Avoid hardcoding the script file name on web platform Urho3DPlayer. Rather attempt to read from CommandLine.txt later once resources are initialized. Setup a default windowed resolution to match the executable web samples.

Source/Tools/Urho3DPlayer/Urho3DPlayer.cpp

@@ -49,6 +49,9 @@ void Urho3DPlayer::Setup()
 {
     FileSystem* filesystem = GetSubsystem<FileSystem>();
 
+    // Web platform depends on the resource system to read any data files. Skip parsing the command line now
+    // and try later when the resource system is live
+#ifndef EMSCRIPTEN
     // Read command line from a file if no arguments given. This is primarily intended for mobile platforms.
     // Note that the command file name uses a hardcoded path that does not utilize the resource system
     // properly (including resource path prefix), as the resource system is not yet initialized at this point
@@ -63,17 +66,8 @@ void Urho3DPlayer::Setup()
         engineParameters_ = Engine::ParseParameters(GetArguments());
     }
 
-    // Check for script file name
-    const Vector<String>& arguments = GetArguments();
-    String scriptFileName;
-    if (arguments.Size() && arguments[0][0] != '-')
-        scriptFileName_ = GetInternalPath(arguments[0]);
-
-    // On Emscripten CommandLine.txt can only be read through the resource system, but it is not yet possible,
-    // so hardcode the script name for now. NinjaSnowWar cannot be used as the Network subsystem doesn't exist
-#ifdef EMSCRIPTEN
-    scriptFileName_ = "Scripts/18_CharacterDemo.as";
-#endif
+    // Check for script file name from the arguments
+    GetScriptFileName();
 
     // Show usage if not found
     if (scriptFileName_.Empty())
@@ -126,6 +120,10 @@ void Urho3DPlayer::Setup()
         // Use the script file name as the base name for the log file
         engineParameters_["LogName"] = filesystem->GetAppPreferencesDir("urho3d", "logs") + GetFileNameAndExtension(scriptFileName_) + ".log";
     }
+#else
+    // On Web platform setup a default windowed resolution similar to the executable samples
+    engineParameters_["FullScreen"]  = false;
+#endif
 
     // Construct a search path to find the resource prefix with two entries:
     // The first entry is an empty path which will be substituted with program/bin directory -- this entry is for binary when it is still in build tree
@@ -136,6 +134,27 @@ void Urho3DPlayer::Setup()
 
 void Urho3DPlayer::Start()
 {
+    // Reattempt reading the command line now on Web platform
+#ifdef EMSCRIPTEN
+    if (GetArguments().Empty())
+    {
+        SharedPtr<File> commandFile = GetSubsystem<ResourceCache>()->GetFile("CommandLine.txt", false);
+        if (commandFile)
+        {
+            String commandLine = commandFile->ReadLine();
+            commandFile->Close();
+            ParseArguments(commandLine, false);
+            GetScriptFileName();
+        }
+    }
+    
+    if (scriptFileName_.Empty())
+    {
+        ErrorExit("Script file name not specified; cannot proceed");
+        return;
+    }
+#endif
+
     String extension = GetExtension(scriptFileName_);
     if (extension != ".lua" && extension != ".luc")
     {
@@ -240,3 +259,10 @@ void Urho3DPlayer::HandleScriptReloadFailed(StringHash eventType, VariantMap& ev
     ErrorExit();
 #endif
 }
+
+void Urho3DPlayer::GetScriptFileName()
+{
+    const Vector<String>& arguments = GetArguments();
+    if (arguments.Size() && arguments[0][0] != '-')
+        scriptFileName_ = GetInternalPath(arguments[0]);
+}

Source/Tools/Urho3DPlayer/Urho3DPlayer.h

@@ -49,6 +49,8 @@ private:
     void HandleScriptReloadFinished(StringHash eventType, VariantMap& eventData);
     /// Handle reload failure of the script file.
     void HandleScriptReloadFailed(StringHash eventType, VariantMap& eventData);
+    /// Parse script file name from the first argument.
+    void GetScriptFileName();
 
     /// Script file name.
     String scriptFileName_;