Reimplement the MusicChange hook

why the fuck was this removed

src/lua_hook.h

@@ -44,6 +44,9 @@ enum hook {
 	hook_HurtMsg,
 	hook_PlayerSpawn,
 	hook_PlayerQuit,
+#ifdef HAVE_LUA_MUSICPLUS
+	hook_MusicChange,
+#endif
 	hook_ShouldSpin,	//SRB2KART
 	hook_ShouldExplode,	//SRB2KART
 	hook_ShouldSquish,	//SRB2KART
@@ -90,6 +93,10 @@ boolean LUAh_PlayerMsg(int source, int target, int flags, char *msg, int mute);
 boolean LUAh_HurtMsg(player_t *player, mobj_t *inflictor, mobj_t *source); // Hook for hurt messages
 #define LUAh_PlayerSpawn(player) LUAh_PlayerHook(player, hook_PlayerSpawn) // Hook for G_SpawnPlayer
 void LUAh_PlayerQuit(player_t *plr, int reason); // Hook for player quitting
+#ifdef HAVE_LUA_MUSICPLUS
+boolean LUAh_MusicChange(const char *oldname, char *newname, UINT16 *mflags, boolean *looping,
+	UINT32 *position, UINT32 *prefadems, UINT32 *fadeinms); // Hook for music changes
+#endif
 
 UINT8 LUAh_ShouldSpin(player_t *player, mobj_t *inflictor, mobj_t *source); // SRB2KART: Should player be spun out?
 UINT8 LUAh_ShouldExplode(player_t *player, mobj_t *inflictor, mobj_t *source); // SRB2KART: Should player be exploded?

src/lua_hooklib.c

@@ -55,6 +55,9 @@ const char *const hookNames[hook_MAX+1] = {
 	"HurtMsg",
 	"PlayerSpawn",
 	"PlayerQuit",
+#ifdef HAVE_LUA_MUSICPLUS
+	"MusicChange",
+#endif
 	"ShouldSpin",
 	"ShouldExplode",
 	"ShouldSquish",
@@ -1213,6 +1216,69 @@ void LUAh_PlayerQuit(player_t *plr, int reason)
 	lua_settop(gL, 0);
 }
 
+#ifdef HAVE_LUA_MUSICPLUS
+
+// Hook for music changes
+boolean LUAh_MusicChange(const char *oldname, char *newname, UINT16 *mflags, boolean *looping,
+	UINT32 *position, UINT32 *prefadems, UINT32 *fadeinms)
+{
+	hook_p hookp;
+	boolean hooked = false;
+
+	if (!gL || !(hooksAvailable[hook_MusicChange/8] & (1<<(hook_MusicChange%8))))
+		return false;
+
+	lua_settop(gL, 0);
+
+	for (hookp = roothook; hookp; hookp = hookp->next)
+		if (hookp->type == hook_MusicChange)
+		{
+			lua_pushfstring(gL, FMT_HOOKID, hookp->id);
+			lua_gettable(gL, LUA_REGISTRYINDEX);
+			lua_pushstring(gL, oldname);
+			lua_pushstring(gL, newname);
+			lua_pushinteger(gL, *mflags);
+			lua_pushboolean(gL, *looping);
+			lua_pushinteger(gL, *position);
+			lua_pushinteger(gL, *prefadems);
+			lua_pushinteger(gL, *fadeinms);
+			if (lua_pcall(gL, 7, 6, 0)) {
+				CONS_Alert(CONS_WARNING,"%s\n",lua_tostring(gL,-1));
+				lua_pop(gL, 1);
+				continue;
+			}
+
+			// output 1: true, false, or string musicname override
+			if (lua_isboolean(gL, -6) && lua_toboolean(gL, -6))
+				hooked = true;
+			else if (lua_isstring(gL, -6))
+				strncpy(newname, lua_tostring(gL, -6), 7);
+			// output 2: mflags override
+			if (lua_isnumber(gL, -5))
+				*mflags = lua_tonumber(gL, -5);
+			// output 3: looping override
+			if (lua_isboolean(gL, -4))
+				*looping = lua_toboolean(gL, -4);
+			// output 4: position override
+			if (lua_isboolean(gL, -3))
+				*position = lua_tonumber(gL, -3);
+			// output 5: prefadems override
+			if (lua_isboolean(gL, -2))
+				*prefadems = lua_tonumber(gL, -2);
+			// output 6: fadeinms override
+			if (lua_isboolean(gL, -1))
+				*fadeinms = lua_tonumber(gL, -1);
+
+			lua_pop(gL, 6);
+		}
+
+	lua_settop(gL, 0);
+	newname[6] = 0;
+	return hooked;
+}
+
+#endif
+
 // Hook for K_SpinPlayer. Determines if yes or no we should get damaged reguardless of circumstances.
 UINT8 LUAh_ShouldSpin(player_t *player, mobj_t *inflictor, mobj_t *source)
 {

src/lua_script.h

@@ -98,4 +98,6 @@ void COM_Lua_f(void);
 	}\
 }
 
+#define HAVE_LUA_MUSICPLUS
+
 #endif