From 2ae14b75de84c27736aec633d12c0d31f0d78e6b Mon Sep 17 00:00:00 2001
From: negativeExponent <negativeExponent@users.noreply.github.com>
Date: Sun, 25 Oct 2020 13:58:06 +0800
Subject: [PATCH] APU: Move duty cycle swapping during apu writes

---
 src/sound.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/sound.c b/src/sound.c
index 40973c2..a3f331b 100644
--- a/src/sound.c
+++ b/src/sound.c
@@ -195,6 +195,8 @@ static DECLFW(Write_PSG) {
 		DoSQ1();
 		EnvUnits[0].Mode = (V & 0x30) >> 4;
 		EnvUnits[0].Speed = (V & 0xF);
+		if (swapDuty)
+			V = (V & 0x3F) | ((V & 0x80) >> 1) | ((V & 0x40) << 1);
 		break;
 	case 0x1:
 		DoSQ1();
@@ -214,6 +216,8 @@ static DECLFW(Write_PSG) {
 		DoSQ2();
 		EnvUnits[1].Mode = (V & 0x30) >> 4;
 		EnvUnits[1].Speed = (V & 0xF);
+		if (swapDuty)
+			V = (V & 0x3F) | ((V & 0x80) >> 1) | ((V & 0x40) << 1);
 		break;
 	case 0x5:
 		DoSQ2();
@@ -561,8 +565,6 @@ static INLINE void RDoSQ(int x) {
 
 		amp <<= 24;
 		dutyCycle = (PSG[(x << 2)] & 0xC0) >> 6;
-		if (swapDuty)
-			dutyCycle = ((dutyCycle & 2) >> 1) | ((dutyCycle & 1) << 1);
 		rthresh = RectDuties[dutyCycle];
 		currdc = RectDutyCount[x];
 		D = &WaveHi[ChannelBC[x]];
@@ -640,8 +642,6 @@ static void RDoSQLQ(void) {
 		if (!inie[x]) amp[x] = 0;	/* Correct? Buzzing in MM2, others otherwise... */
 
 		dutyCycle = (PSG[(x << 2)] & 0xC0) >> 6;
-		if (swapDuty)
-			dutyCycle = ((dutyCycle & 2) >> 1) | ((dutyCycle & 1) << 1);
 		rthresh[x] = RectDuties[dutyCycle];
 
 		for (y = 0; y < 8; y++) {