From ad000bc0c0592899eb7e6ad112451cf36cfb0486 Mon Sep 17 00:00:00 2001
From: Adam Lederer <adam@adamlederer.com>
Date: Fri, 6 Sep 2024 16:27:51 -0700
Subject: [PATCH] fix: volume portamento no longer cancels set vol

in case where volume portamento was active but not complete, using the volume column to set volume to a point past the volume portamento target would be detected as "volume portamento complete" and set volume to the portamento target, even if the portamento target was actually lower/higher than the volume set by the volume command
---
 src/engine/cmdStream.cpp | 7 ++++++-
 src/engine/playback.cpp  | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/engine/cmdStream.cpp b/src/engine/cmdStream.cpp
index 40542ef98..f1b267869 100644
--- a/src/engine/cmdStream.cpp
+++ b/src/engine/cmdStream.cpp
@@ -364,6 +364,7 @@ bool DivCSPlayer::tick() {
     }
 
     if (sendVolume || chan[i].volSpeed!=0) {
+      int preSpeedVol=chan[i].volume;
       chan[i].volume+=chan[i].volSpeed;
       if (chan[i].volSpeedTarget!=-1) {
         bool atTarget=false;
@@ -377,7 +378,11 @@ bool DivCSPlayer::tick() {
         }
 
         if (atTarget) {
-          chan[i].volume=chan[i].volSpeedTarget;
+          if (chan[i].volSpeed>0) {
+            chan[i].volume=MAX(preSpeedVol,chan[i].volSpeedTarget);
+          } else if (chan[i].volSpeed<0) {
+            chan[i].volume=MIN(preSpeedVol,chan[i].volSpeedTarget);
+          }
           chan[i].volSpeed=0;
           chan[i].volSpeedTarget=-1;
         }
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index c1e14109e..2dcb838fb 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -1648,6 +1648,7 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
         if (!song.noSlidesOnFirstTick || !firstTick) {
           if (chan[i].volSpeed!=0) {
             chan[i].volume=(chan[i].volume&0xff)|(dispatchCmd(DivCommand(DIV_CMD_GET_VOLUME,i))<<8);
+            int preSpeedVol=chan[i].volume;
             chan[i].volume+=chan[i].volSpeed;
             if (chan[i].volSpeedTarget!=-1) {
               bool atTarget=false;
@@ -1661,7 +1662,11 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
               }
 
               if (atTarget) {
-                chan[i].volume=chan[i].volSpeedTarget;
+                if (chan[i].volSpeed>0) {
+                  chan[i].volume=MAX(preSpeedVol,chan[i].volSpeedTarget);
+                } else if (chan[i].volSpeed<0) {
+                  chan[i].volume=MIN(preSpeedVol,chan[i].volSpeedTarget);
+                }
                 chan[i].volSpeed=0;
                 chan[i].volSpeedTarget=-1;
                 dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));