clean usage of transitions in existing code

include/area.h

@@ -2,6 +2,7 @@
 #define AREA_H
 
 #include "global.h"
+#include "transitions.h"
 
 #define MAX_ROOMS 64
 
@@ -14,7 +15,7 @@ typedef struct {
     void* map;
     void* metatiles;
     void* bg_anim;
-    void* exits;
+    const Transition* exits;
     void** properties;
 } RoomResInfo;
 static_assert(sizeof(RoomResInfo) == 0x20);

include/transitions.h

@@ -0,0 +1,31 @@
+#ifndef TMC_TRANSITIONS_H
+#define TMC_TRANSITIONS_H
+#include "global.h"
+
+typedef struct Transition {
+    u8 warp_type;
+    u8 subtype;
+    u16 startX;
+    u16 startY;
+    u16 endX;
+    u16 endY;
+    u8 shape;
+    u8 area;
+    u8 room;
+    u8 height;
+    u8 transition_type;
+    u8 facing_direction;
+    u8 unk0;
+    u8 unk1;
+    u8 unk2;
+    u8 unk3;
+} Transition;
+
+extern const Transition gExitList_RoyalValley_ForestMaze[];
+extern const Transition gUnk_08134FBC[];
+extern const Transition gUnk_08135048[];
+extern const Transition gUnk_08135190[];
+extern const Transition gUnk_0813A76C[];
+extern const Transition* const* const gExitLists[];
+
+#endif // TMC_TRANSITIONS_H