updateSource method
Implementation
void updateSource(FlutterAngleTexture texture, [WebGLTexture? sourceTexture]) async {
if (sourceTexture != null) {
texture.rawOpenGl.glClearColor(0.0, 0.0, 0.0, 0.0);
texture.rawOpenGl.glClear(16384 | 256 | 1024);
texture.rawOpenGl.glViewport(0, 0, (texture.options.width*texture.options.dpr).toInt(),( texture.options.height*texture.options.dpr).toInt());
_worker?.renderTexture(sourceTexture,isFBO: true);
texture.rawOpenGl.glFinish();
}
}