);
 }
+
+startTransitionFunction startTransitionOriginal = NULL;
+MxResult MxTransitionManager::InterceptStartTransition(TransitionType animationType, int speed, byte unk, bool playMusicInTransition)
+{
+  std::string animation_type = config.GetString("TransitionType");
+
+  if (animation_type == "No Animation") {
+    animationType = NO_ANIMATION;
+  } else if (animation_type == "Dissolve") {
+    animationType = DISSOLVE;
+  } else if (animation_type == "Pixelation") {
+    animationType = PIXELATION;
+  } else if (animation_type == "Vertical Wipe") {
+    animationType = VERTICAL_WIPE;
+  } else if (animation_type == "Window") {
+    animationType = WINDOW;
+  }
+
+  return (this->*startTransitionOriginal)(animationType, speed, unk, playMusicInTransition);
+}

lib/hooks.h

@@ -69,4 +69,30 @@ typedef _CRTIMP size_t (__cdecl *freadFunction)(void *buffer, size_t size, size_
 extern freadFunction freadOriginal;
 _CRTIMP size_t __cdecl InterceptFread(void *buffer, size_t size, size_t count, FILE *stream);
 
+enum MxResult
+{
+  SUCCESS = 0,
+  FAILURE = 0xFFFFFFFF
+};
+
+enum TransitionType
+{
+  NOT_TRANSITIONING = 0,
+  NO_ANIMATION = 1,
+  DISSOLVE = 2,
+  PIXELATION = 3,
+  VERTICAL_WIPE = 4,
+  WINDOW = 5,
+  BROKEN = 6
+};
+
+class MxTransitionManager
+{
+public:
+  MxResult InterceptStartTransition(TransitionType animationType, int speed, byte unk, bool playMusicInTransition);
+};
+
+typedef MxResult (MxTransitionManager::* startTransitionFunction)(TransitionType, int, byte, bool);
+extern startTransitionFunction startTransitionOriginal;
+
 #endif // HOOKS_H

lib/util.h

@@ -7,6 +7,8 @@ BOOL WriteMemory(LPVOID destination, LPVOID source, size_t length, LPVOID oldDat
 
 LPVOID OverwriteCall(LPVOID destination, LPVOID localCall);
 
+int OverwriteAllCalls(LPVOID imageBase, LPCVOID from, LPCVOID to);
+
 LPVOID SearchPattern(LPVOID imageBase, LPCVOID search, SIZE_T count);
 
 SIZE_T SearchReplacePattern(LPVOID imageBase, LPCVOID search, LPCVOID replace, SIZE_T count, BOOL only_once = FALSE);