Initial commit.

js/Stage.js

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+// Copyright (C) 2013 Massachusetts Institute of Technology
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License version 2,
+// as published by the Free Software Foundation.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+// Scratch HTML5 Player
+// Stage.js
+// Tim Mickel, July 2011 - March 2012
+
+// Provides the basic logic for the Stage, a special kind of Sprite.
+
+'use strict';
+
+var Stage = function(data) {
+    // Place the background layer in the very back.
+    // The pen layer is right above the stage background,
+    // and all sprites are above that.
+    this.z = -2;
+
+    // Pen layer and canvas cache.
+    this.penLayerLoaded = false;
+    this.lineCanvas = document.createElement('canvas');
+    this.lineCanvas.width = 480;
+    this.lineCanvas.height = 360;
+    this.lineCache = this.lineCanvas.getContext('2d');
+
+    Sprite.call(this, data);
+}
+
+Stage.prototype = Object.create(Sprite.prototype);
+Stage.prototype.constructor = Stage;
+  
+Stage.prototype.attachPenLayer = function(scene) {
+    if (this.penLayerLoaded)
+        return;
+    this.penLayerLoaded = true;
+    $(this.lineCanvas).css('position', 'absolute');
+    $(this.lineCanvas).css('z-index', '-1');
+    scene.append(this.lineCanvas);
+}
+  
+Stage.prototype.isLoaded = function() {
+    return (this.penLayerLoaded 
+            && this.costumesLoaded == this.costumes.length
+            && this.soundsLoaded == Object.keys(this.sounds).length);
+}
+  
+// Pen functions
+Stage.prototype.clearPenStrokes = function() {
+    this.lineCache.clearRect(0, 0, 480, 360);
+}
+  
+Stage.prototype.stroke = function(from, to, width, color) {
+    this.lineCache.lineWidth = width;
+    this.lineCache.lineCap = 'round';
+    this.lineCache.beginPath();
+    // Use .5 offsets for canvas rigid pixel drawing
+    this.lineCache.moveTo(from[0] + 240.5, 180.5 - from[1]);
+    this.lineCache.lineTo(to[0] + 240.5, 180.5 - to[1]);
+    this.lineCache.strokeStyle = 'rgb(' + (color >> 16) + ',' + (color >> 8 & 255) + ',' + (color & 255) + ')';
+    this.lineCache.stroke();
+}