This is another post in the Inselkampf series. Having spent much of my career creating “desktop” application, web always feels a bit different. If it’s a website then HTML/CSS/PHP + MySql is a reasonable way of working. But when its a web application like a browser game that uses a SQL database, then there’s a bit of architecting involved.

I’m using Blazor because it lets me write C# that runs in the browser. I’ve never been a JavaScript fan though I realise many people are. I also have to use database. As I’ve said before Blazor gives you two choices- The WebAssembly version that runs completely in the browser and the Server version that talks to a server using a protocol called SignalR.

I’m trying to be clever by using the WebAssembly version but having the C# talk to a restful interface. Restful just means it has a bunch of http calls to do things like update, fetch data, login etc. On the server runs a ASP.NET program implementing this. It’s headless, as in its not outputting any webpages to the browser but just returns data in JSON (or maybe MessagePack).

This avoids having a SignalR connection for every user logged into the site which is one way to bring a server to its knees. When you create a Blazor Server application, it has a few disadvantages. As Microsoft says: when you use Blazor server.

• Higher latency usually exists. Every user interaction involves a network hop.
• There’s no offline support. If the client connection fails, the app stops working.
• Scalability is challenging for apps with many users. The server must manage multiple client connections and handle client state.
• An ASP.NET Core server is required to serve the app. Serverless deployment scenarios aren’t possible, such as serving the app from a Content Delivery Network (CDN).

I’m also not using the Microsoft authentication but rolling my own. Yes it’s possibly not perfect but I’ve done it before. This way I get to generate recovery numbers. (Both GitHub and Gmail offer these). A bunch of one off codes that are used to authenticate you, if you’ve lost your password or messed up your email then you login with your account number and an authentication code. This is the only way you get to change email and/or password. You just have to keep the codes safe.

Rolling my own Interface

So things like logging in, getting current status, updating game play are all done by making a call to an HTTPS routine. This is all behind the scenes so players see nothing. Values are sent as POST parameters and also include a nonce. This word (that unfortunately means sex offender in UK English!) , refers to a special code that has to be supplied with each call to the server to authenticate it. Successful logging in returns a nonce that has to be added as a parameter with every call to the server.

The program on the server that serves the restful calls is a simple ASP.NET Razor pages application (Well maybe Razor, I’m not sure if I need them). Behind the scenes I’m using MySQL which was installed as part of VirtualMin (the excellent software I use to setup the VPS).

I’ve talked about Inselkampf in a previous post. it was an example of a PBBG (Persistent Browser Based Game).  Currently if you want to write a web application that updates part of a page without refreshing itself, you have to do it via a JavaScript toolkit. People have been doing this going back about 15 years or so initially using a technology called AJAX.

Refreshing an entire web page takes a few seconds- some of the pages have got really big what with trackers and other things that bloat them up. So being able to update just part is a massive time saver plus it looks good.  Browser games couldn’t work without it.

Blazor takes things further by letting you update parts of pages, controls but in C#. There are two types of Blazor. WebAssembly (the machine code of the web) which does everything in the browser. It’s how the trains program works. The other type uses a server and does everything server side (controls and data) then sends it to the browser to be rendered.

For my purposes, the WebAssembly one is better. If you have a lot of people connected to a server then the Blazor server can use a fair whack of server resources. Th Blazor WebAssembly will also connect to the server but just to fetch or update data. So I’ve bought a Udemy course and am soaking up Blazor.

There’s still all sorts of questions. For example keeping the tick in synch. PBBG games often have a clock where new resources, building construction happen after a few seconds or longer. If you do this on the server then it’s not so difficult if the browser gets disconnected. In the browser though, it has to update the server or come up with some scheme so the browser and server don’t drift part. These are all part of the fun designing and programming such games. But I definitely think Blazor offers a lot of potential here.

Asteroids was the first full arcade game I ever wrote in C. Asteroids in C# takes things to a whole new level.  The solution contains 12 projects in all: Three Blazor projects, a WinForms version, a WPF version, a UWP (Universal Windows Platform) and a Xamarin Android Forms version (shown).

You can compile and run any of the projects though you will need to install and setup a suitable SDK and emulated (or a real device) for the Android.

Written by Howard Uman and ported by Ernie Salazar, this is a wireframe asteroids, more true to the original than my own raster version. Out of curiosity, I created an Android 9.0 emulator (I don’t have a recent Android phone) and compiled then deployed it to the emulator. The screenshot is grabbed directly from the emulator which has a less than ideal screen ratio. This would work better on a tablet.

The structure of the C# Solution is interesting. All of the game code is in the Base project. All of the other platforms just host the main game window. The game uses the SkiaSharp graphics framework for Android Forms.

This is a very nice open source project and an excellent way to see how Blazor works in both Wasm and Server mode, not to mention the Android, WinForms/WPF and UWP versions.

I have an interest in Blazor which lets you write C# code that runs in the browser very easily.  With a bit of workj, this should be runnable on a Linux webserver as well. Something for me to try…

Web games have been largely Flash in the past though that took a nosedive in the ‘tens (2010 onwards) and Flash is officially no more as of 2021. The spirit lives on in JavaScript games and there are innumerable games in JavaScript. That said, I’ve never been that keen on JavaScript. I talked about Web games in a post back in December and particularly that I saw Blazor as a possible game platform.

Today though I discovered Awesome Blazor on GitHub and it includes 18 Blazor web games including a multiplayer dungeon which is shown (I think it looks like a bit Pacmanish personally) . Most of these are ASP .NET Core 3.1 (which became .NET 5 late last year).

Some games will use wasm (Web Assembly) while other use C# in a terminal. As a simple proof of concept but nicely done, have a look at the virtual train set online.  You can lay track and then run one or more trains along it. Impressive as a demonstration of what you can do with C# and Blazor in a browser.