From 8adb68630ee63c1bf615ada2907cd64e3e959ac4 Mon Sep 17 00:00:00 2001
From: lisyarus <lisyarus@gmail.com>
Date: Sat, 1 Feb 2025 07:16:58 +0100
Subject: [PATCH] Change mainloop for web builds

---
 libs/sdl2/source/main.cpp | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/libs/sdl2/source/main.cpp b/libs/sdl2/source/main.cpp
index 20d433b0..1307cf03 100644
--- a/libs/sdl2/source/main.cpp
+++ b/libs/sdl2/source/main.cpp
@@ -11,6 +11,18 @@
 #include <psemek/util/exception.hpp>
 #include <psemek/util/terminal_color.hpp>
 
+#ifdef __EMSCRIPTEN__
+	#include <emscripten/emscripten.h>
+	#include <emscripten/html5.h>
+	#include <emscripten.h>
+
+	struct em_state
+	{
+		std::unique_ptr<psemek::app::application> application;
+		std::unique_ptr<psemek::sdl2::window> window;
+	} em_state;
+#endif
+
 #undef main
 
 int main(int argc, char ** argv) try
@@ -40,7 +52,12 @@ int main(int argc, char ** argv) try
 	auto const factory = app::make_application_factory();
 	auto const options = factory->options();
 
+#ifdef __EMSCRIPTEN__
+	em_state.window = std::make_unique<sdl2::window>(options);
+	auto & window = *em_state.window;
+#else
 	sdl2::window window(options);
+#endif
 
 	app::application::context context;
 	for (int i = 0; i < argc; ++i)
@@ -61,7 +78,13 @@ int main(int argc, char ** argv) try
 	context.device = window.wgpu_device();
 #endif
 
+
+#ifdef __EMSCRIPTEN__
+	em_state.application = factory->create(options, context);
+	auto application = em_state.application.get();
+#else
 	auto application = factory->create(options, context);
+#endif
 
 	if (!application)
 		return EXIT_FAILURE;
@@ -75,6 +98,21 @@ int main(int argc, char ** argv) try
 
 	SDL_StopTextInput();
 
+#ifdef __EMSCRIPTEN__
+	emscripten_request_animation_frame_loop([](double, void*) -> EM_BOOL {
+		if (sdl2::poll_events(*em_state.application))
+			em_state.application->stop();
+
+		if (!em_state.application->running())
+			return EM_FALSE;
+
+		em_state.application->update();
+		em_state.application->present();
+		em_state.window->swap();
+
+		return EM_TRUE;
+	}, nullptr);
+#else
 	while (application->running())
 	{
 		if (sdl2::poll_events(*application))
@@ -84,6 +122,7 @@ int main(int argc, char ** argv) try
 		application->present();
 		window.swap();
 	}
+#endif
 
 	log::info() << "Quitting";
 	return EXIT_SUCCESS;