From f28d635e64a4a7eb4010a41c687c6d206e154947 Mon Sep 17 00:00:00 2001
From: kkapsner <github@mail.kkapsner.de>
Date: Tue, 10 Oct 2017 20:13:40 +0200
Subject: [PATCH] Better webGL test (also covers webgl2).

---
 test/webGL-Test.js | 46 ++++++++++++++++++++++++++++++----------------
 1 file changed, 30 insertions(+), 16 deletions(-)

diff --git a/test/webGL-Test.js b/test/webGL-Test.js
index 858b471..d580292 100644
--- a/test/webGL-Test.js
+++ b/test/webGL-Test.js
@@ -1,20 +1,34 @@
 (function(){
 	"use strict";
 	
-	var canvas = document.createElement("canvas");
-	canvas.width = 11;
-	canvas.height = 13;
-	var gl = canvas.getContext("webgl");
-	
-	// paint it completely black
-	gl.clearColor(0, 0, 0, 1);
-	gl.clear(gl.COLOR_BUFFER_BIT);
-	
-	var pixels = new Uint8Array(gl.drawingBufferWidth * gl.drawingBufferHeight * 4);
-	gl.readPixels(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
-	var values = {};
-	for (var i = 0; i < pixels.length; i += 1){
-		values[pixels[i]] = (values[pixels[i]] || 0) + 1;
-	}
-	document.getElementById("output").textContent = JSON.stringify(values);
+	["webgl", "webgl2"].forEach(function(context, index){
+		var output = document.createElement("div");
+		document.getElementById("output").appendChild(output);
+		try {
+			var canvas = document.createElement("canvas");
+			canvas.width = 11;
+			canvas.height = 13;
+			var gl = canvas.getContext(context) || canvas.getContext("experimental-" + context);
+			
+			// paint it completely black
+			gl.clearColor(index * 0.25, index * 0.25, index * 0.25, 1);
+			gl.clear(gl.COLOR_BUFFER_BIT);
+			
+			var pixels = new Uint8Array(gl.drawingBufferWidth * gl.drawingBufferHeight * 4);
+			gl.readPixels(0, 0, gl.drawingBufferWidth, gl.drawingBufferHeight, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
+			var values = {};
+			var max = 0;
+			for (var i = 0; i < pixels.length; i += 1){
+				values[pixels[i]] = (values[pixels[i]] || 0) + 1;
+				max = Math.max(max, values[pixels[i]]);
+			}
+
+			output.textContent = context + ": " + (max !== 3 * values[255]? "": "not ") + "faked";
+			output.title = JSON.stringify(values);
+		}
+		catch (e){
+			output.textContent = context + ": ERROR";
+			output.title = e;
+		}
+	});
 }());
\ No newline at end of file