add "auto-insert one tick gap" option

papers/format.md

@@ -29,6 +29,7 @@ furthermore, an `or reserved` indicates this field is always present, but is res
 
 the format versions are:
 
+- 65: Furnace dev65
 - 64: Furnace dev64
 - 63: Furnace dev63
 - 62: Furnace dev62
@@ -205,7 +206,8 @@ size | description
   1  | stop portamento on note off (>=62) or reserved
   1  | continuous vibrato (>=62) or reserved
   1  | broken DAC mode (>=64) or reserved
-  3  | reserved
+  1  | one tick cut (>=65) or reserved
+  2  | reserved
  4?? | pointers to instruments
  4?? | pointers to wavetables
  4?? | pointers to samples

src/engine/engine.h

@@ -37,8 +37,8 @@
     warnings+=(String("\n")+x); \
   }
 
-#define DIV_VERSION "dev64"
-#define DIV_ENGINE_VERSION 64
+#define DIV_VERSION "dev65"
+#define DIV_ENGINE_VERSION 65
 
 enum DivStatusView {
   DIV_STATUS_NOTHING=0,

src/engine/fileOps.cpp

@@ -141,6 +141,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     ds.brokenShortcutSlides=false;
     ds.ignoreDuplicateSlides=true;
     ds.brokenDACMode=true;
+    ds.oneTickCut=false;
 
     // 1.1 compat flags
     if (ds.version>24) {
@@ -803,6 +804,9 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
     if (ds.version<64) {
       ds.brokenDACMode=false;
     }
+    if (ds.version<65) {
+      ds.oneTickCut=false;
+    }
     ds.isDMF=false;
 
     reader.readS(); // reserved
@@ -984,7 +988,12 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
       } else {
         reader.readC();
       }
-      for (int i=0; i<3; i++) reader.readC();
+      if (ds.version>=65) {
+        ds.oneTickCut=reader.readC();
+      } else {
+        reader.readC();
+      }
+      for (int i=0; i<2; i++) reader.readC();
     } else {
       for (int i=0; i<20; i++) reader.readC();
     }
@@ -1427,7 +1436,8 @@ SafeWriter* DivEngine::saveFur() {
   w->writeC(song.stopPortaOnNoteOff);
   w->writeC(song.continuousVibrato);
   w->writeC(song.brokenDACMode);
-  for (int i=0; i<3; i++) {
+  w->writeC(song.oneTickCut);
+  for (int i=0; i<2; i++) {
     w->writeC(0);
   }
 

src/engine/playback.cpp

@@ -1067,7 +1067,24 @@ void DivEngine::nextRow() {
       if (pat->data[curRow][0]!=100 && pat->data[curRow][0]!=101 && pat->data[curRow][0]!=102) {
         if (!chan[i].legato) {
           dispatchCmd(DivCommand(DIV_CMD_PRE_NOTE,i,ticks));
-          //chan[i].cut=ticks;
+
+          if (song.oneTickCut) {
+            bool doPrepareCut=true;
+
+            for (int j=0; j<song.pat[i].effectRows; j++) {
+              if (pat->data[curRow][4+(j<<1)]==0x03) {
+                doPrepareCut=false;
+                break;
+              }
+              if (pat->data[curRow][4+(j<<1)]==0xea) {
+                if (pat->data[curRow][5+(j<<1)]>0) {
+                  doPrepareCut=false;
+                  break;
+                }
+              }
+            }
+            if (doPrepareCut) chan[i].cut=ticks;
+          }
         }
       }
     }

src/engine/song.h

@@ -296,6 +296,7 @@ struct DivSong {
   bool stopPortaOnNoteOff;
   bool continuousVibrato;
   bool brokenDACMode;
+  bool oneTickCut;
 
   DivOrders orders;
   std::vector<DivInstrument*> ins;
@@ -361,7 +362,8 @@ struct DivSong {
     ignoreDuplicateSlides(false),
     stopPortaOnNoteOff(false),
     continuousVibrato(false),
-    brokenDACMode(false) {
+    brokenDACMode(false),
+    oneTickCut(false) {
     for (int i=0; i<32; i++) {
       system[i]=DIV_SYSTEM_NULL;
       systemVol[i]=64;

src/gui/gui.cpp

@@ -2069,7 +2069,7 @@ void FurnaceGUI::drawCompatFlags() {
   }
   if (!compatFlagsOpen) return;
   if (ImGui::Begin("Compatibility Flags",&compatFlagsOpen)) {
-    ImGui::TextWrapped("these flags are stored in the song when saving in .fur format, and are automatically enabled when saving in .dmf format.");
+    ImGui::TextWrapped("these flags are designed to provide better DefleMask/older Furnace compatibility.");
     ImGui::Checkbox("Limit slide range",&e->song.limitSlides);
     if (ImGui::IsItemHovered()) {
       ImGui::SetTooltip("when enabled, slides are limited to a compatible range.\nmay cause problems with slides in negative octaves.");
@@ -2119,6 +2119,10 @@ void FurnaceGUI::drawCompatFlags() {
     if (ImGui::IsItemHovered()) {
       ImGui::SetTooltip("when enabled, the DAC in YM2612 will be disabled if there isn't any sample playing.");
     }
+    ImGui::Checkbox("Auto-insert one tick gap between notes",&e->song.oneTickCut);
+    if (ImGui::IsItemHovered()) {
+      ImGui::SetTooltip("when enabled, a one-tick note cut will be inserted between non-legato/non-portamento notes.\nthis simulates the behavior of some Amiga/SNES music engines.");
+    }
 
     ImGui::Text("Loop modality:");
     if (ImGui::RadioButton("Reset channels",e->song.loopModality==0)) {