Add new function emscripten_is_webgl_context_lost() that allows code to directly query to confirm the WebGL context loss status.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/library_html5.js b/src/library_html5.js
index d9376c2a..d5d0cd66 100644
--- a/src/library_html5.js
+++ b/src/library_html5.js
@@ -1307,6 +1307,12 @@ var LibraryJSEvents = {
     JSEvents.registerWebGlEventCallback(target, userData, useCapture, callbackfunc, {{{ cDefine('EMSCRIPTEN_EVENT_WEBGLCONTEXTRESTORED') }}}, "webglcontextrestored");
     return {{{ cDefine('EMSCRIPTEN_RESULT_SUCCESS') }}};
   },
+
+  emscripten_is_webgl_context_lost: function(target) {
+    // TODO: In the future if multiple GL contexts are supported, use the 'target' parameter to find the canvas to query.
+    if (!Module['ctx']) return true; // No context ~> lost context.
+    return Module['ctx'].isContextLost();
+  }
 };
 
 autoAddDeps(LibraryJSEvents, '$JSEvents');