From 1099c79ec89708d4da614664b7486bcd2010cb74 Mon Sep 17 00:00:00 2001
From: yohannd1 <mitonanan12@gmail.com>
Date: Sun, 28 Sep 2025 12:43:47 -0300
Subject: [PATCH] channel drag copy: initial impl

---
 src/engine/engine.cpp | 35 ++++++++++++++++++++++++++++++++++-
 src/engine/engine.h   |  4 ++++
 src/gui/channels.cpp  |  9 ++++++---
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 065d0b426..10f33cd33 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -603,10 +603,33 @@ void DivEngine::createNewFromDefaults() {
   BUSY_END;
 }
 
+void DivEngine::copyChannel(int src, int dest) {
+  logV("copying channel %d to %d",src,dest);
+  if (src==dest) {
+    logV("not copying because it's the same channel!");
+    return;
+  }
+
+  for (int i=0; i<DIV_MAX_PATTERNS; i++) {
+    curOrders->ord[dest][i]=curOrders->ord[src][i];
+    if (curPat[src].data[i]!=NULL && curPat[dest].data[i]!=NULL) {
+      curPat[src].data[i]->copyOn(curPat[dest].data[i]);
+    }
+  }
+
+  curPat[dest].effectCols=curPat[src].effectCols;
+
+  curSubSong->chanName[dest]=curSubSong->chanName[src];
+  curSubSong->chanShortName[dest]=curSubSong->chanShortName[src];
+  curSubSong->chanShow[dest]=curSubSong->chanShow[src];
+  curSubSong->chanShowChanOsc[dest]=curSubSong->chanShowChanOsc[src];
+  curSubSong->chanCollapse[dest]=curSubSong->chanCollapse[src];
+}
+
 void DivEngine::swapChannels(int src, int dest) {
   logV("swapping channel %d with %d",src,dest);
   if (src==dest) {
-    logV("not swapping channels because it's the same channel!",src,dest);
+    logV("not swapping channels because it's the same channel!");
     return;
   }
 
@@ -746,6 +769,16 @@ void DivEngine::checkAssetDir(std::vector<DivAssetDir>& dir, size_t entries) {
   delete[] inAssetDir;
 }
 
+void DivEngine::copyChannelP(int src, int dest) {
+  if (src<0 || src>=chans) return;
+  if (dest<0 || dest>=chans) return;
+  BUSY_BEGIN;
+  saveLock.lock();
+  copyChannel(src,dest);
+  saveLock.unlock();
+  BUSY_END;
+}
+
 void DivEngine::swapChannelsP(int src, int dest) {
   if (src<0 || src>=chans) return;
   if (dest<0 || dest>=chans) return;
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 48e53fcbd..a0e181c5d 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -649,6 +649,7 @@ class DivEngine {
   void exchangeWave(int one, int two);
   void exchangeSample(int one, int two);
 
+  void copyChannel(int src, int dest);
   void swapChannels(int src, int dest);
   void stompChannel(int ch);
 
@@ -1262,6 +1263,9 @@ class DivEngine {
     // >=0: render specific sample
     void renderSamplesP(int whichSample=-1);
 
+    // public copy channel
+    void copyChannelP(int src, int dest);
+
     // public swap channels
     void swapChannelsP(int src, int dest);
 
diff --git a/src/gui/channels.cpp b/src/gui/channels.cpp
index 6ac636a03..0b4ced5ac 100644
--- a/src/gui/channels.cpp
+++ b/src/gui/channels.cpp
@@ -50,7 +50,7 @@ void FurnaceGUI::drawChannels() {
       ImGui::TableNextColumn();
       ImGui::Text(_("Osc"));
       ImGui::TableNextColumn();
-      ImGui::Text(_("Swap"));
+      ImGui::Text(_("Drg"));
       ImGui::TableNextColumn();
       ImGui::Text(_("Name"));
       for (int i=0; i<e->getTotalChannelCount(); i++) {
@@ -79,14 +79,17 @@ void FurnaceGUI::drawChannels() {
           ImGui::Button(ICON_FA_ARROWS "##ChanDrag");
           ImGui::EndDragDropSource();
         } else if (ImGui::IsItemHovered()) {
-          ImGui::SetTooltip(_("%s #%d\n(drag to swap channels)"),e->getSystemName(e->sysOfChan[i]),e->dispatchChanOfChan[i]);
+          ImGui::SetTooltip(_("%s #%d\n(drag to swap channels)\n(shift+drag to copy channel contents)"),e->getSystemName(e->sysOfChan[i]),e->dispatchChanOfChan[i]);
         }
         if (ImGui::BeginDragDropTarget()) {
           const ImGuiPayload* dragItem=ImGui::AcceptDragDropPayload("FUR_CHAN");
           if (dragItem!=NULL) {
             if (dragItem->IsDataType("FUR_CHAN")) {
               if (chanToMove!=i && chanToMove>=0) {
-                e->swapChannelsP(chanToMove,i);
+                if (ImGui::IsKeyDown(ImGuiKey_LeftShift))
+                  e->copyChannelP(chanToMove,i);
+                else
+                  e->swapChannelsP(chanToMove,i);
                 MARK_MODIFIED;
               }
               chanToMove=-1;