Webclient: In singleplayer, show confirmation dialog before closing page unless map was saved within last 5 seconds

src/Game.c

@@ -649,6 +649,11 @@ static void Game_RunLoop(void) {
 	/*  Now thats there's a main loop, Game_SetFpsLimit will actually do something */
 	Game_SetFpsLimit(Options_GetEnum(OPT_FPS_LIMIT, 0, FpsLimit_Names, FPS_LIMIT_COUNT));
 }
+
+cc_bool Game_ShouldClose(void) {
+	/* Running in multiplayer or map was saved within last 5 seconds */
+	return !Server.IsSinglePlayer || (World.LastSave + 5 >= Game.Time);
+}
 #else
 static void Game_RunLoop(void) {
 	cc_uint64 lastRender, render; 

src/Game.h

@@ -78,6 +78,8 @@ void Game_SetFpsLimit(int method);
 
 /* Runs the main game loop until the window is closed. */
 void Game_Run(int width, int height, const cc_string* title);
+/* Whether the game should be allowed to automatically close */
+cc_bool Game_ShouldClose(void);
 
 /* Represents a game component. */
 struct IGameComponent;

src/Menus.c

@@ -1398,6 +1398,7 @@ static void SaveLevelScreen_SaveMap(struct SaveLevelScreen* s, const cc_string*
 #else
 	Chat_Add1("&eSaved map to: %s", path);
 #endif
+	World.LastSave = Game.Time;
 	Gui_ShowPauseMenu();
 }
 

src/Window.c

@@ -2745,6 +2745,7 @@ void Window_FreeFramebuffer(struct Bitmap* bmp) {
 #include <emscripten/emscripten.h>
 #include <emscripten/html5.h>
 #include <emscripten/key_codes.h>
+#include "Game.h"
 static cc_bool keyboardOpen, needResize;
 
 static int RawDpiScale(int x)    { return (int)(x * emscripten_get_device_pixel_ratio()); }
@@ -2908,6 +2909,12 @@ static EM_BOOL OnFullscreenChange(int type, const EmscriptenFullscreenChangeEven
 }
 
 static const char* OnBeforeUnload(int type, const void* ev, void *data) {
+	if (!Game_ShouldClose()) {
+		/* Exit pointer lock, otherwise when you press Ctrl+W, the */
+		/*  cursor remains invisible in the confirmation dialog */
+		emscripten_exit_pointerlock();
+		return "You have unsaved changes. Are you sure you want to quit?";
+	}
 	Window_Close();
 	return NULL;
 }

src/World.c

@@ -46,7 +46,8 @@ void World_Reset(void) {
 	World.Blocks = NULL;
 
 	World_SetDimensions(0, 0, 0);
-	World.Loaded = false;
+	World.Loaded   = false;
+	World.LastSave = -200;
 	Env_Reset();
 }
 

src/World.h

@@ -44,6 +44,8 @@ CC_VAR extern struct _WorldData {
 	/* Whether the world has finished loading/generating. */
 	/* NOTE: Blocks may still be NULL. (e.g. error during loading) */
 	cc_bool Loaded;
+	/* Point in time the current world was last saved at */
+	double LastSave;
 } World;
 
 /* Frees the blocks array, sets dimensions to 0, resets environment to default. */