From 5ec4f2d1f0fd068d0c35a9971f1ae0fa17ad2d64 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Sun, 20 Nov 2022 14:28:43 -0500
Subject: [PATCH] new ins format, part 7

FM instruments now loadable
---
 papers/newIns.md          |  2 +-
 src/engine/engine.h       |  4 +--
 src/engine/fileOpsIns.cpp | 31 +++++++++++++-----
 src/engine/instrument.cpp | 66 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 93 insertions(+), 10 deletions(-)

diff --git a/papers/newIns.md b/papers/newIns.md
index 6f420de0b..4baab71e1 100644
--- a/papers/newIns.md
+++ b/papers/newIns.md
@@ -1,4 +1,4 @@
-# possible new Furnace instrument format
+# new Furnace instrument format
 
 the main issue with Furnace instrument files is that they are too big, even if the instrument is nothing more than the FM setup...
 
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 4a36b27d7..0c2782050 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -47,8 +47,8 @@
 #define BUSY_BEGIN_SOFT softLocked=true; isBusy.lock();
 #define BUSY_END isBusy.unlock(); softLocked=false;
 
-#define DIV_VERSION "dev125"
-#define DIV_ENGINE_VERSION 125
+#define DIV_VERSION "dev126"
+#define DIV_ENGINE_VERSION 126
 // for imports
 #define DIV_VERSION_MOD 0xff01
 #define DIV_VERSION_FC 0xff02
diff --git a/src/engine/fileOpsIns.cpp b/src/engine/fileOpsIns.cpp
index 83361130b..c002efea2 100644
--- a/src/engine/fileOpsIns.cpp
+++ b/src/engine/fileOpsIns.cpp
@@ -1880,10 +1880,19 @@ std::vector<DivInstrument*> DivEngine::instrumentFromFile(const char* path) {
 
   unsigned char magic[16];
   bool isFurnaceInstr=false;
+  bool isOldFurnaceIns=false;
   try {
-    reader.read(magic,16);
-    if (memcmp("-Furnace instr.-",magic,16)==0) {
+    reader.read(magic,4);
+    if (memcmp("FINS",magic,4)==0) {
       isFurnaceInstr=true;
+      logV("found a new Furnace ins");
+    } else {
+      reader.read(&magic[4],12);
+      if (memcmp("-Furnace instr.-",magic,16)==0) {
+        logV("found an old Furnace ins");
+        isFurnaceInstr=true;
+        isOldFurnaceIns=true;
+      }
     }
   } catch (EndOfFileException& e) {
     reader.seek(0,SEEK_SET);
@@ -1892,17 +1901,25 @@ std::vector<DivInstrument*> DivEngine::instrumentFromFile(const char* path) {
   if (isFurnaceInstr) {
     DivInstrument* ins=new DivInstrument;
     try {
-      short version=reader.readS();
-      reader.readS(); // reserved
+      short version=0;
+      if (isOldFurnaceIns) {
+        version=reader.readS();
+        reader.readS(); // reserved
+      } else {
+        version=reader.readS();
+        reader.seek(0,SEEK_SET);
+      }
 
       if (version>DIV_ENGINE_VERSION) {
         warnings="this instrument is made with a more recent version of Furnace!";
       }
 
-      unsigned int dataPtr=reader.readI();
-      reader.seek(dataPtr,SEEK_SET);
+      if (isOldFurnaceIns) {
+        unsigned int dataPtr=reader.readI();
+        reader.seek(dataPtr,SEEK_SET);
+      }
 
-      if (ins->readInsData(reader,version)!=DIV_DATA_SUCCESS) {
+      if (ins->readInsData(reader,version,&song)!=DIV_DATA_SUCCESS) {
         lastError="invalid instrument header/data!";
         delete ins;
         delete[] buf;
diff --git a/src/engine/instrument.cpp b/src/engine/instrument.cpp
index 622c9b60f..9f9482d9d 100644
--- a/src/engine/instrument.cpp
+++ b/src/engine/instrument.cpp
@@ -1738,6 +1738,71 @@ void DivInstrument::readFeatureNA(SafeReader& reader) {
 void DivInstrument::readFeatureFM(SafeReader& reader) {
   READ_FEAT_BEGIN;
 
+  unsigned char opCount=reader.readC();
+
+  fm.op[0].enable=(opCount&16);
+  fm.op[1].enable=(opCount&32);
+  fm.op[2].enable=(opCount&64);
+  fm.op[3].enable=(opCount&128);
+
+  opCount&=15;
+
+  unsigned char next=reader.readC();
+  fm.alg=(next>>4)&7;
+  fm.fb=next&7;
+
+  next=reader.readC();
+  fm.fms2=(next>>5)&7;
+  fm.ams=(next>>3)&3;
+  fm.fms=next&7;
+
+  next=reader.readC();
+  fm.ams2=(next>>6)&3;
+  fm.ops=(next&32)?4:2;
+  fm.opllPreset=next&31;
+
+  // read operators
+  for (int i=0; i<opCount; i++) {
+    DivInstrumentFM::Operator& op=fm.op[i];
+
+    next=reader.readC();
+    op.ksr=(next&128)?1:0;
+    op.dt=(next>>4)&7;
+    op.mult=next&15;
+
+    next=reader.readC();
+    op.sus=(next&128)?1:0;
+    op.tl=next&127;
+
+    next=reader.readC();
+    op.rs=(next>>6)&3;
+    op.vib=(next&32)?1:0;
+    op.ar=next&31;
+
+    next=reader.readC();
+    op.am=(next&128)?1:0;
+    op.ksl=(next>>5)&3;
+    op.dr=next&31;
+
+    next=reader.readC();
+    op.egt=(next&128)?1:0;
+    op.kvs=(next>>5)&3;
+    op.d2r=next&31;
+
+    next=reader.readC();
+    op.sl=(next>>4)&15;
+    op.rr=next&15;
+
+    next=reader.readC();
+    op.dvb=(next>>4)&15;
+    op.ssgEnv=next&15;
+
+    next=reader.readC();
+    op.dam=(next>>5)&7;
+    op.dt2=(next>>3)&3;
+    op.ws=next&7;
+  }
+
   READ_FEAT_END;
 }
 
@@ -2644,6 +2709,7 @@ DivDataErrors DivInstrument::readInsData(SafeReader& reader, short version, DivS
   }
 
   if (type==1 || type==2) {
+    logV("reading new instrument data...");
     return readInsDataNew(reader,version,type==2,song);
   }
   return readInsDataOld(reader,version);