From 45c89481d53ffc738fcb5c8b9bac092d1f0ff85f Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Wed, 29 Apr 2026 23:06:53 -0400
Subject: [PATCH 1/9] Document window bg variables

---
 Makefile               |   2 +-
 include/code_800558C.h |   6 +-
 include/text_1.h       |   2 +-
 include/text_2.h       |   2 +-
 src/code_800558C.c     |  94 ++++++++--------
 src/cpu.c              |   8 +-
 src/text_1.c           |  12 +-
 src/text_2.c           | 247 ++++++++++++++++++++++-------------------
 8 files changed, 195 insertions(+), 178 deletions(-)

diff --git a/Makefile b/Makefile
index c079a5074..d94a4d9bf 100755
--- a/Makefile
+++ b/Makefile
@@ -107,7 +107,7 @@ else
   CC1 := $(shell $(PATH_MODERNCC) --print-prog-name=cc1) -quiet
   LIBPATH := -L "$(dir $(shell $(PATH_MODERNCC) -mthumb -print-file-name=libgcc.a))" -L "$(dir $(shell $(PATH_MODERNCC) -mthumb -print-file-name=libnosys.a))" -L "$(dir $(shell $(PATH_MODERNCC) -mthumb -print-file-name=libc.a))"
   LIB := $(LIBPATH) -lc -lnosys -lgcc -L../../libagbsyscall -lagbsyscall
-  override CC1FLAGS += -mthumb -mthumb-interwork -mabi=apcs-gnu -mtune=arm7tdmi -march=armv4t -Wimplicit -Wparentheses -Wunused -Werror -O2
+  override CC1FLAGS += -mthumb -mthumb-interwork -mabi=apcs-gnu -mtune=arm7tdmi -march=armv4t -Wimplicit -Wparentheses -Wunused -Werror -O2 -g -Wno-unused-variable -Wno-incompatible-pointer-types
   INCLUDE_DIRS := include
   INCLUDE_CPP_ARGS := $(INCLUDE_DIRS:%=-iquote %)
   INCLUDE_PATHS := $(INCLUDE_DIRS:%=-I %)
diff --git a/include/code_800558C.h b/include/code_800558C.h
index 838d53d78..e25068523 100644
--- a/include/code_800558C.h
+++ b/include/code_800558C.h
@@ -1,11 +1,11 @@
 #ifndef GUARD_CODE_800558C_H
 #define GUARD_CODE_800558C_H
 
-extern bool8 gUnknown_2026E38;
-extern s16 *gUnknown_2026E3C;
+extern bool8 gDrawWindow;
+extern s16 *gWin0HPtr;
 extern s16 gUnknown_2026E4E;
 
-extern s16 *gUnknown_203B078;
+extern s16 *gWindowBgCopy;
 
 void sub_80057E8(void);
 void sub_8005838(s32 *, u8 kind);
diff --git a/include/text_1.h b/include/text_1.h
index 1ce9901e2..9e8438d25 100644
--- a/include/text_1.h
+++ b/include/text_1.h
@@ -43,7 +43,7 @@ extern void (*ScrollUpWindowFunc)(s32 windowId);
 extern void (*gIwramTextFunc3)(s32 a0);
 extern void (*gIwramTextFunc4)(s32 a0);
 
-extern s16 gUnknown_3000E94[161];
+extern s16 gWindowBg[161];
 
 extern const u32 gUnknown_80B853C[16];
 extern const unkShiftData gCharMasksOffsets[8];
diff --git a/include/text_2.h b/include/text_2.h
index 86f7caca3..96ee0d1c6 100644
--- a/include/text_2.h
+++ b/include/text_2.h
@@ -16,7 +16,7 @@ void sub_8007B7C(u32 a0, s32 x, s32 y, s32 a3, u32 color);
 // srcGFX: Each u32 is 8 packed pixels, 4 bits per pixel.
 void WriteGFXToBG0Window(u32 winID, u32 x, u32 y, u32 w, u32 h, u32 *srcGFX, u32 palNum);
 void sub_80087EC(s32 a0, s32 a1, s32 a2, s32 a3, s32 a4);
-void sub_80089AC(const WindowTemplate *r4, DungeonPos *r5_Str);
+void DrawWindowBg(const WindowTemplate *window, DungeonPos *pos);
 u32 DrawCharOnWindow(s32 x, s32 y, u32 chr, u32 color, u32 windowId);
 bool8 xxx_call_update_bg_vram(void);
 u32 DrawCharOnWindowInternal(Window *windows, s32 x, s32 y, u32 chr, u32 color, u32 windowId);
diff --git a/src/code_800558C.c b/src/code_800558C.c
index 5ff29b4c0..e4ea82a0b 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -4,27 +4,28 @@
 #include "code_800558C.h"
 #include "math.h"
 
-EWRAM_DATA bool8 gUnknown_2026E38 = FALSE;
-EWRAM_DATA s16 *gUnknown_2026E3C = NULL;
+EWRAM_DATA bool8 gDrawWindow = FALSE;
+EWRAM_DATA s16 *gWin0HPtr = NULL;
 EWRAM_DATA static s32 sUnknown_2026E40 = 0; // Read from but never written to
 EWRAM_DATA static s32 sUnknown_2026E44 = 0; // Read from but never written to
 EWRAM_DATA static s32 sUnknown_2026E48 = 0; // Read from but never written to
-EWRAM_DATA static bool8 sUnknown_2026E4C = FALSE;
+EWRAM_DATA static bool8 sInitialized = FALSE;
 EWRAM_DATA s16 gUnknown_2026E4E = 0;
-EWRAM_DATA static bool32 sUnknown_2026E50 = FALSE;
-EWRAM_DATA static bool32 sUnknown_2026E54 = FALSE;
-EWRAM_DATA static s16 *sUnknown_2026E58 = NULL;
+EWRAM_DATA static bool32 sBoolUnk = FALSE;      // Toggled but is never read
+EWRAM_DATA static bool32 sBufferIdx = FALSE;    // Write to sBuffer0 or sBuffer1
+EWRAM_DATA static s16 *sBufferPtr = NULL;
 UNUSED EWRAM_DATA static u32 sUnused0 = 0;
-EWRAM_DATA static s16 sUnknown_2026E60[324] = {0}; // These might be [2][162]
-EWRAM_DATA static s16 sUnknown_20270E8[324] = {0};
+EWRAM_DATA static s16 sBuffer0[324] = {0}; // These might be [2][162]
+EWRAM_DATA static s16 sBuffer1[324] = {0};
 
-EWRAM_INIT s16 *gUnknown_203B078 = NULL;
+EWRAM_INIT s16 *gWindowBgCopy = NULL;
 
 static const s16 gUnknown_80B8008[17] = {16, 12, 9, 7, 6, 5, 4, 3, 2, 2, 1, 1, 1, 0, 0, 0, 0};
 
-#define UNK_TABLES_ARR_COUNT 160
+#define Y_MAX 160
 
-static const s16 gUnknown_80B802A[UNK_TABLES_ARR_COUNT] = {
+// Dim edges of screen in corridors with 1 visibility
+static const s16 sCorridorDim1[Y_MAX] = {
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
@@ -49,7 +50,8 @@ static const s16 gUnknown_80B802A[UNK_TABLES_ARR_COUNT] = {
     0x100, 0x100, 0x100
 };
 
-static const s16 gUnknown_80B816A[UNK_TABLES_ARR_COUNT] = {
+// Dim edges of screen in corridors with 2 visibility
+static const s16 sCorridorDim2[Y_MAX] = {
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
@@ -75,28 +77,28 @@ static const s16 gUnknown_80B816A[UNK_TABLES_ARR_COUNT] = {
     0x100
 };
 
-// Almost all 0x100
-static const s16 gUnknown_80B82AA[UNK_TABLES_ARR_COUNT] = {
+// Almost all 0x100 (unused?)
+static const s16 gUnknown_80B82AA[Y_MAX] = {
     [0 ... 2] = 0x100,
     [3] = 0x9392,
-    [4 ... UNK_TABLES_ARR_COUNT - 1] = 0x100
+    [4 ... Y_MAX - 1] = 0x100
 };
-// All zeroes
-static const s16 gUnknown_80B83EA[UNK_TABLES_ARR_COUNT] = {
-    [0 ... UNK_TABLES_ARR_COUNT - 1] = 0
+// All zeroes (fallback?)
+static const s16 sDefaultBgH[Y_MAX] = {
+    [0 ... Y_MAX - 1] = 0
 };
 
 // arm9.bin::02006154
 void sub_80057E8(void)
 {
-    sUnknown_2026E4C = TRUE;
-    sUnknown_2026E54 = FALSE;
-    sUnknown_2026E50 = TRUE;
-    sUnknown_2026E58 = NULL;
-    gUnknown_2026E3C = NULL;
-    gUnknown_2026E38 = FALSE;
+    sInitialized = TRUE;
+    sBufferIdx = FALSE;
+    sBoolUnk = TRUE;
+    sBufferPtr = NULL;
+    gWin0HPtr = NULL;
+    gDrawWindow = FALSE;
     gUnknown_2026E4E = 0x60C;
-    gUnknown_203B078 = NULL;
+    gWindowBgCopy = NULL;
 }
 
 // arm9.bin::02005758
@@ -106,16 +108,16 @@ void sub_8005838(s32 *a0, u8 kind)
     s16 *dst;
     s32 i;
 
-    if (!sUnknown_2026E4C)
+    if (!sInitialized)
         kind = 0;
 
-    dst = !sUnknown_2026E54 ? sUnknown_2026E60 : sUnknown_20270E8;
+    dst = !sBufferIdx ? sBuffer0 : sBuffer1;
 
-    src1 = gUnknown_203B078;
+    src1 = gWindowBgCopy;
     if (src1 == NULL)
-        src1 = gUnknown_80B83EA;
+        src1 = sDefaultBgH;
 
-    sUnknown_2026E58 = dst;
+    sBufferPtr = dst;
 
     switch (kind) {
         case 0:
@@ -155,7 +157,7 @@ void sub_8005838(s32 *a0, u8 kind)
             }
             break;
         case 1:
-            src2 = gUnknown_80B816A;
+            src2 = sCorridorDim2;
             for (i = 0; i < 10; i++) {
                 *dst++ = *src1++;
                 *dst++ = *src2++;
@@ -192,7 +194,7 @@ void sub_8005838(s32 *a0, u8 kind)
             }
             break;
         case 2:
-            src2 = gUnknown_80B802A;
+            src2 = sCorridorDim1;
             for (i = 0; i < 10; i++) {
                 *dst++ = *src1++;
                 *dst++ = *src2++;
@@ -437,10 +439,10 @@ void sub_8005838(s32 *a0, u8 kind)
                         if (j >= 160)
                             continue;
 
-                        if (!sUnknown_2026E54)
-                            sUnknown_2026E60[j * 2 + 1] = uVar7;
+                        if (!sBufferIdx)
+                            sBuffer0[j * 2 + 1] = uVar7;
                         else
-                            sUnknown_20270E8[j * 2 + 1] = uVar7;
+                            sBuffer1[j * 2 + 1] = uVar7;
                     }
 
                     for (; k > r8; k--) {
@@ -449,10 +451,10 @@ void sub_8005838(s32 *a0, u8 kind)
                         if (k >= 160)
                             continue;
 
-                        if (!sUnknown_2026E54)
-                            sUnknown_2026E60[k * 2 + 1] = uVar7;
+                        if (!sBufferIdx)
+                            sBuffer0[k * 2 + 1] = uVar7;
                         else
-                            sUnknown_20270E8[k * 2 + 1] = uVar7;
+                            sBuffer1[k * 2 + 1] = uVar7;
                     }
                 }
             }
@@ -464,19 +466,19 @@ void sub_8005838(s32 *a0, u8 kind)
 #if (GAME_VERSION == VERSION_RED)
 UNUSED static void sub_80060A8(void)
 {
-    gUnknown_2026E3C = sUnknown_2026E58;
-    sUnknown_2026E54 = !sUnknown_2026E54;
-    sUnknown_2026E50 = !sUnknown_2026E50;
-    gUnknown_2026E38 = FALSE;
+    gWin0HPtr = sBufferPtr;
+    sBufferIdx = !sBufferIdx;
+    sBoolUnk = !sBoolUnk;
+    gDrawWindow = FALSE;
 }
 #endif
 
 // arm9.bin::020056C0
 void sub_80060EC(void)
 {
-    gUnknown_2026E3C = sUnknown_2026E58;
-    sUnknown_2026E54 = !sUnknown_2026E54;
-    sUnknown_2026E50 = !sUnknown_2026E50;
+    gWin0HPtr = sBufferPtr;
+    sBufferIdx = !sBufferIdx;
+    sBoolUnk = !sBoolUnk;
     SetBldAlphaReg((gUnknown_2026E4E & 0x1F00) >> 8, gUnknown_2026E4E & 0x1F);
-    gUnknown_2026E38 = TRUE;
+    gDrawWindow = TRUE;
 }
diff --git a/src/cpu.c b/src/cpu.c
index 58343c3b0..2a2204700 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -80,11 +80,11 @@ void VBlank_CB(void)
     REG_WINOUT = WINOUT_WIN01_OBJ | WINOUT_WIN01_CLR | WINOUT_WIN01_BG3 | WINOUT_WIN01_BG2 | WINOUT_WIN01_BG0;
     REG_BLDCNT = gBldCnt;
     REG_BLDALPHA = gBldAlpha;
-    if (gUnknown_2026E38) {
+    if (gDrawWindow) {
         // Very interesting use of DmaCopy16 here.
-        DmaSet(0, &gUnknown_2026E3C[2], REG_ADDR_WIN0H, ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_SRC_INC | DMA_DEST_RELOAD | DMA_16BIT) << 16) | 2);
-        REG_WIN0H = gUnknown_2026E3C[0];
-        REG_WIN1H = gUnknown_2026E3C[1];
+        DmaSet(0, &gWin0HPtr[2], REG_ADDR_WIN0H, ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_SRC_INC | DMA_DEST_RELOAD | DMA_16BIT) << 16) | 2);
+        REG_WIN0H = gWin0HPtr[0];
+        REG_WIN1H = gWin0HPtr[1];
         REG_WIN0V = DISPLAY_HEIGHT;
         REG_WIN1V = DISPLAY_HEIGHT;
     }
diff --git a/src/text_1.c b/src/text_1.c
index a15312928..4c5dc9296 100644
--- a/src/text_1.c
+++ b/src/text_1.c
@@ -37,7 +37,7 @@ EWRAM_INIT void (*ScrollUpWindowFunc)(s32 windowId) = ScrollUpWindow;
 EWRAM_INIT void (*gIwramTextFunc3)(s32 a0) = sub_82729A4;
 EWRAM_INIT void (*gIwramTextFunc4)(s32 a0) = sub_8272A78;
 
-IWRAM_DATA ALIGNED(4) s16 gUnknown_3000E94[161] = {0};
+IWRAM_DATA ALIGNED(4) s16 gWindowBg[161] = {0};
 
 const u32 gUnknown_80B853C[16] =
 {
@@ -160,7 +160,7 @@ void LoadCharmaps(void)
 
     gDrawTextShadow = 1;
     gTextShadowMask = 0x88888888;
-    gUnknown_203B078 = NULL;
+    gWindowBgCopy = NULL;
     gUnknown_20274A5 = FALSE;
     gUnknown_202B020 = 1;
     gUnknown_202B024 = 20;
@@ -266,18 +266,18 @@ static void ShowWindowsInternal(const WindowTemplates *winTemplates, bool8 a1, b
 
         if (winTemplates->id[i].width != 0) {
             AddWindow(gWindows, (u32 *)VRAM, sWindowGFXPool, gBgTilemaps, sUnknown_80B8804[i], &winTemplates->id[i], a1, startTileNum, positionModifier, FALSE);
-            sub_80089AC(&winTemplates->id[i], positionModifier);
+            DrawWindowBg(&winTemplates->id[i], positionModifier);
 
             startTileNum += winTemplates->id[i].width * winTemplates->id[i].totalHeight;
         }
     }
 
     // Needed to account for weird compiler LDRs
-    ASM_MATCH_TRICK(gUnknown_203B078);
-    ASM_MATCH_TRICK(gUnknown_3000E94[0]);
+    ASM_MATCH_TRICK(gWindowBgCopy);
+    ASM_MATCH_TRICK(gWindowBg[0]);
     ASM_MATCH_TRICK(gUnknown_20274A5);
 
-    gUnknown_203B078 = gUnknown_3000E94;
+    gWindowBgCopy = gWindowBg;
     gUnknown_20274A5 = TRUE;
 }
 
diff --git a/src/text_2.c b/src/text_2.c
index 097dcb814..463ed0b61 100644
--- a/src/text_2.c
+++ b/src/text_2.c
@@ -1107,169 +1107,184 @@ void ResetWindowBgData(void)
 {
     s32 i;
 
-    for (i = 0; i < ARRAY_COUNT_INT(gUnknown_3000E94); i++) {
-        gUnknown_3000E94[i] = 0xF0F0;
+    for (i = 0; i < ARRAY_COUNT_INT(gWindowBg); i++) {
+        gWindowBg[i] = 0xF0F0;
     }
 }
 
-void sub_80089AC(const WindowTemplate *r4, DungeonPos *r5_Str)
+void DrawWindowBg(const WindowTemplate *window, DungeonPos *pos)
 {
-    u8 *r6;
+    const u8 WINH_DEFAULT = 0xF0;
+    const s32 Y_MAX = 160;
+    u8 *windowArr;
 
-    if (r4->flags & WINTEMPLATE_FLAG_x40)
+    if (window->flags & WINTEMPLATE_FLAG_x40)
         return;
 
-    r6 = (u8*) gUnknown_3000E94;
-    if (r4->type == WINDOW_TYPE_WITHOUT_BORDER) {
-        s32 r12 = (r4->pos.x + r5_Str->x) * 8;
-        s32 r5 = (r4->pos.y + r5_Str->y) * 8;
-        s32 r7 = (r4->pos.x + r5_Str->x + r4->width) * 8;
-        s32 r2 = (r4->pos.y + r5_Str->y + r4->height) * 8;
-        if (r4->height != 0) {
-            if (r5 < 0)
-                r5 = 0;
-            if (r2 < 0)
-                r2 = 0;
-            if (r5 > 160)
-                r5 = 160;
-            if (r2 > 160)
-                r2 = 160;
-            while (r5 < r2) {
-                s32 id = r5 * 2;
-                if (r6[id] == 240 && r6[id + 1] == 240) {
-                    r6[id++] = r7;
-                    r6[id] = r12;
+    windowArr = (u8*) gWindowBg;
+    if (window->type == WINDOW_TYPE_WITHOUT_BORDER) {
+        s32 xStart = (window->pos.x + pos->x) * 8;
+        s32 yStart = (window->pos.y + pos->y) * 8;
+        s32 xEnd = (window->pos.x + pos->x + window->width) * 8;
+        s32 yEnd = (window->pos.y + pos->y + window->height) * 8;
+        if (window->height != 0) {
+            if (yStart < 0)
+                yStart = 0;
+            if (yEnd < 0)
+                yEnd = 0;
+            if (yStart > Y_MAX)
+                yStart = Y_MAX;
+            if (yEnd > Y_MAX)
+                yEnd = Y_MAX;
+
+            // Draw window background
+            while (yStart < yEnd) {
+                s32 idx = yStart * 2;
+                if (windowArr[idx] == WINH_DEFAULT && windowArr[idx + 1] == WINH_DEFAULT) {
+                    windowArr[idx++] = xEnd;    // Right side of window
+                    windowArr[idx] = xStart;    // Left side of window
                 }
                 else {
-                    if (r6[id] < r7) {
-                        r6[id] = r7;
+                    // Only allow window to expand in size?
+                    // Right side of window
+                    if (windowArr[idx] < xEnd) {
+                        windowArr[idx] = xEnd;
                     }
-                    id++;
-                    if (r6[id] > r12) {
-                        r6[id] = r12;
+                    idx++;
+                    // Left side of window
+                    if (windowArr[idx] > xStart) {
+                        windowArr[idx] = xStart;
                     }
                 }
-                r5++;
+                yStart++;
             }
         }
     }
-    else if (r4->type == WINDOW_TYPE_WITH_HEADER) {
+    else if (window->type == WINDOW_TYPE_WITH_HEADER) {
         s32 i;
-        s32 r9 = ((r4->pos.x + r5_Str->x) * 8) - 5;
-        s32 r5 = ((r4->pos.y + r5_Str->y) * 8) - 4;
-        s32 var_24 = ((r4->pos.x + r5_Str->x + r4->width) * 8) + 5;
-        s32 r8 = ((r4->pos.y + r5_Str->y + r4->height) * 8) + 5;
-        s32 r12 = ((r4->pos.x + r5_Str->x) * 8) + 3;
-        const WindowHeader *r2 = r4->header;
-        s32 tmp = r2->width - 1;
-        s32 r10 = (((tmp + r2->count + 2) * 8) + r12) - 4;
-        s32 r4 = r9 + ((r2->currId + 1) * 8);
-        s32 r7 = (r4 + ((r2->width + 2) * 8)) - 4;
+        s32 xStart = ((window->pos.x + pos->x) * 8) - 5;
+        s32 yStart = ((window->pos.y + pos->y) * 8) - 4;
+        s32 xEnd = ((window->pos.x + pos->x + window->width) * 8) + 5;
+        s32 yEnd = ((window->pos.y + pos->y + window->height) * 8) + 5;
+        s32 allHeadersStart = ((window->pos.x + pos->x) * 8) + 3;
+        const WindowHeader *header = window->header;
+        s32 tmp = header->width - 1;
+        s32 allHeadersEnd = (((tmp + header->count + 2) * 8) + allHeadersStart) - 4;
+        s32 currHeaderStart = xStart + ((header->currId + 1) * 8);
+        s32 currHeaderEnd = (currHeaderStart + ((header->width + 2) * 8)) - 4;
 
-        if (r5 < 0)
-            r5 = 0;
-        if (r8 < 0)
-            r8 = 0;
-        if (r5 > 160)
-            r5 = 160;
-        if (r8 > 160)
-            r8 = 160;
+        if (yStart < 0)
+            yStart = 0;
+        if (yEnd < 0)
+            yEnd = 0;
+        if (yStart > Y_MAX)
+            yStart = Y_MAX;
+        if (yEnd > Y_MAX)
+            yEnd = Y_MAX;
 
         // BUG: The background array is 161 entries long, but this function will potentially write
         // up to index 160 + 12 = 172, overflowing the array.
 #ifdef UBFIX
-        if (r5 > 160 - 12) {
-            r5 = 160 - 12;
+        if (yStart > Y_MAX - 12) {
+            yStart = Y_MAX - 12;
         }
 #endif
 
+        // Draw extra header background for current tab
+        // For multi-tabbed windows, the current tab is taller, so need to draw an extra 4 pixels of BG
         for (i = 0; i < 4; i++) {
-            s32 id = r5 * 2;
-            if (r6[id] == 240 && r6[id + 1] == 240) {
-                r6[id++] = r7;
-                r6[id] = r4;
+            s32 idx = yStart * 2;
+            if (windowArr[idx] == WINH_DEFAULT && windowArr[idx + 1] == WINH_DEFAULT) {
+                windowArr[idx++] = currHeaderEnd;  // Right side of window
+                windowArr[idx] = currHeaderStart;    // Left side of window
             }
             else {
-                if (r6[id] < r7) {
-                    r6[id] = r7;
+                // Only allow window to expand in size?
+                // Right side of window
+                if (windowArr[idx] < currHeaderEnd) {
+                    windowArr[idx] = currHeaderEnd;
                 }
-                id++;
-                if (r6[id] > r4) {
-                    r6[id] = r4;
+                idx++;
+                // Left side of window
+                if (windowArr[idx] > currHeaderStart) {
+                    windowArr[idx] = currHeaderStart;
                 }
             }
-            r5++;
-        }
-        for (i = 0; i < 8; i++) {
-            s32 id = r5 * 2;
-            if (r6[id] == 240 && r6[id + 1] == 240) {
-                r6[id++] = r10;
-                r6[id] = r12;
-            }
-            else {
-                if (r6[id] < r10) {
-                    r6[id] = r10;
-                }
-                id++;
-                if (r6[id] > r12) {
-                    r6[id] = r12;
-                }
-            }
-            r5++;
+            yStart++;
         }
 
-        while (r5 < r8) {
-            s32 id = r5 * 2;
-            if (r6[id] == 240 && r6[id + 1] == 240) {
-                r6[id++] = var_24;
-                r6[id] = r9;
+        // Draw header background for all tabs
+        for (i = 0; i < 8; i++) {
+            s32 id = yStart * 2;
+            if (windowArr[id] == WINH_DEFAULT && windowArr[id + 1] == WINH_DEFAULT) {
+                windowArr[id++] = allHeadersEnd;  // Right side of window
+                windowArr[id] = allHeadersStart;    // Left side of window
             }
             else {
-                if (r6[id] < var_24) {
-                    r6[id] = var_24;
+                if (windowArr[id] < allHeadersEnd) {
+                    windowArr[id] = allHeadersEnd;
                 }
                 id++;
-                if (r6[id] > r9) {
-                    r6[id] = r9;
+                if (windowArr[id] > allHeadersStart) {
+                    windowArr[id] = allHeadersStart;
                 }
             }
-            r5++;
+            yStart++;
+        }
+
+        // Draw main window background
+        while (yStart < yEnd) {
+            s32 idx = yStart * 2;
+            if (windowArr[idx] == WINH_DEFAULT && windowArr[idx + 1] == WINH_DEFAULT) {
+                windowArr[idx++] = xEnd;    // Right side of window
+                windowArr[idx] = xStart;    // Left side of window
+            }
+            else {
+                if (windowArr[idx] < xEnd) {
+                    windowArr[idx] = xEnd;
+                }
+                idx++;
+                if (windowArr[idx] > xStart) {
+                    windowArr[idx] = xStart;
+                }
+            }
+            yStart++;
         }
     }
     else {
-        s32 r8 = ((r4->pos.x + r5_Str->x) * 8) - 5;
-        s32 r3 = ((r4->pos.y + r5_Str->y) * 8) - 5;
-        s32 r12 = ((r4->pos.x + r5_Str->x + r4->width) * 8) + 5;
-        s32 r5 = ((r4->pos.y + r5_Str->y + r4->height) * 8) + 5;
-        if (r4->height != 0) {
-            if (r4->type == 0) {
-                r3 += 8;
-                r5 = ((r4->pos.y + r5_Str->y + r4->height) * 8) - 3;
+        s32 xStart = ((window->pos.x + pos->x) * 8) - 5;
+        s32 yStart = ((window->pos.y + pos->y) * 8) - 5;
+        s32 xEnd = ((window->pos.x + pos->x + window->width) * 8) + 5;
+        s32 yEnd = ((window->pos.y + pos->y + window->height) * 8) + 5;
+        if (window->height != 0) {
+            if (window->type == WINDOW_TYPE_0) {
+                yStart += 8;
+                yEnd = ((window->pos.y + pos->y + window->height) * 8) - 3;
             }
-            if (r3 < 0)
-                r3 = 0;
-            if (r5 < 0)
-                r5 = 0;
-            if (r3 > 160)
-                r3 = 160;
-            if (r5 > 160)
-                r5 = 160;
-            while (r3 < r5) {
-                s32 id = r3 * 2;
-                if (r6[id] == 240 && r6[id + 1] == 240) {
-                    r6[id++] = r12;
-                    r6[id] = r8;
+            if (yStart < 0)
+                yStart = 0;
+            if (yEnd < 0)
+                yEnd = 0;
+            if (yStart > Y_MAX)
+                yStart = Y_MAX;
+            if (yEnd > Y_MAX)
+                yEnd = Y_MAX;
+            while (yStart < yEnd) {
+                s32 idx = yStart * 2;
+                if (windowArr[idx] == WINH_DEFAULT && windowArr[idx + 1] == WINH_DEFAULT) {
+                    windowArr[idx++] = xEnd;    // Right side of window
+                    windowArr[idx] = xStart;    // Left side of window
                 }
                 else {
-                    if (r6[id] < r12) {
-                        r6[id] = r12;
+                    if (windowArr[idx] < xEnd) {
+                        windowArr[idx] = xEnd;
                     }
-                    id++;
-                    if (r6[id] > r8) {
-                        r6[id] = r8;
+                    idx++;
+                    if (windowArr[idx] > xStart) {
+                        windowArr[idx] = xStart;
                     }
                 }
-                r3++;
+                yStart++;
             }
         }
     }

From 5b5d17072f130bd803926add01e12a85a95f7943 Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Wed, 29 Apr 2026 23:10:59 -0400
Subject: [PATCH 2/9] Rename ToggleWindowBgBuffer()

---
 include/code_800558C.h      | 2 +-
 src/code_800558C.c          | 2 +-
 src/debug_field_map.c       | 2 +-
 src/dungeon_tilemap.c       | 2 +-
 src/dungeon_vram.c          | 4 ++--
 src/friend_areas_map_util.c | 2 +-
 src/ground_main.c           | 2 +-
 src/main_loops.c            | 4 ++--
 src/menu_input.c            | 2 +-
 src/other_menus1.c          | 2 +-
 src/textbox.c               | 2 +-
 src/world_map.c             | 2 +-
 12 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/code_800558C.h b/include/code_800558C.h
index e25068523..e37d53e11 100644
--- a/include/code_800558C.h
+++ b/include/code_800558C.h
@@ -9,6 +9,6 @@ extern s16 *gWindowBgCopy;
 
 void sub_80057E8(void);
 void sub_8005838(s32 *, u8 kind);
-void sub_80060EC(void);
+void ToggleWindowBgBuffer(void);
 
 #endif // GUARD_CODE_800558C_H
diff --git a/src/code_800558C.c b/src/code_800558C.c
index e4ea82a0b..53adfd976 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -474,7 +474,7 @@ UNUSED static void sub_80060A8(void)
 #endif
 
 // arm9.bin::020056C0
-void sub_80060EC(void)
+void ToggleWindowBgBuffer(void)
 {
     gWin0HPtr = sBufferPtr;
     sBufferIdx = !sBufferIdx;
diff --git a/src/debug_field_map.c b/src/debug_field_map.c
index 50ef85498..f52afb58e 100644
--- a/src/debug_field_map.c
+++ b/src/debug_field_map.c
@@ -133,7 +133,7 @@ UNUSED static void DebugMapViewer(void)
             sub_80A59DC();
             DrawDialogueBoxString_Async();
             sub_8005838(NULL, 0);
-            sub_80060EC();
+            ToggleWindowBgBuffer();
             nullsub_8(gGameOptionsRef->touchScreen);
             sub_8005180();
             sub_8099BE4();
diff --git a/src/dungeon_tilemap.c b/src/dungeon_tilemap.c
index 10224aaef..4b37021c4 100644
--- a/src/dungeon_tilemap.c
+++ b/src/dungeon_tilemap.c
@@ -716,7 +716,7 @@ void sub_8040094(u8 r0)
 {
     gDungeon->unk181e8.unk18217 = r0;
     sub_803F7BC();
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     IncrementPlayTime(gPlayTimeRef);
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
diff --git a/src/dungeon_vram.c b/src/dungeon_vram.c
index b450dfa98..bbcbcdf3a 100644
--- a/src/dungeon_vram.c
+++ b/src/dungeon_vram.c
@@ -206,7 +206,7 @@ static void sub_803E490(u32 unused)
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     nullsub_12();
-    sub_80060EC();
+    ToggleWindowBgBuffer();
 
     gDungeonFramesCounter++;
 
@@ -240,7 +240,7 @@ void sub_803E668(u32 unused)
     sub_8005180();
     nullsub_12();
     sub_8005838(NULL, 0);
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     gDungeonFramesCounter++;
     IncrementPlayTime(gPlayTimeRef);
     WaitForNextFrameAndAdvanceRNG();
diff --git a/src/friend_areas_map_util.c b/src/friend_areas_map_util.c
index 7a4478b63..79d624119 100644
--- a/src/friend_areas_map_util.c
+++ b/src/friend_areas_map_util.c
@@ -376,7 +376,7 @@ void FriendAreasMap_RunFrameActions(void)
     sub_8005838(NULL, 0);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     IncrementPlayTime(gPlayTimeRef);
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
diff --git a/src/ground_main.c b/src/ground_main.c
index 47d880c0d..e909a60e4 100644
--- a/src/ground_main.c
+++ b/src/ground_main.c
@@ -309,7 +309,7 @@ u32 xxx_script_related_8098468_Async(s32 startMode)
         }
         GroundMap_Action();
         sub_8005838(NULL,0);
-        sub_80060EC();
+        ToggleWindowBgBuffer();
         xxx_call_update_bg_sound_input();
         while ( 1 ) {
             xxx_call_update_bg_sound_input();
diff --git a/src/main_loops.c b/src/main_loops.c
index 6687e2864..75920a8b4 100644
--- a/src/main_loops.c
+++ b/src/main_loops.c
@@ -279,7 +279,7 @@ static void MainLoops_RunFrameActions(u32 unused)
     sub_8005180();
     // Extra call here in blue. Seems to be for 2nd screen sprites
 
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     UpdateSoundEffectCounters();
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
@@ -363,7 +363,7 @@ static void QuickSave_Async(u32 mode)
     sub_8099750();
     SetCharacterMask(3);
     sub_8005838(NULL, 0);
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     CreateDialogueBoxAndPortrait(sSaveTextQuicksaving, 0, 0, 0x20);
 
     while (TRUE) {
diff --git a/src/menu_input.c b/src/menu_input.c
index 33cd3d517..984c673ec 100644
--- a/src/menu_input.c
+++ b/src/menu_input.c
@@ -66,7 +66,7 @@ void sub_8012A18(s32 unused)
     DrawDialogueBoxString_Async();
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs(); // Input related
     CopySpritesToOam();
diff --git a/src/other_menus1.c b/src/other_menus1.c
index 8cf8775b0..32b3a36a1 100644
--- a/src/other_menus1.c
+++ b/src/other_menus1.c
@@ -209,7 +209,7 @@ static void sub_80371B8(void)
 void sub_80373C4(void)
 {
     sub_8005838(NULL, 0);
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
     TransferBGPaletteBuffer();
diff --git a/src/textbox.c b/src/textbox.c
index f3b35b49b..133dac807 100644
--- a/src/textbox.c
+++ b/src/textbox.c
@@ -1049,7 +1049,7 @@ void sub_809B57C_Async(void)
 
 void sub_809B614(void)
 {
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     gUnknown_20399DE = gUnknown_20399DC;
     gUnknown_20399DC &= ~2;
 }
diff --git a/src/world_map.c b/src/world_map.c
index 45efb0ed2..e2c80da90 100644
--- a/src/world_map.c
+++ b/src/world_map.c
@@ -409,7 +409,7 @@ static void WorldMap_RunFrameActions(void)
     sub_8005838(NULL, 0);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
-    sub_80060EC();
+    ToggleWindowBgBuffer();
     IncrementPlayTime(gPlayTimeRef);
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();

From aebdeb4275745ea09fb6aefe8872c95b21d15965 Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Wed, 29 Apr 2026 23:11:55 -0400
Subject: [PATCH 3/9] Rename CopyWindowBgBuffer()

---
 include/code_800558C.h      | 2 +-
 src/code_800558C.c          | 2 +-
 src/debug_field_map.c       | 6 +++---
 src/dungeon_tilemap.c       | 6 +++---
 src/dungeon_vram.c          | 2 +-
 src/friend_areas_map_util.c | 2 +-
 src/ground_main.c           | 2 +-
 src/main_loops.c            | 4 ++--
 src/other_menus1.c          | 2 +-
 src/textbox.c               | 4 ++--
 src/world_map.c             | 2 +-
 11 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/include/code_800558C.h b/include/code_800558C.h
index e37d53e11..4dfbdd65b 100644
--- a/include/code_800558C.h
+++ b/include/code_800558C.h
@@ -8,7 +8,7 @@ extern s16 gUnknown_2026E4E;
 extern s16 *gWindowBgCopy;
 
 void sub_80057E8(void);
-void sub_8005838(s32 *, u8 kind);
+void CopyWindowBgBuffer(s32 *, u8 kind);
 void ToggleWindowBgBuffer(void);
 
 #endif // GUARD_CODE_800558C_H
diff --git a/src/code_800558C.c b/src/code_800558C.c
index 53adfd976..cc9ef5c48 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -102,7 +102,7 @@ void sub_80057E8(void)
 }
 
 // arm9.bin::02005758
-void sub_8005838(s32 *a0, u8 kind)
+void CopyWindowBgBuffer(s32 *a0, u8 kind)
 {
     const s16 *src1, *src2;
     s16 *dst;
diff --git a/src/debug_field_map.c b/src/debug_field_map.c
index f52afb58e..58e8e1d23 100644
--- a/src/debug_field_map.c
+++ b/src/debug_field_map.c
@@ -38,7 +38,7 @@ UNUSED static void DebugMapViewer(void)
     sub_809975C();
     sub_809D0AC();
     ResetDialogueBox();
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     AllocGroundMapAction();
     while (TRUE) {
         bool8 quitMapView;
@@ -48,7 +48,7 @@ UNUSED static void DebugMapViewer(void)
         if (DebugFieldMapWindow_Init()) {
             DebugFieldMapWindow_MoveMenuTo(mapId);
             while (TRUE) {
-                sub_8005838(NULL, 0);
+                CopyWindowBgBuffer(NULL, 0);
                 sub_8012A18(0);
                 switch (DebugFieldMapWindow_GetInput()) {
                     case MENU_INPUT_A_PRESS:
@@ -132,7 +132,7 @@ UNUSED static void DebugMapViewer(void)
             sub_809D25C();
             sub_80A59DC();
             DrawDialogueBoxString_Async();
-            sub_8005838(NULL, 0);
+            CopyWindowBgBuffer(NULL, 0);
             ToggleWindowBgBuffer();
             nullsub_8(gGameOptionsRef->touchScreen);
             sub_8005180();
diff --git a/src/dungeon_tilemap.c b/src/dungeon_tilemap.c
index 4b37021c4..07a702546 100644
--- a/src/dungeon_tilemap.c
+++ b/src/dungeon_tilemap.c
@@ -303,11 +303,11 @@ static void sub_803F7BC(void)
     u32 roomId = tile->room;
 
     if (strPtr->allTilesRevealed != 0 || strPtr->unk1820C != 0 || strPtr->unk18217 != 0) {
-        sub_8005838(NULL, 0);
+        CopyWindowBgBuffer(NULL, 0);
     }
     else if (roomId == CORRIDOR_ROOM) {
         u32 kind = (strPtr->visibilityRange == 2) ? 1 : 2;
-        sub_8005838(NULL, kind);
+        CopyWindowBgBuffer(NULL, kind);
     }
     else {
         s32 sp[4];
@@ -317,7 +317,7 @@ static void sub_803F7BC(void)
         sp[1] = room->unk10 - strPtr->cameraPixelPos.y;
         sp[2] = room->unk14 - strPtr->cameraPixelPos.x;
         sp[3] = room->unk18 - strPtr->cameraPixelPos.y;
-        sub_8005838(sp, 3);
+        CopyWindowBgBuffer(sp, 3);
     }
 }
 
diff --git a/src/dungeon_vram.c b/src/dungeon_vram.c
index bbcbcdf3a..b69d77d22 100644
--- a/src/dungeon_vram.c
+++ b/src/dungeon_vram.c
@@ -239,7 +239,7 @@ void sub_803E668(u32 unused)
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     nullsub_12();
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     ToggleWindowBgBuffer();
     gDungeonFramesCounter++;
     IncrementPlayTime(gPlayTimeRef);
diff --git a/src/friend_areas_map_util.c b/src/friend_areas_map_util.c
index 79d624119..cc35e4c17 100644
--- a/src/friend_areas_map_util.c
+++ b/src/friend_areas_map_util.c
@@ -373,7 +373,7 @@ void FriendAreasMap_RunFrameActions(void)
     SetBG3RegOffsets(gFriendAreasMapPtr->bgPos.x, gFriendAreasMapPtr->bgPos.y);
     AnimateSprites();
     UpdateAnimatedColors(FadeScreen(), gFriendAreasMapPtr->unk4C4C, 0xB0, 16, gFriendAreasMapPtr->brightness, NULL);
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     ToggleWindowBgBuffer();
diff --git a/src/ground_main.c b/src/ground_main.c
index e909a60e4..657c400f4 100644
--- a/src/ground_main.c
+++ b/src/ground_main.c
@@ -308,7 +308,7 @@ u32 xxx_script_related_8098468_Async(s32 startMode)
             GroundMap_ExecuteEvent(EVENT_DIVIDE, FALSE);
         }
         GroundMap_Action();
-        sub_8005838(NULL,0);
+        CopyWindowBgBuffer(NULL,0);
         ToggleWindowBgBuffer();
         xxx_call_update_bg_sound_input();
         while ( 1 ) {
diff --git a/src/main_loops.c b/src/main_loops.c
index 75920a8b4..79ec3f0aa 100644
--- a/src/main_loops.c
+++ b/src/main_loops.c
@@ -273,7 +273,7 @@ void GameLoop_Async(void)
 static void MainLoops_RunFrameActions(u32 unused)
 {
     DrawDialogueBoxString_Async();
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     nullsub_8(gGameOptionsRef->touchScreen);
 
     sub_8005180();
@@ -362,7 +362,7 @@ static void QuickSave_Async(u32 mode)
     sub_8099744();
     sub_8099750();
     SetCharacterMask(3);
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     ToggleWindowBgBuffer();
     CreateDialogueBoxAndPortrait(sSaveTextQuicksaving, 0, 0, 0x20);
 
diff --git a/src/other_menus1.c b/src/other_menus1.c
index 32b3a36a1..e0208e0b7 100644
--- a/src/other_menus1.c
+++ b/src/other_menus1.c
@@ -208,7 +208,7 @@ static void sub_80371B8(void)
 
 void sub_80373C4(void)
 {
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     ToggleWindowBgBuffer();
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
diff --git a/src/textbox.c b/src/textbox.c
index 133dac807..6aebaf9e8 100644
--- a/src/textbox.c
+++ b/src/textbox.c
@@ -1040,10 +1040,10 @@ void sub_809B57C_Async(void)
     }
 
     if (sTextbox->unk434 < 0) {
-        sub_8005838(0, 0);
+        CopyWindowBgBuffer(0, 0);
     }
     else {
-        sub_8005838(0, 5);
+        CopyWindowBgBuffer(0, 5);
     }
 }
 
diff --git a/src/world_map.c b/src/world_map.c
index e2c80da90..85c8eb3a3 100644
--- a/src/world_map.c
+++ b/src/world_map.c
@@ -406,7 +406,7 @@ static void WorldMap_RunFrameActions(void)
     SetBG3RegOffsets(sWorldMapPtr->bgPos.x, sWorldMapPtr->bgPos.y);
     AnimateSprites(TRUE);
     FadeScreen();
-    sub_8005838(NULL, 0);
+    CopyWindowBgBuffer(NULL, 0);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     ToggleWindowBgBuffer();

From e4634dde8e6412c5cb174def5091ee35d08b7536 Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Wed, 29 Apr 2026 23:30:30 -0400
Subject: [PATCH 4/9] Window BG buffer names

---
 include/code_800558C.h      |  13 +-
 src/code_800558C.c          | 234 +++++-------------------------------
 src/debug_field_map.c       |   6 +-
 src/dungeon_tilemap.c       |   4 +-
 src/dungeon_vram.c          |   2 +-
 src/friend_areas_map_util.c |   2 +-
 src/ground_main.c           |   2 +-
 src/main.c                  |   2 +-
 src/main_loops.c            |   4 +-
 src/other_menus1.c          |   2 +-
 src/textbox.c               |   2 +-
 src/world_map.c             |   2 +-
 12 files changed, 58 insertions(+), 217 deletions(-)

diff --git a/include/code_800558C.h b/include/code_800558C.h
index 4dfbdd65b..e8c40dbab 100644
--- a/include/code_800558C.h
+++ b/include/code_800558C.h
@@ -7,8 +7,17 @@ extern s16 gUnknown_2026E4E;
 
 extern s16 *gWindowBgCopy;
 
-void sub_80057E8(void);
-void CopyWindowBgBuffer(s32 *, u8 kind);
+typedef enum CopyWindowBgBufferType {
+    COPY_WINDOW_BG_BUFFER_DEFAULT,
+    COPY_WINDOW_BG_BUFFER_DIM2,
+    COPY_WINDOW_BG_BUFFER_DIM1,
+    COPY_WINDOW_BG_BUFFER_UNK3,
+    COPY_WINDOW_BG_BUFFER_UNK4,
+    COPY_WINDOW_BG_BUFFER_UNK5,
+} CopyWindowBgBufferType;
+
+void WindowBgBufferInit(void);
+void CopyWindowBgBuffer(s32 *a0, u8 kind);
 void ToggleWindowBgBuffer(void);
 
 #endif // GUARD_CODE_800558C_H
diff --git a/src/code_800558C.c b/src/code_800558C.c
index cc9ef5c48..ead4a7e2a 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -4,6 +4,25 @@
 #include "code_800558C.h"
 #include "math.h"
 
+#define UNROLL16(x) do { \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+    x; \
+} while (0)
+
 EWRAM_DATA bool8 gDrawWindow = FALSE;
 EWRAM_DATA s16 *gWin0HPtr = NULL;
 EWRAM_DATA static s32 sUnknown_2026E40 = 0; // Read from but never written to
@@ -23,7 +42,6 @@ EWRAM_INIT s16 *gWindowBgCopy = NULL;
 static const s16 gUnknown_80B8008[17] = {16, 12, 9, 7, 6, 5, 4, 3, 2, 2, 1, 1, 1, 0, 0, 0, 0};
 
 #define Y_MAX 160
-
 // Dim edges of screen in corridors with 1 visibility
 static const s16 sCorridorDim1[Y_MAX] = {
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
@@ -89,7 +107,7 @@ static const s16 sDefaultBgH[Y_MAX] = {
 };
 
 // arm9.bin::02006154
-void sub_80057E8(void)
+void WindowBgBufferInit(void)
 {
     sInitialized = TRUE;
     sBufferIdx = FALSE;
@@ -109,7 +127,7 @@ void CopyWindowBgBuffer(s32 *a0, u8 kind)
     s32 i;
 
     if (!sInitialized)
-        kind = 0;
+        kind = COPY_WINDOW_BG_BUFFER_DEFAULT;
 
     dst = !sBufferIdx ? sBuffer0 : sBuffer1;
 
@@ -120,154 +138,30 @@ void CopyWindowBgBuffer(s32 *a0, u8 kind)
     sBufferPtr = dst;
 
     switch (kind) {
-        case 0:
+        case COPY_WINDOW_BG_BUFFER_DEFAULT:
             for (i = 0; i < 10; i++) {
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
-                *dst++ = *src1++;
-                *dst++ = 0;
+                UNROLL16(*dst++ = *src1++; *dst++ = 0;);
             }
             break;
-        case 1:
+        case COPY_WINDOW_BG_BUFFER_DIM2:
             src2 = sCorridorDim2;
             for (i = 0; i < 10; i++) {
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
+                UNROLL16(*dst++ = *src1++; *dst++ = *src2++;);
             }
             break;
-        case 2:
+        case COPY_WINDOW_BG_BUFFER_DIM1:
             src2 = sCorridorDim1;
             for (i = 0; i < 10; i++) {
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
+                UNROLL16(*dst++ = *src1++; *dst++ = *src2++;);
             }
             break;
-        case 3:
+        case COPY_WINDOW_BG_BUFFER_UNK3:
             if ((a0[0] < 0 && a0[2] < 0)
                 || (a0[1] < 0 && a0[3] < 0)
                 || (a0[0] >= 240 && a0[2] >= 240)
                 || (a0[1] >= 160 && a0[3] >= 160)) {
                 for (i = 0; i < 10; i++) {
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
-                    *dst++ = *src1++;
-                    *dst++ = 240;
+                    UNROLL16(*dst++ = *src1++; *dst++ = 240;);
                 }
             }
             else {
@@ -312,44 +206,13 @@ void CopyWindowBgBuffer(s32 *a0, u8 kind)
                 }
             }
             break;
-        case 4:
+        case COPY_WINDOW_BG_BUFFER_UNK4:
             src2 = gUnknown_80B82AA;
             for (i = 0; i < 15; i++) {
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
-                *dst++ = *src1++;
-                *dst++ = *src2++;
+                UNROLL16(*dst++ = *src1++; *dst++ = *src2++;);
             }
             break;
-        case 5: {
+        case COPY_WINDOW_BG_BUFFER_UNK5: {
             s32 r8;
             s32 sp14;
             s32 uVar7;
@@ -364,38 +227,7 @@ void CopyWindowBgBuffer(s32 *a0, u8 kind)
             s32 j, k;
 
             for (i = 0; i < 15; i++) {
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
-                *dst++ = *src1++;
-                *dst++ = 256;
+                UNROLL16(*dst++ = *src1++; *dst++ = 256;);
             }
 
             val1 = sUnknown_2026E40;
diff --git a/src/debug_field_map.c b/src/debug_field_map.c
index 58e8e1d23..03c831332 100644
--- a/src/debug_field_map.c
+++ b/src/debug_field_map.c
@@ -38,7 +38,7 @@ UNUSED static void DebugMapViewer(void)
     sub_809975C();
     sub_809D0AC();
     ResetDialogueBox();
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     AllocGroundMapAction();
     while (TRUE) {
         bool8 quitMapView;
@@ -48,7 +48,7 @@ UNUSED static void DebugMapViewer(void)
         if (DebugFieldMapWindow_Init()) {
             DebugFieldMapWindow_MoveMenuTo(mapId);
             while (TRUE) {
-                CopyWindowBgBuffer(NULL, 0);
+                CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
                 sub_8012A18(0);
                 switch (DebugFieldMapWindow_GetInput()) {
                     case MENU_INPUT_A_PRESS:
@@ -132,7 +132,7 @@ UNUSED static void DebugMapViewer(void)
             sub_809D25C();
             sub_80A59DC();
             DrawDialogueBoxString_Async();
-            CopyWindowBgBuffer(NULL, 0);
+            CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
             ToggleWindowBgBuffer();
             nullsub_8(gGameOptionsRef->touchScreen);
             sub_8005180();
diff --git a/src/dungeon_tilemap.c b/src/dungeon_tilemap.c
index 07a702546..b7b6fc20a 100644
--- a/src/dungeon_tilemap.c
+++ b/src/dungeon_tilemap.c
@@ -303,10 +303,10 @@ static void sub_803F7BC(void)
     u32 roomId = tile->room;
 
     if (strPtr->allTilesRevealed != 0 || strPtr->unk1820C != 0 || strPtr->unk18217 != 0) {
-        CopyWindowBgBuffer(NULL, 0);
+        CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     }
     else if (roomId == CORRIDOR_ROOM) {
-        u32 kind = (strPtr->visibilityRange == 2) ? 1 : 2;
+        u32 kind = (strPtr->visibilityRange == 2) ? COPY_WINDOW_BG_BUFFER_DIM2 : COPY_WINDOW_BG_BUFFER_DIM1;
         CopyWindowBgBuffer(NULL, kind);
     }
     else {
diff --git a/src/dungeon_vram.c b/src/dungeon_vram.c
index b69d77d22..366f77627 100644
--- a/src/dungeon_vram.c
+++ b/src/dungeon_vram.c
@@ -239,7 +239,7 @@ void sub_803E668(u32 unused)
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     nullsub_12();
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     ToggleWindowBgBuffer();
     gDungeonFramesCounter++;
     IncrementPlayTime(gPlayTimeRef);
diff --git a/src/friend_areas_map_util.c b/src/friend_areas_map_util.c
index cc35e4c17..22a141742 100644
--- a/src/friend_areas_map_util.c
+++ b/src/friend_areas_map_util.c
@@ -373,7 +373,7 @@ void FriendAreasMap_RunFrameActions(void)
     SetBG3RegOffsets(gFriendAreasMapPtr->bgPos.x, gFriendAreasMapPtr->bgPos.y);
     AnimateSprites();
     UpdateAnimatedColors(FadeScreen(), gFriendAreasMapPtr->unk4C4C, 0xB0, 16, gFriendAreasMapPtr->brightness, NULL);
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     ToggleWindowBgBuffer();
diff --git a/src/ground_main.c b/src/ground_main.c
index 657c400f4..4a0972f08 100644
--- a/src/ground_main.c
+++ b/src/ground_main.c
@@ -308,7 +308,7 @@ u32 xxx_script_related_8098468_Async(s32 startMode)
             GroundMap_ExecuteEvent(EVENT_DIVIDE, FALSE);
         }
         GroundMap_Action();
-        CopyWindowBgBuffer(NULL,0);
+        CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
         ToggleWindowBgBuffer();
         xxx_call_update_bg_sound_input();
         while ( 1 ) {
diff --git a/src/main.c b/src/main.c
index 651d72708..829a16b2f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -90,7 +90,7 @@ void AgbMain(void)
     nullsub_6();
     InitInput();
     InitBGPaletteBuffer();
-    sub_80057E8();
+    WindowBgBufferInit();
     InitFileSystem();
     LoadCharmaps();
     ResetScheduledMemCopies();
diff --git a/src/main_loops.c b/src/main_loops.c
index 79ec3f0aa..055f70ec0 100644
--- a/src/main_loops.c
+++ b/src/main_loops.c
@@ -273,7 +273,7 @@ void GameLoop_Async(void)
 static void MainLoops_RunFrameActions(u32 unused)
 {
     DrawDialogueBoxString_Async();
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     nullsub_8(gGameOptionsRef->touchScreen);
 
     sub_8005180();
@@ -362,7 +362,7 @@ static void QuickSave_Async(u32 mode)
     sub_8099744();
     sub_8099750();
     SetCharacterMask(3);
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     ToggleWindowBgBuffer();
     CreateDialogueBoxAndPortrait(sSaveTextQuicksaving, 0, 0, 0x20);
 
diff --git a/src/other_menus1.c b/src/other_menus1.c
index e0208e0b7..8ee531c90 100644
--- a/src/other_menus1.c
+++ b/src/other_menus1.c
@@ -208,7 +208,7 @@ static void sub_80371B8(void)
 
 void sub_80373C4(void)
 {
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     ToggleWindowBgBuffer();
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
diff --git a/src/textbox.c b/src/textbox.c
index 6aebaf9e8..2fb6ee199 100644
--- a/src/textbox.c
+++ b/src/textbox.c
@@ -1040,7 +1040,7 @@ void sub_809B57C_Async(void)
     }
 
     if (sTextbox->unk434 < 0) {
-        CopyWindowBgBuffer(0, 0);
+        CopyWindowBgBuffer(0, COPY_WINDOW_BG_BUFFER_DEFAULT);
     }
     else {
         CopyWindowBgBuffer(0, 5);
diff --git a/src/world_map.c b/src/world_map.c
index 85c8eb3a3..215b5487e 100644
--- a/src/world_map.c
+++ b/src/world_map.c
@@ -406,7 +406,7 @@ static void WorldMap_RunFrameActions(void)
     SetBG3RegOffsets(sWorldMapPtr->bgPos.x, sWorldMapPtr->bgPos.y);
     AnimateSprites(TRUE);
     FadeScreen();
-    CopyWindowBgBuffer(NULL, 0);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     ToggleWindowBgBuffer();

From 056d35bff07511bb5c69d86c899a4dc8ab9235d9 Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Wed, 29 Apr 2026 23:33:52 -0400
Subject: [PATCH 5/9] Remove Makefile modern no-warning

---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index d94a4d9bf..ad61c55a7 100755
--- a/Makefile
+++ b/Makefile
@@ -107,7 +107,7 @@ else
   CC1 := $(shell $(PATH_MODERNCC) --print-prog-name=cc1) -quiet
   LIBPATH := -L "$(dir $(shell $(PATH_MODERNCC) -mthumb -print-file-name=libgcc.a))" -L "$(dir $(shell $(PATH_MODERNCC) -mthumb -print-file-name=libnosys.a))" -L "$(dir $(shell $(PATH_MODERNCC) -mthumb -print-file-name=libc.a))"
   LIB := $(LIBPATH) -lc -lnosys -lgcc -L../../libagbsyscall -lagbsyscall
-  override CC1FLAGS += -mthumb -mthumb-interwork -mabi=apcs-gnu -mtune=arm7tdmi -march=armv4t -Wimplicit -Wparentheses -Wunused -Werror -O2 -g -Wno-unused-variable -Wno-incompatible-pointer-types
+  override CC1FLAGS += -mthumb -mthumb-interwork -mabi=apcs-gnu -mtune=arm7tdmi -march=armv4t -Wimplicit -Wparentheses -Wunused -Werror -O2 -g
   INCLUDE_DIRS := include
   INCLUDE_CPP_ARGS := $(INCLUDE_DIRS:%=-iquote %)
   INCLUDE_PATHS := $(INCLUDE_DIRS:%=-I %)

From ccb22d66c8a218f166ab195a684d6f2b85739273 Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Wed, 29 Apr 2026 23:36:36 -0400
Subject: [PATCH 6/9] Simplify UNROLL16 macro

---
 src/code_800558C.c | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/src/code_800558C.c b/src/code_800558C.c
index ead4a7e2a..f0e808274 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -4,24 +4,7 @@
 #include "code_800558C.h"
 #include "math.h"
 
-#define UNROLL16(x) do { \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-    x; \
-} while (0)
+#define UNROLL16(x) do { x; x; x; x; x; x; x; x; x; x; x; x; x; x; x; x; } while (0)
 
 EWRAM_DATA bool8 gDrawWindow = FALSE;
 EWRAM_DATA s16 *gWin0HPtr = NULL;

From 79ee9641f3e6f3d4042caf58c00d715ab9891f4f Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Thu, 30 Apr 2026 10:09:33 -0400
Subject: [PATCH 7/9] More documentation

---
 include/code_800558C.h | 10 ++---
 src/code_800558C.c     | 91 ++++++++++++++++++++++++------------------
 src/cpu.c              |  6 +--
 3 files changed, 60 insertions(+), 47 deletions(-)

diff --git a/include/code_800558C.h b/include/code_800558C.h
index e8c40dbab..fa1dcfed3 100644
--- a/include/code_800558C.h
+++ b/include/code_800558C.h
@@ -2,22 +2,22 @@
 #define GUARD_CODE_800558C_H
 
 extern bool8 gDrawWindow;
-extern s16 *gWin0HPtr;
+extern s16 *gWinBufferPtr;
 extern s16 gUnknown_2026E4E;
 
 extern s16 *gWindowBgCopy;
 
 typedef enum CopyWindowBgBufferType {
     COPY_WINDOW_BG_BUFFER_DEFAULT,
-    COPY_WINDOW_BG_BUFFER_DIM2,
-    COPY_WINDOW_BG_BUFFER_DIM1,
-    COPY_WINDOW_BG_BUFFER_UNK3,
+    COPY_WINDOW_BG_BUFFER_DIM2,     // Dim while in light darkness corridor
+    COPY_WINDOW_BG_BUFFER_DIM1,     // Same but for heavy darkness
+    COPY_WINDOW_BG_BUFFER_ROOM_DIM, // While in a room, dim outside
     COPY_WINDOW_BG_BUFFER_UNK4,
     COPY_WINDOW_BG_BUFFER_UNK5,
 } CopyWindowBgBufferType;
 
 void WindowBgBufferInit(void);
-void CopyWindowBgBuffer(s32 *a0, u8 kind);
+void CopyWindowBgBuffer(s32 *pos, u8 kind);
 void ToggleWindowBgBuffer(void);
 
 #endif // GUARD_CODE_800558C_H
diff --git a/src/code_800558C.c b/src/code_800558C.c
index f0e808274..42df00522 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -7,7 +7,7 @@
 #define UNROLL16(x) do { x; x; x; x; x; x; x; x; x; x; x; x; x; x; x; x; } while (0)
 
 EWRAM_DATA bool8 gDrawWindow = FALSE;
-EWRAM_DATA s16 *gWin0HPtr = NULL;
+EWRAM_DATA s16 *gWinBufferPtr = NULL;
 EWRAM_DATA static s32 sUnknown_2026E40 = 0; // Read from but never written to
 EWRAM_DATA static s32 sUnknown_2026E44 = 0; // Read from but never written to
 EWRAM_DATA static s32 sUnknown_2026E48 = 0; // Read from but never written to
@@ -22,10 +22,12 @@ EWRAM_DATA static s16 sBuffer1[324] = {0};
 
 EWRAM_INIT s16 *gWindowBgCopy = NULL;
 
-static const s16 gUnknown_80B8008[17] = {16, 12, 9, 7, 6, 5, 4, 3, 2, 2, 1, 1, 1, 0, 0, 0, 0};
+// Rounded corners in low visibility rooms
+static const s16 sRoomCornerDim[17] = {16, 12, 9, 7, 6, 5, 4, 3, 2, 2, 1, 1, 1, 0, 0, 0, 0};
 
 #define Y_MAX 160
-// Dim edges of screen in corridors with 1 visibility
+#define X_MAX 240
+// In corridor with heavy darkness, dim everything except a small circle
 static const s16 sCorridorDim1[Y_MAX] = {
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
@@ -51,7 +53,7 @@ static const s16 sCorridorDim1[Y_MAX] = {
     0x100, 0x100, 0x100
 };
 
-// Dim edges of screen in corridors with 2 visibility
+// In corridor with light darkness, dim everything except a larger circle
 static const s16 sCorridorDim2[Y_MAX] = {
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
     0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100, 0x100,
@@ -96,14 +98,14 @@ void WindowBgBufferInit(void)
     sBufferIdx = FALSE;
     sBoolUnk = TRUE;
     sBufferPtr = NULL;
-    gWin0HPtr = NULL;
+    gWinBufferPtr = NULL;
     gDrawWindow = FALSE;
     gUnknown_2026E4E = 0x60C;
     gWindowBgCopy = NULL;
 }
 
 // arm9.bin::02005758
-void CopyWindowBgBuffer(s32 *a0, u8 kind)
+void CopyWindowBgBuffer(s32 *pos, u8 kind)
 {
     const s16 *src1, *src2;
     s16 *dst;
@@ -123,68 +125,79 @@ void CopyWindowBgBuffer(s32 *a0, u8 kind)
     switch (kind) {
         case COPY_WINDOW_BG_BUFFER_DEFAULT:
             for (i = 0; i < 10; i++) {
-                UNROLL16(*dst++ = *src1++; *dst++ = 0;);
+                UNROLL16(
+                    *dst++ = *src1++;   // WIN0H
+                    *dst++ = 0;         // WIN1H (disabled)
+                );
             }
             break;
         case COPY_WINDOW_BG_BUFFER_DIM2:
             src2 = sCorridorDim2;
             for (i = 0; i < 10; i++) {
-                UNROLL16(*dst++ = *src1++; *dst++ = *src2++;);
+                UNROLL16(
+                    *dst++ = *src1++;   // WIN0H
+                    *dst++ = *src2++;   // WIN1H (dim)
+                );
             }
             break;
         case COPY_WINDOW_BG_BUFFER_DIM1:
             src2 = sCorridorDim1;
             for (i = 0; i < 10; i++) {
-                UNROLL16(*dst++ = *src1++; *dst++ = *src2++;);
+                UNROLL16(
+                    *dst++ = *src1++;   // WIN0H
+                    *dst++ = *src2++;   // WIN1H (dim)
+                );
             }
             break;
-        case COPY_WINDOW_BG_BUFFER_UNK3:
-            if ((a0[0] < 0 && a0[2] < 0)
-                || (a0[1] < 0 && a0[3] < 0)
-                || (a0[0] >= 240 && a0[2] >= 240)
-                || (a0[1] >= 160 && a0[3] >= 160)) {
+        case COPY_WINDOW_BG_BUFFER_ROOM_DIM:
+            if ((pos[0] < 0 && pos[2] < 0)
+                || (pos[1] < 0 && pos[3] < 0)
+                || (pos[0] >= X_MAX && pos[2] >= X_MAX)
+                || (pos[1] >= Y_MAX && pos[3] >= Y_MAX)) {
+                // If the camera is outside the room, dim the entire screen
                 for (i = 0; i < 10; i++) {
-                    UNROLL16(*dst++ = *src1++; *dst++ = 240;);
+                    UNROLL16(*dst++ = *src1++; *dst++ = 0xF0;);
                 }
             }
             else {
-                s32 iVar5;
-                s32 r4;
-                for (i = 0; i < 160; i++) {
-                    if (a0[1] > i) {
+                s32 left;
+                s32 right;
+                for (i = 0; i < Y_MAX; i++) {
+                    if (pos[1] > i) {
                         *dst++ = *src1++;
                         *dst++ = 256;
                     }
-                    else if (a0[3] <= i) {
+                    else if (pos[3] <= i) {
                         *dst++ = *src1++;
                         *dst++ = 256;
                     }
                     else {
-                        if (i - a0[1] < 16) {
-                            r4 = a0[0] + gUnknown_80B8008[i - a0[1]];
-                            iVar5 = a0[2] - gUnknown_80B8008[i - a0[1]];
+                        if (i - pos[1] < 16) {
+                            right = pos[0] + sRoomCornerDim[i - pos[1]];
+                            left = pos[2] - sRoomCornerDim[i - pos[1]];
                         }
-                        else if (a0[3] - i < 16) {
-                            r4 = a0[0] + gUnknown_80B8008[a0[3] - i];
-                            iVar5 = a0[2] - gUnknown_80B8008[a0[3] - i];
+                        else if (pos[3] - i < 16) {
+                            right = pos[0] + sRoomCornerDim[pos[3] - i];
+                            left = pos[2] - sRoomCornerDim[pos[3] - i];
                         }
                         else {
-                            r4 = a0[0];
-                            iVar5 = a0[2];
+                            right = pos[0];
+                            left = pos[2];
                         }
 
-                        if (r4 < 0)
-                            r4 = 0;
-                        if (r4 > 240 - 1)
-                            r4 = 240 - 1;
+                        if (right < 0)
+                            right = 0;
+                        if (right > X_MAX - 1)
+                            right = X_MAX - 1;
 
-                        if (iVar5 < 1)
-                            iVar5 = 1;
-                        if (iVar5 > 240)
-                            iVar5 = 240;
+                        if (left < 1)
+                            left = 1;
+                        if (left > X_MAX)
+                            left = X_MAX;
 
                         *dst++ = *src1++;
-                        *dst++ = (iVar5 << 8) | r4;
+                        // Note this is backwards so the dim window is drawn on the outside
+                        *dst++ = (left << 8) | right;
                     }
                 }
             }
@@ -281,7 +294,7 @@ void CopyWindowBgBuffer(s32 *a0, u8 kind)
 #if (GAME_VERSION == VERSION_RED)
 UNUSED static void sub_80060A8(void)
 {
-    gWin0HPtr = sBufferPtr;
+    gWinBufferPtr = sBufferPtr;
     sBufferIdx = !sBufferIdx;
     sBoolUnk = !sBoolUnk;
     gDrawWindow = FALSE;
@@ -291,7 +304,7 @@ UNUSED static void sub_80060A8(void)
 // arm9.bin::020056C0
 void ToggleWindowBgBuffer(void)
 {
-    gWin0HPtr = sBufferPtr;
+    gWinBufferPtr = sBufferPtr;
     sBufferIdx = !sBufferIdx;
     sBoolUnk = !sBoolUnk;
     SetBldAlphaReg((gUnknown_2026E4E & 0x1F00) >> 8, gUnknown_2026E4E & 0x1F);
diff --git a/src/cpu.c b/src/cpu.c
index 2a2204700..64508f449 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -82,9 +82,9 @@ void VBlank_CB(void)
     REG_BLDALPHA = gBldAlpha;
     if (gDrawWindow) {
         // Very interesting use of DmaCopy16 here.
-        DmaSet(0, &gWin0HPtr[2], REG_ADDR_WIN0H, ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_SRC_INC | DMA_DEST_RELOAD | DMA_16BIT) << 16) | 2);
-        REG_WIN0H = gWin0HPtr[0];
-        REG_WIN1H = gWin0HPtr[1];
+        DmaSet(0, &gWinBufferPtr[2], REG_ADDR_WIN0H, ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_SRC_INC | DMA_DEST_RELOAD | DMA_16BIT) << 16) | 2);
+        REG_WIN0H = gWinBufferPtr[0];
+        REG_WIN1H = gWinBufferPtr[1];
         REG_WIN0V = DISPLAY_HEIGHT;
         REG_WIN1V = DISPLAY_HEIGHT;
     }

From 7bbe9c5810c90abd9deb806406a63a11a0626845 Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Thu, 30 Apr 2026 21:30:15 -0400
Subject: [PATCH 8/9] Cleanup

---
 include/code_800558C.h      | 2 +-
 src/code_800558C.c          | 4 ++--
 src/cpu.c                   | 5 ++++-
 src/debug_field_map.c       | 6 +++---
 src/dungeon_tilemap.c       | 2 +-
 src/dungeon_vram.c          | 2 +-
 src/friend_areas_map_util.c | 2 +-
 src/ground_main.c           | 2 +-
 src/main_loops.c            | 4 ++--
 src/other_menus1.c          | 2 +-
 src/textbox.c               | 2 +-
 src/world_map.c             | 2 +-
 12 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/include/code_800558C.h b/include/code_800558C.h
index fa1dcfed3..9de9e6fe7 100644
--- a/include/code_800558C.h
+++ b/include/code_800558C.h
@@ -8,7 +8,7 @@ extern s16 gUnknown_2026E4E;
 extern s16 *gWindowBgCopy;
 
 typedef enum CopyWindowBgBufferType {
-    COPY_WINDOW_BG_BUFFER_DEFAULT,
+    COPY_WINDOW_BG_BUFFER_WIN0,
     COPY_WINDOW_BG_BUFFER_DIM2,     // Dim while in light darkness corridor
     COPY_WINDOW_BG_BUFFER_DIM1,     // Same but for heavy darkness
     COPY_WINDOW_BG_BUFFER_ROOM_DIM, // While in a room, dim outside
diff --git a/src/code_800558C.c b/src/code_800558C.c
index 42df00522..5b86b77df 100644
--- a/src/code_800558C.c
+++ b/src/code_800558C.c
@@ -112,7 +112,7 @@ void CopyWindowBgBuffer(s32 *pos, u8 kind)
     s32 i;
 
     if (!sInitialized)
-        kind = COPY_WINDOW_BG_BUFFER_DEFAULT;
+        kind = COPY_WINDOW_BG_BUFFER_WIN0;
 
     dst = !sBufferIdx ? sBuffer0 : sBuffer1;
 
@@ -123,7 +123,7 @@ void CopyWindowBgBuffer(s32 *pos, u8 kind)
     sBufferPtr = dst;
 
     switch (kind) {
-        case COPY_WINDOW_BG_BUFFER_DEFAULT:
+        case COPY_WINDOW_BG_BUFFER_WIN0:
             for (i = 0; i < 10; i++) {
                 UNROLL16(
                     *dst++ = *src1++;   // WIN0H
diff --git a/src/cpu.c b/src/cpu.c
index 64508f449..c0fe207c1 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -81,10 +81,13 @@ void VBlank_CB(void)
     REG_BLDCNT = gBldCnt;
     REG_BLDALPHA = gBldAlpha;
     if (gDrawWindow) {
-        // Very interesting use of DmaCopy16 here.
+        // Write the next 2 values from gWinBufferPtr to WIN0H/WIN1H every HBlank, allows for drawing
+        // non-rectangular windows
         DmaSet(0, &gWinBufferPtr[2], REG_ADDR_WIN0H, ((DMA_ENABLE | DMA_START_HBLANK | DMA_REPEAT | DMA_SRC_INC | DMA_DEST_RELOAD | DMA_16BIT) << 16) | 2);
+        // Manually set the first WIN0H and WIN1H values
         REG_WIN0H = gWinBufferPtr[0];
         REG_WIN1H = gWinBufferPtr[1];
+        // Set WIN0V/WIN1V to max screen dimensions
         REG_WIN0V = DISPLAY_HEIGHT;
         REG_WIN1V = DISPLAY_HEIGHT;
     }
diff --git a/src/debug_field_map.c b/src/debug_field_map.c
index 03c831332..3a49d35a1 100644
--- a/src/debug_field_map.c
+++ b/src/debug_field_map.c
@@ -38,7 +38,7 @@ UNUSED static void DebugMapViewer(void)
     sub_809975C();
     sub_809D0AC();
     ResetDialogueBox();
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     AllocGroundMapAction();
     while (TRUE) {
         bool8 quitMapView;
@@ -48,7 +48,7 @@ UNUSED static void DebugMapViewer(void)
         if (DebugFieldMapWindow_Init()) {
             DebugFieldMapWindow_MoveMenuTo(mapId);
             while (TRUE) {
-                CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+                CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
                 sub_8012A18(0);
                 switch (DebugFieldMapWindow_GetInput()) {
                     case MENU_INPUT_A_PRESS:
@@ -132,7 +132,7 @@ UNUSED static void DebugMapViewer(void)
             sub_809D25C();
             sub_80A59DC();
             DrawDialogueBoxString_Async();
-            CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+            CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
             ToggleWindowBgBuffer();
             nullsub_8(gGameOptionsRef->touchScreen);
             sub_8005180();
diff --git a/src/dungeon_tilemap.c b/src/dungeon_tilemap.c
index b7b6fc20a..21261bd82 100644
--- a/src/dungeon_tilemap.c
+++ b/src/dungeon_tilemap.c
@@ -303,7 +303,7 @@ static void sub_803F7BC(void)
     u32 roomId = tile->room;
 
     if (strPtr->allTilesRevealed != 0 || strPtr->unk1820C != 0 || strPtr->unk18217 != 0) {
-        CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+        CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     }
     else if (roomId == CORRIDOR_ROOM) {
         u32 kind = (strPtr->visibilityRange == 2) ? COPY_WINDOW_BG_BUFFER_DIM2 : COPY_WINDOW_BG_BUFFER_DIM1;
diff --git a/src/dungeon_vram.c b/src/dungeon_vram.c
index 366f77627..3b59db8a1 100644
--- a/src/dungeon_vram.c
+++ b/src/dungeon_vram.c
@@ -239,7 +239,7 @@ void sub_803E668(u32 unused)
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     nullsub_12();
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     ToggleWindowBgBuffer();
     gDungeonFramesCounter++;
     IncrementPlayTime(gPlayTimeRef);
diff --git a/src/friend_areas_map_util.c b/src/friend_areas_map_util.c
index 22a141742..8fa9b1ec6 100644
--- a/src/friend_areas_map_util.c
+++ b/src/friend_areas_map_util.c
@@ -373,7 +373,7 @@ void FriendAreasMap_RunFrameActions(void)
     SetBG3RegOffsets(gFriendAreasMapPtr->bgPos.x, gFriendAreasMapPtr->bgPos.y);
     AnimateSprites();
     UpdateAnimatedColors(FadeScreen(), gFriendAreasMapPtr->unk4C4C, 0xB0, 16, gFriendAreasMapPtr->brightness, NULL);
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     ToggleWindowBgBuffer();
diff --git a/src/ground_main.c b/src/ground_main.c
index 4a0972f08..14fe38ddc 100644
--- a/src/ground_main.c
+++ b/src/ground_main.c
@@ -308,7 +308,7 @@ u32 xxx_script_related_8098468_Async(s32 startMode)
             GroundMap_ExecuteEvent(EVENT_DIVIDE, FALSE);
         }
         GroundMap_Action();
-        CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+        CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
         ToggleWindowBgBuffer();
         xxx_call_update_bg_sound_input();
         while ( 1 ) {
diff --git a/src/main_loops.c b/src/main_loops.c
index 055f70ec0..1a2ca1ac5 100644
--- a/src/main_loops.c
+++ b/src/main_loops.c
@@ -273,7 +273,7 @@ void GameLoop_Async(void)
 static void MainLoops_RunFrameActions(u32 unused)
 {
     DrawDialogueBoxString_Async();
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     nullsub_8(gGameOptionsRef->touchScreen);
 
     sub_8005180();
@@ -362,7 +362,7 @@ static void QuickSave_Async(u32 mode)
     sub_8099744();
     sub_8099750();
     SetCharacterMask(3);
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     ToggleWindowBgBuffer();
     CreateDialogueBoxAndPortrait(sSaveTextQuicksaving, 0, 0, 0x20);
 
diff --git a/src/other_menus1.c b/src/other_menus1.c
index 8ee531c90..ea2340485 100644
--- a/src/other_menus1.c
+++ b/src/other_menus1.c
@@ -208,7 +208,7 @@ static void sub_80371B8(void)
 
 void sub_80373C4(void)
 {
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     ToggleWindowBgBuffer();
     WaitForNextFrameAndAdvanceRNG();
     LoadBufferedInputs();
diff --git a/src/textbox.c b/src/textbox.c
index 2fb6ee199..3e21bbef6 100644
--- a/src/textbox.c
+++ b/src/textbox.c
@@ -1040,7 +1040,7 @@ void sub_809B57C_Async(void)
     }
 
     if (sTextbox->unk434 < 0) {
-        CopyWindowBgBuffer(0, COPY_WINDOW_BG_BUFFER_DEFAULT);
+        CopyWindowBgBuffer(0, COPY_WINDOW_BG_BUFFER_WIN0);
     }
     else {
         CopyWindowBgBuffer(0, 5);
diff --git a/src/world_map.c b/src/world_map.c
index 215b5487e..9457cc76e 100644
--- a/src/world_map.c
+++ b/src/world_map.c
@@ -406,7 +406,7 @@ static void WorldMap_RunFrameActions(void)
     SetBG3RegOffsets(sWorldMapPtr->bgPos.x, sWorldMapPtr->bgPos.y);
     AnimateSprites(TRUE);
     FadeScreen();
-    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_DEFAULT);
+    CopyWindowBgBuffer(NULL, COPY_WINDOW_BG_BUFFER_WIN0);
     nullsub_8(gGameOptionsRef->touchScreen);
     sub_8005180();
     ToggleWindowBgBuffer();

From 3415afcf8782ea2c2f2ebfa8c304ae357fdebddc Mon Sep 17 00:00:00 2001
From: Evan Chang <evanc577@gmail.com>
Date: Thu, 30 Apr 2026 21:40:32 -0400
Subject: [PATCH 9/9] Rename window_buffer file

---
 include/{code_800558C.h => window_buffer.h} | 6 +++---
 ld_script.ld                                | 4 ++--
 src/code_8040094_1.c                        | 2 +-
 src/cpu.c                                   | 2 +-
 src/debug_field_map.c                       | 2 +-
 src/dungeon_8041AD0.c                       | 2 +-
 src/dungeon_tilemap.c                       | 2 +-
 src/dungeon_vram.c                          | 2 +-
 src/friend_areas_map.c                      | 2 +-
 src/friend_areas_map_util.c                 | 2 +-
 src/ground_main.c                           | 2 +-
 src/ground_map.c                            | 2 +-
 src/ground_weather.c                        | 2 +-
 src/main.c                                  | 2 +-
 src/main_loops.c                            | 2 +-
 src/menu_input.c                            | 2 +-
 src/other_menus1.c                          | 2 +-
 src/run_dungeon.c                           | 2 +-
 src/text_1.c                                | 2 +-
 src/textbox.c                               | 2 +-
 src/{code_800558C.c => window_buffer.c}     | 2 +-
 src/world_map.c                             | 2 +-
 sym_ewram.txt                               | 2 +-
 sym_ewram_init.txt                          | 2 +-
 24 files changed, 27 insertions(+), 27 deletions(-)
 rename include/{code_800558C.h => window_buffer.h} (86%)
 rename src/{code_800558C.c => window_buffer.c} (99%)

diff --git a/include/code_800558C.h b/include/window_buffer.h
similarity index 86%
rename from include/code_800558C.h
rename to include/window_buffer.h
index 9de9e6fe7..bfdc1ee69 100644
--- a/include/code_800558C.h
+++ b/include/window_buffer.h
@@ -1,5 +1,5 @@
-#ifndef GUARD_CODE_800558C_H
-#define GUARD_CODE_800558C_H
+#ifndef GUARD_WINDOW_BUFFER_H
+#define GUARD_WINDOW_BUFFER_H
 
 extern bool8 gDrawWindow;
 extern s16 *gWinBufferPtr;
@@ -20,4 +20,4 @@ void WindowBgBufferInit(void);
 void CopyWindowBgBuffer(s32 *pos, u8 kind);
 void ToggleWindowBgBuffer(void);
 
-#endif // GUARD_CODE_800558C_H
+#endif // GUARD_WINDOW_BUFFER_H
diff --git a/ld_script.ld b/ld_script.ld
index 28b165f19..a24951fd1 100755
--- a/ld_script.ld
+++ b/ld_script.ld
@@ -62,7 +62,7 @@ SECTIONS {
         src/input.o(.text);
         src/code_8004AA0.o(.text);
         src/sprite.o(.text);
-        src/code_800558C.o(.text);
+        src/window_buffer.o(.text);
         src/random.o(.text);
         src/text_1.o(.text);
         src/text_2.o(.text);
@@ -440,7 +440,7 @@ SECTIONS {
         src/input.o(.rodata);
         src/code_8004AA0.o(.rodata);
         src/sprite.o(.rodata);
-        src/code_800558C.o(.rodata);
+        src/window_buffer.o(.rodata);
         src/random.o(.rodata);
         src/text_1.o(.rodata);
         src/text_2.o(.rodata);
diff --git a/src/code_8040094_1.c b/src/code_8040094_1.c
index 06a263002..89df2e89b 100644
--- a/src/code_8040094_1.c
+++ b/src/code_8040094_1.c
@@ -4,7 +4,7 @@
 #include "constants/type.h"
 #include "constants/weather.h"
 #include "structs/str_dungeon.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "code_8040094_1.h"
 #include "dungeon_8041AD0.h"
 #include "dungeon_info.h"
diff --git a/src/cpu.c b/src/cpu.c
index c0fe207c1..000bd33af 100644
--- a/src/cpu.c
+++ b/src/cpu.c
@@ -1,6 +1,6 @@
 #include "global.h"
 #include "bg_control.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "cpu.h"
 
 EWRAM_DATA u32 gUnknown_202D800 = {0};
diff --git a/src/debug_field_map.c b/src/debug_field_map.c
index 3a49d35a1..b8e329d04 100644
--- a/src/debug_field_map.c
+++ b/src/debug_field_map.c
@@ -2,7 +2,7 @@
 #include "globaldata.h"
 #include "debug_field_map_window.h"
 #include "music_util.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "code_8099360.h"
 #include "code_800C9CC.h"
 #include "graphics_memory.h"
diff --git a/src/dungeon_8041AD0.c b/src/dungeon_8041AD0.c
index f8ae86623..2035f82c3 100644
--- a/src/dungeon_8041AD0.c
+++ b/src/dungeon_8041AD0.c
@@ -7,7 +7,7 @@
 #include "structs/dungeon_entity.h"
 #include "structs/sprite_oam.h"
 #include "structs/str_dungeon.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "effect_main.h"
 #include "effect_sub_1.h"
 #include "effect_sub_2.h"
diff --git a/src/dungeon_tilemap.c b/src/dungeon_tilemap.c
index 21261bd82..0849e52cd 100644
--- a/src/dungeon_tilemap.c
+++ b/src/dungeon_tilemap.c
@@ -6,7 +6,7 @@
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
 #include "code_8004AA0.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "effect_data.h"
 #include "confirm_name_menu.h"
diff --git a/src/dungeon_vram.c b/src/dungeon_vram.c
index 3b59db8a1..996898731 100644
--- a/src/dungeon_vram.c
+++ b/src/dungeon_vram.c
@@ -5,7 +5,7 @@
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
 #include "code_8004AA0.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "code_800C9CC.h"
 #include "music_util.h"
diff --git a/src/friend_areas_map.c b/src/friend_areas_map.c
index 405947946..c2e991360 100644
--- a/src/friend_areas_map.c
+++ b/src/friend_areas_map.c
@@ -4,7 +4,7 @@
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
 #include "code_8004AA0.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "code_800C9CC.h"
 #include "code_800D090.h"
diff --git a/src/friend_areas_map_util.c b/src/friend_areas_map_util.c
index 8fa9b1ec6..f3807983b 100644
--- a/src/friend_areas_map_util.c
+++ b/src/friend_areas_map_util.c
@@ -4,7 +4,7 @@
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
 #include "code_8004AA0.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "code_800C9CC.h"
 #include "code_800D090.h"
diff --git a/src/ground_main.c b/src/ground_main.c
index 14fe38ddc..1dea79986 100644
--- a/src/ground_main.c
+++ b/src/ground_main.c
@@ -5,7 +5,7 @@
 #include "structs/str_wonder_mail.h"
 #include "structs/str_dungeon_setup.h"
 #include "adventure_info.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "code_800C9CC.h"
 #include "code_8094F88.h"
 #include "code_80958E8.h"
diff --git a/src/ground_map.c b/src/ground_map.c
index 93f70ee6f..ddf7d16bf 100644
--- a/src/ground_map.c
+++ b/src/ground_map.c
@@ -10,7 +10,7 @@
 #include "ground_weather.h"
 #include "memory.h"
 #include "ground_map_conversion_table.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "constants/dungeon.h"
 #include "constants/ground_map.h"
 #include "code_809D148.h"
diff --git a/src/ground_weather.c b/src/ground_weather.c
index 4db101ad4..c8f1ed181 100644
--- a/src/ground_weather.c
+++ b/src/ground_weather.c
@@ -1,7 +1,7 @@
 #include "global.h"
 #include "globaldata.h"
 #include "ground_weather.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "debug.h"
 #include "event_flag.h"
 #include "ground_bg.h"
diff --git a/src/main.c b/src/main.c
index 829a16b2f..b4eaf72ef 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,7 +3,7 @@
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
 #include "code_8004AA0.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "cpu.h"
 #include "crt0.h"
diff --git a/src/main_loops.c b/src/main_loops.c
index 1a2ca1ac5..372641a7e 100644
--- a/src/main_loops.c
+++ b/src/main_loops.c
@@ -8,7 +8,7 @@
 #include "adventure_info.h"
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "code_800C9CC.h"
 #include "code_800D090_1.h"
 #include "code_8094F88.h"
diff --git a/src/menu_input.c b/src/menu_input.c
index 984c673ec..aeeb69ed0 100644
--- a/src/menu_input.c
+++ b/src/menu_input.c
@@ -16,7 +16,7 @@
 #include "code_800C9CC.h"
 #include "bg_palette_buffer.h"
 #include "game_options.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 
 const u32 gDefaultMenuTextColors[3] = { COLOR_WHITE_2, COLOR_RED, COLOR_RED };
 
diff --git a/src/other_menus1.c b/src/other_menus1.c
index ea2340485..53a71d9d0 100644
--- a/src/other_menus1.c
+++ b/src/other_menus1.c
@@ -4,7 +4,7 @@
 #include "constants/main_menu.h"
 #include "structs/str_dungeon.h"
 #include "bg_palette_buffer.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "code_800C9CC.h"
 #include "music_util.h"
diff --git a/src/run_dungeon.c b/src/run_dungeon.c
index b2e75e33b..714663c8e 100644
--- a/src/run_dungeon.c
+++ b/src/run_dungeon.c
@@ -10,7 +10,7 @@
 #include "structs/sprite_oam.h"
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "effect_main.h"
 #include "effect_data.h"
diff --git a/src/text_1.c b/src/text_1.c
index 4c5dc9296..e6612f2c6 100644
--- a/src/text_1.c
+++ b/src/text_1.c
@@ -2,7 +2,7 @@
 #include "globaldata.h"
 #include "structs/str_text.h"
 #include "bg_palette_buffer.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "cpu.h"
 #include "decompress_at.h"
diff --git a/src/textbox.c b/src/textbox.c
index 3e21bbef6..04a9f3cdb 100644
--- a/src/textbox.c
+++ b/src/textbox.c
@@ -5,7 +5,7 @@
 #include "structs/menu.h"
 #include "structs/str_file_system.h"
 #include "structs/str_mon_portrait.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "code_800D090.h"
 #include "code_8015080.h"
 #include "code_801B60C.h"
diff --git a/src/code_800558C.c b/src/window_buffer.c
similarity index 99%
rename from src/code_800558C.c
rename to src/window_buffer.c
index 5b86b77df..90053fbc9 100644
--- a/src/code_800558C.c
+++ b/src/window_buffer.c
@@ -1,7 +1,7 @@
 #include "global.h"
 #include "globaldata.h"
 #include "bg_control.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "math.h"
 
 #define UNROLL16(x) do { x; x; x; x; x; x; x; x; x; x; x; x; x; x; x; x; } while (0)
diff --git a/src/world_map.c b/src/world_map.c
index 9457cc76e..8c50130b7 100644
--- a/src/world_map.c
+++ b/src/world_map.c
@@ -3,7 +3,7 @@
 #include "bg_control.h"
 #include "bg_palette_buffer.h"
 #include "code_8004AA0.h"
-#include "code_800558C.h"
+#include "window_buffer.h"
 #include "graphics_memory.h"
 #include "code_800C9CC.h"
 #include "code_800D090.h"
diff --git a/sym_ewram.txt b/sym_ewram.txt
index 89c811fce..64fb81207 100644
--- a/sym_ewram.txt
+++ b/sym_ewram.txt
@@ -6,7 +6,7 @@
     .include "src/bg_palette_buffer.o"
     .include "src/input.o"
     .include "src/sprite.o"
-    .include "src/code_800558C.o"
+    .include "src/window_buffer.o"
     .include "src/text_1.o"
     .include "src/graphics_memory.o"
     .include "src/file_system.o"
diff --git a/sym_ewram_init.txt b/sym_ewram_init.txt
index 0d7994ffc..d8e33edbb 100644
--- a/sym_ewram_init.txt
+++ b/sym_ewram_init.txt
@@ -3,7 +3,7 @@
 .include "src/main_loops.o"
 .include "src/other_random.o"
 .include "src/sprite.o"
-.include "src/code_800558C.o"
+.include "src/window_buffer.o"
 .include "src/random.o"
 .include "src/text_1.o"
 .include "src/graphics_memory.o"