[Impeller] GL backend has a race around surface setup and toImage/toImageSync #124635
Description
See #124181
This code:
import 'dart:ui';
void main() async {
final recorder = PictureRecorder();
final canvas = Canvas(recorder);
canvas.drawCircle(Offset.zero, 10, Paint());
final picture = recorder.endRecording();
final image = picture.toImageSync(20, 20); // Image was null
final byteData = await image.toByteData(
format: ImageByteFormat.png,
);
print(byteData!.buffer.asUint32List());
}May fail even after flutter/engine#41059, because we need to make sure the GL context is current before doing the rendering.
This isn't a problem on Metal or Vulkan, where there's no current context to worry about, so I'd like to land the fix for Metal independently of GLES - especially since that patch is already pretty large and will be looking to cherry pick it.