From f0f0b7fcd6e43749965251a723a44c552e77e6ad Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Wed, 17 Jul 2024 04:11:24 -0500
Subject: [PATCH] implement DCxx effect

delayed mute
---
 src/engine/engine.cpp     |  2 ++
 src/engine/engine.h       |  3 ++-
 src/engine/fileOps/xm.cpp | 18 +++++++++++++++++-
 src/engine/playback.cpp   | 15 +++++++++++++++
 src/gui/guiConst.cpp      |  2 +-
 5 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 7ca58611b..6efaddd16 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -98,6 +98,8 @@ const char* DivEngine::getEffectDesc(unsigned char effect, int chan, bool notNul
       break;
     case 0xc0: case 0xc1: case 0xc2: case 0xc3:
       return _("Cxxx: Set tick rate (hz)");
+    case 0xdc:
+      return _("DCxx: Delayed mute");
     case 0xe0:
       return _("E0xx: Set arp speed");
     case 0xe1:
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 288f1af2b..8ef789704 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -133,7 +133,7 @@ struct DivAudioExportOptions {
 struct DivChannelState {
   std::vector<DivDelayedCommand> delayed;
   int note, oldNote, lastIns, pitch, portaSpeed, portaNote;
-  int volume, volSpeed, cut, legatoDelay, legatoTarget, rowDelay, volMax;
+  int volume, volSpeed, cut, volCut, legatoDelay, legatoTarget, rowDelay, volMax;
   int delayOrder, delayRow, retrigSpeed, retrigTick;
   int vibratoDepth, vibratoRate, vibratoPos, vibratoPosGiant, vibratoShape, vibratoFine;
   int tremoloDepth, tremoloRate, tremoloPos;
@@ -158,6 +158,7 @@ struct DivChannelState {
     volume(0x7f00),
     volSpeed(0),
     cut(-1),
+    volCut(-1),
     legatoDelay(-1),
     legatoTarget(0),
     rowDelay(0),
diff --git a/src/engine/fileOps/xm.cpp b/src/engine/fileOps/xm.cpp
index d4b7c6ca0..0d616968b 100644
--- a/src/engine/fileOps/xm.cpp
+++ b/src/engine/fileOps/xm.cpp
@@ -1077,8 +1077,24 @@ bool DivEngine::loadXM(unsigned char* file, size_t len) {
                     p->data[j][effectCol[k]++]=0x0c;
                     p->data[j][effectCol[k]++]=(effectVal&15);
                     break;
+                  case 0xa: // vol slide up (fine)
+                    volSlideStatus[k]=((effectVal&15)<<4)|0xf;
+                    volSlideStatusChanged[k]=true;
+                    if (hasNote || hasIns) {
+                      volSlideStatusChanged[k]=true;
+                    }
+                    volSliding[k]=true;
+                    break;
+                  case 0xb: // vol slide down (fine)
+                    volSlideStatus[k]=0xf0|(effectVal&15);
+                    volSlideStatusChanged[k]=true;
+                    if (hasNote || hasIns) {
+                      volSlideStatusChanged[k]=true;
+                    }
+                    volSliding[k]=true;
+                    break;
                   case 0xc:
-                    p->data[j][effectCol[k]++]=0xec;
+                    p->data[j][effectCol[k]++]=0xdc;
                     p->data[j][effectCol[k]++]=MAX(1,effectVal&15);
                     break;
                   case 0xd:
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index efa0959fb..b7b8098b6 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -932,6 +932,12 @@ void DivEngine::processRow(int i, bool afterDelay) {
         clockDrift=0;
         subticks=0;
         break;
+      case 0xdc: // delayed mute
+        if (effectVal>0 && (song.delayBehavior==2 || effectVal<nextSpeed)) {
+          chan[i].volCut=effectVal+1;
+          chan[i].cutType=0;
+        }
+        break;
       case 0xe0: // arp speed
         if (effectVal>0) {
           curSubSong->arpLen=effectVal;
@@ -1781,6 +1787,15 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
           }
         }
 
+        // volume cut/mute
+        if (chan[i].volCut>0) {
+          if (--chan[i].volCut<1) {
+            chan[i].volume=0;
+            dispatchCmd(DivCommand(DIV_CMD_VOLUME,i,chan[i].volume>>8));
+            dispatchCmd(DivCommand(DIV_CMD_HINT_VOLUME,i,chan[i].volume>>8));
+          }
+        }
+
         // arpeggio
         if (chan[i].resetArp) {
           dispatchCmd(DivCommand(DIV_CMD_LEGATO,i,chan[i].note));
diff --git a/src/gui/guiConst.cpp b/src/gui/guiConst.cpp
index ca7a26b44..2595827b0 100644
--- a/src/gui/guiConst.cpp
+++ b/src/gui/guiConst.cpp
@@ -482,7 +482,7 @@ const FurnaceGUIColors fxColors[256]={
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
-  GUI_COLOR_PATTERN_EFFECT_INVALID,
+  GUI_COLOR_PATTERN_EFFECT_VOLUME, // DC
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_INVALID,
   GUI_COLOR_PATTERN_EFFECT_MISC, // DF