From 91621fe0f59211fab31f73d6566fedb2a0c78123 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Sat, 4 Jun 2022 01:03:58 -0500
Subject: [PATCH] YM2612: DualPCM per-channel osc

fixes #516
---
 src/engine/platform/genesis.cpp | 21 +++++++++++++++++----
 src/engine/platform/genesis.h   |  4 +++-
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/engine/platform/genesis.cpp b/src/engine/platform/genesis.cpp
index 0d18ddf47..683fa3b2a 100644
--- a/src/engine/platform/genesis.cpp
+++ b/src/engine/platform/genesis.cpp
@@ -147,10 +147,13 @@ void DivPlatformGenesis::processDAC() {
           DivSample* s=parent->getSample(chan[i].dacSample);
           if (!isMuted[i] && s->samples>0) {
             if (parent->song.noOPN2Vol) {
-              sample+=s->data8[chan[i].dacDirection?(s->samples-chan[i].dacPos-1):chan[i].dacPos];
+              chan[i].dacOutput=s->data8[chan[i].dacDirection?(s->samples-chan[i].dacPos-1):chan[i].dacPos];
             } else {
-              sample+=(s->data8[chan[i].dacDirection?(s->samples-chan[i].dacPos-1):chan[i].dacPos]*dacVolTable[chan[i].outVol])>>7;
+              chan[i].dacOutput=(s->data8[chan[i].dacDirection?(s->samples-chan[i].dacPos-1):chan[i].dacPos]*dacVolTable[chan[i].outVol])>>7;
             }
+            sample+=chan[i].dacOutput;
+          } else {
+            chan[i].dacOutput=0;
           }
           chan[i].dacPeriod+=chan[i].dacRate;
           if (chan[i].dacPeriod>=(chipClock/576)) {
@@ -254,7 +257,12 @@ void DivPlatformGenesis::acquire_nuked(short* bufL, short* bufR, size_t start, s
       //OPN2_Write(&fm,0,0);
       if (i==5) {
         if (fm.dacen) {
-          oscBuf[i]->data[oscBuf[i]->needle++]=fm.dacdata<<7;
+          if (softPCM) {
+            oscBuf[5]->data[oscBuf[5]->needle++]=chan[5].dacOutput<<7;
+            oscBuf[6]->data[oscBuf[6]->needle++]=chan[6].dacOutput<<7;
+          } else {
+            oscBuf[i]->data[oscBuf[i]->needle++]=fm.dacdata<<7;
+          }
         } else {
           oscBuf[i]->data[oscBuf[i]->needle++]=fm.ch_out[i]<<7;
         }
@@ -306,7 +314,12 @@ void DivPlatformGenesis::acquire_ymfm(short* bufL, short* bufR, size_t start, si
     for (int i=0; i<6; i++) {
       if (i==5) {
         if (fm_ymfm->debug_dac_enable()) {
-          oscBuf[i]->data[oscBuf[i]->needle++]=fm_ymfm->debug_dac_data()<<7;
+          if (softPCM) {
+            oscBuf[5]->data[oscBuf[5]->needle++]=chan[5].dacOutput<<7;
+            oscBuf[6]->data[oscBuf[6]->needle++]=chan[6].dacOutput<<7;
+          } else {
+            oscBuf[i]->data[oscBuf[i]->needle++]=fm_ymfm->debug_dac_data()<<7;
+          }
         } else {
           oscBuf[i]->data[oscBuf[i]->needle++]=(fme->debug_channel(i)->debug_output(0)+fme->debug_channel(i)->debug_output(1))<<6;
         }
diff --git a/src/engine/platform/genesis.h b/src/engine/platform/genesis.h
index b4862427d..26c6c58b3 100644
--- a/src/engine/platform/genesis.h
+++ b/src/engine/platform/genesis.h
@@ -51,6 +51,7 @@ class DivPlatformGenesis: public DivDispatch {
       bool dacReady;
       bool dacDirection;
       unsigned char sampleBank;
+      signed char dacOutput;
       void macroInit(DivInstrument* which) {
         std.init(which);
         pitch2=0;
@@ -85,7 +86,8 @@ class DivPlatformGenesis: public DivDispatch {
         dacDelay(0),
         dacReady(true),
         dacDirection(false),
-        sampleBank(0) {}
+        sampleBank(0),
+        dacOutput(0) {}
     };
     Channel chan[10];
     DivDispatchOscBuffer* oscBuf[10];