fix(package): update twgl.js to version 4.5.0

Add ability to get a snapshot of the next frame

package.json

@@ -37,12 +37,12 @@
     "gh-pages": "^1.0.0",
     "jsdoc": "^3.5.5",
     "json": "^9.0.4",
-    "scratch-vm": "0.2.0-prerelease.20180802142248",
+    "scratch-vm": "0.2.0-prerelease.20180824135031",
     "tap": "^11.0.0",
     "travis-after-all": "^1.4.4",
     "uglifyjs-webpack-plugin": "^1.2.5",
     "webpack": "^4.8.0",
-    "webpack-cli": "^2.0.15",
+    "webpack-cli": "^3.1.0",
     "webpack-dev-server": "^3.1.4"
   },
   "dependencies": {
@@ -52,8 +52,8 @@
     "linebreak": "0.3.0",
     "minilog": "3.1.0",
     "raw-loader": "^0.5.1",
-    "scratch-storage": "^0.4.0",
-    "scratch-svg-renderer": "0.2.0-prerelease.20180817005452",
-    "twgl.js": "4.4.0"
+    "scratch-storage": "^1.0.0",
+    "scratch-svg-renderer": "0.2.0-prerelease.20180926143036",
+    "twgl.js": "4.5.0"
   }
 }

src/RenderWebGL.js

@@ -178,6 +178,9 @@ class RenderWebGL extends EventEmitter {
         /** @type {function} */
         this._exitRegion = null;
 
+        /** @type {Array.<snapshotCallback>} */
+        this._snapshotCallbacks = [];
+
         this._svgTextBubble = new SVGTextBubble();
 
         this._createGeometry();
@@ -201,6 +204,13 @@ class RenderWebGL extends EventEmitter {
         return this._gl;
     }
 
+    /**
+     * @returns {HTMLCanvasElement} the canvas of the WebGL rendering context associated with this renderer.
+     */
+    get canvas () {
+        return this._gl && this._gl.canvas;
+    }
+
     /**
      * Set the physical size of the stage in device-independent pixels.
      * This will be multiplied by the device's pixel ratio on high-DPI displays.
@@ -589,6 +599,11 @@ class RenderWebGL extends EventEmitter {
         gl.clear(gl.COLOR_BUFFER_BIT);
 
         this._drawThese(this._drawList, ShaderManager.DRAW_MODE.default, this._projection);
+        if (this._snapshotCallbacks.length > 0) {
+            const snapshot = gl.canvas.toDataURL();
+            this._snapshotCallbacks.forEach(cb => cb(snapshot));
+            this._snapshotCallbacks = [];
+        }
     }
 
     /**
@@ -1704,6 +1719,18 @@ class RenderWebGL extends EventEmitter {
         dst[2] += blendAlpha * 255;
         return dst;
     }
+
+    /**
+     * @callback RenderWebGL#snapshotCallback
+     * @param {string} dataURI Data URI of the snapshot of the renderer
+     */
+
+    /**
+     * @param {snapshotCallback} callback Function called in the next frame with the snapshot data
+     */
+    requestSnapshot (callback) {
+        this._snapshotCallbacks.push(callback);
+    }
 }
 
 // :3