Basic documentation of overlay 18 (link shop) (#367)

Author: Chesyon

headers/data/overlay18.h

@@ -23,5 +23,6 @@ extern struct simple_menu_id_item LINK_SHOP_SUBMENU_ITEMS_6[9];
 extern struct simple_menu_id_item LINK_SHOP_SUBMENU_ITEMS_7[9];
 extern void* OVERLAY18_FUNCTION_POINTER_TABLE[76];
 extern undefined4 OV18_STATIC_INITIALIZER;
+extern struct link_shop* LINK_SHOP_PTR;
 
 #endif

headers/functions/functions.h

@@ -9,6 +9,7 @@
 #include "overlay11.h"
 #include "overlay13.h"
 #include "overlay14.h"
+#include "overlay18.h"
 #include "overlay19.h"
 #include "overlay29.h"
 #include "overlay30.h"

headers/functions/overlay18.h

@@ -0,0 +1,8 @@
+#ifndef HEADERS_FUNCTIONS_OVERLAY18_H_
+#define HEADERS_FUNCTIONS_OVERLAY18_H_
+
+int LinkShopEntryPoint(void);
+void LinkShopDestructor(void);
+int LinkShopMainManager(void);
+
+#endif

headers/types/ground_mode/ground_mode.h

@@ -968,4 +968,61 @@ struct ground_bg {
 };
 ASSERT_SIZE(struct ground_bg, 1372);
 
+struct link_shop {
+    int8_t window_id_0x0;
+    int8_t portrait_window_id; // 0x1
+    int8_t window_id_0x2;
+    int8_t window_id_0x3;
+    int8_t window_id_0x4;
+    int8_t window_id_0x5;
+    int8_t window_id_0x6;
+    int8_t window_id_0x7;
+    int8_t window_id_0x8;
+    int8_t scroll_box_window_id; // 0x9
+    int8_t window_id_0xa;
+    int8_t window_id_0xb;
+    int8_t window_id_0xc;
+    int8_t window_id_0xd;
+    int8_t window_id_0xe;
+    int8_t window_id_0xf;
+    bool unk_0x10;
+    undefined padding_0x11[3];
+    struct preprocessor_args preprocessor_args; // 0x14
+    struct portrait_params portrait_params;     // 0x64
+    undefined4
+        unk_0x74;   // Potentially also some state value; used in a switch in LinkShopMainManager.
+    uint32_t state; // 0x78: Current state of the link shop menu; used in a switch in
+                    // LinkShopMainManager. Could be an enum.
+    undefined4
+        unk_0x7c; // Potentially also some state value; used in a switch in LinkShopMainManager.
+    uint32_t next_state; // 0x80: Next value for state.
+    undefined4 unk_0x84;
+    undefined4 unk_0x88;
+    undefined2 unk_0x8c;
+    undefined2 padding_0x8e;
+    struct window_extra_info extra_info_1; // 0x90
+    struct window_extra_info extra_info_2; // 0x128
+    struct window_extra_info extra_info_3; // 0x1C0
+    struct window_extra_info extra_info_4; // 0x258
+    struct window_extra_info extra_info_5; // 0x2F0
+    undefined2 unk_0x388;
+    undefined2 unk_0x38a;
+    int16_t member_idx; // 0x38C: Index in TEAM_MEMBER_TABLE for the selected monster.
+    undefined2 padding_0x38e;
+    undefined4 unk_0x390;
+    uint8_t unk_0x394[8];
+    undefined4 unk_0x39c;
+    undefined4 unk_0x3a0;
+    undefined2 unk_0x3a4;
+    undefined1 unk_0x3a6; // This through 0x3AD is filled with a memcpy; may be a smaller struct.
+    undefined1 unk_0x3a7; // Could not find direct use of this; may be padding.
+    undefined2 unk_0x3a8;
+    undefined2 unk_0x3aa;
+    undefined1 unk_0x3ac;
+    undefined1 unk_0x3ad;
+    char name[10];           // 0x3AE: Name of the selected monster.
+    undefined unk_0x3b8[12]; // Could not find direct use of this, probably not padding though.
+};
+ASSERT_SIZE(struct link_shop, 964);
+
 #endif

symbols/overlay18.yml

@@ -12,7 +12,36 @@ overlay18:
     NA: 0x3500
     JP: 0x3520
   description: Controls the Electivire Link Shop.
-  functions: []
+  functions:
+    - name: LinkShopEntryPoint
+      address:
+        EU: 0x238AC80
+        NA: 0x238A140
+        JP: 0x238B6A0
+      description: |-
+        Is the entrypoint of the overlay_load_entry, and seems to run once to initiate the Link Shop. Is not called anywhere else.
+        Allocates space for link_shop, and initializes many of its fields.
+        
+        return: Always returns 1.
+    - name: LinkShopDestructor
+      address:
+        EU: 0x238BB14
+        NA: 0x238AFD4
+        JP: 0x238C530
+      description: |-
+        Is the destructor of the overlay_load_entry, and seems to run once on closing the Link Shop. Is not called anywhere else.
+        Frees up the allocated space for link_shop if it is not already empty.
+        
+        No params.
+    - name: LinkShopMainManager
+      address:
+        EU: 0x238BB5C
+        NA: 0x238B01C
+        JP: 0x238C578
+      description: |-
+        Called every frame the Electivire Link Shop is open. Handles the majority of the menu.
+        
+        return: Usually returns 1. Returns 4 when exiting the Link Shop.
   data:
     - name: LINK_SHOP_WINDOW_PARAMS_1
       address:
@@ -214,14 +243,16 @@ overlay18:
         NA: 0x4
         JP: 0x4
       description: Static initializer for overlay 18.
-    - name: OVERLAY18_UNKNOWN_POINTER__NA_238D620
+    - name: LINK_SHOP_PTR
       address:
         EU: 0x238E160
         NA: 0x238D620
         JP: 0x238EBA0
       length:
+        EU: 0x4
         NA: 0x4
-      description: "Note: unverified, ported from Irdkwia's notes"
+        JP: 0x4
+      description: Pointer to the heap-allocated link_shop struct.
     - name: OVERLAY18_UNKNOWN_POINTER__NA_238D624
       address:
         NA: 0x238D624