1 files changed, 47 insertions, 5 deletions

diff --git a/platform/javascript/javascript_main.cpp b/platform/javascript/javascript_main.cpp
index fd61c46e63..99672745e7 100644
--- a/platform/javascript/javascript_main.cpp
+++ b/platform/javascript/javascript_main.cpp
@@ -30,11 +30,13 @@
 
 #include "core/io/resource_loader.h"
 #include "main/main.h"
-#include "os_javascript.h"
+#include "platform/javascript/display_server_javascript.h"
+#include "platform/javascript/os_javascript.h"
 
 #include <emscripten/emscripten.h>
 
 static OS_JavaScript *os = nullptr;
+static uint64_t target_ticks = 0;
 
 void exit_callback() {
 	emscripten_cancel_main_loop(); // After this, we can exit!
@@ -46,12 +48,32 @@ void exit_callback() {
 }
 
 void main_loop_callback() {
+	uint64_t current_ticks = os->get_ticks_usec();
+
+	bool force_draw = DisplayServerJavaScript::get_singleton()->check_size_force_redraw();
+	if (force_draw) {
+		Main::force_redraw();
+	} else if (current_ticks < target_ticks) {
+		return; // Skip frame.
+	}
+
+	int target_fps = Engine::get_singleton()->get_target_fps();
+	if (target_fps > 0) {
+		target_ticks += (uint64_t)(1000000 / target_fps);
+	}
 	if (os->main_loop_iterate()) {
 		emscripten_cancel_main_loop(); // Cancel current loop and wait for finalize_async.
+		/* clang-format off */
 		EM_ASM({
 			// This will contain the list of operations that need to complete before cleanup.
-			Module.async_finish = [];
+			Module.async_finish = [
+				// Always contains at least one async promise, to avoid firing immediately if nothing is added.
+				new Promise(function(accept, reject) {
+					setTimeout(accept, 0);
+				})
+			];
 		});
+		/* clang-format on */
 		os->get_main_loop()->finish();
 		os->finalize_async(); // Will add all the async finish functions.
 		EM_ASM({
@@ -79,13 +101,35 @@ extern "C" EMSCRIPTEN_KEEPALIVE void main_after_fs_sync(char *p_idbfs_err) {
 	ResourceLoader::set_abort_on_missing_resources(false);
 	Main::start();
 	os->get_main_loop()->init();
-	emscripten_resume_main_loop();
 	// Immediately run the first iteration.
 	// We are inside an animation frame, we want to immediately draw on the newly setup canvas.
 	main_loop_callback();
+	emscripten_resume_main_loop();
 }
 
 int main(int argc, char *argv[]) {
+	// Create and mount userfs immediately.
+	EM_ASM({
+		FS.mkdir('/userfs');
+		FS.mount(IDBFS, {}, '/userfs');
+	});
+
+	// Configure locale.
+	char locale_ptr[16];
+	/* clang-format off */
+	EM_ASM({
+		stringToUTF8(Module['locale'], $0, 16);
+	}, locale_ptr);
+	/* clang-format on */
+	setenv("LANG", locale_ptr, true);
+
+	// Ensure the canvas ID.
+	/* clang-format off */
+	EM_ASM({
+		stringToUTF8("#" + Module['canvas'].id, $0, 255);
+	}, DisplayServerJavaScript::canvas_id);
+	/* clang-format on */
+
 	os = new OS_JavaScript();
 	Main::setup(argv[0], argc - 1, &argv[1], false);
 	emscripten_set_main_loop(main_loop_callback, -1, false);
@@ -95,8 +139,6 @@ int main(int argc, char *argv[]) {
 	// run the 'main_after_fs_sync' function.
 	/* clang-format off */
 	EM_ASM({
-		FS.mkdir('/userfs');
-		FS.mount(IDBFS, {}, '/userfs');
 		FS.syncfs(true, function(err) {
 			requestAnimationFrame(function() {
 				ccall('main_after_fs_sync', null, ['string'], [err ? err.message : ""]);