set up proper levelscript system

asm/macros/script.inc

@@ -4950,4 +4950,92 @@
 	.short 254, 0
 	.endm
 
+	    /*
+     * This flag is used by ScriptEntry and ScriptEntryEnd to control where
+     * a user can add ScriptEntry commands (i.e., only at the start of the
+     * input file). It is NOT meant for direct usage.
+     */
+    .set F_ACCEPT_SCRIPT_ENTRIES, TRUE
+
+    .macro ScriptEntry name
+    .if F_ACCEPT_SCRIPT_ENTRIES == TRUE
+        .long \name-.-4
+    .else
+        .error "cannot specify ScriptEntry after ScriptEntryEnd"
+    .endif
+    .endm
+
+    .macro ScriptEntryEnd
+    .set F_ACCEPT_SCRIPT_ENTRIES, FALSE
+    .short 0xFD13
+    .endm
+
+    .set F_INIT_SCRIPT_FRAME_TABLE_OPENED, FALSE
+    .set F_INIT_SCRIPT_FRAME_TABLE_CLOSED, FALSE
+
+    .macro InitScriptEntry_Fixed type, scriptID
+    .if F_ACCEPT_SCRIPT_ENTRIES == TRUE
+        .byte \type
+        .short \scriptID, 0
+    .else
+        .error "cannot specify InitScriptEntry after InitScriptEntryEnd"
+    .endif
+    .endm
+
+    .macro InitScriptEntry_OnFrameTable checksLabel
+    .if F_ACCEPT_SCRIPT_ENTRIES == TRUE
+        .set F_INIT_SCRIPT_FRAME_TABLE_OPENED, TRUE
+        .byte INIT_SCRIPT_ON_FRAME_TABLE
+        ScriptEntry \checksLabel
+    .else
+        .error "cannot specify InitScriptEntry after InitScriptEntryEnd"
+    .endif
+    .endm
+
+    .macro InitScriptEntry_OnTransition scriptID
+    InitScriptEntry_Fixed INIT_SCRIPT_ON_TRANSITION, \scriptID
+    .endm
+
+    .macro InitScriptEntry_OnResume scriptID
+    InitScriptEntry_Fixed INIT_SCRIPT_ON_RESUME, \scriptID
+    .endm
+
+    .macro InitScriptEntry_OnLoad scriptID
+    InitScriptEntry_Fixed INIT_SCRIPT_ON_LOAD, \scriptID
+    .endm
+
+    .macro InitScriptEntryEnd
+    .set F_ACCEPT_SCRIPT_ENTRIES, FALSE
+    .byte 0
+    .endm
+
+    .macro InitScriptGoToIfEqual var1, var2, scriptID
+    .if F_INIT_SCRIPT_FRAME_TABLE_OPENED == TRUE
+        .if F_INIT_SCRIPT_FRAME_TABLE_CLOSED == FALSE
+            .short \var1, \var2, \scriptID
+        .else
+            .error "cannot specify InitScriptGoToIfEqual after InitScriptFrameTableEnd"
+        .endif
+    .else
+        .error "cannot specify InitScriptGoToIfEqual before InitScriptEntry_OnFrameTable"
+    .endif
+    .endm
+
+    .macro InitScriptFrameTableEnd
+    .set F_INIT_SCRIPT_FRAME_TABLE_CLOSED, TRUE
+    .short 0
+    .endm
+
+    .macro InitScriptEnd
+    .if F_ACCEPT_SCRIPT_ENTRIES == TRUE
+        .error "cannot specify InitScriptEnd before InitScriptEntryEnd"
+    .endif
+    .if F_INIT_SCRIPT_FRAME_TABLE_OPENED == TRUE
+        .if F_INIT_SCRIPT_FRAME_TABLE_CLOSED == FALSE
+            .error "must close InitScriptEntry_OnFrameTable with InitScriptFrameTableEnd before InitScriptEnd"
+        .endif
+    .endif
+    .balign 4, 0
+    .endm
+
 	.endif ; ASM_SCRIPT_INC

include/constants/init_script_types.h

@@ -0,0 +1,44 @@
+#ifndef POKEPLATINUM_CONSTANTS_INIT_SCRIPT_TYPE_H
+#define POKEPLATINUM_CONSTANTS_INIT_SCRIPT_TYPE_H
+
+/*
+    Init Script Types
+    These constants describe types of non-event scripts which are defined for a particular map.
+    Each map has at most one script of each type, other than ON_FRAME_TABLE.
+    To see where each script type is run, look for calls to FieldSystem_RunInitScript.
+*/
+
+/*
+    Init Script Type: INIT_SCRIPT_ON_FRAME_TABLE
+    Before each frame of input processing, a table of conditions for the map is checked.
+    Runs the first script where its two condition variables are equal.
+    Therefore, any script invoked this way must at some point make its own condition false.
+    The first check only occurs after all other init script types have run.
+*/
+#define INIT_SCRIPT_ON_FRAME_TABLE 1
+
+/*
+    Init Script Type: INIT_SCRIPT_ON_TRANSITION
+    Runs upon first entering a map, including when starting a new game or loading a save.
+    Runs before all other init script types, including ON_FRAME_TABLE.
+    Primary roles: modify object events, manage persisted map features
+*/
+#define INIT_SCRIPT_ON_TRANSITION 2
+
+/*
+    Init Script Type: INIT_SCRIPT_ON_RESUME
+    Runs after the map has been fully loaded and drawn.
+    Can run again without leaving the map, e.g., when using a field move or item.
+    Primary roles: hide the player, modify object events
+*/
+#define INIT_SCRIPT_ON_RESUME 3
+
+/*
+    Init Script Type: INIT_SCRIPT_ON_LOAD
+    Runs after the map layout is loaded (but not drawn yet).
+    Can run again without leaving the map, e.g., when using a field move or item.
+    Primary roles: modify warp events, set/unset flags tied to object events
+*/
+#define INIT_SCRIPT_ON_LOAD 4
+
+#endif // POKEPLATINUM_CONSTANTS_INIT_SCRIPT_TYPE_H

include/constants/scrcmd.h

@@ -23,6 +23,7 @@
 #include "constants/std_script.h"
 #include "constants/trainers.h"
 #include "constants/vars.h"
+#include "constants/init_script_types.h"
 
 #define lt 0
 #define eq 1