From ed0405c83af131d6e7166f44534ac477c816fe6f Mon Sep 17 00:00:00 2001
From: Jan Niklas Hasse <jhasse@bixense.com>
Date: Fri, 6 Oct 2023 21:40:44 +0200
Subject: [PATCH] Turn jngl::App back into some kind of singleton

Otherwise isPixelArt crashes on emscripten since mainLoop() gets exited
there.
---
 src/App.cpp              | 22 ++++++++++++++--------
 src/App.hpp              |  8 +++++---
 src/ios/JNGLView.mm      |  2 +-
 src/unittest/Fixture.cpp |  3 ---
 4 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/src/App.cpp b/src/App.cpp
index 6bbc4bad5..64f7ab6fa 100644
--- a/src/App.cpp
+++ b/src/App.cpp
@@ -12,6 +12,7 @@
 #include "windowptr.hpp"
 
 #include <cmath>
+#include <memory>
 #include <set>
 #include <stdexcept>
 
@@ -32,15 +33,11 @@ struct App::Impl {
 	std::set<ShaderProgram*> shaderPrograms{};
 };
 
-App::App(AppParameters params)
-: impl(new Impl{ std::move(params.displayName), params.pixelArt, params.steamAppId }) {
+App::App() {
 	if (self) {
 		throw std::runtime_error("You may only create one instance of jngl::App.");
 	}
 	self = this;
-	if (auto id = impl->steamAppId) {
-		jngl::initSteam(*id);
-	}
 }
 
 App::~App() {
@@ -49,11 +46,16 @@ App::~App() {
 
 App& App::instance() {
 	if (!self) {
-		self = new App({});
+		self = new App;
 	}
 	return *self;
 }
 
+void App::init(AppParameters params) {
+	impl = std::make_unique<App::Impl>(
+	    App::Impl{ std::move(params.displayName), params.pixelArt, params.steamAppId });
+}
+
 std::string App::getDisplayName() const {
 	return impl->displayName;
 }
@@ -100,7 +102,11 @@ void App::updateProjectionMatrix() const {
 namespace internal {
 
 void mainLoop(AppParameters params) {
-	App app(params);
+	App::instance().init(params);
+	if (auto id = params.steamAppId) {
+		jngl::initSteam(*id);
+	}
+
 	bool fullscreen = false;
 #if (!defined(__EMSCRIPTEN__) && defined(NDEBUG)) || defined(__ANDROID__)
 	fullscreen = true;
@@ -141,7 +147,7 @@ void mainLoop(AppParameters params) {
 	           fullscreen, params.minAspectRatio ? *params.minAspectRatio : minAspectRatio,
 	           params.maxAspectRatio ? *params.maxAspectRatio : maxAspectRatio);
 	setWork(params.start());
-	app.mainLoop();
+	App::instance().mainLoop();
 }
 
 } // namespace internal
diff --git a/src/App.hpp b/src/App.hpp
index 50ac7c9a2..27568c281 100644
--- a/src/App.hpp
+++ b/src/App.hpp
@@ -26,9 +26,6 @@ class ShaderProgram;
 /// \endcode
 class App {
 public:
-	/// Do not call this constructor yourself, it gets called by JNGL_MAIN_BEGIN
-	explicit App(AppParameters);
-
 	~App();
 	App(const App&) = delete;
 	App& operator=(const App&) = delete;
@@ -58,7 +55,12 @@ class App {
 	/// Internal function used by JNGL when the Window is resized
 	void updateProjectionMatrix() const;
 
+	/// Do not call this function yourself, it gets called by JNGL_MAIN_BEGIN
+	void init(AppParameters);
+
 private:
+	App();
+
 	void registerShaderProgram(ShaderProgram*);
 	void unregisterShaderProgram(ShaderProgram*);
 
diff --git a/src/ios/JNGLView.mm b/src/ios/JNGLView.mm
index 517a8c929..a03d682ca 100644
--- a/src/ios/JNGLView.mm
+++ b/src/ios/JNGLView.mm
@@ -60,7 +60,7 @@ - (instancetype) initWithFrame: (CGRect)frame withAppParameters: (const jngl::Ap
 		glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &width);
 		glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &height);
 
-		jnglApp.reset(new jngl::App(params));
+        jngl::App::instance().init(params);
 		jngl::showWindow("", width, height, true,
 		                 params.minAspectRatio ? *params.minAspectRatio : std::make_pair(1, 3),
 		                 params.maxAspectRatio ? *params.maxAspectRatio : std::make_pair(3, 1));
diff --git a/src/unittest/Fixture.cpp b/src/unittest/Fixture.cpp
index 81dad1c3f..902d89426 100644
--- a/src/unittest/Fixture.cpp
+++ b/src/unittest/Fixture.cpp
@@ -3,8 +3,6 @@
 
 #include "Fixture.hpp"
 
-#include "../App.hpp"
-
 #include <boost/ut.hpp>
 #include <cmath>
 #include <jngl.hpp>
@@ -12,7 +10,6 @@
 
 Fixture::Fixture(const double scaleFactor) {
 	jngl::setScaleFactor(scaleFactor);
-	static jngl::App app(jngl::AppParameters{});
 	jngl::showWindow("unit test", static_cast<int>(std::lround(320 * scaleFactor)),
 	                 static_cast<int>(std::lround(70 * scaleFactor)), false, { 32, 7 }, { 32, 7 });
 	reset();