[webgl] Fix worker mode, closes #1804

spine-ts/build/spine-all.js

@@ -11031,7 +11031,7 @@ var spine;
 			function ManagedWebGLRenderingContext(canvasOrContext, contextConfig) {
 				if (contextConfig === void 0) { contextConfig = { alpha: "true" }; }
 				this.restorables = new Array();
-				if (canvasOrContext instanceof HTMLCanvasElement || canvasOrContext instanceof EventTarget) {
+				if (!((canvasOrContext instanceof WebGLRenderingContext) || (canvasOrContext instanceof WebGL2RenderingContext))) {
 					this.setupCanvas(canvasOrContext, contextConfig);
 				}
 				else {

spine-ts/build/spine-player.js

@@ -10763,7 +10763,7 @@ var spine;
 			function ManagedWebGLRenderingContext(canvasOrContext, contextConfig) {
 				if (contextConfig === void 0) { contextConfig = { alpha: "true" }; }
 				this.restorables = new Array();
-				if (canvasOrContext instanceof HTMLCanvasElement || canvasOrContext instanceof EventTarget) {
+				if (!((canvasOrContext instanceof WebGLRenderingContext) || (canvasOrContext instanceof WebGL2RenderingContext))) {
 					this.setupCanvas(canvasOrContext, contextConfig);
 				}
 				else {

spine-ts/build/spine-webgl.js

@@ -10763,7 +10763,7 @@ var spine;
 			function ManagedWebGLRenderingContext(canvasOrContext, contextConfig) {
 				if (contextConfig === void 0) { contextConfig = { alpha: "true" }; }
 				this.restorables = new Array();
-				if (canvasOrContext instanceof HTMLCanvasElement || canvasOrContext instanceof EventTarget) {
+				if (!((canvasOrContext instanceof WebGLRenderingContext) || (canvasOrContext instanceof WebGL2RenderingContext))) {
 					this.setupCanvas(canvasOrContext, contextConfig);
 				}
 				else {

spine-ts/webgl/src/WebGL.ts

@@ -34,7 +34,7 @@ module spine.webgl {
 		private restorables = new Array<Restorable>();
 
 		constructor(canvasOrContext: HTMLCanvasElement | WebGLRenderingContext | EventTarget | WebGL2RenderingContext, contextConfig: any = { alpha: "true" }) {
-			if (canvasOrContext instanceof HTMLCanvasElement || canvasOrContext instanceof EventTarget) {
+			if (!((canvasOrContext instanceof WebGLRenderingContext) || (canvasOrContext instanceof WebGL2RenderingContext))) {
 				this.setupCanvas(canvasOrContext, contextConfig);
 			} else {
 				this.gl = canvasOrContext;