Tag: GameDev

We already announced some new features in April (PLY, InlineGeometry, web: URL parameters and TCastleDownload). Below we report more goodies 🙂 Enjoy!

1. Check out Training Timer 2: Zero Time project by Serufu Yua, available for Windows and Android. Downloads on itch.io and source code on GitHub (thank you!).

   See also ready UI list box components also from Serufu Yua. Thank you!

2. View changes (setting Container.View:=.., calling Container.PushView, Container.PopView) may be now performed with a delay. We have extensive documentation what it means, and why we do it, here. The forum thread, with even more information and reasons, is here. Thanks to Vlad (Phomm) for reporting this — this was a critical design problem we had, now “defused”.

   Please note that this change may require to adjust your code in some cases. We tried to make it backward-compatible, and in many cases it is, but it cannot be 100% — inherently, some things are now done later -> so some assumptions break.

   For example, you can no longer assume that new view is started right after PushView:

   procedure TViewMainMenu.ButtonClick; begin Container.PushView(ViewInventory); // THIS IS LIKELY INVALID NOW, // published ViewInventory.Label1 is not initialized // because ViewInventory.Start is not yet done. ViewInventory.Label1.Caption := 'Something'; // Solution is to pass information using a public field, // which will be applied in TViewInventory.Start: ViewInventory.DesiredLabel1Caption := 'Something'; end;

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   procedure TViewMainMenu.ButtonClick; begin   Container.PushView(ViewInventory);     // THIS IS LIKELY INVALID NOW,   // published ViewInventory.Label1 is not initialized   // because ViewInventory.Start is not yet done.   ViewInventory.Label1.Caption := 'Something';     // Solution is to pass information using a public field,   // which will be applied in TViewInventory.Start:   ViewInventory.DesiredLabel1Caption := 'Something'; end;

   Another example (of logic that will no longer work) is if you assumed that old view is stopped right away:

   procedure TViewMainMenu.ButtonClick; begin Container.View := nil; // THIS IS INVALID NOW, // if you assumed that ViewPlay.Stop is already executed // and did something with LastSavedSaveGame. LastSavedSaveGame.Done := true; end;

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   procedure TViewMainMenu.ButtonClick; begin   Container.View := nil;     // THIS IS INVALID NOW,   // if you assumed that ViewPlay.Stop is already executed   // and did something with LastSavedSaveGame.   LastSavedSaveGame.Done := true; end;

3. We have a new utility to process URLs of the model (useful before saving it) to e.g. force URLs to be relative or embedded. See ProcessUrls and TUrlProcessing API for the possibilities. See also pull request for all details. Thank you to Jan Adamec for implementing this!

4. We have added documentation how to install web prerequisites using “WA” button in FpcUpDeluxe. Thanks to Vlad (Phomm)!

5. I (Michalis) attended FOSS Backstage 2026 conference recently and enjoyed a lot of talks with fellow open-source devs (and walking in Berlin!). The talk “AI generated violations of FOSS Licences” was in particular informative, and fun, and sad -> because AIs indeed ignore copyrights and licenses. To put it bluntly, all the open-source code in the wild has been abused — it is now reproduced, ignoring copyrights. Watch it and maybe you can spot the back of my bald(ing) head in the front :).

   There’s a lot of related discussion and opinions, see e.g. here at Gitea and this article.

   I have added a suitable section about it to our AI guidelines.

6. Finally, something in progress: we work on audio playback on the web using WebAudio. Current progress is on branch webaudio. Details what works / what needs to be completed before merge in forum post here.

Enjoy using our engine? Please support us on Patreon. And have fun making games:)

We add 2 new features to our web target:

1. New methods to read URL through which your page was accessed, and get query parameters of this URL. The use-case is creating webpages that react to URL parameters, e.g. expose a model viewer on URL like https://viewer.castle-engine.io/?url=http://example.org/model.gltf (working version of this coming soon!). Use these methods:
   • Application.PageUrl – get entire URL as a string,

   • Application.PageUrlQuery – get query part of the URL (the part from ?), as a string,

   • Application.PageUrlParameter – get value of a specific query parameter,

   • Application.PageUrlParameters – get all query parameters as a dictionary

   This API exists on all platforms, just returns nothing on non-web platforms. So you don’t need to use any $ifdef WASI when accessing this.

2. TCastleDownload class works on the web now. It allows to make HTTP requests, e.g. download files or communicate with REST APIs. See URLs, loading resources and Multi-player (network communication) for general usage description.

   Underneath, it uses XMLHttpRequest which is the standard way to make HTTP requests on the web. It supports all HTTP methods, custom headers, progress monitoring and generally all features of our TCastleDownload.

   Examples:

   • examples/network/asynchronous_download/ – simply download real data from various real servers. Downloads asynchronously (without blocking the UI, animations etc.) I added to this example showing (in log) MD5 and SHA-256 checksums of the downloaded contents, so we can easily confirm that indeed it downloads 100% correct data.

   • examples/network/random_image_from_unsplash/ – communicate using REST with Unsplash API. Shows that, beyond simple downloading, also TCastleDownload.HttpHeader works.

   • examples/network/remote_logging/ – send using POST (Request.HttpMethod := hmPost, Request.HttpPostData.Values[ParameterKey] := ParameterValue). I verified on the server (that receives data using simplest PHP script that logs POST parameter) that it received correct data.

   Note that CORS (Cross-Origin Resource Sharing) security will prevent our application on the web from downloading things from other domains.

   This is a standard security feature of web browsers. It is unavoidable from our side (application living inside a web page). All web application (using JS or WebAssembly) have to deal with it.

   • For development, you can disable CORS in your browser. E.g. on Firefox with CORS Everywhere extension does the job. Chrome supports --disable-web-security command-line option. Search the web for details specific to your browser.

   • For real usage, the server has to be configured to allow downloading from it. It generally involves configuring the server to return appropriate header, like Access-Control-Allow-Origin: *. See CORS documentation at MDN and example configuration for Apache.