Update cwftoflux to handle index information from CWF files.

lib/fluxmap.cc

@@ -53,6 +53,12 @@ Fluxmap& Fluxmap::appendInterval(uint32_t ticks)
     return *this;
 }
 
+Fluxmap& Fluxmap::appendIndex()
+{
+    appendByte(0x81);
+    return *this;
+}
+
 void Fluxmap::precompensate(int threshold_ticks, int amount_ticks)
 {
     uint8_t junk = 0xff;

lib/fluxmap.h

@@ -20,6 +20,7 @@ public:
 	}
 
     Fluxmap& appendInterval(uint32_t ticks);
+    Fluxmap& appendIndex();
 
     Fluxmap& appendBytes(const Bytes& bytes);
     Fluxmap& appendBytes(const uint8_t* ptr, size_t len);

tools/cwftoflux.cc

@@ -88,9 +88,12 @@ static void read_track()
 
     Fluxmap fluxmap;
     uint32_t pending = 0;
+    bool oldindex = true;
     for (unsigned cursor = 0; cursor < length; cursor++)
     {
-        uint32_t b = inputdata[cursor] & 0x7f;
+        uint32_t b = inputdata[cursor];
+        bool index = !!(b & 0x80);
+        b &= 0x7f;
         if (b == 0x7f)
         {
             pending += 0x7f;
@@ -101,6 +104,10 @@ static void read_track()
 
         double interval_us = b * (1e6/clockRate);
         fluxmap.appendInterval(interval_us / US_PER_TICK);
+
+        if (index && !oldindex)
+            fluxmap.appendIndex();
+        oldindex = index;
     }
 
     std::cout << fmt::format(" {} ms in {} output bytes\n",