Fix drawingBufferSize computation when context is lost

Author: greggman

src/utils.js

@@ -104,6 +104,9 @@ export function getDrawingbufferInfo(gl) {
 }
 export function computeDrawingbufferSize(gl, drawingBufferInfo) {
   // this will need to change for hi-color support
+  if (gl.isContextLost()) {
+    return 0;
+  }
   const {samples, depthBits, contextAttributes} = drawingBufferInfo;
   const size = gl.drawingBufferWidth * gl.drawingBufferHeight * 4 || 0;
   const depth = contextAttributes.depth ? 1 : 0;

test/tests/contextloss-tests.js

@@ -14,7 +14,7 @@ function createExposedPromise() {
 
 const wait = ms => new Promise(resolve => setTimeout(resolve, ms));
 
-describe('webgl context loss tests', () => {
+describe('webgl context lost tests', () => {
 
   async function testContextLost(gl) {
     const contextLostExposedPromise = createExposedPromise();

test/tests/test-utils.js

@@ -6,13 +6,15 @@ export class MemInfoTracker {
     assertTruthy(gl);
     this.ext = gl.getExtension('GMAN_webgl_memory');
     assertTruthy(this.ext);
-    this.drawingbufferSize = computeDrawingbufferSize(gl, getDrawingbufferInfo(gl));
+    this.gl = gl;
     this.numObjects = 0;
     this.memSize = 0;
     this.type = type;
   }
   check() {
-    const {ext, type, memSize, numObjects, drawingbufferSize} = this;
+    const {gl} = this;
+    const drawingbufferSize = computeDrawingbufferSize(gl, getDrawingbufferInfo(gl));
+    const {ext, type, memSize, numObjects} = this;
     const {memory, resources} = ext.getMemoryInfo();
     if (memory[type] !== undefined) {
       assertEqual(memory[type], memSize, `memory.${type}`);