Add comment about audio engine perfect pitch bug (#451)

Co-authored-by: preeyan <preeyan>
pret · May 23, 2024 · d38cf52 · d38cf52
1 parent 5f7b444
commit d38cf52
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Showing 3 changed files with 6 additions and 3 deletions.
diff --git a/audio/engine_1.asm b/audio/engine_1.asm
@@ -831,7 +831,8 @@ Audio1_note_pitch:
 	bit BIT_PERFECT_PITCH, [hl] ; has toggle_perfect_pitch been used?
 	jr z, .skipFrequencyInc
 	inc e                       ; if yes, increment the frequency by 1
-	jr nc, .skipFrequencyInc
+	jr nc, .skipFrequencyInc    ; Likely a mistake, because `inc` does not set flag C.
+	                            ; Fortunately this does not seem to affect any notes that actually occur.
 	inc d
 .skipFrequencyInc
 	ld hl, wChannelFrequencyLowBytes

diff --git a/audio/engine_2.asm b/audio/engine_2.asm
@@ -842,7 +842,8 @@ Audio2_note_pitch:
 	bit BIT_PERFECT_PITCH, [hl] ; has toggle_perfect_pitch been used?
 	jr z, .skipFrequencyInc
 	inc e                       ; if yes, increment the frequency by 1
-	jr nc, .skipFrequencyInc
+	jr nc, .skipFrequencyInc    ; Likely a mistake, because `inc` does not set flag C.
+	                            ; Fortunately this does not seem to affect any notes that actually occur.
 	inc d
 .skipFrequencyInc
 	ld hl, wChannelFrequencyLowBytes

diff --git a/audio/engine_3.asm b/audio/engine_3.asm
@@ -831,7 +831,8 @@ Audio3_note_pitch:
 	bit BIT_PERFECT_PITCH, [hl] ; has toggle_perfect_pitch been used?
 	jr z, .skipFrequencyInc
 	inc e                       ; if yes, increment the frequency by 1
-	jr nc, .skipFrequencyInc
+	jr nc, .skipFrequencyInc    ; Likely a mistake, because `inc` does not set flag C.
+	                            ; Fortunately this does not seem to affect any notes that actually occur.
 	inc d
 .skipFrequencyInc
 	ld hl, wChannelFrequencyLowBytes