fix j

static/qrplay/v2c.html

@@ -28,25 +28,26 @@
 <p><a href=http://nycki.net/qrplay>qrplay v2c</a></p>
 <textarea id=f style=width:min(40em,99%);height:9lh></textarea><p>
 <button onclick='
-s=f.value.toLowerCase();
+s=`@`+f.value.toLowerCase();
 f.A?.close();
 A=f.A=new AudioContext;
 // time per-channel
 T=[];
 // tempo in beats per minute
 u=137;
-// volume. 50 is max, 45 is half, 40 is half again...
+// volume. 40 is default, 35 is half, 30 is half again.
 v=40;
 for(
-	c=t=o=k=Z=0,l=3;D=s[c+1],E=D+s[c+2],C=s[c++];
+	c=t=k=Z=0;D=s[c+1],E=D+s[c+2],C=s[c++];
 	// no match
 	z<0?0:
 	// comments
 	z<2?k=z:k?0:
 	// - + octave
 	z<4?o+=C+12|0:
-	// triplets and dots
+	// dots and triplets
-	z<6?l*=3/d:
+	z<5?l*=3/2:
+	z<6?l/=3:
 	// note or rest (percussion not implemented)
 	z<23?(
 		z-=6,
@@ -54,24 +55,22 @@ for(
 			type:`square`,
 			detune:100*(z*2-(z>3)-(D==`!`)+(D==`#`)+o-9)
 		}),
-		G=new GainNode(A,{gain:z<7&&.5**(11-v/5)}),
+		G=new GainNode(A,{gain:z<7&&.5**(12-v/5)}),
 		O.connect(G),
 		G.connect(A.destination),
 		O.start(t),
-		O.stop(t+=2.5*l/u)
+		O.stop(t+=7.5*l/u)
 	):
 	// reset octave and duration
-	z<24?(o=0,l=3):
+	z<24?(o=0,l=1):
 	// set note length
-	z<31?l=3<<(z-25):
+	z<31?l=2**(z-25):
 	// change channel
 	z<32?(T[Z]=t,t=T[Z=E]|0,c+=2):
 	// change tempo
 	z<33?u=E+s[c+=2,c++]:
 	// change volume
     (v=E,c+=2)
-	// TODO combine all these slice operations into one branch
-	// d is additional data that varies with the operation.
 )z=`\n;-+.3cdefgab012456789x@jtsiqhwzuv`.indexOf(C)
 '>#play</button> <button onclick=f.A.close()>#stop</button>
 <!-- stop snipping here -->