Unify custom instruments and regular ones

shared/nflags.lua

@@ -1,9 +1,8 @@
 nflags=klass()
 function nflags:init(o)
- self.c = o.c or 0  -- custom
  self.e = o.e or 0 -- effect
  self.v = o.v or 0 -- volume
- self.w = o.w or 0 -- waveform
+ self.w = o.w or 0 -- waveform and custom
  self.p = o.p or 0 -- pitch
 
  self:validate()
@@ -14,32 +13,33 @@ function nflags:clone()
 end
 
 function nflags:validate()
- local c,e,v,w,p
-  =self.c,self.e,self.v,self.w,self.p
+ local e,v,w,p
+  =self.e,self.v,self.w,self.p
 
- assert_range(c,0,2,"custom")
  assert_range(e,0,8,"effect")
  assert_range(v,0,8,"volume")
- assert_range(w,0,8,"waveform")
+ assert_range(w,0,16,"waveform")
  assert_range(p,0,64,"pitch")
 end
 
 function nflags:encode()
  self:validate()
- local c,e,v,w,p
-  =self.c,self.e,self.v,self.w,self.p
+ local e,v,w,p
+  =self.e,self.v,self.w,self.p
 
- c &= 0xffff
  e &= 0xffff
  v &= 0xffff
  w &= 0xffff
  p &= 0xffff
 
+ local wlow = w&7;
+ local whi = (w&8)>>3;
+
  return (
-  (c << 15) |
+  (whi << 15) |
   (e << 12) |
   (v << 9) |
-  (w << 6) |
+  (wlow << 6) |
   (p)
  )
 end