dev78 - new compat flag that fixes ExtCh

papers/format.md

@@ -29,6 +29,7 @@ furthermore, an `or reserved` indicates this field is always present, but is res
 
 the format versions are:
 
+- 78: Furnace dev78
 - 77: Furnace dev77
 - 76: Furnace dev76
 - 75: Furnace dev75/April Fools' 0.6pre0
@@ -248,7 +249,8 @@ size | description
   1  | ignore jump at end (>=71) or reserved
   1  | buggy portamento after slide (>=72) or reserved
   1  | new ins affects envelope (Game Boy) (>=72) or reserved
- 26  | reserved
+  1  | ExtCh channel state is shared (>=78) or reserved
+ 25  | reserved
 ```
 
 # instrument

src/engine/engine.h

@@ -42,8 +42,8 @@
 #define BUSY_BEGIN_SOFT softLocked=true; isBusy.lock();
 #define BUSY_END isBusy.unlock(); softLocked=false;
 
-#define DIV_VERSION "dev77"
-#define DIV_ENGINE_VERSION 77
+#define DIV_VERSION "dev78"
+#define DIV_ENGINE_VERSION 78
 
 // for imports
 #define DIV_VERSION_MOD 0xff01

src/engine/fileOps.cpp

@@ -890,6 +890,9 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
       ds.buggyPortaAfterSlide=true;
       ds.gbInsAffectsEnvelope=false;
     }
+    if (ds.version<78) {
+      ds.sharedExtStat=false;
+    }
     ds.isDMF=false;
 
     reader.readS(); // reserved
@@ -1222,7 +1225,12 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
         reader.readC();
         reader.readC();
       }
-      for (int i=0; i<26; i++) {
+      if (ds.version>=78) {
+        ds.sharedExtStat=reader.readC();
+      } else {
+        reader.readC();
+      }
+      for (int i=0; i<25; i++) {
         reader.readC();
       }
     }
@@ -2125,7 +2133,8 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
   w->writeC(song.ignoreJumpAtEnd);
   w->writeC(song.buggyPortaAfterSlide);
   w->writeC(song.gbInsAffectsEnvelope);
-  for (int i=0; i<26; i++) {
+  w->writeC(song.sharedExtStat);
+  for (int i=0; i<25; i++) {
     w->writeC(0);
   }
 

src/engine/platform/genesisext.cpp

@@ -112,7 +112,12 @@ int DivPlatformGenesisExt::dispatch(DivCommand c) {
       } else {
         opChan[ch].pan=((c.value&15)>0)|(((c.value>>4)>0)<<1);
       }
-      // TODO: ???
+      if (parent->song.sharedExtStat) {
+        for (int i=0; i<4; i++) {
+          if (ch==i) continue;
+          opChan[i].pan=opChan[ch].pan;
+        }
+      }
       rWrite(chanOffs[2]+0xb4,(opChan[ch].pan<<6)|(chan[2].state.fms&7)|((chan[2].state.ams&3)<<4));
       break;
     }

src/engine/platform/ym2610bext.cpp

@@ -105,7 +105,12 @@ int DivPlatformYM2610BExt::dispatch(DivCommand c) {
         opChan[ch].pan=((c.value&15)>0)|(((c.value>>4)>0)<<1);
       }
       DivInstrument* ins=parent->getIns(opChan[ch].ins);
-      // TODO: ???
+      if (parent->song.sharedExtStat) {
+        for (int i=0; i<4; i++) {
+          if (ch==i) continue;
+          opChan[i].pan=opChan[ch].pan;
+        }
+      }
       rWrite(chanOffs[2]+0xb4,(opChan[ch].pan<<6)|(ins->fm.fms&7)|((ins->fm.ams&3)<<4));
       break;
     }

src/engine/platform/ym2610ext.cpp

@@ -105,7 +105,12 @@ int DivPlatformYM2610Ext::dispatch(DivCommand c) {
         opChan[ch].pan=((c.value&15)>0)|(((c.value>>4)>0)<<1);
       }
       DivInstrument* ins=parent->getIns(opChan[ch].ins);
-      // TODO: ???
+      if (parent->song.sharedExtStat) {
+        for (int i=0; i<4; i++) {
+          if (ch==i) continue;
+          opChan[i].pan=opChan[ch].pan;
+        }
+      }
       rWrite(chanOffs[1]+0xb4,(opChan[ch].pan<<6)|(ins->fm.fms&7)|((ins->fm.ams&3)<<4));
       break;
     }

src/engine/song.h

@@ -308,6 +308,7 @@ struct DivSong {
   bool ignoreJumpAtEnd;
   bool buggyPortaAfterSlide;
   bool gbInsAffectsEnvelope;
+  bool sharedExtStat;
 
   DivOrders orders;
   std::vector<DivInstrument*> ins;
@@ -386,7 +387,8 @@ struct DivSong {
     rowResetsArpPos(false),
     ignoreJumpAtEnd(false),
     buggyPortaAfterSlide(false),
-    gbInsAffectsEnvelope(true) {
+    gbInsAffectsEnvelope(true),
+    sharedExtStat(true) {
     for (int i=0; i<32; i++) {
       system[i]=DIV_SYSTEM_NULL;
       systemVol[i]=64;

src/gui/compatFlags.cpp

@@ -154,6 +154,10 @@ void FurnaceGUI::drawCompatFlags() {
     if (ImGui::IsItemHovered()) {
       ImGui::SetTooltip("behavior changed in 0.6");
     }
+    ImGui::Checkbox("ExtCh channel status is shared among operators",&e->song.sharedExtStat);
+    if (ImGui::IsItemHovered()) {
+      ImGui::SetTooltip("behavior changed in 0.6");
+    }
   }
   if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_COMPAT_FLAGS;
   ImGui::End();