add tutorial screen

public/src/js/assets.js

@@ -86,7 +86,9 @@ var assets = {
 		'bgm_songsel.ogg',
 		'bgm_songsel_loop.ogg',
 		'bgm_result.ogg',
-		'bgm_result_loop.ogg'
+		'bgm_result_loop.ogg',
+		'bgm_setsume.ogg',
+		'bgm_setsume_loop.ogg'
 	),
 	
 	songs: new Array(),

public/src/js/songselect.js

@@ -35,7 +35,9 @@ function SongSelect(){
 
 	this.endPreview = function() {
 		clearTimeout(_preview_to);
-		_preview.pause();
+		if (_preview) {
+			_preview.pause();
+		};
 	};
     
     this.run = function(){
@@ -46,6 +48,14 @@ function SongSelect(){
 		
 		var menuLoop = setInterval(_this.refresh, 20);
 		$("#song-container").show();
+
+		$('#songsel-help').click(function(){
+			bgm.pause();
+			_this.endPreview();
+			assets.sounds['don'].playAsset();
+
+			new Tutorial();
+		});
 		
 		$(".difficulty").click(function(e){
 			_this.endPreview();

public/src/js/titlescreen.js

@@ -41,7 +41,11 @@ function Titlescreen(){
     	assets.sounds["title"].currentTime = 0;
 
 		assets.sounds["don"].playAsset();
-        new SongSelect();
+        if (localStorage.getItem('tutorial') !== 'true') {
+        	new Tutorial();
+        } else {
+        	new SongSelect();
+        };
     }
     
 	$("#screen").load("/src/views/titlescreen.html", _this.run);

public/src/js/tutorial.js

@@ -0,0 +1,21 @@
+function Tutorial() {
+    var _this = this;
+
+    this.run = function() {
+        bgm = new BufferedLoop(
+            {url: '/assets/audio/bgm_setsume.ogg', duration: 1.054},
+            {url: '/assets/audio/bgm_setsume_loop.ogg', duration: 15}
+        );
+        bgm.play();
+
+        $('#tutorial-end-button').click(function(){
+            bgm.pause();
+            assets.sounds['don'].playAsset();
+
+            localStorage.setItem('tutorial', 'true');
+            new SongSelect();
+        });
+    };
+
+    $('#screen').load('/src/views/tutorial.html', _this.run);
+};