From 7bbfe3af7c8cab34ca65d9416e5dd0cedebc7d1e Mon Sep 17 00:00:00 2001
From: cam900 <dbtlrchl@naver.com>
Date: Tue, 7 Jun 2022 23:59:50 +0900
Subject: [PATCH] Fix per-channel osc

---
 src/engine/platform/sms.cpp           | 24 ++++++++++++++----------
 src/engine/platform/sound/sn76496.cpp |  2 +-
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/engine/platform/sms.cpp b/src/engine/platform/sms.cpp
index e5be23045..35bb9c40c 100644
--- a/src/engine/platform/sms.cpp
+++ b/src/engine/platform/sms.cpp
@@ -101,7 +101,20 @@ void DivPlatformSMS::acquire_mame(short* bufL, short* bufR, size_t start, size_t
       sn->write(w.val);
     writes.pop();
   }
-  sn->sound_stream_update(snBuf,len);
+  for (size_t h=0; h<len; h++) {
+    short* outs[2]={
+      &snBuf[0][h],
+      &snBuf[1][h],
+    };
+    sn->sound_stream_update(outs,1);
+    for (int i=0; i<4; i++) {
+      if (isMuted[i]) {
+        oscBuf[i]->data[oscBuf[i]->needle++]=0;
+      } else {
+        oscBuf[i]->data[oscBuf[i]->needle++]=sn->get_channel_output(i);
+      }
+    }
+  }
   if (stereo) {
     for (size_t i=0; i<len; i++) {
       bufL[i+start]=snBuf[0][i];
@@ -113,15 +126,6 @@ void DivPlatformSMS::acquire_mame(short* bufL, short* bufR, size_t start, size_t
       bufR[i+start]=bufL[i+start];
     }
   }
-  for (size_t h=start; h<start+len; h++) {
-    for (int i=0; i<4; i++) {
-      if (isMuted[i]) {
-        oscBuf[i]->data[oscBuf[i]->needle++]=0;
-      } else {
-        oscBuf[i]->data[oscBuf[i]->needle++]=sn->get_channel_output(i);
-      }
-    }
-  }
 }
 
 void DivPlatformSMS::acquire(short* bufL, short* bufR, size_t start, size_t len) {
diff --git a/src/engine/platform/sound/sn76496.cpp b/src/engine/platform/sound/sn76496.cpp
index afb82ad3a..4bbb5848a 100644
--- a/src/engine/platform/sound/sn76496.cpp
+++ b/src/engine/platform/sound/sn76496.cpp
@@ -411,7 +411,7 @@ void sn76496_base_device::sound_stream_update(short** outputs, int outLen)
 		if (m_negate) { out = -out; out2 = -out2; }
 
 		outputs[0][sampindex]=out;
-		if (m_stereo)
+		if (m_stereo && (outputs[1] != nullptr))
 			outputs[1][sampindex]=out;
 	}
 }