Make sure to obey hidpi to off by default, as present in project settings. Set it to on by default for editor.

Many integrated GPUs can't really get enough performance to play games at hidpi, so this should be enabled manually.

core/os/os.cpp

@@ -541,7 +541,7 @@ OS::OS() {
 
 	_render_thread_mode = RENDER_THREAD_SAFE;
 
-	_allow_hidpi = true;
+	_allow_hidpi = false;
 	_stack_bottom = (void *)(&stack_bottom);
 
 	_logger = NULL;

main/main.cpp

@@ -774,6 +774,9 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 	GLOBAL_DEF("rendering/quality/intended_usage/framebuffer_allocation", 2);
 	GLOBAL_DEF("rendering/quality/intended_usage/framebuffer_allocation.mobile", 3);
 
+	if (editor) {
+		OS::get_singleton()->_allow_hidpi = true; //editors always in hidpi
+	}
 	Engine::get_singleton()->_pixel_snap = GLOBAL_DEF("rendering/quality/2d/use_pixel_snap", false);
 	OS::get_singleton()->_keep_screen_on = GLOBAL_DEF("display/window/energy_saving/keep_screen_on", true);
 	if (rtm == -1) {