From 95d86bb823ad98581fd54b1ab7997b8083c800c3 Mon Sep 17 00:00:00 2001
From: Keith Clark <keith@keithclark.co.uk>
Date: Fri, 7 Aug 2020 17:39:19 +0100
Subject: [PATCH] Ensure channel panning value always resolves to a number. Add
 note to README about the optional value behaviour.

---
 README.md    | 2 +-
 zzfxm.js     | 4 ++--
 zzfxm.min.js | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index f30ef5c..a9ebb57 100644
--- a/README.md
+++ b/README.md
@@ -182,7 +182,7 @@ Param | Description | Default | Min Value | Max Value
 ```
 
 Channel data is a single array containing the instrument, panning and note data the current pattern.
-The first slot indicates which instrument to use for playing notes. Slot 2 contains the channel panning value and slots 3 onwards hold the note.
+The first slot indicates which instrument to use for playing notes. Slot 2 contains the channel panning value and slots 3 onwards hold the note. If the array slot for an instrument, panning or note value is left empty it will coalesced to `0`.
 
 ## `<channel-instrument>` structure
 
diff --git a/zzfxm.js b/zzfxm.js
index 1fdc8e2..92e1183 100644
--- a/zzfxm.js
+++ b/zzfxm.js
@@ -30,7 +30,7 @@
  * @returns {Array.<Array.<Number>>} Left and right channel sample data.
  */
 
-const zzfxM = (instruments, patterns, sequence, BPM = 125) => {
+zzfxM = (instruments, patterns, sequence, BPM = 125) => {
   let instrumentParameters;
   let i;
   let j;
@@ -97,7 +97,7 @@ const zzfxM = (instruments, patterns, sequence, BPM = 125) => {
         if (note) {
           // set attenuation
           attenuation = note % 1;
-          panning = patternChannel[1];
+          panning = patternChannel[1] || 0;
           if (note |= 0) {
             // get cached sample
             sampleBuffer = sampleCache[
diff --git a/zzfxm.min.js b/zzfxm.min.js
index e7911da..5b7b3cc 100644
--- a/zzfxm.min.js
+++ b/zzfxm.min.js
@@ -1,2 +1,2 @@
 //! ZzFXM (v2.0.1) | (C) Keith Clark | MIT | https://github.com/keithclark/ZzFXM
-zzfxM=(f,n,o,t=125)=>{let z,e,l,r,g,h,x,a,u,c,d,i,m,p,G,M,R=[],b=[],j=[],k=0,q=1,s={},v=zzfxR/t*60>>2;for(;q;k++)R=[q=a=d=m=0],o.map((t,d)=>{for(x=n[t][k]||[0,0,0],q|=!!n[t][k],G=m+(n[t][0].length-2-!a)*v,e=2,r=m;e<x.length+(d==o.length-1);a=++e){for(g=x[e],u=c!=(x[0]||0)|g|0,l=0;l<v&&a;l++>v-99&&u?i+=(i<1)/99:0)h=(1-i)*R[p++]/2||0,b[r]=(b[r]||0)+h*M-h,j[r]=(j[r++]||0)+h*M+h;g&&(i=g%1,M=x[1],(g|=0)&&(R=s[[c=x[p=0]||0,g]]=s[[c,g]]||(z=[...f[c]],z[2]*=2**((g-12)/12),zzfxG(...z))))}m=G});return[b,j]}
\ No newline at end of file
+zzfxM=(f,n,o,t=125)=>{let z,e,l,r,g,h,x,a,u,c,d,i,m,p,G,M,R=[],b=[],j=[],k=0,q=1,s={},v=zzfxR/t*60>>2;for(;q;k++)R=[q=a=d=m=0],o.map((t,d)=>{for(x=n[t][k]||[0,0,0],q|=!!n[t][k],G=m+(n[t][0].length-2-!a)*v,e=2,r=m;e<x.length+(d==o.length-1);a=++e){for(g=x[e],u=c!=(x[0]||0)|g|0,l=0;l<v&&a;l++>v-99&&u?i+=(i<1)/99:0)h=(1-i)*R[p++]/2||0,b[r]=(b[r]||0)+h*M-h,j[r]=(j[r++]||0)+h*M+h;g&&(i=g%1,M=x[1]||0,(g|=0)&&(R=s[[c=x[p=0]||0,g]]=s[[c,g]]||(z=[...f[c]],z[2]*=2**((g-12)/12),zzfxG(...z))))}m=G});return[b,j]}
\ No newline at end of file