Document Sequence Modes and Related Functions (#1046)

* Document Audio_SetSequenceMode

* Cleanup surrounding docs

* format

* Clean-up

* fix capital `I` in `playeridx`

* Dist -> DistSq

* `SetCamModeAndSeqMode` -> `UpdateCamAndSeqModes`

* Get rid of extra padding

* PR Feedback

3 files changed, 230 insertions, 105 deletions

diff --git a/src/code/code_800EC960.c b/src/code/code_800EC960.c
index b1af38f95..64a1419da 100644
--- a/src/code/code_800EC960.c
+++ b/src/code/code_800EC960.c
@@ -121,27 +121,134 @@ s8 sAudioCutsceneFlag = 0;
 s8 sSpecReverb = 0;
 s8 sAudioEnvReverb = 0;
 s8 sAudioCodeReverb = 0;
-u8 D_8013061C = 0;
+u8 sPrevSeqMode = 0;
 f32 sAudioEnemyDist = 0.0f;
 s8 sAudioEnemyVol = 127;
 u16 D_80130628 = NA_BGM_DISABLED;
 u8 D_8013062C = 0;
 u8 D_80130630 = NA_BGM_GENERAL_SFX;
-u32 D_80130634 = 0;
-u32 D_80130638 = 0;
+u32 sNumFramesStill = 0;
+u32 sNumFramesMoving = 0;
 u8 sAudioBaseFilter = 0;
 u8 sAudioExtraFilter = 0;
 u8 sAudioBaseFilter2 = 0;
 u8 sAudioExtraFilter2 = 0;
 Vec3f* sSariaBgmPtr = NULL;
 f32 D_80130650 = 2000.0f;
-u8 D_80130654 = 0;
-u8 D_80130658[0x70] = {
-    2,   1,  0,  0,  0,  0, 0, 0, 0, 0, 0, 0,  0, 0, 0,   0, 0,   0,   0,   0, 0,   0, 0,  0, 33, 16, 0, 136,
-    1,   0,  0,  32, 0,  0, 2, 4, 2, 2, 1, 16, 0, 0, 1,   2, 1,   0,   128, 0, 128, 0, 2,  2, 2,  2,  2, 2,
-    136, 2,  0,  2,  17, 2, 1, 1, 0, 0, 0, 2,  2, 2, 2,   2, 2,   2,   0,   0, 0,   0, 32, 0, 16, 2,  0, 0,
-    4,   32, 64, 64, 1,  2, 2, 1, 1, 2, 0, 17, 0, 0, 128, 0, 128, 128, 0,   0, 0,   0, 0,  0, 8,  0,  0, 0,
+u8 sSeqModeInput = 0;
+u8 sSeqFlags[0x6E] = {
+    0x2,  // NA_BGM_GENERAL_SFX
+    0x1,  // NA_BGM_NATURE_BACKGROUND
+    0,    // NA_BGM_FIELD_LOGIC
+    0,    // NA_BGM_FIELD_INIT
+    0,    // NA_BGM_FIELD_DEFAULT_1
+    0,    // NA_BGM_FIELD_DEFAULT_2
+    0,    // NA_BGM_FIELD_DEFAULT_3
+    0,    // NA_BGM_FIELD_DEFAULT_4
+    0,    // NA_BGM_FIELD_DEFAULT_5
+    0,    // NA_BGM_FIELD_DEFAULT_6
+    0,    // NA_BGM_FIELD_DEFAULT_7
+    0,    // NA_BGM_FIELD_DEFAULT_8
+    0,    // NA_BGM_FIELD_DEFAULT_9
+    0,    // NA_BGM_FIELD_DEFAULT_A
+    0,    // NA_BGM_FIELD_DEFAULT_B
+    0,    // NA_BGM_FIELD_ENEMY_INIT
+    0,    // NA_BGM_FIELD_ENEMY_1
+    0,    // NA_BGM_FIELD_ENEMY_2
+    0,    // NA_BGM_FIELD_ENEMY_3
+    0,    // NA_BGM_FIELD_ENEMY_4
+    0,    // NA_BGM_FIELD_STILL_1
+    0,    // NA_BGM_FIELD_STILL_2
+    0,    // NA_BGM_FIELD_STILL_3
+    0,    // NA_BGM_FIELD_STILL_4
+    0x21, // NA_BGM_DUNGEON
+    0x10, // NA_BGM_KAKARIKO_ADULT
+    0,    // NA_BGM_ENEMY
+    0x88, // NA_BGM_BOSS
+    0x1,  // NA_BGM_INSIDE_DEKU_TREE
+    0,    // NA_BGM_MARKET
+    0,    // NA_BGM_TITLE
+    0x20, // NA_BGM_LINK_HOUSE
+    0,    // NA_BGM_GAME_OVER
+    0,    // NA_BGM_BOSS_CLEAR
+    0x2,  // NA_BGM_ITEM_GET
+    0x4,  // NA_BGM_OPENING_GANON
+    0x2,  // NA_BGM_HEART_GET
+    0x2,  // NA_BGM_OCA_LIGHT
+    0x1,  // NA_BGM_JABU_JABU
+    0x10, // NA_BGM_KAKARIKO_KID
+    0,    // NA_BGM_GREAT_FAIRY
+    0,    // NA_BGM_ZELDA_THEME
+    0x1,  // NA_BGM_FIRE_TEMPLE
+    0x2,  // NA_BGM_OPEN_TRE_BOX
+    0x1,  // NA_BGM_FOREST_TEMPLE
+    0,    // NA_BGM_COURTYARD
+    0x80, // NA_BGM_GANON_TOWER
+    0,    // NA_BGM_LONLON
+    0x80, // NA_BGM_GORON_CITY
+    0,    // NA_BGM_FIELD_MORNING
+    0x2,  // NA_BGM_SPIRITUAL_STONE
+    0x2,  // NA_BGM_OCA_BOLERO
+    0x2,  // NA_BGM_OCA_MINUET
+    0x2,  // NA_BGM_OCA_SERENADE
+    0x2,  // NA_BGM_OCA_REQUIEM
+    0x2,  // NA_BGM_OCA_NOCTURNE
+    0x88, // NA_BGM_MINI_BOSS
+    0x2,  // NA_BGM_SMALL_ITEM_GET
+    0,    // NA_BGM_TEMPLE_OF_TIME
+    0x2,  // NA_BGM_EVENT_CLEAR
+    0x11, // NA_BGM_KOKIRI
+    0x2,  // NA_BGM_OCA_FAIRY_GET
+    0x1,  // NA_BGM_SARIA_THEME
+    0x1,  // NA_BGM_SPIRIT_TEMPLE
+    0,    // NA_BGM_HORSE
+    0,    // NA_BGM_HORSE_GOAL
+    0,    // NA_BGM_INGO
+    0x2,  // NA_BGM_MEDALLION_GET
+    0x2,  // NA_BGM_OCA_SARIA
+    0x2,  // NA_BGM_OCA_EPONA
+    0x2,  // NA_BGM_OCA_ZELDA
+    0x2,  // NA_BGM_OCA_SUNS
+    0x2,  // NA_BGM_OCA_TIME
+    0x2,  // NA_BGM_OCA_STORM
+    0,    // NA_BGM_NAVI_OPENING
+    0,    // NA_BGM_DEKU_TREE_CS
+    0,    // NA_BGM_WINDMILL
+    0,    // NA_BGM_HYRULE_CS
+    0x20, // NA_BGM_MINI_GAME
+    0,    // NA_BGM_SHEIK
+    0x10, // NA_BGM_ZORA_DOMAIN
+    0x2,  // NA_BGM_APPEAR
+    0,    // NA_BGM_ADULT_LINK
+    0,    // NA_BGM_MASTER_SWORD
+    0x4,  // NA_BGM_INTRO_GANON
+    0x20, // NA_BGM_SHOP
+    0x40, // NA_BGM_CHAMBER_OF_SAGES
+    0x40, // NA_BGM_FILE_SELECT
+    0x1,  // NA_BGM_ICE_CAVERN
+    0x2,  // NA_BGM_DOOR_OF_TIME
+    0x2,  // NA_BGM_OWL
+    0x1,  // NA_BGM_SHADOW_TEMPLE
+    0x1,  // NA_BGM_WATER_TEMPLE
+    0x2,  // NA_BGM_BRIDGE_TO_GANONS
+    0,    // NA_BGM_OCARINA_OF_TIME
+    0x11, // NA_BGM_GERUDO_VALLEY
+    0,    // NA_BGM_POTION_SHOP
+    0,    // NA_BGM_KOTAKE_KOUME
+    0x80, // NA_BGM_ESCAPE
+    0,    // NA_BGM_UNDERGROUND
+    0x80, // NA_BGM_GANON_BATTLE_1
+    0x80, // NA_BGM_GANON_BATTLE_2
+    0,    // NA_BGM_END_DEMO
+    0,    // NA_BGM_STAFF_1
+    0,    // NA_BGM_STAFF_2
+    0,    // NA_BGM_STAFF_3
+    0,    // NA_BGM_STAFF_4
+    0,    // NA_BGM_FIRE_BOSS
+    0x8,  // NA_BGM_MINI_GAME_2
+    0,    // NA_BGM_VARIOUS_SFX
 };
+
 s8 sSpecReverbs[20] = { 0, 0, 0, 0, 0, 0, 0, 40, 0, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
 D_801306DC_s D_801306DC[20] = {
@@ -1480,7 +1587,7 @@ f32 D_80131C8C = 0.0f;
 
 // === Audio Debugging ===
 
-// These variables come between in-function statics in func_800EE824 and func_800F510C
+// These variables come between in-function statics in func_800EE824 and Audio_SplitBgmChannels
 
 f32 sAudioUpdateDuration = 0.0f;
 f32 sAudioUpdateDurationMax = 0.0f;
@@ -2213,8 +2320,8 @@ void AudioDebug_Draw(GfxPrint* printer) {
             GfxPrint_Printf(printer, "SOUND GAME FRAME MAX %f", sAudioUpdateDurationMax);
 
             GfxPrint_SetPos(printer, 3, 9);
-            GfxPrint_Printf(printer, "SWITCH BGM MODE %d %d %d (FLAG %d)", D_8013061C, D_80130634, D_80130638,
-                            D_80130654);
+            GfxPrint_Printf(printer, "SWITCH BGM MODE %d %d %d (FLAG %d)", sPrevSeqMode, sNumFramesStill,
+                            sNumFramesMoving, sSeqModeInput);
 
             GfxPrint_SetPos(printer, 3, 10);
             GfxPrint_Printf(printer, "ENEMY DIST %f VOL %3d", sAudioEnemyDist, sAudioEnemyVol);
@@ -2639,7 +2746,7 @@ void AudioDebug_ProcessInput_BlkChgBgm(void) {
     if (CHECK_BTN_ANY(sDebugPadPress, BTN_DLEFT)) {
         sAudioBlkChgBgmWork[sAudioBlkChgBgmSel]--;
         if (sAudioBlkChgBgmSel == 1) {
-            func_800F5E90(sAudioBlkChgBgmWork[1]);
+            Audio_SetSequenceMode(sAudioBlkChgBgmWork[1]);
             ; // might be a fake match?
         }
     }
@@ -2647,7 +2754,7 @@ void AudioDebug_ProcessInput_BlkChgBgm(void) {
     if (CHECK_BTN_ANY(sDebugPadPress, BTN_DRIGHT)) {
         sAudioBlkChgBgmWork[sAudioBlkChgBgmSel]++;
         if (sAudioBlkChgBgmSel == 1) {
-            func_800F5E90(sAudioBlkChgBgmWork[1]);
+            Audio_SetSequenceMode(sAudioBlkChgBgmWork[1]);
         }
     }
 
@@ -3248,7 +3355,7 @@ void Audio_ResetSfxChannelState(void) {
     }
 
     sSfxChannelState[SFX_PLAYER_CHANNEL_OCARINA].unk_0C = 0;
-    D_8013061C = 0;
+    sPrevSeqMode = 0;
     sAudioCodeReverb = 0;
 }
 
@@ -3609,39 +3716,48 @@ void Audio_ClearSariaBgmAtPos(Vec3f* pos) {
     }
 }
 
-void func_800F510C(s8 volSplit) {
-    u8 vol;
-    u8 prio;
+/**
+ * Turns on and off channels from both bgm players in a way that splits
+ * equally between the two bgm channels. Split based on note priority
+ */
+void Audio_SplitBgmChannels(s8 volSplit) {
+    u8 volume;
+    u8 notePriority;
     u16 channelBits;
-    u8 players[2] = { SEQ_PLAYER_BGM_MAIN, SEQ_PLAYER_BGM_SUB };
+    u8 bgmPlayers[2] = { SEQ_PLAYER_BGM_MAIN, SEQ_PLAYER_BGM_SUB };
+    u8 channelIdx;
     u8 i;
-    u8 j;
 
     if ((func_800FA0B4(SEQ_PLAYER_FANFARE) == NA_BGM_DISABLED) &&
         (func_800FA0B4(SEQ_PLAYER_BGM_SUB) != NA_BGM_LONLON)) {
-        for (i = 0; i < 2; i++) {
+        for (i = 0; i < ARRAY_COUNT(bgmPlayers); i++) {
             if (i == 0) {
-                vol = volSplit;
+                // Main Bgm SeqPlayer
+                volume = volSplit;
             } else {
-                vol = 0x7F - volSplit;
+                // Sub Bgm SeqPlayer
+                volume = 0x7F - volSplit;
             }
 
-            if (vol > 100) {
-                prio = 11;
-            } else if (vol < 20) {
-                prio = 2;
+            if (volume > 100) {
+                notePriority = 11;
+            } else if (volume < 20) {
+                notePriority = 2;
             } else {
-                prio = ((vol - 20) / 10) + 2;
+                notePriority = ((volume - 20) / 10) + 2;
             }
 
             channelBits = 0;
-            for (j = 0; j < 0x10; j++) {
-                if (gAudioContext.seqPlayers[players[i]].channels[j]->notePriority < prio) {
-                    channelBits += (1 << j);
+            for (channelIdx = 0; channelIdx < 16; channelIdx++) {
+                if (notePriority > gAudioContext.seqPlayers[bgmPlayers[i]].channels[channelIdx]->notePriority) {
+                    // If the note currently playing in the channel is a high enough priority,
+                    // then keep the channel on by setting a channelBit
+                    // If this condition fails, then the channel will be shut off
+                    channelBits += (1 << channelIdx);
                 }
             }
 
-            Audio_SeqCmdA(players[i], channelBits);
+            Audio_SeqCmdA(bgmPlayers[i], channelBits);
         }
     }
 }
@@ -3685,7 +3801,7 @@ void Audio_PlaySariaBgm(Vec3f* pos, u16 seqId, u16 distMax) {
     }
 
     if (seqId != NA_BGM_GREAT_FAIRY) {
-        func_800F510C(vol);
+        Audio_SplitBgmChannels(vol);
     }
 
     Audio_SetVolScale(SEQ_PLAYER_BGM_SUB, 3, vol, 0);
@@ -3711,7 +3827,7 @@ void func_800F5550(u16 seqId) {
             Audio_QueueCmdS32(0xF8000000, 0);
         }
 
-        if ((D_80130658[D_80130630] & 0x20) && D_80130658[(seqId & 0xFF) & 0xFF] & 0x10) {
+        if ((sSeqFlags[D_80130630] & 0x20) && sSeqFlags[(seqId & 0xFF) & 0xFF] & 0x10) {
 
             if ((D_8013062C & 0x3F) != 0) {
                 sp27 = 0x1E;
@@ -3721,9 +3837,9 @@ void func_800F5550(u16 seqId) {
 
             D_8013062C = 0;
         } else {
-            nv = (D_80130658[(seqId & 0xFF) & 0xFF] & 0x40) ? 1 : 0xFF;
+            nv = (sSeqFlags[(seqId & 0xFF) & 0xFF] & 0x40) ? 1 : 0xFF;
             func_800F5E18(SEQ_PLAYER_BGM_MAIN, seqId, 0, 7, nv);
-            if (!(D_80130658[seqId] & 0x20)) {
+            if (!(sSeqFlags[seqId] & 0x20)) {
                 D_8013062C = 0xC0;
             }
         }
@@ -3737,7 +3853,7 @@ void func_800F56A8(void) {
 
     temp_v0 = func_800FA0B4(SEQ_PLAYER_BGM_MAIN);
     bvar = temp_v0 & 0xFF;
-    if ((temp_v0 != NA_BGM_DISABLED) && ((D_80130658[bvar] & 0x10) != 0)) {
+    if ((temp_v0 != NA_BGM_DISABLED) && (sSeqFlags[bvar] & 0x10)) {
         if (D_8013062C != 0xC0) {
             D_8013062C = gAudioContext.seqPlayers[SEQ_PLAYER_BGM_MAIN].soundScriptIO[3];
         } else {
@@ -3770,9 +3886,9 @@ void func_800F5918(void) {
 void func_800F595C(u16 arg0) {
     u8 arg0b = arg0 & 0xFF;
 
-    if (D_80130658[arg0b] & 2) {
+    if (sSeqFlags[arg0b] & 2) {
         Audio_PlayFanfare(arg0);
-    } else if (D_80130658[arg0b] & 4) {
+    } else if (sSeqFlags[arg0b] & 4) {
         Audio_StartSeq(SEQ_PLAYER_FANFARE, 0, arg0);
 
     } else {
@@ -3784,9 +3900,9 @@ void func_800F595C(u16 arg0) {
 void func_800F59E8(u16 arg0) {
     u8 arg0b = arg0 & 0xFF;
 
-    if (D_80130658[arg0b] & 2) {
+    if (sSeqFlags[arg0b] & 2) {
         Audio_SeqCmd1(SEQ_PLAYER_FANFARE, 0);
-    } else if (D_80130658[arg0b] & 4) {
+    } else if (sSeqFlags[arg0b] & 4) {
         Audio_SeqCmd1(SEQ_PLAYER_FANFARE, 0);
     } else {
         Audio_SeqCmd1(SEQ_PLAYER_BGM_MAIN, 0);
@@ -3796,9 +3912,9 @@ void func_800F59E8(u16 arg0) {
 s32 func_800F5A58(u8 arg0) {
     u8 phi_a1 = 0;
 
-    if (D_80130658[arg0 & 0xFF] & 2) {
+    if (sSeqFlags[arg0 & 0xFF] & 2) {
         phi_a1 = 1;
-    } else if (D_80130658[arg0 & 0xFF] & 4) {
+    } else if (sSeqFlags[arg0 & 0xFF] & 4) {
         phi_a1 = 1;
     }
 
@@ -3814,7 +3930,7 @@ void func_800F5ACC(u16 seqId) {
 
     temp_v0 = func_800FA0B4(SEQ_PLAYER_BGM_MAIN);
     if ((temp_v0 & 0xFF) != NA_BGM_GANON_TOWER && (temp_v0 & 0xFF) != NA_BGM_ESCAPE && temp_v0 != seqId) {
-        func_800F5E90(3);
+        Audio_SetSequenceMode(SEQ_MODE_IGNORE);
         if (temp_v0 != NA_BGM_DISABLED) {
             D_80130628 = temp_v0;
         } else {
@@ -3826,7 +3942,7 @@ void func_800F5ACC(u16 seqId) {
 
 void func_800F5B58(void) {
     if ((func_800FA0B4(SEQ_PLAYER_BGM_MAIN) != NA_BGM_DISABLED) && (D_80130628 != NA_BGM_DISABLED) &&
-        (D_80130658[func_800FA0B4(SEQ_PLAYER_BGM_MAIN) & 0xFF] & 8)) {
+        (sSeqFlags[func_800FA0B4(SEQ_PLAYER_BGM_MAIN) & 0xFF] & 8)) {
         if (D_80130628 == NA_BGM_DISABLED) {
             Audio_SeqCmd1(SEQ_PLAYER_BGM_MAIN, 0);
         } else {
@@ -3908,77 +4024,83 @@ void func_800F5E18(u8 playerIdx, u16 seqId, u8 fadeTimer, s8 arg3, s8 arg4) {
     Audio_StartSeq(playerIdx, fadeTimer, seqId);
 }
 
-void func_800F5E90(u8 arg0) {
-    s32 phi_t0;
-    u16 phi_t1;
-    u8 phi_a3;
+void Audio_SetSequenceMode(u8 seqMode) {
+    s32 volumeFadeInTimer;
+    u16 seqId;
+    u8 volumeFadeOutTimer;
 
-    D_80130654 = arg0;
+    sSeqModeInput = seqMode;
     if (D_80130628 == NA_BGM_DISABLED) {
         if (sAudioCutsceneFlag) {
-            arg0 = 3;
+            seqMode = SEQ_MODE_IGNORE;
         }
-        phi_t1 = D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254;
-        if (phi_t1 == NA_BGM_FIELD_LOGIC && func_800FA0B4(SEQ_PLAYER_BGM_SUB) == (NA_BGM_ENEMY | 0x800)) {
-            arg0 = 3;
+
+        seqId = D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254;
+
+        if (seqId == NA_BGM_FIELD_LOGIC && func_800FA0B4(SEQ_PLAYER_BGM_SUB) == (NA_BGM_ENEMY | 0x800)) {
+            seqMode = SEQ_MODE_IGNORE;
         }
 
-        phi_a3 = phi_t1 & 0xFF;
-        if ((phi_t1 == NA_BGM_DISABLED) || ((D_80130658[phi_a3] & 1) != 0) || ((D_8013061C & 0x7F) == 1)) {
-            if (arg0 != (D_8013061C & 0x7F)) {
-                if (arg0 == 1) {
+        if ((seqId == NA_BGM_DISABLED) || (sSeqFlags[(u8)(seqId & 0xFF)] & 1) ||
+            ((sPrevSeqMode & 0x7F) == SEQ_MODE_ENEMY)) {
+            if (seqMode != (sPrevSeqMode & 0x7F)) {
+                if (seqMode == SEQ_MODE_ENEMY) {
+                    // Start playing enemy bgm
                     if (D_8016E750[SEQ_PLAYER_BGM_SUB].volScales[1] - sAudioEnemyVol < 0) {
-                        phi_t0 = -(D_8016E750[SEQ_PLAYER_BGM_SUB].volScales[1] - sAudioEnemyVol);
+                        volumeFadeInTimer = -(D_8016E750[SEQ_PLAYER_BGM_SUB].volScales[1] - sAudioEnemyVol);
                     } else {
-                        phi_t0 = D_8016E750[SEQ_PLAYER_BGM_SUB].volScales[1] - sAudioEnemyVol;
+                        volumeFadeInTimer = D_8016E750[SEQ_PLAYER_BGM_SUB].volScales[1] - sAudioEnemyVol;
                     }
-                    Audio_SetVolScale(SEQ_PLAYER_BGM_SUB, 3, sAudioEnemyVol, phi_t0);
+
+                    Audio_SetVolScale(SEQ_PLAYER_BGM_SUB, 3, sAudioEnemyVol, volumeFadeInTimer);
                     Audio_StartSeq(SEQ_PLAYER_BGM_SUB, 10, NA_BGM_ENEMY | 0x800);
-                    if (phi_t1 != NA_BGM_NATURE_AMBIENCE) {
+
+                    if (seqId != NA_BGM_NATURE_AMBIENCE) {
                         Audio_SetVolScale(SEQ_PLAYER_BGM_MAIN, 3, (0x7F - sAudioEnemyVol) & 0xFF, 0xA);
-                        func_800F510C(sAudioEnemyVol);
+                        Audio_SplitBgmChannels(sAudioEnemyVol);
                     }
-                } else {
-                    if ((D_8013061C & 0x7F) == 1) {
-                        Audio_SeqCmd1(SEQ_PLAYER_BGM_SUB, 10);
-                        if (arg0 == 3) {
-                            phi_a3 = 0;
-                        } else {
-                            phi_a3 = 10;
-                        }
-
-                        Audio_SetVolScale(SEQ_PLAYER_BGM_MAIN, 3, 0x7F, phi_a3);
-                        func_800F510C(0);
+                } else if ((sPrevSeqMode & 0x7F) == SEQ_MODE_ENEMY) {
+                    // Stop playing enemy bgm
+                    Audio_SeqCmd1(SEQ_PLAYER_BGM_SUB, 10);
+                    if (seqMode == SEQ_MODE_IGNORE) {
+                        volumeFadeOutTimer = 0;
+                    } else {
+                        volumeFadeOutTimer = 10;
                     }
+
+                    Audio_SetVolScale(SEQ_PLAYER_BGM_MAIN, 3, 0x7F, volumeFadeOutTimer);
+                    Audio_SplitBgmChannels(0);
                 }
 
-                D_8013061C = arg0 + 0x80;
+                sPrevSeqMode = seqMode + 0x80;
             }
         } else {
-            if (arg0 == 0) {
-                if (D_8013061C == 2) {
-                    D_80130638 = 0;
+            // Hyrule Field will play slightly different bgm music depending on whether player is standing
+            // still or moving. This is the logic to determine the transition between those two states
+            if (seqMode == SEQ_MODE_DEFAULT) {
+                if (sPrevSeqMode == SEQ_MODE_STILL) {
+                    sNumFramesMoving = 0;
                 }
-                D_80130634 = 0;
-                D_80130638++;
+                sNumFramesStill = 0;
+                sNumFramesMoving++;
             } else {
-                D_80130634++;
+                sNumFramesStill++;
             }
 
-            if (arg0 == 2 && D_80130634 < 0x1E && D_80130638 >= 0x15) {
-                arg0 = 0;
+            if (seqMode == SEQ_MODE_STILL && sNumFramesStill < 30 && sNumFramesMoving > 20) {
+                seqMode = SEQ_MODE_DEFAULT;
             }
 
-            D_8013061C = arg0;
-            Audio_SeqCmd7(SEQ_PLAYER_BGM_MAIN, 2, arg0);
+            sPrevSeqMode = seqMode;
+            Audio_SeqCmd7(SEQ_PLAYER_BGM_MAIN, 2, seqMode);
         }
     }
 }
 
-void func_800F6114(f32 dist) {
+void Audio_SetBgmEnemyVolume(f32 dist) {
     f32 adjDist;
 
-    if (D_8013061C == 0x81) {
+    if (sPrevSeqMode == (0x80 | SEQ_MODE_ENEMY)) {
         if (dist != sAudioEnemyDist) {
             if (dist < 150.0f) {
                 adjDist = 0.0f;
@@ -3989,13 +4111,13 @@ void func_800F6114(f32 dist) {
             }
 
             sAudioEnemyVol = ((350.0f - adjDist) * 127.0f) / 350.0f;
-            Audio_SetVolScale(SEQ_PLAYER_BGM_SUB, 3, sAudioEnemyVol, 0xA);
+            Audio_SetVolScale(SEQ_PLAYER_BGM_SUB, 3, sAudioEnemyVol, 10);
             if (D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254 != NA_BGM_NATURE_AMBIENCE) {
-                Audio_SetVolScale(SEQ_PLAYER_BGM_MAIN, 3, (0x7F - sAudioEnemyVol), 0xA);
+                Audio_SetVolScale(SEQ_PLAYER_BGM_MAIN, 3, (0x7F - sAudioEnemyVol), 10);
             }
         }
         if (D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254 != NA_BGM_NATURE_AMBIENCE) {
-            func_800F510C(sAudioEnemyVol);
+            Audio_SplitBgmChannels(sAudioEnemyVol);
         }
     }
     sAudioEnemyDist = dist;
@@ -4241,7 +4363,7 @@ void Audio_PreNMI(void) {
 }
 
 void func_800F6C34(void) {
-    D_8013061C = 0;
+    sPrevSeqMode = 0;
     D_8016B7A8 = 1.0f;
     D_8016B7B0 = 1.0f;
     sAudioBaseFilter = 0;
@@ -4336,7 +4458,7 @@ void func_800F6FB4(u8 arg0) {
     u8 b2;
 
     if ((D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254 == NA_BGM_DISABLED) ||
-        ((D_80130658[((u8)D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254) & 0xFF] & 0x80) == 0)) {
+        !(sSeqFlags[((u8)D_8016E750[SEQ_PLAYER_BGM_MAIN].unk_254) & 0xFF] & 0x80)) {
         func_800F6E7C(D_801306DC[arg0].unk_00, D_801306DC[arg0].unk_02);
         while ((D_801306DC[arg0].unk_04[i] != 0xFF) && (i < 100)) {
             // Probably a fake match, using Audio_SeqCmd8 doesn't work.
diff --git a/src/code/code_800F9280.c b/src/code/code_800F9280.c
index e6dd4b67d..36857b0de 100644
--- a/src/code/code_800F9280.c
+++ b/src/code/code_800F9280.c
@@ -391,14 +391,14 @@ void func_800FA174(u8 playerIdx) {
     D_8016E348[playerIdx] = 0;
 }
 
-void func_800FA18C(u8 playeridx, u8 arg1) {
+void func_800FA18C(u8 playerIdx, u8 arg1) {
     u8 i;
 
-    for (i = 0; i < D_8016E750[playeridx].unk_4D; i++) {
-        u8 unkb = (D_8016E750[playeridx].unk_2C[i] & 0xF00000) >> 20;
+    for (i = 0; i < D_8016E750[playerIdx].unk_4D; i++) {
+        u8 unkb = (D_8016E750[playerIdx].unk_2C[i] & 0xF00000) >> 20;
 
         if (unkb == arg1) {
-            D_8016E750[playeridx].unk_2C[i] = 0xFF000000;
+            D_8016E750[playerIdx].unk_2C[i] = 0xFF000000;
         }
     }
 }
diff --git a/src/code/z_actor.c b/src/code/z_actor.c
index 0318e51f0..5d5f86f1a 100644
--- a/src/code/z_actor.c
+++ b/src/code/z_actor.c
@@ -286,7 +286,7 @@ void func_8002C0C0(TargetContext* targetCtx, Actor* actor, GlobalContext* global
     targetCtx->targetedActor = NULL;
     targetCtx->unk_40 = 0.0f;
     targetCtx->unk_8C = NULL;
-    targetCtx->unk_90 = NULL;
+    targetCtx->bgmEnemy = NULL;
     targetCtx->unk_4B = 0;
     targetCtx->unk_4C = 0;
     func_8002BF60(targetCtx, actor, actor->category, globalCtx);
@@ -2836,8 +2836,8 @@ Actor* Actor_Delete(ActorContext* actorCtx, Actor* actor, GlobalContext* globalC
         actorCtx->targetCtx.unk_8C = NULL;
     }
 
-    if (actor == actorCtx->targetCtx.unk_90) {
-        actorCtx->targetCtx.unk_90 = NULL;
+    if (actor == actorCtx->targetCtx.bgmEnemy) {
+        actorCtx->targetCtx.bgmEnemy = NULL;
     }
 
     Audio_StopSfxByPos(&actor->projectedPos);
@@ -2873,7 +2873,7 @@ s32 func_80032880(GlobalContext* globalCtx, Actor* actor) {
 Actor* D_8015BBE8;
 Actor* D_8015BBEC;
 f32 D_8015BBF0;
-f32 D_8015BBF4;
+f32 sbgmEnemyDistSq;
 s32 D_8015BBF8;
 s16 D_8015BBFC;
 
@@ -2890,10 +2890,13 @@ void func_800328D4(GlobalContext* globalCtx, ActorContext* actorCtx, Player* pla
 
     while (actor != NULL) {
         if ((actor->update != NULL) && ((Player*)actor != player) && ((actor->flags & 1) == 1)) {
+
+            // This block below is for determining the closest actor to player in determining the volume
+            // used while playing enemy bgm music
             if ((actorCategory == ACTORCAT_ENEMY) && ((actor->flags & 5) == 5) &&
-                (actor->xyzDistToPlayerSq < 250000.0f) && (actor->xyzDistToPlayerSq < D_8015BBF4)) {
-                actorCtx->targetCtx.unk_90 = actor;
-                D_8015BBF4 = actor->xyzDistToPlayerSq;
+                (actor->xyzDistToPlayerSq < SQ(500.0f)) && (actor->xyzDistToPlayerSq < sbgmEnemyDistSq)) {
+                actorCtx->targetCtx.bgmEnemy = actor;
+                sbgmEnemyDistSq = actor->xyzDistToPlayerSq;
             }
 
             if (actor != sp84) {
@@ -2929,13 +2932,13 @@ Actor* func_80032AF0(GlobalContext* globalCtx, ActorContext* actorCtx, Actor** a
     u8* entry;
 
     D_8015BBE8 = D_8015BBEC = NULL;
-    D_8015BBF0 = D_8015BBF4 = FLT_MAX;
+    D_8015BBF0 = sbgmEnemyDistSq = FLT_MAX;
     D_8015BBF8 = 0x7FFFFFFF;
 
     if (!Player_InCsMode(globalCtx)) {
         entry = &D_801160A0[0];
 
-        actorCtx->targetCtx.unk_90 = NULL;
+        actorCtx->targetCtx.bgmEnemy = NULL;
         D_8015BBFC = player->actor.shape.rot.y;
 
         for (i = 0; i < 3; i++) {