Working on loading screen

src/Game.h

@@ -10,6 +10,7 @@
 #include "items/Item.h"
 #include "items/InteractiveObject.h"
 #include <queue>
+#include <functional>
 #include <vector>
 #include <string>
 #include <memory>
@@ -49,6 +50,22 @@ namespace ZL {
 		VertexRenderStruct loadingMesh;
 		bool loadingCompleted = false;
 
+		// setupPart2() populates this queue with one closure per loading step instead of
+		// running the work itself; Game::update() drains one step per frame so the window
+		// keeps pumping events / repainting (and, on Emscripten, the browser keeps the tab
+		// responsive) instead of freezing for the whole duration of loading.
+		std::queue<std::function<void()>> loadSteps;
+		size_t loadStepsTotal = 0;
+		size_t loadStepsDone = 0;
+		float currentLoadingProgress() const {
+			return loadStepsTotal ? (float)loadStepsDone / (float)loadStepsTotal : resourcesDownloadProgress;
+		}
+
+		// The progress bar only reflects the initial resource load (its steps are
+		// pre-counted upfront). Later loadSteps runs, like MenuManager's localized
+		// content reload, don't have a meaningful denominator, so the bar is hidden.
+		bool showLoadingProgressBar = true;
+
 		GameState gameState;
 
 		EditorMode editorMode = EditorMode::None;
@@ -138,8 +155,13 @@ namespace ZL {
 		static void onResourcesZipLoaded(unsigned handle, void* userData, const char* filename);
 		static void onResourcesZipError(unsigned handle, void* userData, int httpStatus);
 		static void onResourcesZipProgress(unsigned handle, void* userData, int percentComplete);
-
+#endif
+		// Only meaningful during the Emscripten zip-download phase, before loadSteps
+		// exists (see currentLoadingProgress() above); harmless/unused on other platforms.
 		float resourcesDownloadProgress = 0.0f;
+
+		// Progress bar assets/meshes, loaded and drawn on every platform so setupPart2's
+		// step-by-step progress is visible during desktop/Android loading too.
 		std::shared_ptr<Texture> loadingProgressBarTexture;
 		std::shared_ptr<Texture> loadingProgressBarFrameTexture;
 		VertexRenderStruct loadingProgressBarFrameMesh;
@@ -147,7 +169,6 @@ namespace ZL {
 		float loadingBarLastRenderedProgress = -1.0f;
 		float loadingBarLastW = -1.0f;
 		float loadingBarLastH = -1.0f;
-#endif
 
 		// Screen-flash transition state (shared by darklands and night transitions)
 		float darklandsFlashAlpha = 0.0f;