Adapt for web

src/main.cpp

@@ -5,15 +5,87 @@
 #include <android/log.h>
 #endif
 
+#ifdef EMSCRIPTEN
+#include <emscripten.h>
+#include <emscripten/html5.h>
+#endif
 
+
+// For Emscripten the game is heap-allocated so it can be destroyed and
+// re-created when the WebGL context is lost and restored (e.g. fullscreen).
+// For Android and Desktop a plain global value is used (no context loss).
+#ifdef EMSCRIPTEN
+ZL::Game* g_game = nullptr;
+#else
 ZL::Game game;
+#endif
 
 
 void MainLoop() {
+#ifdef EMSCRIPTEN
+    if (g_game) g_game->update();
+#else
     game.update();
+#endif
 }
 
 
+#ifdef EMSCRIPTEN
+
+EM_BOOL onWebGLContextLost(int /*eventType*/, const void* /*reserved*/, void* /*userData*/) {
+    delete g_game;
+    g_game = nullptr;
+    return EM_TRUE;
+}
+
+EM_BOOL onWebGLContextRestored(int /*eventType*/, const void* /*reserved*/, void* /*userData*/) {
+    g_game = new ZL::Game();
+    g_game->setup();
+    return EM_TRUE;
+}
+
+// Resize the canvas, notify SDL, and push a synthetic SDL_WINDOWEVENT_RESIZED
+// so Game::update()'s existing handler updates Environment::width/height and clears caches.
+static void applyResize(int w, int h) {
+    if (w <= 0 || h <= 0) return;
+    // Resize the actual WebGL canvas — without this the rendered pixels stay at
+    // the original size no matter what Environment::width/height say.
+    emscripten_set_canvas_element_size("#canvas", w, h);
+    if (ZL::Environment::window)
+        SDL_SetWindowSize(ZL::Environment::window, w, h);
+    SDL_Event e = {};
+    e.type = SDL_WINDOWEVENT;
+    e.window.event = SDL_WINDOWEVENT_RESIZED;
+    e.window.data1 = w;
+    e.window.data2 = h;
+    SDL_PushEvent(&e);
+}
+
+EM_BOOL onWindowResized(int /*eventType*/, const EmscriptenUiEvent* e, void* /*userData*/) {
+    // Use the event's window dimensions — querying the canvas element would
+    // return its old fixed size (e.g. 1280x720) before it has been resized.
+    applyResize(e->windowInnerWidth, e->windowInnerHeight);
+    return EM_FALSE;
+}
+
+EM_BOOL onFullscreenChanged(int /*eventType*/, const EmscriptenFullscreenChangeEvent* e, void* /*userData*/) {
+    if (e->isFullscreen) {
+        // e->screenWidth/screenHeight comes from screen.width/screen.height in JS,
+        // which on mobile browsers returns physical pixels (e.g. 2340x1080),
+        // causing the canvas to extend far off-screen. window.innerWidth/innerHeight
+        // always gives CSS logical pixels and is correct on both desktop and mobile.
+        int w = EM_ASM_INT({ return window.innerWidth; });
+        int h = EM_ASM_INT({ return window.innerHeight; });
+        applyResize(w, h);
+    }
+    // Exiting fullscreen: the browser fires a window resize event next,
+    // which onWindowResized handles automatically.
+    return EM_FALSE;
+}
+
+#endif
+
+
 #ifdef __ANDROID__
 
 extern "C" int SDL_main(int argc, char* argv[]) {
@@ -34,7 +106,7 @@ extern "C" int SDL_main(int argc, char* argv[]) {
 
     __android_log_print(ANDROID_LOG_INFO, "Game", "Display resolution: %dx%d",
                        ZL::Environment::width, ZL::Environment::height);
-					   
+
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
@@ -52,13 +124,13 @@ extern "C" int SDL_main(int argc, char* argv[]) {
         ZL::Environment::width, ZL::Environment::height,
         SDL_WINDOW_FULLSCREEN | SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN
     );
-	
+
 	if (!ZL::Environment::window) {
         __android_log_print(ANDROID_LOG_ERROR, "Game", "Failed to create window: %s", SDL_GetError());
         SDL_Quit();
         return 1;
     }
-	
+
 	SDL_GLContext ctx = SDL_GL_CreateContext(ZL::Environment::window);
     if (!ctx) {
         __android_log_print(ANDROID_LOG_ERROR, "Game", "SDL_GL_CreateContext failed: %s", SDL_GetError());
@@ -94,7 +166,7 @@ extern "C" int SDL_main(int argc, char* argv[]) {
     }
 
     return 0;
-	
+
 }
 
 
@@ -103,8 +175,8 @@ extern "C" int SDL_main(int argc, char* argv[]) {
 int main(int argc, char *argv[]) {
     try
     {
-		
-		
+
+
         constexpr int CONST_WIDTH = 1280;
         constexpr int CONST_HEIGHT = 720;
 
@@ -142,6 +214,20 @@ int main(int argc, char *argv[]) {
         SDL_GL_MakeCurrent(win, glContext);
 
         ZL::Environment::window = win;
+
+        g_game = new ZL::Game();
+        g_game->setup();
+
+        // Re-create the game object when the WebGL context is lost and restored
+        // (this happens e.g. when the user toggles fullscreen in the browser).
+        emscripten_set_webglcontextlost_callback("#canvas", nullptr, EM_TRUE, onWebGLContextLost);
+        emscripten_set_webglcontextrestored_callback("#canvas", nullptr, EM_TRUE, onWebGLContextRestored);
+
+        // Keep Environment::width/height in sync when the canvas is resized.
+        emscripten_set_resize_callback(EMSCRIPTEN_EVENT_TARGET_WINDOW, nullptr, EM_FALSE, onWindowResized);
+        emscripten_set_fullscreenchange_callback(EMSCRIPTEN_EVENT_TARGET_DOCUMENT, nullptr, EM_FALSE, onFullscreenChanged);
+
+        emscripten_set_main_loop(MainLoop, 0, 1);
 #else
         if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS) != 0) {
             SDL_Log("SDL init failed: %s", SDL_GetError());
@@ -161,13 +247,9 @@ int main(int argc, char *argv[]) {
 
         SDL_GLContext ctx = SDL_GL_CreateContext(ZL::Environment::window);
         SDL_GL_MakeCurrent(ZL::Environment::window, ctx);
-#endif
 
         game.setup();
 
-#ifdef EMSCRIPTEN   
-        emscripten_set_main_loop(MainLoop, 0, 1);
-#else
         while (!game.shouldExit()) {
             game.update();
             SDL_Delay(2);
@@ -182,4 +264,4 @@ int main(int argc, char *argv[]) {
 
     return 0;
 }
-#endif
+#endif