From 667526e4141111340f7ee7870b8ae7f10cac2a05 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Sun, 19 Dec 2021 00:27:04 -0500
Subject: [PATCH] further improve the accuracy of 03xx

---
 src/engine/engine.h     |  5 +++--
 src/engine/playback.cpp | 11 ++++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/engine/engine.h b/src/engine/engine.h
index 1a2da9ef9..502b61e8e 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -29,7 +29,7 @@ struct DivChannelState {
   int vibratoDepth, vibratoRate, vibratoPos, vibratoDir, vibratoFine;
   int tremoloDepth, tremoloRate, tremoloPos;
   unsigned char arp, arpStage, arpTicks;
-  bool doNote, legato, portaStop, keyOn, nowYouCanStop, stopOnOff, arpYield, delayLocked;
+  bool doNote, legato, portaStop, keyOn, nowYouCanStop, stopOnOff, arpYield, delayLocked, inPorta;
 
   DivChannelState():
     note(-1),
@@ -62,7 +62,8 @@ struct DivChannelState {
     nowYouCanStop(true),
     stopOnOff(false),
     arpYield(false),
-    delayLocked(false) {}
+    delayLocked(false),
+    inPorta(false) {}
 };
 
 class DivEngine {
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 8f4cfe9f3..139211738 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -403,6 +403,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         if (effectVal==0) {
           chan[i].portaNote=-1;
           chan[i].portaSpeed=-1;
+          chan[i].inPorta=false;
         } else {
           chan[i].portaNote=0x60;
           chan[i].portaSpeed=effectVal;
@@ -415,6 +416,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         if (effectVal==0) {
           chan[i].portaNote=-1;
           chan[i].portaSpeed=-1;
+          chan[i].inPorta=false;
         } else {
           chan[i].portaNote=0x00;
           chan[i].portaSpeed=effectVal;
@@ -427,17 +429,19 @@ void DivEngine::processRow(int i, bool afterDelay) {
         if (effectVal==0) {
           chan[i].portaNote=-1;
           chan[i].portaSpeed=-1;
+          chan[i].inPorta=false;
           dispatchCmd(DivCommand(DIV_CMD_PRE_PORTA,i,false));
         } else {
-          if (chan[i].note==chan[i].oldNote) {
+          if (chan[i].note==chan[i].oldNote && !chan[i].inPorta) {
             chan[i].portaNote=chan[i].note;
-            chan[i].portaSpeed=0;
+            chan[i].portaSpeed=-1;
           } else {
             chan[i].portaNote=chan[i].note;
             chan[i].portaSpeed=effectVal;
+            chan[i].inPorta=true;
           }
           chan[i].portaStop=true;
-          chan[i].doNote=false;
+          if (chan[i].keyOn) chan[i].doNote=false;
           chan[i].stopOnOff=true;
           dispatchCmd(DivCommand(DIV_CMD_PRE_PORTA,i,true));
         }
@@ -735,6 +739,7 @@ bool DivEngine::nextTick() {
         chan[i].portaSpeed=0;
         chan[i].oldNote=chan[i].note;
         chan[i].note=chan[i].portaNote;
+        chan[i].inPorta=false;
         dispatchCmd(DivCommand(DIV_CMD_LEGATO,i,chan[i].note));
       }
     }