new ins format, part 5

papers/newIns.md

@@ -6,6 +6,8 @@ the aim of this new format is to greatly reduce the size of a resulting instrume
 
 # header
 
+.fui files use the following header:
+
 ```
 size | description
 -----|------------------------------------
@@ -15,6 +17,18 @@ size | description
  ??? | features...
 ```
 
+instruments in a .fur file use the following header instead:
+
+```
+size | description
+-----|------------------------------------
+  4  | "INS2" block ID
+  4  | size of this block
+  2  | format version
+  2  | instrument type
+ ??? | features...
+```
+
 a feature uses the following format:
 
 ```
@@ -51,6 +65,7 @@ the following feature codes are recognized:
 - `EN`: end of features
   - if you find this feature code, stop reading the instrument.
   - it will usually appear only when there sample/wave lists.
+  - instruments in a .fur shall end with this feature code.
 
 # instrument name (NA)
 

src/engine/instrument.cpp

@@ -1720,17 +1720,16 @@ void DivInstrument::putInsData(SafeWriter* w) {
   w->seek(0,SEEK_END);
 }
 
+DivDataErrors DivInstrument::readInsDataNew(SafeReader& reader, short version, bool fui) {
+  logE("new ins reading not implemented yet!");
+  return DIV_DATA_INVALID_DATA;
+}
+
 #define READ_MACRO_VALS(x,y) \
   for (int macroValPos=0; macroValPos<y; macroValPos++) x[macroValPos]=reader.readI();
 
-DivDataErrors DivInstrument::readInsData(SafeReader& reader, short version) {
-  char magic[4];
-  reader.read(magic,4);
-  if (memcmp(magic,"INST",4)!=0) {
-    logE("invalid instrument header!");
-    return DIV_DATA_INVALID_HEADER;
-  }
-  reader.readI();
+DivDataErrors DivInstrument::readInsDataOld(SafeReader &reader, short version) {
+  reader.readI(); // length. ignored.
 
   reader.readS(); // format version. ignored.
   type=(DivInstrumentType)reader.readC();
@@ -2438,6 +2437,31 @@ DivDataErrors DivInstrument::readInsData(SafeReader& reader, short version) {
   return DIV_DATA_SUCCESS;
 }
 
+DivDataErrors DivInstrument::readInsData(SafeReader& reader, short version) {
+  // 0: old (INST)
+  // 1: new (INS2, length)
+  // 2: new (FINS, no length)
+  int type=-1;
+
+  char magic[4];
+  reader.read(magic,4);
+  if (memcmp(magic,"INST",4)==0) {
+    type=0;
+  } else if (memcmp(magic,"INS2",4)==0) {
+    type=1;
+  } else if (memcmp(magic,"FINS",4)==0) {
+    type=2;
+  } else {
+    logE("invalid instrument header!");
+    return DIV_DATA_INVALID_HEADER;
+  }
+
+  if (type==1 || type==2) {
+    return readInsDataNew(reader,version,type==2);
+  }
+  return readInsDataOld(reader,version);
+}
+
 bool DivInstrument::save(const char* path) {
   SafeWriter* w=new SafeWriter();
   w->init();

src/engine/instrument.h

@@ -661,6 +661,9 @@ struct DivInstrument {
   void writeFeatureSU(SafeWriter* w);
   void writeFeatureES(SafeWriter* w);
   void writeFeatureX1(SafeWriter* w);
+
+  DivDataErrors readInsDataOld(SafeReader& reader, short version);
+  DivDataErrors readInsDataNew(SafeReader& reader, short version, bool fui);
   
   /**
    * save the instrument to a SafeWriter.