From 5d52ef7f008b7ecae51b99835613e3d6e9a81f09 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Thu, 7 Apr 2022 20:13:11 -0500
Subject: [PATCH] support .dmf with 6-bit wavetables

---
 src/engine/fileOps.cpp | 26 ++++++++++++++++++++++----
 src/engine/song.h      |  2 ++
 src/gui/gui.cpp        |  6 +++---
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 8ed6551b9..e14cd8b3b 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -69,7 +69,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     }
     ds.version=(unsigned char)reader.readC();
     logI("module version %d (0x%.2x)\n",ds.version,ds.version);
-    if (ds.version>0x19) {
+    if (ds.version>0x1a) {
       logE("this version is not supported by Furnace yet!\n");
       lastError="this version is not supported by Furnace yet";
       delete[] file;
@@ -580,6 +580,12 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
             wave->data[j]=reader.readI();
           }
         }
+        // #FDS4Bit
+        if (ds.system[0]==DIV_SYSTEM_NES_FDS && ds.version<0x1a) {
+          for (int j=0; j<wave->len; j++) {
+            wave->data[j]*=4;
+          }
+        }
         ds.wave.push_back(wave);
       }
     }
@@ -2222,7 +2228,7 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
 
 SafeWriter* DivEngine::saveDMF(unsigned char version) {
   // fail if version is not supported
-  if (version<24 || version>25) {
+  if (version<24 || version>26) {
     logE("cannot save in this version!\n");
     lastError="invalid version to save in! this is a bug!";
     return NULL;
@@ -2273,6 +2279,12 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
     lastError="NES + VRC7 not supported in 1.0/legacy .dmf!";
     return NULL;
   }
+  // fail if the system is FDS and version<25
+  if (version<25 && song.system[0]==DIV_SYSTEM_NES && song.system[1]==DIV_SYSTEM_FDS) {
+    logE("FDS not supported in 1.0/legacy .dmf!\n");
+    lastError="FDS not supported in 1.0/legacy .dmf!";
+    return NULL;
+  }
   // fail if the system is Furnace-exclusive
   if (!isFlat && systemToFileDMF(song.system[0])==0) {
     logE("cannot save Furnace-exclusive system song!\n");
@@ -2308,7 +2320,7 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
     sys=DIV_SYSTEM_NES_VRC7;
   } else if (song.system[0]==DIV_SYSTEM_NES && song.system[1]==DIV_SYSTEM_FDS) {
     w->writeC(systemToFileDMF(DIV_SYSTEM_NES_FDS));
-    sys=DIV_SYSTEM_NES_VRC7;
+    sys=DIV_SYSTEM_NES_FDS;
   } else {
     w->writeC(systemToFileDMF(song.system[0]));
     sys=song.system[0];
@@ -2481,7 +2493,13 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
   w->writeC(song.wave.size());
   for (DivWavetable* i: song.wave) {
     w->writeI(i->len);
-    w->write(i->data,4*i->len);
+    if (sys==DIV_SYSTEM_NES_FDS && version<26) {
+      for (int j=0; j<i->len; j++) {
+        w->writeI(i->data[j]>>2);
+      }
+    } else {
+      w->write(i->data,4*i->len);
+    }
   }
 
   for (int i=0; i<getChannelCount(sys); i++) {
diff --git a/src/engine/song.h b/src/engine/song.h
index 7dca56b47..438c22143 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -102,6 +102,8 @@ struct DivSong {
   // version number used for saving the song.
   // Furnace will save using the latest possible version,
   // known version numbers:
+  // - 26: v1.1.3
+  //   - changes height of FDS wave to 6-bit (it was 4-bit before)
   // - 25: v1.1
   //   - adds pattern names (in a rather odd way)
   //   - introduces SMS+OPLL system
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 6c35f6c37..55911a3cc 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -1300,8 +1300,8 @@ void FurnaceGUI::openFileDialog(FurnaceGUIFileDialogs type) {
       hasOpened=fileDialog->openSave(
         "Save File",
         {"Furnace song", "*.fur",
-         "DefleMask 1.1 module", "*.dmf"},
-        "Furnace song{.fur},DefleMask 1.1 module{.dmf}",
+         "DefleMask 1.1.3 module", "*.dmf"},
+        "Furnace song{.fur},DefleMask 1.1.3 module{.dmf}",
         workingDirSong,
         dpiScale
       );
@@ -2714,7 +2714,7 @@ bool FurnaceGUI::loop() {
                   showError(fmt::sprintf("Error while saving file! (%s)",lastError));
                 }
               } else {
-                if (save(copyOfName,25)>0) {
+                if (save(copyOfName,26)>0) {
                   showError(fmt::sprintf("Error while saving file! (%s)",lastError));
                 }
               }