Bricks Color Pick – free Android game made using Castle Game Engine

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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!

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Engine improvements – Spine improvements, dragging demo, package formats

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The Unholy Society - sister talk

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.

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Huge Camera and Navigation Improvements – Thank You Patrons!

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Castle Game Engine editor with 3 viewports (scene managers)
Castle Game Engine editor with scene manager menu

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.

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Triggers (detecting collisions) and physics settings

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Collision trigger

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.

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Numerous optimizations and dynamic batching

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Effects of dynamic batching

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.

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Configurable FPC and Lazarus location in the editor

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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.)

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Big improvements to camera API coming soon, and check out our game on Nintendo Switch

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"Escape from the Universe" space map
  1. If you have Nintendo Switch console, by sure to check out Escape from the Universe on Nintendo Switch, a game released last month by Cat-astrophe Games.

    The game uses our Castle Game Engine for everything, of course. It depends on CGE Nintendo Switch support. A Japanese version of the game is also coming, using CGE UI localization system.

  2. I’m working on a big refactor of camera and navigation API in the engine. It is not merged yet, but you can see the in-progress work in camera-refactor branch (or see the differences from master branch).

    The current API of camera has a few drawbacks that the refactor addresses:

    • Current camera settings (“what do you see in a viewport”) are mixed with navigation logic (“how do you use keyboard/mouse to change the camera”). They are mixed within the TCamera class, and this causes various headaches when setting or auto-detecting them. All games need the same camera API, but various games need wildly different navigation logic. Many games want to just “roll their own” navigation code.

      This is addressed in the new branch, by splitting into SceneManager.Camera and SceneManager.Navigation instances. The mechanism to auto-detect their settings (based on scene bounding box, X3D nodes etc.) can be now easily disabled by SceneManager.AutoDetectCamera and SceneManager.AutoDetectNavigation .

    • Currently SceneManager.Camera may not be created before the first rendering, which is not comfortable. It causes the need for methods like SceneManager.RequiredCamera or checking SceneManager.Camera <> nil.

      In the new branch, it’s simpler. The SceneManager.Camera is never nil. In contrast, SceneManager.Navigation may be nil, and it may even remain nil forever, unless you want to use some built-in navigation logic.

    • Changing projection parameters using SceneManager.OnProjection is not comfortable. Changing projection parameters using CGE editor was not possible.

      In the new branch, you can just use SceneManager.Camera.ProjectionXxx parameters. It’s natural both in code, and in CGE editor.

    • Ideally, the class TCastle2DSceneManager should be deprecated and later removed. It should be trivially easy to get the same effect (orthographic camera, projection API comfortable for 2D games) with the base TCastleSceneManager.

    • I want to create an easy class for 3rd-person navigation. This means that input drives some character, while camera follows this character. This was requested by Robert Daniel Murphy on Patreon.

    Stay tuned for more information about this:)

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ImageBackground node, Android SDK version bump to 28, Andrzej articles about monotonic clock on Android, FPC 3.3.1 updates

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  1. We have implemented a new X3D node ImageBackground (see the documentation). It allows to define a background using a simple image, and may be useful to view3dscene users.

    Demos are inside demo-models: background/background_image.x3dv, background/background_image_partial.x3dv, background/background_image_animated.x3d .

    It is compatible with InstantReality.

    Note that programmers using Castle Game Engine have already more powerful ways of defining a background :), e.g. you can use TCastleSceneManager.Transparent := true and then place any UI control underneath the scene manager.

  2. We have updated the Android SDK API level to 28, following Google requirements. Along with it, various services on Android versions were bumped. Also our Docker image was updated to include the proper tools already downloaded.

    Thanks go to Andrzej Kilijański for doing this!

  3. More articles about Castle Game Engine are available at Andrzej Kilijański site. In particular read about:

  4. We have updated small bits in CGE code and build tool to account for the latest Free Pascal Compiler 3.3.1 behaviour (fixed iOS and Nintendo Switch using FPC linkXXX.res files, avoid a flood of warnings caused by new FPC “case” completeness analysis). Also FPC version inside our Docker image was updated.

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Castle Game Engine on Raspberry Pi

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New Raspberry Pi in Michalis hands :)
The Unholy Society ( ) on Raspberry Pi
The Unholy Society ( ) on Raspberry Pi

Recently I got my Raspberry Pi 4 device, and I am excited by the possibilities (small+cheap device with fully functional Linux). I was happy to see that Castle Game Engine runs perfectly on it 🙂 Here are some screenshots of The Unholy Society running on Raspberry Pi.

If you’re interested in using CGE on Raspberry Pi:

  • Just install FPC using the package repository (apt-get install fpc)
  • Get CGE source code

  • Build CGE build tool running castle_game_engine/tools/build-tool/

  • Build your application as usual, running castle-engine compile.

  • Raspberry Pi is just Linux OS + ARM CPU, rendering using OpenGLES. Everything just works, no surprises 🙂

  • It should also be possible to run Lazarus and CGE editor, although I didn’t do it yet.

  • Note that the default backend uses X. It is also possible to get CastleWindow backend using DispmanX (without X), although it is not yet merged into latest CGE.

Have fun with CGE on all your devices!

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Streaming sound tracks, FMOD linking improved

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Castle Game Engine logo with title
  1. Our sound engine now supports streaming sounds.

    “Streaming” means that we decompress the sound (like OggVorbis) during playback, in parts (as needed). This technique allows much faster sound loading (loading sound as “streamed” is almost instant). It adds a small run-time overhead to playing given sound, although in practice it is not noticeable at all, even on mobile devices (where the benefits — much faster loading — will be very noticeable 🙂 ).

    In general case, I advise to use it for longer sounds (like music tracks).

    The default remains to load sounds “complete”, just like before.

    To use this feature, call LoadBuffer method with slStreaming or use <sound ... stream="true" /> in sounds XML file. See the manual about sound for general information how to play sounds, including LoadBuffer and sounds XML files. An example is in our play_sounds example, just uncomment proper lines in gamestatemain.pas and CastleEngineManifest.xml (search for “streaming”).

    This feature works with both OpenAL and FMOD sound backends.

    Thousand thanks for implementing this feature go to Andrzej Kilijański!

  2. FMOD dynamic loading is now improved, which is particularly useful for Linux users.

    • The FMOD library no longed needs to be present at compile-time on Linux, it only needs to be present at run-time. You no longer need to pass -k-L... to FPC to link with FMOD.

    • If the FMOD library is not present at run-time, we make a warning (in log) and continue using existing backend. In effect, you can have the application use FMOD if possible, but fallback on OpenAL. This applies to all platforms using dynamic loading of FMOD, like Windows and Linux.

    • It fixes problems with linking with FMOD using GNU binutils 2.32 (like in Debian
      Testing). The linker was previously reporting errors bad value.

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