mediocre-blog/assets/trading-in-the-rain/MIDI.js/inc/shim/WebMIDIAPI.js
2020-04-26 18:15:15 -06:00

422 lines
14 KiB
JavaScript

/* Copyright 2013 Chris Wilson
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
// Initialize the MIDI library.
(function (global) {
'use strict';
var midiIO, _requestMIDIAccess, MIDIAccess, _onReady, MIDIPort, MIDIInput, MIDIOutput, _midiProc;
function Promise() {
}
Promise.prototype.then = function(accept, reject) {
this.accept = accept;
this.reject = reject;
}
Promise.prototype.succeed = function(access) {
if (this.accept)
this.accept(access);
}
Promise.prototype.fail = function(error) {
if (this.reject)
this.reject(error);
}
function _JazzInstance() {
this.inputInUse = false;
this.outputInUse = false;
// load the Jazz plugin
var o1 = document.createElement("object");
o1.id = "_Jazz" + Math.random() + "ie";
o1.classid = "CLSID:1ACE1618-1C7D-4561-AEE1-34842AA85E90";
this.activeX = o1;
var o2 = document.createElement("object");
o2.id = "_Jazz" + Math.random();
o2.type="audio/x-jazz";
o1.appendChild(o2);
this.objRef = o2;
var e = document.createElement("p");
e.appendChild(document.createTextNode("This page requires the "));
var a = document.createElement("a");
a.appendChild(document.createTextNode("Jazz plugin"));
a.href = "http://jazz-soft.net/";
e.appendChild(a);
e.appendChild(document.createTextNode("."));
o2.appendChild(e);
var insertionPoint = document.getElementById("MIDIPlugin");
if (!insertionPoint) {
// Create hidden element
var insertionPoint = document.createElement("div");
insertionPoint.id = "MIDIPlugin";
insertionPoint.style.position = "absolute";
insertionPoint.style.visibility = "hidden";
insertionPoint.style.left = "-9999px";
insertionPoint.style.top = "-9999px";
document.body.appendChild(insertionPoint);
}
insertionPoint.appendChild(o1);
if (this.objRef.isJazz)
this._Jazz = this.objRef;
else if (this.activeX.isJazz)
this._Jazz = this.activeX;
else
this._Jazz = null;
if (this._Jazz) {
this._Jazz._jazzTimeZero = this._Jazz.Time();
this._Jazz._perfTimeZero = window.performance.now();
}
}
_requestMIDIAccess = function _requestMIDIAccess() {
var access = new MIDIAccess();
return access._promise;
};
// API Methods
MIDIAccess = function() {
this._jazzInstances = new Array();
this._jazzInstances.push( new _JazzInstance() );
this._promise = new Promise;
if (this._jazzInstances[0]._Jazz) {
this._Jazz = this._jazzInstances[0]._Jazz;
window.setTimeout( _onReady.bind(this), 3 );
} else {
window.setTimeout( _onNotReady.bind(this), 3 );
}
};
_onReady = function _onReady() {
if (this._promise)
this._promise.succeed(this);
};
function _onNotReady() {
if (this._promise)
this._promise.fail( { code: 1 } );
};
MIDIAccess.prototype.inputs = function( ) {
if (!this._Jazz)
return null;
var list=this._Jazz.MidiInList();
var inputs = new Array( list.length );
for ( var i=0; i<list.length; i++ ) {
inputs[i] = new MIDIInput( this, list[i], i );
}
return inputs;
}
MIDIAccess.prototype.outputs = function( ) {
if (!this._Jazz)
return null;
var list=this._Jazz.MidiOutList();
var outputs = new Array( list.length );
for ( var i=0; i<list.length; i++ ) {
outputs[i] = new MIDIOutput( this, list[i], i );
}
return outputs;
};
MIDIInput = function MIDIInput( midiAccess, name, index ) {
this._listeners = [];
this._midiAccess = midiAccess;
this._index = index;
this._inLongSysexMessage = false;
this._sysexBuffer = new Uint8Array();
this.id = "" + index + "." + name;
this.manufacturer = "";
this.name = name;
this.type = "input";
this.version = "";
this.onmidimessage = null;
var inputInstance = null;
for (var i=0; (i<midiAccess._jazzInstances.length)&&(!inputInstance); i++) {
if (!midiAccess._jazzInstances[i].inputInUse)
inputInstance=midiAccess._jazzInstances[i];
}
if (!inputInstance) {
inputInstance = new _JazzInstance();
midiAccess._jazzInstances.push( inputInstance );
}
inputInstance.inputInUse = true;
this._jazzInstance = inputInstance._Jazz;
this._input = this._jazzInstance.MidiInOpen( this._index, _midiProc.bind(this) );
};
// Introduced in DOM Level 2:
MIDIInput.prototype.addEventListener = function (type, listener, useCapture ) {
if (type !== "midimessage")
return;
for (var i=0; i<this._listeners.length; i++)
if (this._listeners[i] == listener)
return;
this._listeners.push( listener );
};
MIDIInput.prototype.removeEventListener = function (type, listener, useCapture ) {
if (type !== "midimessage")
return;
for (var i=0; i<this._listeners.length; i++)
if (this._listeners[i] == listener) {
this._listeners.splice( i, 1 ); //remove it
return;
}
};
MIDIInput.prototype.preventDefault = function() {
this._pvtDef = true;
};
MIDIInput.prototype.dispatchEvent = function (evt) {
this._pvtDef = false;
// dispatch to listeners
for (var i=0; i<this._listeners.length; i++)
if (this._listeners[i].handleEvent)
this._listeners[i].handleEvent.bind(this)( evt );
else
this._listeners[i].bind(this)( evt );
if (this.onmidimessage)
this.onmidimessage( evt );
return this._pvtDef;
};
MIDIInput.prototype.appendToSysexBuffer = function ( data ) {
var oldLength = this._sysexBuffer.length;
var tmpBuffer = new Uint8Array( oldLength + data.length );
tmpBuffer.set( this._sysexBuffer );
tmpBuffer.set( data, oldLength );
this._sysexBuffer = tmpBuffer;
};
MIDIInput.prototype.bufferLongSysex = function ( data, initialOffset ) {
var j = initialOffset;
while (j<data.length) {
if (data[j] == 0xF7) {
// end of sysex!
j++;
this.appendToSysexBuffer( data.slice(initialOffset, j) );
return j;
}
j++;
}
// didn't reach the end; just tack it on.
this.appendToSysexBuffer( data.slice(initialOffset, j) );
this._inLongSysexMessage = true;
return j;
};
_midiProc = function _midiProc( timestamp, data ) {
// Have to use createEvent/initEvent because IE10 fails on new CustomEvent. Thanks, IE!
var length = 0;
var i,j;
var isSysexMessage = false;
// Jazz sometimes passes us multiple messages at once, so we need to parse them out
// and pass them one at a time.
for (i=0; i<data.length; i+=length) {
if (this._inLongSysexMessage) {
i = this.bufferLongSysex(data,i);
if ( data[i-1] != 0xf7 ) {
// ran off the end without hitting the end of the sysex message
return;
}
isSysexMessage = true;
} else {
isSysexMessage = false;
switch (data[i] & 0xF0) {
case 0x80: // note off
case 0x90: // note on
case 0xA0: // polyphonic aftertouch
case 0xB0: // control change
case 0xE0: // channel mode
length = 3;
break;
case 0xC0: // program change
case 0xD0: // channel aftertouch
length = 2;
break;
case 0xF0:
switch (data[i]) {
case 0xf0: // variable-length sysex.
i = this.bufferLongSysex(data,i);
if ( data[i-1] != 0xf7 ) {
// ran off the end without hitting the end of the sysex message
return;
}
isSysexMessage = true;
break;
case 0xF1: // MTC quarter frame
case 0xF3: // song select
length = 2;
break;
case 0xF2: // song position pointer
length = 3;
break;
default:
length = 1;
break;
}
break;
}
}
var evt = document.createEvent( "Event" );
evt.initEvent( "midimessage", false, false );
evt.receivedTime = parseFloat( timestamp.toString()) + this._jazzInstance._perfTimeZero;
if (isSysexMessage || this._inLongSysexMessage) {
evt.data = new Uint8Array( this._sysexBuffer );
this._sysexBuffer = new Uint8Array(0);
this._inLongSysexMessage = false;
} else
evt.data = new Uint8Array(data.slice(i, length+i));
this.dispatchEvent( evt );
}
};
MIDIOutput = function MIDIOutput( midiAccess, name, index ) {
this._listeners = [];
this._midiAccess = midiAccess;
this._index = index;
this.id = "" + index + "." + name;
this.manufacturer = "";
this.name = name;
this.type = "output";
this.version = "";
var outputInstance = null;
for (var i=0; (i<midiAccess._jazzInstances.length)&&(!outputInstance); i++) {
if (!midiAccess._jazzInstances[i].outputInUse)
outputInstance=midiAccess._jazzInstances[i];
}
if (!outputInstance) {
outputInstance = new _JazzInstance();
midiAccess._jazzInstances.push( outputInstance );
}
outputInstance.outputInUse = true;
this._jazzInstance = outputInstance._Jazz;
this._jazzInstance.MidiOutOpen(this.name);
};
function _sendLater() {
this.jazz.MidiOutLong( this.data ); // handle send as sysex
}
MIDIOutput.prototype.send = function( data, timestamp ) {
var delayBeforeSend = 0;
if (data.length === 0)
return false;
if (timestamp)
delayBeforeSend = Math.floor( timestamp - window.performance.now() );
if (timestamp && (delayBeforeSend>1)) {
var sendObj = new Object();
sendObj.jazz = this._jazzInstance;
sendObj.data = data;
window.setTimeout( _sendLater.bind(sendObj), delayBeforeSend );
} else {
this._jazzInstance.MidiOutLong( data );
}
return true;
};
//init: create plugin
if (!window.navigator.requestMIDIAccess)
window.navigator.requestMIDIAccess = _requestMIDIAccess;
}(window));
// Polyfill window.performance.now() if necessary.
(function (exports) {
var perf = {}, props;
function findAlt() {
var prefix = ['moz', 'webkit', 'o', 'ms'],
i = prefix.length,
//worst case, we use Date.now()
props = {
value: (function (start) {
return function () {
return Date.now() - start;
};
}(Date.now()))
};
//seach for vendor prefixed version
for (; i >= 0; i--) {
if ((prefix[i] + "Now") in exports.performance) {
props.value = function (method) {
return function () {
exports.performance[method]();
}
}(prefix[i] + "Now");
return props;
}
}
//otherwise, try to use connectionStart
if ("timing" in exports.performance && "connectStart" in exports.performance.timing) {
//this pretty much approximates performance.now() to the millisecond
props.value = (function (start) {
return function() {
Date.now() - start;
};
}(exports.performance.timing.connectStart));
}
return props;
}
//if already defined, bail
if (("performance" in exports) && ("now" in exports.performance))
return;
if (!("performance" in exports))
Object.defineProperty(exports, "performance", {
get: function () {
return perf;
}});
//otherwise, performance is there, but not "now()"
props = findAlt();
Object.defineProperty(exports.performance, "now", props);
}(window));