Better integration in other environments plus minor improvements

[jlbocquet]

File : player.js
Changes are identified with "@@@ JLB"
See my integration at https://webaudiostudio.jlbee.fr

/*
front end wrapper class for format-specific player classes
(c) 2015-2017 firehawk/tda
*/

// @@@ JLB : added 2 optionnal parameters
function Modplayer(audioContext, bConnectToDest)
{
this.supportedformats=new Array('mod', 's3m', 'xm');

this.url="";
this.format="s3m";

this.state="standby";
this.request=null;

this.loading=false;
this.playing=false;
this.paused=false;
this.repeat=false;

this.separation=1;
this.mixval=8.0;

this.amiga500=false;

this.filter=false;
this.endofsong=false;

this.autostart=false;
this.bufferstodelay=4; // adjust this if you get stutter after loading new song
this.delayfirst=0;
this.delayload=0;

this.onReady=function(){};
this.onPlay=function(){};
this.onStop=function(){};

this.buffer=0;
this.mixerNode=0;

// @@@ JLB
this.bConnectToDest = bConnectToDest;
this.context=audioContext;

this.samplerate=44100;
this.bufferlen=4096;

this.chvu=new Float32Array(32);

// format-specific player
this.player=null;

// read-only data from player class
this.title="";
this.signature="....";
this.songlen=0;
this.channels=0;
this.patterns=0;
this.samplenames=new Array();

// @@@ JLB
this.createContext();
}

// load module from url into local buffer
Modplayer.prototype.load = function(url)
{
// try to identify file format from url and create a new
// player class for it
this.url=url;
var ext=url.split('.').pop().toLowerCase().trim();
if (this.supportedformats.indexOf(ext)==-1) {
// unknown extension, maybe amiga-style prefix?
ext=url.split('/').pop().split('.').shift().toLowerCase().trim();
if (this.supportedformats.indexOf(ext)==-1) {
// ok, give up
return false;
}
}
this.format=ext;

switch (ext) {
case 'mod':
this.player=new Protracker();
break;
case 's3m':
this.player=new Screamtracker();
break;
case 'xm':
this.player=new Fasttracker();
break;
}

this.player.onReady=this.loadSuccess;

this.state="loading..";
var request = new XMLHttpRequest();
request.open("GET", this.url, true);
request.responseType = "arraybuffer";
this.request = request;
this.loading=true;
var asset = this;
request.onprogress = function(oe) {
asset.state="loading ("+Math.floor(100*oe.loaded/oe.total)+"%)..";
};
request.onload = function() {
var buffer=new Uint8Array(request.response);
this.state="parsing..";
if (asset.player.parse(buffer)) {
// copy static data from player
asset.title=asset.player.title
asset.signature=asset.player.signature;
asset.songlen=asset.player.songlen;
asset.channels=asset.player.channels;
asset.patterns=asset.player.patterns;
asset.filter=asset.player.filter;
if (asset.context) asset.setfilter(asset.filter);
asset.mixval=asset.player.mixval; // usually 8.0, though
asset.samplenames=new Array(32)
for(i=0;i<32;i++) asset.samplenames[i]="";
if (asset.format=='xm' || asset.format=='it') {
for(i=0;i<asset.player.instrument.length;i++) asset.samplenames[i]=asset.player.instrument[i].name;
} else {
for(i=0;i<asset.player.sample.length;i++) asset.samplenames[i]=asset.player.sample[i].name;
}

  asset.state="ready";
  asset.loading=false;
  asset.onReady();
  if (asset.autostart) asset.play();
} else {
  asset.state="error";
  asset.loading=false;
}

}
request.send();
return true;
}

// play loaded and parsed module with webaudio context
Modplayer.prototype.play = function()
{
if (this.loading) return false;
if (this.player) {
// @@@ JLB if (this.context == null) this.createContext();
this.player.samplerate=this.samplerate;
if (this.context) this.setfilter(this.player.filter);

if (this.player.paused) {
  this.player.paused=false;
  return true;
}

this.endofsong=false;
this.player.endofsong=false;
this.player.paused=false;
this.player.initialize();
this.player.flags=1+2;
this.player.playing=true;
this.playing=true;

this.chvu=new Float32Array(this.player.channels);
for(i=0;i<this.player.channels;i++) this.chvu[i]=0.0;

this.onPlay();

this.player.delayfirst=this.bufferstodelay;
return true;

} else {
return false;
}
}

// pause playback
Modplayer.prototype.pause = function()
{
if (this.player) {
if (!this.player.paused) {
this.player.paused=true;
} else {
this.player.paused=false;
}
}
}

// stop playback
Modplayer.prototype.stop = function()
{
this.paused=false;
this.playing=false;
if (this.player) {
this.player.paused=false;
this.player.playing=false;
this.player.delayload=1;
}
this.onStop();
}

// stop playing but don't call callbacks
Modplayer.prototype.stopaudio = function(st)
{
if (this.player) {
this.player.playing=st;
}
}

// jump positions forward/back
Modplayer.prototype.jump = function(step)
{
if (this.player) {
this.player.tick=0;
this.player.row=0;
this.player.position+=step;
this.player.flags=1+2;
if (this.player.position<0) this.player.position=0;
if (this.player.position >= this.player.songlen) this.stop();
}
this.position=this.player.position;
this.row=this.player.row;
}

// @@@ JLB
Modplayer.prototype.getPercentPlayed = function() {
if (this.player === null) return 0;
var totalstep = this.player.songlen * 64;
var curstep = this.player.position * 64 + this.player.row;
if (totalstep === 0) return 0;
return curstep * 100 / totalstep;
}

// set whether module repeats after songlen
Modplayer.prototype.setrepeat = function(rep)
{
this.repeat=rep;
if (this.player) this.player.repeat=rep;
}

// set stereo separation mode (0=standard, 1=65/35 mix, 2=mono)
Modplayer.prototype.setseparation = function(sep)
{
this.separation=sep;
if (this.player) this.player.separation=sep;
}

// set autostart to play immediately after loading
Modplayer.prototype.setautostart = function(st)
{
this.autostart=st;
}

// set amiga model - changes lowpass filter state
Modplayer.prototype.setamigamodel = function(amiga)
{
if (amiga=="600" || amiga=="1200" || amiga=="4000") {
this.amiga500=false;
if (this.filterNode) this.filterNode.frequency.value=22050;
} else {
this.amiga500=true;
if (this.filterNode) this.filterNode.frequency.value=6000;
}
}

// amiga "LED" filter
Modplayer.prototype.setfilter = function(f)
{
if (f) {
this.lowpassNode.frequency.value=3275;
} else {
this.lowpassNode.frequency.value=28867;
}
this.filter=f;
if (this.player) this.player.filter=f;
}

// are there E8x sync events queued?
Modplayer.prototype.hassyncevents = function()
{
if (this.player) return (this.player.syncqueue.length != 0);
return false;
}

// pop oldest sync event nybble from the FIFO queue
Modplayer.prototype.popsyncevent = function()
{
if (this.player) return this.player.syncqueue.pop();
}

// ger current pattern number
Modplayer.prototype.currentpattern = function()
{
if (this.player) return this.player.patterntable[this.player.position];
// @@@ JLB
return 0;
}

// get current pattern in standard unpacked format (note, sample, volume, command, data)
// note: 254=noteoff, 255=no note
// sample: 0=no instrument, 1..255=sample number
// volume: 255=no volume set, 0..64=set volume, 65..239=ft2 volume commands
// command: 0x2e=no command, 0..0x24=effect command
// data: 0..255
Modplayer.prototype.patterndata = function(pn)
{
var i, c, patt;
if (this.format=='mod') {
patt=new Uint8Array(this.player.pattern_unpack[pn]);
for(i=0;i<64;i++) for(c=0;c<this.player.channels;c++) {
if (patt[i5this.channels+c5+3]==0 && patt[i5this.channels+c5+4]==0) {
patt[i5this.channels+c5+3]=0x2e;
} else {
patt[i5this.channels+c5+3]+=0x37;
if (patt[i5this.channels+c5+3]<0x41) patt[i5this.channels+c5+3]-=0x07;
}
}
} else if (this.format=='s3m') {
patt=new Uint8Array(this.player.pattern[pn]);
for(i=0;i<64;i++) for(c=0;c<this.player.channels;c++) {
if (patt[i5this.channels+c5+3]==255) patt[i5this.channels+c5+3]=0x2e;
else patt[i5this.channels+c5+3]+=0x40;
}
} else if (this.format=='xm') {
patt=new Uint8Array(this.player.pattern[pn]);
for(i=0;i<this.player.patternlen[pn];i++) for(c=0;c<this.player.channels;c++) {
if (patt[i5this.channels+c5+0]<97)
patt[i5this.channels+c5+0]=(patt[i5this.channels+c5+0]%12)|(Math.floor(patt[i5this.channels+c5+0]/12)<<4);
if (patt[i5this.channels+c5+3]==255) patt[i5this.channels+c5+3]=0x2e;
else {
if (patt[i5this.channels+c5+3]<0x0a) {
patt[i5this.channels+c5+3]+=0x30;
} else {
patt[i5this.channels+c5+3]+=0x41-0x0a;
}
}
}
}
return patt;
}

// check if a channel has a note on
Modplayer.prototype.noteon = function(ch)
{
if (ch>=this.channels) return 0;
return this.player.channel[ch].noteon;
}

// get currently active sample on channel
Modplayer.prototype.currentsample = function(ch)
{
if (ch>=this.channels) return 0;
if (this.format=="xm" || this.format=="it") return this.player.channel[ch].instrument;
return this.player.channel[ch].sample;
}

// get length of currently playing pattern
Modplayer.prototype.currentpattlen = function()
{
if (this.format=="mod" || this.format=="s3m") return 64;
return this.player.patternlen[this.player.patterntable[this.player.position]];
}

// create the web audio context
Modplayer.prototype.createContext = function()
{
// @@@ JLB
if (this.context === null || this.context === undefined) {
if ( typeof AudioContext !== 'undefined') {
this.context = new AudioContext();
} else {
this.context = new webkitAudioContext();
}
}

this.samplerate=this.context.sampleRate;
this.bufferlen=(this.samplerate > 44100) ? 4096 : 2048;

// Amiga 500 fixed filter at 6kHz. WebAudio lowpass is 12dB/oct, whereas
// older Amigas had a 6dB/oct filter at 4900Hz.
this.filterNode=this.context.createBiquadFilter();
if (this.amiga500) {
this.filterNode.frequency.value=6000;
} else {
this.filterNode.frequency.value=22050;
}

// "LED filter" at 3275kHz - off by default
this.lowpassNode=this.context.createBiquadFilter();
this.setfilter(this.filter);

// mixer
if ( typeof this.context.createJavaScriptNode === 'function') {
this.mixerNode=this.context.createJavaScriptNode(this.bufferlen, 1, 2);
} else {
this.mixerNode=this.context.createScriptProcessor(this.bufferlen, 1, 2);
}
this.mixerNode.module=this;
this.mixerNode.onaudioprocess=Modplayer.prototype.mix;

// patch up some cables :)
this.mixerNode.connect(this.filterNode);
this.filterNode.connect(this.lowpassNode);

if (this.bConnectToDest === true) { // @@@ JLB
this.lowpassNode.connect(this.context.destination);
}
}

// @@@ JLB
Modplayer.prototype.getOutputNode = function() {
return this.lowpassNode;
}

// scriptnode callback - pass through to player class
Modplayer.prototype.mix = function(ape) {
var mod;

if (ape.srcElement) {
mod=ape.srcElement.module;
} else {
mod=this.module;
}

if (mod.player && mod.delayfirst==0) {
mod.player.repeat=mod.repeat;

var bufs=new Array(ape.outputBuffer.getChannelData(0), ape.outputBuffer.getChannelData(1));
var buflen=ape.outputBuffer.length;
mod.player.mix(mod.player, bufs, buflen);

// apply stereo separation and soft clipping
var outp=new Float32Array(2);
for(var s=0;s<buflen;s++) {
  outp[0]=bufs[0][s];
  outp[1]=bufs[1][s];

  // a more headphone-friendly stereo separation
  if (mod.separation) {
    t=outp[0];
    if (mod.separation==2) { // mono
      outp[0]=outp[0]*0.5 + outp[1]*0.5;
      outp[1]=outp[1]*0.5 + t*0.5;
    } else { // narrow stereo
      outp[0]=outp[0]*0.65 + outp[1]*0.35;
      outp[1]=outp[1]*0.65 + t*0.35;
    }
  }

  // scale down and soft clip
  outp[0]/=mod.mixval; outp[0]=0.5*(Math.abs(outp[0]+0.975)-Math.abs(outp[0]-0.975));
  outp[1]/=mod.mixval; outp[1]=0.5*(Math.abs(outp[1]+0.975)-Math.abs(outp[1]-0.975));
  
  bufs[0][s]=outp[0];
  bufs[1][s]=outp[1];
}

mod.row=mod.player.row;
mod.position=mod.player.position;
mod.speed=mod.player.speed;
mod.bpm=mod.player.bpm;
mod.endofsong=mod.player.endofsong;

if (mod.player.filter != mod.filter) {
  mod.setfilter(mod.player.filter);
}

if (mod.endofsong && mod.playing) mod.stop();

if (mod.delayfirst>0) mod.delayfirst--;
mod.delayload=0;

// update this.chvu from player channel vu
if (mod.playing && ! mod.paused) { // @@@ JLB
	for(var i=0;i<mod.player.channels;i++) {
	  mod.chvu[i]=mod.chvu[i]*0.25 + mod.player.chvu[i]*0.75;    
	  mod.player.chvu[i]=0.0;
	}
  } else {
	for(var i=0;i<mod.player.channels;i++) {
		mod.chvu[i] = 0;
	}
  }

}

}