MIDI.js/js/MIDI/loadPlugin.js
2013-01-18 23:39:42 -08:00

184 lines
5.2 KiB
JavaScript

/*
-----------------------------------------------------------
MIDI.loadPlugin : 0.1.2 : 01/18/2012
-----------------------------------------------------------
https://github.com/mudcube/MIDI.js
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MIDI.loadPlugin({
instrument: "acoustic_grand_piano", // or 1 (default)
instruments: [ "acoustic_grand_piano", "acoustic_guitar_nylon" ], // or multiple instruments
callback: function() { }
});
*/
if (typeof (MIDI) === "undefined") var MIDI = {};
if (typeof (MIDI.Soundfont) === "undefined") MIDI.Soundfont = {};
(function() { "use strict";
// Turn on to get "onprogress" event. XHR will not work from file://
var USE_XHR = false;
MIDI.loadPlugin = function(conf) {
if (typeof(conf) === "function") conf = { callback: conf };
/// Get the instrument name.
var instruments = conf.instruments || conf.instrument || "acoustic_grand_piano";
if (typeof(instruments) !== "object") instruments = [ instruments ];
instruments.map(function(data) {
if (typeof(data) === "number") data = MIDI.GeneralMIDI.byId[data];
return data;
});
///
MIDI.soundfontUrl = conf.soundfontUrl || MIDI.soundfontUrl || "./soundfont/";
/// Detect the best type of audio to use.
MIDI.audioDetect(function(types) {
var type = "";
// use the most appropriate plugin if not specified
if (typeof(type) === 'undefined') {
if (plugins[window.location.hash]) {
type = window.location.hash.substr(1);
} else { //
type = "";
}
}
if (type === "") {
if (window.webkitAudioContext) { // Chrome
type = "webaudio";
} else if (window.Audio) { // Firefox
type = "audiotag";
} else { // Internet Explorer
type = "flash";
}
}
if (!connect[type]) return;
// use audio/ogg when supported
var filetype = types["audio/ogg"] ? "ogg" : "mp3";
// load the specified plugin
connect[type](filetype, instruments, conf.callback);
});
};
///
var connect = {};
connect.java = function(filetype, instruments, callback) {
// works well cross-browser, and fully featured, but has delay when Java machine starts.
if (MIDI.loader) MIDI.loader.message("Java API...");
MIDI.Java.connect(callback);
};
connect.flash = function(filetype, instruments, callback) {
// fairly quick, but requires loading of individual MP3s (more http requests).
if (MIDI.loader) MIDI.loader.message("Flash API...");
DOMLoader.script.add({
src: "./inc/SoundManager2/script/soundmanager2.js",
verify: "SoundManager",
callback: function () {
MIDI.Flash.connect(callback);
}
});
};
connect.audiotag = function(filetype, instruments, callback) {
if (MIDI.loader) MIDI.loader.message("HTML5 Audio API...");
// works ok, kinda like a drunken tuna fish, across the board.
var queue = createQueue({
items: instruments,
getNext: function(instrumentId) {
if (USE_XHR) {
DOMLoader.sendRequest({
url: MIDI.soundfontUrl + instrumentId + "-" + filetype + ".js",
onprogress: getPercent,
onload: function (response) {
MIDI.Soundfont[instrumentId] = JSON.parse(response.responseText);
if (MIDI.loader) MIDI.loader.update(null, "Downloading", 100);
queue.getNext();
}
});
} else {
DOMLoader.script.add({
src: MIDI.soundfontUrl + instrumentId + "-" + filetype + ".js",
verify: instrumentId,
callback: function() {
if (MIDI.loader) MIDI.loader.update(null, "Downloading...", 100);
queue.getNext();
}
});
}
},
onComplete: function() {
MIDI.AudioTag.connect(callback);
}
});
};
connect.webaudio = function(filetype, instruments, callback) {
if (MIDI.loader) MIDI.loader.message("Web Audio API...");
// works awesome! safari and chrome support
var queue = createQueue({
items: instruments,
getNext: function(instrumentId) {
if (USE_XHR) {
DOMLoader.sendRequest({
url: MIDI.soundfontUrl + instrumentId + "-" + filetype + ".js",
onprogress: getPercent,
onload: function(response) {
MIDI.Soundfont[instrumentId] = JSON.parse(response.responseText);
if (MIDI.loader) MIDI.loader.update(null, "Downloading...", 100);
queue.getNext();
}
});
} else {
DOMLoader.script.add({
src: MIDI.soundfontUrl + instrumentId + "-" + filetype + ".js",
verify: "MIDI.Soundfont." + instrumentId,
callback: function() {
if (MIDI.loader) MIDI.loader.update(null, "Downloading...", 100);
queue.getNext();
}
});
}
},
onComplete: function() {
MIDI.WebAudioAPI.connect(callback);
}
});
};
/// Helpers
var plugins = {
"#webaudio": true,
"#audiotag": true,
"#java": true,
"#flash": true
};
var getPercent = function(event) {
if (!this.totalSize) {
if (this.getResponseHeader("Content-Length-Raw")) {
this.totalSize = parseInt(this.getResponseHeader("Content-Length-Raw"));
} else {
this.totalSize = event.total;
}
}
var percent = this.totalSize ? Math.round(event.loaded / this.totalSize * 100) : "";
if (MIDI.loader) MIDI.loader.update(null, "Downloading...", percent);
};
var createQueue = function(conf) {
var self = {};
self.queue = [];
for (var key in conf.items) {
self.queue.push(conf.items[key]);
}
self.getNext = function() {
if (!self.queue.length) return conf.onComplete();
conf.getNext(self.queue.shift());
};
setTimeout(self.getNext, 1);
return self;
};
})();