tempTest="code ";

var w=sourceCanv.width;
var h=sourceCanv.height;
var sourceCtx=sourceCanv.getContext('2d');
var prevCtx=prevCanv.getContext('2d');
var copyCtx=copyCanv.getContext('2d');
var destCtx=destCanv.getContext('2d');
var nowMs=Date.now();

var flow=0;
var zoom=w;
var rotation=0;
var composite="difference";
var oVal=.5;
var rVal=0;
var bVal=0;
var zVal=1;
var nVal=0;
if(visObj.noise>-1){
 bVal=(visObj.noise/3000)%1;
 tempTest+=" noise "+visObj.noise;
}
if(visObj.drone>-1){
 flow+=.02*w*((visObj.drone-2000)/1000);
 zVal-=(visObj.drone-500)/1000;
 tempTest+=" drone "+visObj.drone;
}

if(visObj.music>-1){
 rVal=((nowMs/20+visObj.music/1500)%(msPerBar*6))/(msPerBar*6);// 0-1 in 6s
 tempTest+=" music "+visObj.music+' '+msPerBar;
}
if(visObj.beat>-1){
 zVal=(visObj.beat-1000)/1000;
 rVal=0;
 tempTest+=" beat "+visObj.beat;
 }
zoom+=w*zVal;
rotation=toRadians(rVal*360);
tempTest+=" oVal: "+oVal+" rVal "+rVal;
tempTest+=" bVal: "+bVal+" zVal "+zVal;
tempTest+=" nVal: "+nVal+" deg "+(rVal*360);
tempTest+=" zoom "+zoom;

destCtx.globalCompositeOperation="source-over";
destCtx.globalAlpha=1;
destCtx.drawImage(destCanv,flow/2,flow/2,w-flow,h-flow);
copyCanv.width=w;
copyCtx.globalAlpha=.5;
copyCtx.save();
copyCtx.translate(w/2,w/2);
copyCtx.rotate(rotation);
if(visObj.drone>0){
  copyCtx.fillStyle="black";
  copyCtx.beginPath();
  copyCtx.arc(0,0,w/24,0,pi*2,true);
  copyCtx.fill();
}
copyCtx.globalAlpha=1;
destCtx.globalCompositeOperation="source-over";
copyCtx.drawImage(sourceCanv,-w/2+zoom/2,-w/2+zoom/2,w-zoom,h-zoom);
copyCtx.globalAlpha=oVal;
copyCtx.globalCompositeOperation="difference";
copyCtx.drawImage(prevCanv,-w/2+zoom/2,-w/2+zoom/2,w-zoom,h-zoom);
copyCtx.restore();
destCtx.globalAlpha=.3;
destCtx.globalCompositeOperation="source-over";

destCtx.drawImage(copyCanv,0,0);
destCtx.globalAlpha=1;
tempTest+=" COMPLETED";

if(bVal>0){canvBend(destCanv, bVal);}
if(visObj.beat+visObj.drone+visObj.noise+visObj.music<0){canvNoise(destCanv, .1,100,false);}

Hello

Sup?