Document fldeff_flash and map_preview_screen

10 files changed, 251 insertions, 248 deletions

diff --git a/asm/overworld.s b/asm/overworld.s
index 571d305b4..14afde17a 100644
--- a/asm/overworld.s
+++ b/asm/overworld.s
@@ -1739,7 +1739,7 @@ _080558D4:
 	bl DoCurrentWeather
 	bl ResetFieldTasksArgs
 	bl mapheader_run_script_with_tag_x5
-	bl sub_80561B4
+	bl GetLastUsedWarpMapSectionId
 	ldr r1, _0805591C @ =gMapHeader
 	lsls r0, 24
 	lsrs r0, 24
@@ -2899,8 +2899,8 @@ GetCurrentMapType: @ 8056188
 _0805619C: .4byte gSaveBlock1Ptr
 	thumb_func_end GetCurrentMapType
 
-	thumb_func_start get_map_light_from_warp0
-get_map_light_from_warp0: @ 80561A0
+	thumb_func_start GetLastUsedWarpMapType
+GetLastUsedWarpMapType: @ 80561A0
 	push {lr}
 	ldr r0, _080561B0 @ =gUnknown_2031DB4
 	bl get_map_light_level_from_warp
@@ -2910,10 +2910,10 @@ get_map_light_from_warp0: @ 80561A0
 	bx r1
 	.align 2, 0
 _080561B0: .4byte gUnknown_2031DB4
-	thumb_func_end get_map_light_from_warp0
+	thumb_func_end GetLastUsedWarpMapType
 
-	thumb_func_start sub_80561B4
-sub_80561B4: @ 80561B4
+	thumb_func_start GetLastUsedWarpMapSectionId
+GetLastUsedWarpMapSectionId: @ 80561B4
 	push {lr}
 	ldr r1, _080561D4 @ =gUnknown_2031DB4
 	movs r0, 0
@@ -2931,7 +2931,7 @@ sub_80561B4: @ 80561B4
 	bx r1
 	.align 2, 0
 _080561D4: .4byte gUnknown_2031DB4
-	thumb_func_end sub_80561B4
+	thumb_func_end GetLastUsedWarpMapSectionId
 
 	thumb_func_start IsMapTypeOutdoors
 IsMapTypeOutdoors: @ 80561D8
@@ -3579,7 +3579,7 @@ CB2_LoadMap: @ 805671C
 	bl ScriptContext2_Disable
 	movs r0, 0
 	bl SetMainCallback1
-	ldr r0, _08056740 @ =sub_80C9BFC
+	ldr r0, _08056740 @ =CB2_DoChangeMap
 	bl SetMainCallback2
 	ldr r1, _08056744 @ =gMain
 	ldr r0, _08056748 @ =sub_805674C
@@ -3587,7 +3587,7 @@ CB2_LoadMap: @ 805671C
 	pop {r0}
 	bx r0
 	.align 2, 0
-_08056740: .4byte sub_80C9BFC
+_08056740: .4byte CB2_DoChangeMap
 _08056744: .4byte gMain
 _08056748: .4byte sub_805674C
 	thumb_func_end CB2_LoadMap
@@ -4196,7 +4196,7 @@ _08056C72:
 	bl InitTilesetAnimations
 	b _08056CCA
 _08056C78:
-	bl sub_80561B4
+	bl GetLastUsedWarpMapSectionId
 	ldr r5, _08056CA4 @ =gMapHeader
 	lsls r0, 24
 	lsrs r0, 24
@@ -4205,13 +4205,13 @@ _08056C78:
 	beq _08056CA8
 	ldrb r0, [r5, 0x14]
 	movs r1, 0x1
-	bl sub_80F8154
+	bl MapHasPreviewScreen_HandleQLState2
 	cmp r0, 0x1
 	bne _08056CA8
 	ldrb r0, [r5, 0x14]
-	bl sub_80F819C
+	bl MapPreview_LoadGfx
 	ldrb r0, [r5, 0x14]
-	bl sub_80F8268
+	bl MapPreview_StartForestTransition
 	b _08056CCA
 	.align 2, 0
 _08056CA4: .4byte gMapHeader
@@ -4922,7 +4922,7 @@ sub_805726C: @ 805726C
 	bl ScriptContext2_Disable
 	movs r0, 0
 	bl SetMainCallback1
-	ldr r0, _0805729C @ =sub_80C9BFC
+	ldr r0, _0805729C @ =CB2_DoChangeMap
 	bl SetMainCallback2
 	ldr r1, _080572A0 @ =gMain
 	ldr r0, _080572A4 @ =sub_80572D8
@@ -4931,7 +4931,7 @@ sub_805726C: @ 805726C
 	bx r0
 	.align 2, 0
 _08057298: .4byte gUnknown_2036E28
-_0805729C: .4byte sub_80C9BFC
+_0805729C: .4byte CB2_DoChangeMap
 _080572A0: .4byte gMain
 _080572A4: .4byte sub_80572D8
 	thumb_func_end sub_805726C
diff --git a/include/fldeff.h b/include/fldeff.h
index 00f2d01f4..9dd6121b2 100644
--- a/include/fldeff.h
+++ b/include/fldeff.h
@@ -13,8 +13,8 @@ bool8 CheckObjectGraphicsInFrontOfPlayer(u8 graphicsId);
 u8 CreateFieldEffectShowMon(void);
 
 // flash
-u8 sub_80C9DCC(u8 lightLevel, u8 mapType);
-u8 sub_80C9D7C(u8 mapType1, u8 mapType2);
+u8 MapTransitionIsExit(u8 lightLevel, u8 mapType);
+u8 MapTransitionIsEnter(u8 mapType1, u8 mapType2);
 bool8 SetUpFieldMove_Flash(void);
 
 // cut
diff --git a/include/map_preview_screen.h b/include/map_preview_screen.h
index 195e86929..b884403ca 100644
--- a/include/map_preview_screen.h
+++ b/include/map_preview_screen.h
@@ -37,23 +37,23 @@ enum MapPreviewScreenId
 struct MapPreviewScreen
 {
     u8 mapsec;
-    bool8 forceFirstTime;
+    bool8 type;
     u16 flagId;
     const void * tilesptr;
     const void * tilemapptr;
     const void * palptr;
 };
 
-u16 sub_80F8318(u8 id);
-void sub_80F85BC(u16 a0);
-u16 sub_80F856C(u8 id);
-bool8 sub_80F8110(u8 mapsec, bool8 forceFirstTime);
-bool32 sub_80F83B0(void);
+u16 MapPreview_CreateMapNameWindow(u8 id);
+void MapPreview_SetFlag(u16 a0);
+u16 MapPreview_GetDuration(u8 id);
+bool8 MapHasPreviewScreen(u8 mapsec, bool8 type);
+bool32 ForestMapPreviewScreenIsRunning(void);
 const struct MapPreviewScreen * GetDungeonMapPreviewScreenInfo(u8 mapsec);
-bool32 sub_80F8154(u8 mapsec, u8 forceFirstTime);
-void sub_80F8180(void);
-void sub_80F819C(u8 mapsec);
-bool32 sub_80F8258(void);
-void sub_80F8234(s32 windowId);
+bool32 MapHasPreviewScreen_HandleQLState2(u8 mapsec, u8 type);
+void MapPreview_InitBgs(void);
+void MapPreview_LoadGfx(u8 mapsec);
+bool32 MapPreview_IsGfxLoadFinished(void);
+void MapPreview_Unload(s32 windowId);
 
 #endif //GUARD_MAP_PREVIEW_SCREEN_H
diff --git a/include/overworld.h b/include/overworld.h
index 06d4bcb8e..02492f74b 100644
--- a/include/overworld.h
+++ b/include/overworld.h
@@ -157,7 +157,7 @@ void Overworld_ResetStateAfterDigEscRope(void);
 bool32 sub_8058244(void);
 u8 GetCurrentMapType(void);
 
-u8 get_map_light_from_warp0(void);
+u8 GetLastUsedWarpMapType(void);
 const struct MapHeader *warp1_get_mapheader(void);
 void TryFadeOutOldMapMusic(void);
 void CB2_ReturnToFieldCableClub(void);
@@ -192,7 +192,7 @@ void sub_8057F48(void);
 void SetMainCallback1(MainCallback cb);
 void CB1_Overworld(void);
 void sub_80568C4(void);
-u8 sub_80561B4(void);
+u8 GetLastUsedWarpMapSectionId(void);
 
 extern u16 gHeldKeyCodeToSend;
 
diff --git a/include/quest_log.h b/include/quest_log.h
index 3241046bc..b2645954f 100644
--- a/include/quest_log.h
+++ b/include/quest_log.h
@@ -26,7 +26,7 @@ extern const u16 gUnknown_84566A8[];
 void sub_8112720(u8);
 void SetQuestLogEvent(u16, const u16 *);
 void sub_811539C(void);
-void sub_8115748(u16);
+void QuestLog_RecordEnteredMap(u16);
 u8 sub_8112CAC(void);
 bool8 QuestLog_SchedulePlaybackCB(void (*func)(void));
 void sub_8111F38(u16 offset, u16 idx);
diff --git a/src/field_fadetransition.c b/src/field_fadetransition.c
index 4ff105056..eeca2e171 100644
--- a/src/field_fadetransition.c
+++ b/src/field_fadetransition.c
@@ -52,7 +52,7 @@ void palette_bg_faded_fill_black(void)
 
 void WarpFadeInScreen(void)
 {
-    switch (sub_80C9DCC(get_map_light_from_warp0(), GetCurrentMapType()))
+    switch (MapTransitionIsExit(GetLastUsedWarpMapType(), GetCurrentMapType()))
     {
     case 0:
         palette_bg_faded_fill_black();
@@ -69,7 +69,7 @@ void WarpFadeInScreen(void)
 
 static void sub_807DBAC(void)
 {
-    switch (sub_80C9DCC(get_map_light_from_warp0(), GetCurrentMapType()))
+    switch (MapTransitionIsExit(GetLastUsedWarpMapType(), GetCurrentMapType()))
     {
     case 0:
         palette_bg_faded_fill_black();
@@ -94,11 +94,11 @@ void FadeInFromBlack(void)
 void WarpFadeOutScreen(void)
 {
     const struct MapHeader *header = warp1_get_mapheader();
-    if (header->regionMapSectionId != gMapHeader.regionMapSectionId && sub_80F8110(header->regionMapSectionId, FALSE))
+    if (header->regionMapSectionId != gMapHeader.regionMapSectionId && MapHasPreviewScreen(header->regionMapSectionId, FALSE))
         FadeScreen(1, 0);
     else
     {
-        switch (sub_80C9D7C(GetCurrentMapType(), header->mapType))
+        switch (MapTransitionIsEnter(GetCurrentMapType(), header->mapType))
         {
         case 0:
             FadeScreen(1, 0);
@@ -112,7 +112,7 @@ void WarpFadeOutScreen(void)
 
 static void sub_807DC70(void)
 {
-    switch (sub_80C9D7C(GetCurrentMapType(), warp1_get_mapheader()->mapType))
+    switch (MapTransitionIsEnter(GetCurrentMapType(), warp1_get_mapheader()->mapType))
     {
     case 0:
         FadeScreen(1, 3);
@@ -246,7 +246,7 @@ static void sub_807DE78(bool8 a0)
     if (MetatileBehavior_IsWarpDoor_2(behavior) == TRUE)
     {
         func = sub_807DFBC;
-        switch (sub_80C9DCC(get_map_light_from_warp0(), GetCurrentMapType()))
+        switch (MapTransitionIsExit(GetLastUsedWarpMapType(), GetCurrentMapType()))
         {
         case 0:
             palette_bg_faded_fill_black();
@@ -521,7 +521,7 @@ static bool32 sub_807E40C(void)
 
 bool32 sub_807E418(void)
 {
-    if (IsWeatherNotFadingIn() == TRUE && sub_80F83B0())
+    if (IsWeatherNotFadingIn() == TRUE && ForestMapPreviewScreenIsRunning())
         return TRUE;
     else
         return FALSE;
diff --git a/src/fldeff_flash.c b/src/fldeff_flash.c
index 7f40558d9..f6bfd6e62 100644
--- a/src/fldeff_flash.c
+++ b/src/fldeff_flash.c
@@ -9,6 +9,7 @@
 #include "party_menu.h"
 #include "script.h"
 #include "constants/songs.h"
+#include "constants/map_types.h"
 
 struct FlashStruct
 {
@@ -20,136 +21,136 @@ struct FlashStruct
     void (*func2)(u8 mapSecId);
 };
 
-static void sub_80C9B74(void);
-static void sub_80C9BB0(void);
-static bool8 sub_80C9CE8(void);
-static void sub_80C9E1C(void);
-static void sub_80C9E30(u8 taskId);
-static void sub_80C9E4C(u8 taskId);
-static void sub_80C9EF0(u8 taskId);
-static void sub_80C9F38(u8 taskId);
-static void sub_80C9FA0(u8 taskId);
-static void sub_80C9FD4(void);
-static void sub_80C9FE8(u8 taskId);
-static void sub_80CA004(u8 taskId);
-static void sub_80CA0A4(u8 taskId);
-static void sub_80CA108(u8 taskId);
-static void sub_80CA160(u8 mapsecId);
-static void sub_80CA190(u8 taskId);
+static void FieldCallback_Flash(void);
+static void FldEff_UseFlash(void);
+static bool8 TryDoMapTransition(void);
+static void FlashTransition_Exit(void);
+static void Task_FlashTransition_Exit_0(u8 taskId);
+static void Task_FlashTransition_Exit_1(u8 taskId);
+static void Task_FlashTransition_Exit_2(u8 taskId);
+static void Task_FlashTransition_Exit_3(u8 taskId);
+static void Task_FlashTransition_Exit_4(u8 taskId);
+static void FlashTransition_Enter(void);
+static void Task_FlashTransition_Enter_0(u8 taskId);
+static void Task_FlashTransition_Enter_1(u8 taskId);
+static void Task_FlashTransition_Enter_2(u8 taskId);
+static void Task_FlashTransition_Enter_3(u8 taskId);
+static void RunMapPreviewScreen(u8 mapsecId);
+static void Task_MapPreviewScreen_0(u8 taskId);
 
-static const struct FlashStruct gUnknown_83F5738[] = {
+static const struct FlashStruct sTransitionTypes[] = {
     {
-        .fromType = 1,
-        .toType = 4,
+        .fromType = MAP_TYPE_TOWN,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 2,
-        .toType = 4,
+        .fromType = MAP_TYPE_CITY,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 3,
-        .toType = 4,
+        .fromType = MAP_TYPE_ROUTE,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 5,
-        .toType = 4,
+        .fromType = MAP_TYPE_UNDERWATER,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 6,
-        .toType = 4,
+        .fromType = MAP_TYPE_OCEAN_ROUTE,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 7,
-        .toType = 4,
+        .fromType = MAP_TYPE_UNKNOWN,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 8,
-        .toType = 4,
+        .fromType = MAP_TYPE_INDOOR,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 9,
-        .toType = 4,
+        .fromType = MAP_TYPE_SECRET_BASE,
+        .toType = MAP_TYPE_UNDERGROUND,
         .isEnter = TRUE,
         .isExit = FALSE,
-        .func1 = sub_80C9FD4,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Enter,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 1,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_TOWN,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 2,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_CITY,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 3,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_ROUTE,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 5,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_UNDERWATER,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 6,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_OCEAN_ROUTE,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 7,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_UNKNOWN,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 8,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_INDOOR,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {
-        .fromType = 4,
-        .toType = 9,
+        .fromType = MAP_TYPE_UNDERGROUND,
+        .toType = MAP_TYPE_SECRET_BASE,
         .isEnter = FALSE,
         .isExit = TRUE,
-        .func1 = sub_80C9E1C,
-        .func2 = sub_80CA160
+        .func1 = FlashTransition_Exit,
+        .func2 = RunMapPreviewScreen
     }, {0}
 };
 
@@ -168,26 +169,28 @@ bool8 SetUpFieldMove_Flash(void)
         return FALSE;
 
     gFieldCallback2 = FieldCallback_PrepareFadeInFromMenu;
-    gPostMenuFieldCallback = sub_80C9B74;
+    gPostMenuFieldCallback = FieldCallback_Flash;
     return TRUE;
 }
 
-static void sub_80C9B74(void)
+static void FieldCallback_Flash(void)
 {
     u8 taskId = CreateFieldEffectShowMon();
     gFieldEffectArguments[0] = GetCursorSelectionMonId();
-    gTasks[taskId].data[8] = ((uintptr_t)sub_80C9BB0) >> 16;
-    gTasks[taskId].data[9] = ((uintptr_t)sub_80C9BB0);
+    gTasks[taskId].data[8] = ((uintptr_t)FldEff_UseFlash) >> 16;
+    gTasks[taskId].data[9] = ((uintptr_t)FldEff_UseFlash);
 }
 
-static void sub_80C9BB0(void)
+static void FldEff_UseFlash(void)
 {
     PlaySE(SE_W115);
     FlagSet(FLAG_SYS_FLASH_ACTIVE);
     ScriptContext1_SetupScript(EventScript_FldEffFlash);
 }
 
-static void sub_80C9BD0(void)
+// Map transition animatics
+
+static void CB2_ChangeMapMain(void)
 {
     RunTasks();
     AnimateSprites();
@@ -195,14 +198,14 @@ static void sub_80C9BD0(void)
     UpdatePaletteFade();
 }
 
-static void sub_80C9BE8(void)
+static void VBC_ChangeMapVBlank(void)
 {
     LoadOam();
     ProcessSpriteCopyRequests();
     TransferPlttBuffer();
 }
 
-void sub_80C9BFC(void)
+void CB2_DoChangeMap(void)
 {
     SetVBlankCallback(NULL);
 
@@ -224,74 +227,74 @@ void sub_80C9BFC(void)
     ResetTasks();
     ResetSpriteData();
     EnableInterrupts(INTR_FLAG_VBLANK);
-    SetVBlankCallback(sub_80C9BE8);
-    SetMainCallback2(sub_80C9BD0);
-    if (!sub_80C9CE8())
+    SetVBlankCallback(VBC_ChangeMapVBlank);
+    SetMainCallback2(CB2_ChangeMapMain);
+    if (!TryDoMapTransition())
         SetMainCallback2(gMain.savedCallback);
 }
 
-static bool8 sub_80C9CE8(void)
+static bool8 TryDoMapTransition(void)
 {
-    u8 fromType = get_map_light_from_warp0();
+    u8 fromType = GetLastUsedWarpMapType();
     u8 toType = GetCurrentMapType();
     u8 i = 0;
-    if (sub_80561B4() != gMapHeader.regionMapSectionId && sub_80F8154(gMapHeader.regionMapSectionId, FALSE) == TRUE)
+    if (GetLastUsedWarpMapSectionId() != gMapHeader.regionMapSectionId && MapHasPreviewScreen_HandleQLState2(gMapHeader.regionMapSectionId, FALSE) == TRUE)
     {
-        sub_80CA160(gMapHeader.regionMapSectionId);
+        RunMapPreviewScreen(gMapHeader.regionMapSectionId);
         return TRUE;
     }
-    for (; gUnknown_83F5738[i].fromType != 0; i++)
+    for (; sTransitionTypes[i].fromType != 0; i++)
     {
-        if (gUnknown_83F5738[i].fromType == fromType && gUnknown_83F5738[i].toType == toType)
+        if (sTransitionTypes[i].fromType == fromType && sTransitionTypes[i].toType == toType)
         {
-            gUnknown_83F5738[i].func1();
+            sTransitionTypes[i].func1();
             return TRUE;
         }
     }
     return FALSE;
 }
 
-bool8 sub_80C9D7C(u8 _fromType, u8 _toType)
+bool8 MapTransitionIsEnter(u8 _fromType, u8 _toType)
 {
     u8 fromType = _fromType;
     u8 toType = _toType;
     u8 i = 0;
-    for (; gUnknown_83F5738[i].fromType != 0; i++)
+    for (; sTransitionTypes[i].fromType != 0; i++)
     {
-        if (gUnknown_83F5738[i].fromType == fromType && gUnknown_83F5738[i].toType == toType)
+        if (sTransitionTypes[i].fromType == fromType && sTransitionTypes[i].toType == toType)
         {
-            return gUnknown_83F5738[i].isEnter;
+            return sTransitionTypes[i].isEnter;
         }
     }
     return FALSE;
 }
 
-bool8 sub_80C9DCC(u8 _fromType, u8 _toType)
+bool8 MapTransitionIsExit(u8 _fromType, u8 _toType)
 {
     u8 fromType = _fromType;
     u8 toType = _toType;
     u8 i = 0;
-    for (; gUnknown_83F5738[i].fromType != 0; i++)
+    for (; sTransitionTypes[i].fromType != 0; i++)
     {
-        if (gUnknown_83F5738[i].fromType == fromType && gUnknown_83F5738[i].toType == toType)
+        if (sTransitionTypes[i].fromType == fromType && sTransitionTypes[i].toType == toType)
         {
-            return gUnknown_83F5738[i].isExit;
+            return sTransitionTypes[i].isExit;
         }
     }
     return FALSE;
 }
 
-static void sub_80C9E1C(void)
+static void FlashTransition_Exit(void)
 {
-    CreateTask(sub_80C9E30, 0);
+    CreateTask(Task_FlashTransition_Exit_0, 0);
 }
 
-static void sub_80C9E30(u8 taskId)
+static void Task_FlashTransition_Exit_0(u8 taskId)
 {
-    gTasks[taskId].func = sub_80C9E4C;
+    gTasks[taskId].func = Task_FlashTransition_Exit_1;
 }
 
-static void sub_80C9E4C(u8 taskId)
+static void Task_FlashTransition_Exit_1(u8 taskId)
 {
     SetGpuReg(REG_OFFSET_DISPCNT, 0);
     LZ77UnCompVram(gUnknown_83F5A44, (void *)BG_CHAR_ADDR(3));
@@ -303,12 +306,12 @@ static void sub_80C9E4C(u8 taskId)
     SetGpuReg(REG_OFFSET_BLDY, 0);
     SetGpuReg(REG_OFFSET_BG0CNT, BGCNT_PRIORITY(0) | BGCNT_CHARBASE(3) | BGCNT_SCREENBASE(31));
     SetGpuReg(REG_OFFSET_DISPCNT, DISPCNT_MODE_0 | DISPCNT_OBJ_1D_MAP | DISPCNT_BG0_ON | DISPCNT_OBJ_ON);
-    gTasks[taskId].func = sub_80C9EF0;
+    gTasks[taskId].func = Task_FlashTransition_Exit_2;
     gTasks[taskId].data[0] = 16;
     gTasks[taskId].data[1] = 0;
 }
 
-static void sub_80C9EF0(u8 taskId)
+static void Task_FlashTransition_Exit_2(u8 taskId)
 {
     u16 r4 = gTasks[taskId].data[1];
     SetGpuReg(REG_OFFSET_BLDALPHA, (16 << 8) + r4);
@@ -319,11 +322,11 @@ static void sub_80C9EF0(u8 taskId)
     else
     {
         gTasks[taskId].data[2] = 0;
-        gTasks[taskId].func = sub_80C9F38;
+        gTasks[taskId].func = Task_FlashTransition_Exit_3;
     }
 }
 
-static void sub_80C9F38(u8 taskId)
+static void Task_FlashTransition_Exit_3(u8 taskId)
 {
     u16 r4;
     SetGpuReg(REG_OFFSET_BLDALPHA, (16 << 8) + 16);
@@ -336,12 +339,12 @@ static void sub_80C9F38(u8 taskId)
     else
     {
         LoadPalette(gUnknown_83F5804, 0x00, 0x20);
-        gTasks[taskId].func = sub_80C9FA0;
+        gTasks[taskId].func = Task_FlashTransition_Exit_4;
         gTasks[taskId].data[2] = 8;
     }
 }
 
-static void sub_80C9FA0(u8 taskId)
+static void Task_FlashTransition_Exit_4(u8 taskId)
 {
     if (gTasks[taskId].data[2] != 0)
         gTasks[taskId].data[2]--;
@@ -349,17 +352,17 @@ static void sub_80C9FA0(u8 taskId)
         SetMainCallback2(gMain.savedCallback);
 }
 
-static void sub_80C9FD4(void)
+static void FlashTransition_Enter(void)
 {
-    CreateTask(sub_80C9FE8, 0);
+    CreateTask(Task_FlashTransition_Enter_0, 0);
 }
 
-static void sub_80C9FE8(u8 taskId)
+static void Task_FlashTransition_Enter_0(u8 taskId)
 {
-    gTasks[taskId].func = sub_80CA004;
+    gTasks[taskId].func = Task_FlashTransition_Enter_1;
 }
 
-static void sub_80CA004(u8 taskId)
+static void Task_FlashTransition_Enter_1(u8 taskId)
 {
     SetGpuReg(REG_OFFSET_DISPCNT, 0);
     LZ77UnCompVram(gUnknown_83F5A44, (void *)BG_CHAR_ADDR(3));
@@ -371,13 +374,13 @@ static void sub_80CA004(u8 taskId)
     SetGpuReg(REG_OFFSET_DISPCNT, DISPCNT_MODE_0 | DISPCNT_OBJ_1D_MAP | DISPCNT_BG0_ON | DISPCNT_OBJ_ON);
     LoadPalette(gUnknown_83F5804, 0xE0, 0x20);
     LoadPalette(gUnknown_83F5824, 0, 0x20);
-    gTasks[taskId].func = sub_80CA0A4;
+    gTasks[taskId].func = Task_FlashTransition_Enter_2;
     gTasks[taskId].data[0] = 16;
     gTasks[taskId].data[1] = 0;
     gTasks[taskId].data[2] = 0;
 }
 
-static void sub_80CA0A4(u8 taskId)
+static void Task_FlashTransition_Enter_2(u8 taskId)
 {
     u16 r4;
     r4 = gTasks[taskId].data[2];
@@ -391,11 +394,11 @@ static void sub_80CA0A4(u8 taskId)
     {
         SetGpuReg(REG_OFFSET_BLDALPHA, (16 << 8) + 16);
         SetGpuReg(REG_OFFSET_BLDCNT, BLDCNT_TGT1_BG0 | BLDCNT_EFFECT_BLEND | BLDCNT_TGT2_BG1 | BLDCNT_TGT2_BG2 | BLDCNT_TGT2_BG3 | BLDCNT_TGT2_OBJ | BLDCNT_TGT2_BD);
-        gTasks[taskId].func = sub_80CA108;
+        gTasks[taskId].func = Task_FlashTransition_Enter_3;
     }
 }
 
-static void sub_80CA108(u8 taskId)
+static void Task_FlashTransition_Enter_3(u8 taskId)
 {
     u16 r4 = 16 - gTasks[taskId].data[1];
     SetGpuReg(REG_OFFSET_BLDALPHA, (16 << 8) + r4);
@@ -410,13 +413,13 @@ static void sub_80CA108(u8 taskId)
     }
 }
 
-static void sub_80CA160(u8 mapSecId)
+static void RunMapPreviewScreen(u8 mapSecId)
 {
-    u8 taskId = CreateTask(sub_80CA190, 0);
+    u8 taskId = CreateTask(Task_MapPreviewScreen_0, 0);
     gTasks[taskId].data[3] = mapSecId;
 }
 
-static void sub_80CA190(u8 taskId)
+static void Task_MapPreviewScreen_0(u8 taskId)
 {
     s16 *data = gTasks[taskId].data;
     switch (data[0])
@@ -424,15 +427,15 @@ static void sub_80CA190(u8 taskId)
     case 0:
         SetWordTaskArg(taskId, 5, (uintptr_t)gMain.vblankCallback);
         SetVBlankCallback(NULL);
-        sub_80F8180();
-        sub_80F819C(data[3]);
+        MapPreview_InitBgs();
+        MapPreview_LoadGfx(data[3]);
         BlendPalettes(0xFFFFFFFF, 0x10, RGB_BLACK);
         data[0]++;
         break;
     case 1:
-        if (!sub_80F8258())
+        if (!MapPreview_IsGfxLoadFinished())
         {
-            data[4] = sub_80F8318(data[3]);
+            data[4] = MapPreview_CreateMapNameWindow(data[3]);
             CopyWindowToVram(data[4], 3);
             data[0]++;
         }
@@ -448,7 +451,7 @@ static void sub_80CA190(u8 taskId)
     case 3:
         if (!UpdatePaletteFade())
         {
-            data[2] = sub_80F856C(data[3]);
+            data[2] = MapPreview_GetDuration(data[3]);
             data[0]++;
         }
         break;
@@ -468,8 +471,8 @@ static void sub_80CA190(u8 taskId)
             {
                 data[i] = 0;
             }
-            sub_80F8234(data[4]);
-            gTasks[taskId].func = sub_80CA004;
+            MapPreview_Unload(data[4]);
+            gTasks[taskId].func = Task_FlashTransition_Enter_1;
         }
         break;
     }
diff --git a/src/map_preview_screen.c b/src/map_preview_screen.c
index a553ca122..3f45c7833 100644
--- a/src/map_preview_screen.c
+++ b/src/map_preview_screen.c
@@ -16,10 +16,10 @@
 #include "map_preview_screen.h"
 #include "constants/region_map.h"
 
-static EWRAM_DATA bool8 gUnknown_203ABEC = FALSE;
-static EWRAM_DATA bool8 gUnknown_203ABED = FALSE;
+static EWRAM_DATA bool8 sHasVisitedMapBefore = FALSE;
+static EWRAM_DATA bool8 sAllocedBg0TilemapBuffer = FALSE;
 
-static void sub_80F83D0(u8 taskId);
+static void Task_RunMapPreviewScreenForest(u8 taskId);
 
 static const u8 gViridianForestMapPreviewPalette[] = INCBIN_U8("data/map_preview/viridian_forest_pal.gbapal");
 static const u8 gViridianForestMapPreviewTiles[] = INCBIN_U8("data/map_preview/viridian_forest_tiles.4bpp.lz");
@@ -88,7 +88,7 @@ static const u8 gAlteringCaveMapPreviewTilemap[] = INCBIN_U8("data/map_preview/a
 static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     [MPS_VIRIDIAN_FOREST] = {
         .mapsec = MAPSEC_VIRIDIAN_FOREST,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_VIRIDIAN_FOREST,
         .tilesptr = gViridianForestMapPreviewTiles,
         .tilemapptr = gViridianForestMapPreviewTilemap,
@@ -96,7 +96,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_MT_MOON] = {
         .mapsec = MAPSEC_MT_MOON,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_MT_MOON_1F,
         .tilesptr = gMtMoonMapPreviewTiles,
         .tilemapptr = gMtMoonMapPreviewTilemap,
@@ -104,7 +104,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_DIGLETTS_CAVE] = {
         .mapsec = MAPSEC_DIGLETTS_CAVE,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_DIGLETTS_CAVE_B1F,
         .tilesptr = gDiglettsCaveMapPreviewTiles,
         .tilemapptr = gDiglettsCaveMapPreviewTilemap,
@@ -112,7 +112,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_ROCK_TUNNEL] = {
         .mapsec = MAPSEC_ROCK_TUNNEL,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_ROCK_TUNNEL_1F,
         .tilesptr = gRockTunnelMapPreviewTiles,
         .tilemapptr = gRockTunnelMapPreviewTilemap,
@@ -120,7 +120,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_POKEMON_TOWER] = {
         .mapsec = MAPSEC_POKEMON_TOWER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_POKEMON_TOWER_1F,
         .tilesptr = gPokemonTowerMapPreviewTiles,
         .tilemapptr = gPokemonTowerMapPreviewTilemap,
@@ -128,7 +128,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_SAFARI_ZONE] = {
         .mapsec = MAPSEC_KANTO_SAFARI_ZONE,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_SAFARI_ZONE_CENTER,
         .tilesptr = gKantoSafariZoneMapPreviewTiles,
         .tilemapptr = gKantoSafariZoneMapPreviewTilemap,
@@ -136,7 +136,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_SEAFOAM_ISLANDS] = {
         .mapsec = MAPSEC_SEAFOAM_ISLANDS,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEAFOAM_ISLANDS_1F,
         .tilesptr = gSeafoamIslandsMapPreviewTiles,
         .tilemapptr = gSeafoamIslandsMapPreviewTilemap,
@@ -144,7 +144,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_POKEMON_MANSION] = {
         .mapsec = MAPSEC_POKEMON_MANSION,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_POKEMON_MANSION_1F,
         .tilesptr = gPokemonMansionMapPreviewTiles,
         .tilemapptr = gPokemonMansionMapPreviewTilemap,
@@ -152,7 +152,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_ROCKET_HIDEOUT] = {
         .mapsec = MAPSEC_ROCKET_HIDEOUT,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_ROCKET_HIDEOUT_B1F,
         .tilesptr = gRocketHideoutMapPreviewTiles,
         .tilemapptr = gRocketHideoutMapPreviewTilemap,
@@ -160,7 +160,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_SILPH_CO] = {
         .mapsec = MAPSEC_SILPH_CO,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SILPH_CO_1F,
         .tilesptr = gSilphCoMapPreviewTiles,
         .tilemapptr = gSilphCoMapPreviewTilemap,
@@ -168,7 +168,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_VICTORY_ROAD] = {
         .mapsec = MAPSEC_KANTO_VICTORY_ROAD,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_VICTORY_ROAD_1F,
         .tilesptr = gKantoVictoryRoadMapPreviewTiles,
         .tilemapptr = gKantoVictoryRoadMapPreviewTilemap,
@@ -176,7 +176,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_CERULEAN_CAVE] = {
         .mapsec = MAPSEC_CERULEAN_CAVE,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_CERULEAN_CAVE_1F,
         .tilesptr = gCeruleanCaveMapPreviewTiles,
         .tilemapptr = gCeruleanCaveMapPreviewTilemap,
@@ -184,7 +184,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_POWER_PLANT] = {
         .mapsec = MAPSEC_POWER_PLANT,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_POWER_PLANT,
         .tilesptr = gPowerPlantMapPreviewTiles,
         .tilemapptr = gPowerPlantMapPreviewTilemap,
@@ -192,7 +192,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_MT_EMBER] = {
         .mapsec = MAPSEC_MT_EMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_MT_EMBER_EXTERIOR,
         .tilesptr = gMtEmberMapPreviewTiles,
         .tilemapptr = gMtEmberMapPreviewTilemap,
@@ -200,7 +200,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_ROCKET_WAREHOUSE] = {
         .mapsec = MAPSEC_ROCKET_WAREHOUSE,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_THREE_ISLAND_BERRY_FOREST,
         .tilesptr = gRocketWarehouseMapPreviewTiles,
         .tilemapptr = gRocketWarehouseMapPreviewTilemap,
@@ -208,7 +208,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_MONEAN_CHAMBER] = {
         .mapsec = MAPSEC_MONEAN_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -216,7 +216,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_DOTTED_HOLE] = {
         .mapsec = MAPSEC_DOTTED_HOLE,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SIX_ISLAND_DOTTED_HOLE_1F,
         .tilesptr = gDottedHoleMapPreviewTiles,
         .tilemapptr = gDottedHoleMapPreviewTilemap,
@@ -224,7 +224,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_BERRY_FOREST] = {
         .mapsec = MAPSEC_BERRY_FOREST,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_THREE_ISLAND_BERRY_FOREST,
         .tilesptr = gBerryForestMapPreviewTiles,
         .tilemapptr = gBerryForestMapPreviewTilemap,
@@ -232,7 +232,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_ICEFALL_CAVE] = {
         .mapsec = MAPSEC_ICEFALL_CAVE,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_FOUR_ISLAND_ICEFALL_CAVE_ENTRANCE,
         .tilesptr = gIcefallCaveMapPreviewTiles,
         .tilemapptr = gIcefallCaveMapPreviewTilemap,
@@ -240,7 +240,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_LOST_CAVE] = {
         .mapsec = MAPSEC_LOST_CAVE,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_FIVE_ISLAND_LOST_CAVE_ENTRANCE,
         .tilesptr = gLostCaveMapPreviewTiles,
         .tilemapptr = gLostCaveMapPreviewTilemap,
@@ -248,7 +248,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_ALTERING_CAVE] = {
         .mapsec = MAPSEC_ALTERING_CAVE,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SIX_ISLAND_ALTERING_CAVE,
         .tilesptr = gAlteringCaveMapPreviewTiles,
         .tilemapptr = gAlteringCaveMapPreviewTilemap,
@@ -256,7 +256,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_PATTERN_BUSH] = {
         .mapsec = MAPSEC_PATTERN_BUSH,
-        .forceFirstTime = TRUE,
+        .type = TRUE,
         .flagId = FLAG_WORLD_MAP_SIX_ISLAND_PATTERN_BUSH,
         .tilesptr = gViridianForestMapPreviewTiles,
         .tilemapptr = gViridianForestMapPreviewTilemap,
@@ -264,7 +264,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_LIPTOO_CHAMBER] = {
         .mapsec = MAPSEC_LIPTOO_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -272,7 +272,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_WEEPTH_CHAMBER] = {
         .mapsec = MAPSEC_WEEPTH_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -280,7 +280,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_TDILFORD_CHAMBER] = {
         .mapsec = MAPSEC_DILFORD_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -288,7 +288,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_SCUFIB_CHAMBER] = {
         .mapsec = MAPSEC_SCUFIB_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -296,7 +296,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_RIXY_CHAMBER] = {
         .mapsec = MAPSEC_RIXY_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -304,7 +304,7 @@ static const struct MapPreviewScreen sMapPreviewScreenData[MPS_COUNT] = {
     },
     [MPS_VIAPOIS_CHAMBER] = {
         .mapsec = MAPSEC_VIAPOIS_CHAMBER,
-        .forceFirstTime = FALSE,
+        .type = FALSE,
         .flagId = FLAG_WORLD_MAP_SEVEN_ISLAND_TANOBY_RUINS_MONEAN_CHAMBER,
         .tilesptr = gMoneanChamberMapPreviewTiles,
         .tilemapptr = gMoneanChamberMapPreviewTilemap,
@@ -328,7 +328,7 @@ static const struct BgTemplate sMapPreviewBgTemplate[1] = {
     }
 };
 
-static u8 sub_80F80E4(u8 mapsec)
+static u8 GetMapPreviewScreenIdx(u8 mapsec)
 {
     s32 i;
 
@@ -342,20 +342,20 @@ static u8 sub_80F80E4(u8 mapsec)
     return MPS_COUNT;
 }
 
-bool8 sub_80F8110(u8 mapsec, u8 forceFirstTime)
+bool8 MapHasPreviewScreen(u8 mapsec, u8 type)
 {
     u8 idx;
 
-    idx = sub_80F80E4(mapsec);
+    idx = GetMapPreviewScreenIdx(mapsec);
     if (idx != MPS_COUNT)
     {
-        if (forceFirstTime == 2)
+        if (type == 2)
         {
             return TRUE;
         }
         else
         {
-            return sMapPreviewScreenData[idx].forceFirstTime == forceFirstTime ? TRUE : FALSE;
+            return sMapPreviewScreenData[idx].type == type ? TRUE : FALSE;
         }
     }
     else
@@ -364,29 +364,29 @@ bool8 sub_80F8110(u8 mapsec, u8 forceFirstTime)
     }
 }
 
-bool32 sub_80F8154(u8 mapsec, u8 forceFirstTime)
+bool32 MapHasPreviewScreen_HandleQLState2(u8 mapsec, u8 type)
 {
-    if (gQuestLogState == 2)
+    if (gQuestLogState == QL_STATE_2)
     {
         return FALSE;
     }
     else
     {
-        return sub_80F8110(mapsec, forceFirstTime);
+        return MapHasPreviewScreen(mapsec, type);
     }
 }
 
-void sub_80F8180(void)
+void MapPreview_InitBgs(void)
 {
     InitBgsFromTemplates(0, sMapPreviewBgTemplate, NELEMS(sMapPreviewBgTemplate));
     ShowBg(0);
 }
 
-void sub_80F819C(u8 mapsec)
+void MapPreview_LoadGfx(u8 mapsec)
 {
     u8 idx;
 
-    idx = sub_80F80E4(mapsec);
+    idx = GetMapPreviewScreenIdx(mapsec);
     if (idx != MPS_COUNT)
     {
        ResetTempTileDataBuffers();
@@ -395,55 +395,55 @@ void sub_80F819C(u8 mapsec)
        if (GetBgTilemapBuffer(0) == NULL)
        {
            SetBgTilemapBuffer(0, Alloc(BG_SCREEN_SIZE));
-           gUnknown_203ABED = TRUE;
+           sAllocedBg0TilemapBuffer = TRUE;
        }
        else
        {
-           gUnknown_203ABED = FALSE;
+           sAllocedBg0TilemapBuffer = FALSE;
        }
        CopyToBgTilemapBuffer(0, sMapPreviewScreenData[idx].tilemapptr, 0, 0x000);
        CopyBgTilemapBufferToVram(0);
     }
 }
 
-void sub_80F8234(s32 windowId)
+void MapPreview_Unload(s32 windowId)
 {
     RemoveWindow(windowId);
-    if (gUnknown_203ABED)
+    if (sAllocedBg0TilemapBuffer)
     {
         Free(GetBgTilemapBuffer(0));
     }
 }
 
-bool32 sub_80F8258(void)
+bool32 MapPreview_IsGfxLoadFinished(void)
 {
     return FreeTempTileDataBuffersIfPossible();
 }
 
-void sub_80F8268(u8 mapsec)
+void MapPreview_StartForestTransition(u8 mapsec)
 {
     u8 taskId;
 
-    taskId = CreateTask(sub_80F83D0, 0);
+    taskId = CreateTask(Task_RunMapPreviewScreenForest, 0);
     gTasks[taskId].data[2] = GetBgAttribute(0, BG_ATTR_PRIORITY);
     gTasks[taskId].data[4] = GetGpuReg(REG_OFFSET_BLDCNT);
     gTasks[taskId].data[5] = GetGpuReg(REG_OFFSET_BLDALPHA);
     gTasks[taskId].data[3] = GetGpuReg(REG_OFFSET_DISPCNT);
     gTasks[taskId].data[6] = GetGpuReg(REG_OFFSET_WININ);
     gTasks[taskId].data[7] = GetGpuReg(REG_OFFSET_WINOUT);
-    gTasks[taskId].data[10] = sub_80F856C(mapsec);
+    gTasks[taskId].data[10] = MapPreview_GetDuration(mapsec);
     gTasks[taskId].data[8] = 16;
     gTasks[taskId].data[9] = 0;
     SetBgAttribute(0, BG_ATTR_PRIORITY, 0);
     SetGpuReg(REG_OFFSET_BLDCNT, BLDCNT_TGT1_BG0 | BLDCNT_EFFECT_BLEND | BLDCNT_TGT2_BG1 | BLDCNT_TGT2_BG2 | BLDCNT_TGT2_BG3 | BLDCNT_TGT2_OBJ | BLDCNT_TGT2_BD);
     SetGpuReg(REG_OFFSET_BLDALPHA, BLDALPHA_BLEND(16, 0));
-    SetGpuRegBits(REG_OFFSET_WININ, 0x2020);
-    SetGpuRegBits(REG_OFFSET_WINOUT, 0x0020);
-    gTasks[taskId].data[11] = sub_80F8318(mapsec);
+    SetGpuRegBits(REG_OFFSET_WININ, WININ_WIN0_CLR | WININ_WIN1_CLR);
+    SetGpuRegBits(REG_OFFSET_WINOUT, WINOUT_WIN01_CLR);
+    gTasks[taskId].data[11] = MapPreview_CreateMapNameWindow(mapsec);
     ScriptContext2_Enable();
 }
 
-u16 sub_80F8318(u8 mapsec)
+u16 MapPreview_CreateMapNameWindow(u8 mapsec)
 {
     u16 windowId;
     u32 xctr;
@@ -452,18 +452,18 @@ u16 sub_80F8318(u8 mapsec)
     windowId = AddWindow(&sMapNameWindow);
     FillWindowPixelBuffer(windowId, PIXEL_FILL(1));
     PutWindowTilemap(windowId);
-    color[0] = 1; // Access violation
-    color[1] = 4; // Access violation
-    color[2] = 3; // Access violation
+    color[0] = TEXT_COLOR_WHITE; // Access violation
+    color[1] = TEXT_COLOR_RED; // Access violation
+    color[2] = TEXT_COLOR_LIGHT_GREY; // Access violation
     GetMapName(gStringVar4, mapsec, 0);
     xctr = 104 - GetStringWidth(2, gStringVar4, 0);
     AddTextPrinterParameterized4(windowId, 2, xctr / 2, 2, 0, 0, color/* Access violation */, -1, gStringVar4);
     return windowId;
 }
 
-bool32 sub_80F83B0(void)
+bool32 ForestMapPreviewScreenIsRunning(void)
 {
-    if (FuncIsActiveTask(sub_80F83D0) == TRUE)
+    if (FuncIsActiveTask(Task_RunMapPreviewScreenForest) == TRUE)
     {
         return FALSE;
     }
@@ -473,7 +473,7 @@ bool32 sub_80F83B0(void)
     }
 }
 
-static void sub_80F83D0(u8 taskId)
+static void Task_RunMapPreviewScreenForest(u8 taskId)
 {
     s16 * data;
 
@@ -481,7 +481,7 @@ static void sub_80F83D0(u8 taskId)
     switch (data[0])
     {
     case 0:
-        if (!sub_80F8258() && !IsDma3ManagerBusyWithBgCopy())
+        if (!MapPreview_IsGfxLoadFinished() && !IsDma3ManagerBusyWithBgCopy())
         {
             CopyWindowToVram(data[11], 3);
             data[0]++;
@@ -539,7 +539,7 @@ static void sub_80F83D0(u8 taskId)
     case 5:
         if (!IsDma3ManagerBusyWithBgCopy())
         {
-            sub_80F8234(data[11]);
+            MapPreview_Unload(data[11]);
             SetBgAttribute(0, BG_ATTR_PRIORITY, data[2]);
             SetGpuReg(REG_OFFSET_DISPCNT, data[3]);
             SetGpuReg(REG_OFFSET_BLDCNT, data[4]);
@@ -556,7 +556,7 @@ const struct MapPreviewScreen * GetDungeonMapPreviewScreenInfo(u8 mapsec)
 {
     u8 idx;
 
-    idx = sub_80F80E4(mapsec);
+    idx = GetMapPreviewScreenIdx(mapsec);
     if (idx == MPS_COUNT)
     {
         return NULL;
@@ -567,18 +567,18 @@ const struct MapPreviewScreen * GetDungeonMapPreviewScreenInfo(u8 mapsec)
     }
 }
 
-u16 sub_80F856C(u8 mapsec)
+u16 MapPreview_GetDuration(u8 mapsec)
 {
     u8 idx;
     u16 flagId;
 
-    idx = sub_80F80E4(mapsec);
+    idx = GetMapPreviewScreenIdx(mapsec);
     if (idx == MPS_COUNT)
     {
         return 0;
     }
     flagId = sMapPreviewScreenData[idx].flagId;
-    if (!sMapPreviewScreenData[idx].forceFirstTime)
+    if (sMapPreviewScreenData[idx].type == 0)
     {
         if (!FlagGet(flagId))
         {
@@ -590,7 +590,7 @@ u16 sub_80F856C(u8 mapsec)
         }
     }
     else {
-        if (gUnknown_203ABEC)
+        if (sHasVisitedMapBefore)
         {
             return 120;
         }
@@ -601,15 +601,15 @@ u16 sub_80F856C(u8 mapsec)
     }
 }
 
-void sub_80F85BC(u16 flagId)
+void MapPreview_SetFlag(u16 flagId)
 {
     if (!FlagGet(flagId))
     {
-        gUnknown_203ABEC = TRUE;
+        sHasVisitedMapBefore = TRUE;
     }
     else
     {
-        gUnknown_203ABEC = FALSE;
+        sHasVisitedMapBefore = FALSE;
     }
     FlagSet(flagId);
 }
diff --git a/src/quest_log.c b/src/quest_log.c
index 5d260b58f..8f53f9c5e 100644
--- a/src/quest_log.c
+++ b/src/quest_log.c
@@ -4294,7 +4294,7 @@ static const u16 sQuestLogWorldMapFlags[] =
     FLAG_WORLD_MAP_SIX_ISLAND
 };
 
-void sub_8115748(u16 worldMapFlag)
+void QuestLog_RecordEnteredMap(u16 worldMapFlag)
 {
     s32 i;
 
diff --git a/src/scrcmd.c b/src/scrcmd.c
index b4605e9d5..7eaa98c76 100644
--- a/src/scrcmd.c
+++ b/src/scrcmd.c
@@ -598,8 +598,8 @@ bool8 ScrCmd_comparestattoword(struct ScriptContext * ctx)
 bool8 ScrCmd_setworldmapflag(struct ScriptContext * ctx)
 {
     u16 value = ScriptReadHalfword(ctx);
-    sub_8115748(value);
-    sub_80F85BC(value);
+    QuestLog_RecordEnteredMap(value);
+    MapPreview_SetFlag(value);
     return FALSE;
 }