As the 2019 is ending, it’s a good moment for a summary. What did we achieve, and what do we want in 2020?

1. First of all, I’m very happy with a huge number of new engine features. This includes CGE visual editor, significant improvements to the important APIs (viewports, cameras, user interfaces), Nintendo Switch support, glTF support.

   This leads me also to our most critical TODO for 2020: We really need to release the next CGE version 7.0, as a “stable” version. Yes, it will be called 7.0 (not just 6.6) — we have a number of new major features (and some unavoidable incompatible changes).

   The release-blocker now is making the “gizmos” to allow to comfortably transform TCastleTransform in the editor.

2. I want to say enormous “thank you” to everyone who contributed to the engine in 2019, or made games using CGE. In particular big thank you goes to the Eugene Loza, Andrzej Kilijański and Kagamma for your pull requests and all the conversations.

   This point also leads me to another TODO: I want to manage our work better. We want to make the best open-source game engine, and I’m not going to stop until we get there 🙂 For this purpose, I created public Trello boards to manage CGE work. If you’d like to join CGE on Trello, just let me (Michalis) know. Everyone is invited.

   Note that Trello is not supposed to replace GitHub issues. GitHub is still great to submit bugs (issues) or PRs. But Trello may be better to organize tasks (by task here I mean ““something that needs to be done”, which isn’t always a bug, and some tasks have complicated dependencies — some tasks are blocked by other tasks, have subtasks etc.). I feel that Trello is great to manage such tasks.

3. Technical most important features to implement in 2020:

   1. Delphi compatibility. You asked for it, and it’s started. It will open us to a whole new pool of engine users (and potential contributors).

   2. Support glTF skinned animations. glTF is becoming the de-facto standard for interchanging 3D animated models. We already support glTF, but we miss this important feature.

   3. Physically-Based Rendering. I’m leading the X3D 4.0 specification changes related to this. We want to finish the spec in January, and later implement PBR in CGE.

   That’s it, in summary. Of course I have more plans 🙂

Have the best 2020! Let’s make good code, and good games. We are open-source, we love writing code, we love telling stories, we love designing fun games. Let’s do it:)

This week I finished the last big engine API change before the next release! TCastleSceneManager is now deprecated: instead you should use TCastleViewport to display 3D models. This makes things much simpler, and it allowed me to make TCastleViewport defaults much better.

1. TCastleViewport

A simplest working source code demonstrating this (it will compile — get the engine and test it!) looks like this:

See the CGE examples: 3d_rendering_processing/view_3d_model_basic.lpr for a complete code with some additional comments.

The advantages of the new approach:

1. The API is simpler (easier to explain and use).

   Previously, TCastleViewport was in most practical cases reserved for “secondary viewport”, that shows something also visible in the “primary viewport”. The “primary viewport” was TCastleSceneManager with DefaultViewport = true. This entire complication (and complication of terminology – “how is scene manager different from viewport”) no longer exists.

   Now you just use TCastleViewport to display a world (composed from a tree of TCastleTransform and TCastleScene). Period.

   To display the same world from two cameras, just copy one TCastleViewport.Items to another. Or assign the same TCastleRootTransform instance to two TCastleViewport.Items.

   To have multiple viewports (cameras) display the same world, simply assign the Items property of one TCastleViewport to another. You can also create your own TCastleRootTransform instance and assign it to as many TCastleViewport.Items properties as you want. Demo of this is inside CGE examples: 3d_rendering_processing/multiple_viewports.lpr.

   So all previous use-cases are covered in a more natural way.

2. Moreover, this allowed me to minimize compatibility break while still changing some defaults. Since TCastleViewport was so seldom used, we change it’s default properties:

   • TCastleViewport.FullSize is now by default false
   • TCastleViewport.AutoCamera is now by default false
   • TCastleViewport.AutoNavigation is now by default false

   The FullSize=false default is consistent with all other UI controls. This way it is less surprising (when instantiating from code or in CGE editor).

   The AutoCamera=false and AutoNavigation=false are better defaults after recent camera refactor. The “false” default on these properties makes more sense — while the auto-detection is nice for quick demos, it is bothersome and sometimes surprising for non-trivial applications, so it’s best to have the auto-detection “off” by default.

   On TCastleSceneManager these defaults do not change (as it would undoubtedly cause a lot of breakage, since you use TCastleSceneManager so much in existing applications).

2. TCastleWindowBase, TCastleControlBase

Also TCastleWindow and TCastleControl are deprecated, in favour of their “Base” counterparts: TCastleWindowBase and TCastleControlBase. Why:

• This way you don’t have a default viewport (scene manager) instance, which avoids some traps (the default navigation may catch some keys), and it is often not necessary.

• This way you create the TCastleViewport yourself, as many as you need. So you have more power over the engine. This way it is clear that TCastleViewport is just a regular user-interface class: you can create it as many times as needed, you can position and resize it however you like.

• This way you can create and adjust the TCastleViewport using CGE editor, just like any other UI control.

Many parts of the manual and examples have been updated to show “the new approach”. I’m working to finish updating the manual now.

Rafael Campos submitted a new game using Castle Game Engine. Race against the clock to complete the three tracks: park, city and beach. In order to win you will must evade the obstacles and your competitors.

Download the game for free from itch.io!

This game was submitted to the game jam “I’m using a lot of assembly language” also hosted by Rafael. 50% of game code is assembler (14000 lines of ASM code), which main objective is the subdivision of 3D triangles.

By the way, I also reworked our Gallery, and added various missing entries. It is now split into:

• Games
• Tools
• Additional Components
• Graphic Assets

November/December engine improvements:

• We no longer use the GtkGlExt library on Unix. It was not necessary (we had a code to initialize OpenGL directly using glX on X11, and it is simpler). And this way user has one less library that needs to be installed before our application can be run.

• Loading optimizations: The TCastleTransform resources are no longer freed prematurely in some scenarios. You can also define CASTLE_SLIM_NODES to have a little faster node creation.

• You can specify in CastleEngineManifest.xml to build using lazbuild. This way our build tool and editor run under the hood lazbuild instead of “bare” FPC. It’s quite useful if your application uses some Lazarus packages (like LCL). For caveats see the documentation of lazarus_project and build_using_lazbuild.

• New version of model_3d_with_2d_controls example shows how to use CGE editor within Lazarus (LCL) application. We design CGE UI in CGE editor, and then load it into TCastleControlBase on a regular Lazarus form.

• Reimplemented TCastleInspectorControl, it is much more useful now to inspect the UI hiierarchy. Just add it to your window like Window.Controls.InsertFront(TCastleInspectorControl.Create(...)). Toggle visibility with F12.

• TwoSidedMaterial X3D node is supported.

• I’m working on introducing PBR to X3D specification, and then to CGE! We’ve talked a lot, and my pull request to introduce it into the Web3d specification is in-progress. We also have some initial examples how it will look like. In short: there will be a new node PhysicalMaterial.

• Log file location changed on Windows: We cannot assume we can write into the directory of the exe (because we cannot, e.g. if exe is in read-only “Program Files”). Instead we write into the log in user config directory. You can use LogOutput to print this value. See the new, extended manual page about logging.

• Container.Focus fixed.

We’re proud to present a new game made using Castle Game Engine: Bricks Color Pick. It’s a new approach to the classic arkanoid games, with a twist: there is no paddle. The challenge is to switch the color of the ball to match the bricks. You need to do it quickly — because the ball will bounce all around the level using physics.

Made by Andrzej Kilijański who also wrote a lot of articles about Castle Game Engine. Andrzej also submitted a number of pull requests related to our physics support (based on Kraft) — and now we know why 🙂

Check out the game on your Android, it’s completely free!

We were incredibly busy lately, preparing the release of The Unholy Society for PC (Windows, Linux) and Nintendo Switch. It’s a game by Cat-astrophe Games, using Castle Game Engine, programming by two of CGE developers — Michalis Kamburelis and Eugene Loza. Check out our trailer and game information on the game page and wishlist us on Steam!.

In the meantime, we have a number of improvements to the engine from November:

• We have exposed methods to perform “mouse look”. They can be used to make mouse dragging without being constrained by window borders. New demo of both dragging methods is available in examples/2d_standard_ui/dragging_test.

• We support a new Spine feature to export a single atlas for multiple skeletons. It’s quite cool, often allows to significantly reduce the total necessary atlas sizes. To use it, you need to open Spine file through an URL like this: my_animation.json#atlas:my_atlas_name instead of just my_animation.json. See our Spine documentation for details.

• New OrientationInterpolation2D allows more efficient 2D rotation interpolation. It is automatically used by Spine animations.

• Our build tool allows to configure package format by --package-format option (allowed values for now are: default, directory, zip, targz). You can also configure whether version number appears in the resulting filename by --package-name-no-version option.

• Programs using Application.ParseStandardParameters will now automatically handle the --log-file command-line option, that allows the user the configure output log file. Note that, in order to make this work, you should not call InitializeLog before command-line options are parsed. Our examples, like portable_game_skeleton, show how to do this.

• The default sound “importance” is now 10, instead of “maximum”. This seems much more reasonable. See our new docs of sounds XML files.

To celebrate #ThankYouPatrons day in the weirdest and most-programmer-friendly way possible, today we merge into the “master” branch of Castle Game Engine a big refactor of the camera code! This is a huge work, started 4 months ago, and causing 110 new commits.

It includes a number of new inter-connected features:

1. The API to control the camera (viewer position, direction, up, projection etc.) and navigation is now much simpler. Check out API docs about new TCastleAbstactViewport.Camera and TCastleAbstactViewport.Navigation.

2. You can now configure both camera and navigation visually, using the CGE editor.

   When you select a viewport (most usually a TCastleSceneManager instance), or anything inside a viewport (like a TCastleScene), there will appear a new set of buttons on the toolbar. The “hamburger” button there contains a menu with useful operations to configure camera and navigation. The “initial” camera vectors will be stored in the design, as well as the chosen navigation component.

   (The buttons to translate/rotate/scale scenes are not yet handled — coming soon!)

3. We split previous camera class into two concepts, TCastleCamera (“what is current viewer position/orientation and projection”) and TCastleNavigation (“how to handle user input to change the viewer position/orientation”).

   This caused a lot of work to make it right, and also to keep backward-compatibility as much as possible. I’ll list reasons for making it in another post — it’s a story in itself.

4. We provide easy means to turn off “auto-detection” of camera and navigation. Just set AutoCamera and/or AutoNavigation to false.

   I recognize now that this “auto-detection” is sometimes undesired or even surprising. I would advise most games to set both AutoCamera and AutoNavigation to false right after creating TCastleSceneManager. CGE editor will do it by default too, soon.

5. TCastle2DSceneManager is now deprecated, as it is useless. You can now easily request orthographic camera with TCastleSceneManager (call Setup2D method, or just set yourself Camera.ProjectionType = ptOrthographic and configure Camera.Orthographic properties). This makes things much simpler. We never needed any special class for 2D, our TCastleSceneManager is for both 2D and 3D — now it’s obvious 🙂

6. It is now configurable which camera (from which viewport) controls “central” features like headlight, X3D ProximitySensor, audio listener. Set TCastleSceneManager.MainCamera for this.

7. CGE editor received a number of smaller improvements along the way. E.g. you can now duplicate (Ctrl + D) transformations/scenes too, assigning SceneManager.MainScene and other references works.

Thanks to Andrzej Kilijański and our physics engine Kraft, we add two features to our physics support:

1. We now support triggers. A trigger is a rigid body through which other objects “pass through”, but it still reports a collision. This is useful to observe when something passes through something else.

   E.g. coins in “Mario” games could be implemented as triggers — when player collides with them, they are consumed, and player does not “bounce off” them like from a wall.

   An example of using trigger is available in examples/physics/physics_2d_collisions, the green rectangle acts as a trigger there.

2. You can adjust physics properties by adjusting SceneManager.PhysicsProperties.Xxx. See the TPhysicsProperties docs.

Thanks to many sessions dedicated to optimizing CGE rendering and animation, we have a number of new optimizations (some enabled by default, some experimental — you need to enable them yourself) and new ways to profile your applications.

1. Various “bottlenecks” (things that noticeably affect the speed) are now drastically optimized. This includes iterating over shapes (it now uses a cache and is instant), transforming frustum (uses a different algorithm that is > 2x faster), avoiding unnecessary preparing of resources (when everything is prepared), avoiding useless passes when shadow volumes are not used.

   You’re most encouraged to test your code with the new engine version, and report the results 🙂

2. A new optimization, enabled by default: frustum culling of the whole scene (TCastleScene.SceneFrustumCulling). This works hand-in-hand with the existing per-shape frustum culling, which can be improved when using an octree (if ssRendering is in TCastleScene.Spatial).

3. A new experimental powerful optimization called “dynamic batching” is implemented. Multiple X3D shapes (with the same appearance) can be merged into one, and rendered using one “draw call” to OpenGL/OpenGLES. In some applications, this offers incredible speedup — if you have a lot of simple shapes with the same appearance.

   You need to activate this optimization explicitly by setting DynamicBatching (global Boolean variable) to true. See also the the relevant section in the manual.

   Please treat this optimization as “experimental” for now. There are many corner cases, and I’m not yet sure whether I covered them all. IOW, it is (temporarily) possible that this optimization will break rendering in some cases. It is also certain that we don’t use all merging possibilities, yet. This will be extended, and hardened, in the future.

   Also be aware that this optimization is not guaranteed to be beneficial. We will spend some time, each frame, analyzing which shapes are “good candidates for merging”. While I tried to make this analysis very fast, but there are definitely cases when we will waste more time than we gain. If you have thousands of shapes, all using a completely different appearance, then “dynamic batching” will not merge anything, and will only waste time trying.

4. Another new experimental powerful optimization is implemented for animations that heavily transform the shapes (e.g. typical Spine animations). You can activate it by assigning the global variable InternalFastTransformUpdate to true.

   See the documentation of InternalFastTransformUpdate for the risks. This optimization assumes that your animations only transform shapes. If you use X3D animations to transform e.g. lights, then they will fail. I will fix it at some point, and then enable this optimization by default, always.

5. A new simple way to observe what is rendered: just display somewhere (e.g. using TCastleLabel) SceneManager.Statistics.ToString.

6. A new FrameProfiler, to observe what is eating time per-frame (e.g. whether the problem is in OnRender or OnUpdate).

7. On Nintendo Switch, we are integrated with a cool profiler from Nintendo.

8. To activate risky optimization on Aarch64, you can define CASTLE_ENGINE_ENABLE_AARCH64_OPTIMIZER symbol to true. We’re working on making them non-risky (we need to reproduce and submit some cases to FPC), at which point we will activate them automatically.

The manual page about optimizations was updated to describe various features mentioned here.

The CGE editor now has a “Preferences” window where you can configure the location of FPC / Lazarus.

Basically, if you use the CGE editor, you no longer have to worry about adjusting your environment variables. No need to place FPC / Lazarus in $PATH anymore, and no need to define $CASTLE_ENGINE_PATH. This should make the editor more user-friendly — I’m aware that editing environment variables isn’t comfortable for everyone on all operating systems 🙂

The editor now also displays more prominently whether it detected FPC (and what version it detected), and the “Preferences” window includes a helpful text leading to Lazarus + FPC download. All this will hopefully lead to more straightforward experience for people new to Lazarus/FPC.

(The next step will be, one day, to bundle FPC/Lazarus with CGE editor… but it’s not something I want to attempt now, for nearest release. Especially since advanced users would like to have an “unbundled” download anyway, as you probably want more control over FPC/Lazaus version.)