Use title passed to showWindow as display name if none has been set

examples/videoplayer.cpp

@@ -18,4 +18,5 @@ JNGL_MAIN_BEGIN {
 		}
 		jngl::swapBuffers();
 	}
+	jngl::trace("quit");
 } JNGL_MAIN_END

src/App.cpp

@@ -76,7 +76,7 @@ void App::callAtExitFunctions() {
 }
 
 std::string App::getDisplayName() const {
-	return impl->displayName;
+	return impl ? impl->displayName : "";
 }
 
 void App::setDisplayName(const std::string& displayName) {

src/jngl/Vec2.hpp

@@ -46,7 +46,7 @@ class Vec2 {
 	/// returns true if both x and y are exactly 0
 	bool isNull() const;
 
-	/// rotates the vector clock-wise
+	/// rotates the vector clock-wise by \a angle (radian)
 	void rotate(float angle);
 
 	/// Helper function to use with cereal or Boost.Serialization

src/jngl/window.hpp

@@ -16,6 +16,9 @@
 namespace jngl {
 
 /// Creates the main window
+///
+/// If you haven't set a display name for your app using AppParameters::displayName, \a title will
+/// set for the display name.
 void showWindow(const std::string& title, int width, int height, bool fullscreen = false,
                 std::pair<int, int> minAspectRatio = { 4, 3 },
                 std::pair<int, int> maxAspectRatio = { 16, 9 });

src/main.cpp

@@ -264,6 +264,9 @@ void showWindow(const std::string& title, const int width, const int height, boo
 		throw std::runtime_error("Height Is 0");
 	}
 	pWindow.Set(new Window(title, width, height, fullscreen, minAspectRatio, maxAspectRatio));
+	if (App::instance().getDisplayName().empty()) {
+		App::instance().setDisplayName(title);
+	}
 	pWindow->SetMouseVisible(isMouseVisible);
 	setAntiAliasing(antiAliasingEnabled);
 	pWindow->initGlObjects();