libgdx loading screen

OBS: This code uses an older version of Libgdx. You may want to take a look at:

• Libgdx 1.2.0-branch contributed by EyeOfMidas.
• Libgdx 1.4.1-branch contributed by Deathsbreed.
• Libgdx 1.9.9-branch contributed by LaurenceWarne.

What is this?

This is an example of how to make a loading screen in libgdx. It loads the game resources asynchronously in the background, e.g. non-blocking, which makes it possible to have an animated loading bar showing the progress and other responsive features. The bar is interpolated to make the progress less 'jerky'.
[Video example] 1

Featured in book

This repository's code is used in the book LibGDX Game Development Essentials by Juwal Bose for Packt Publishing.

How does it work?

Check out the [LoadingScreen.java] 4 file, which is commented.
It relies on the [AssetManager] 6 to load the assets in another thread. This gives it the opportunity to show a responsive screen instead of having the game freeze while assets are being loaded.

First it loads the assets needed to show the loading screen. For this, it is calling AssetManager's finishLoading();
This will make the screen wait until all the loading assets are loaded before moving on.
Then it should tell the AssetManager what to load next.

In the resize() method we are placing all the components.
NOTE: If you check the code you will see that the loadingBar is actually never resized or moved. Instead it is hidden from the beginning, and then showing more and more as the assets are being loaded.

In the render() method AssetManager.update() is being constantly called to make it load the assets. This method will return TRUE when everything is loaded, so then it would be a good time to move on to some other screen. In this example, it moves on to MainMenuScreen after a touch.
The percentage value given by the manager is interpolated to give a more smooth bar. Try changing the value from 0.1f to 1f to see the difference. Or check this [video with no interpolation] 5

Links

[Libgdx] 2
[Vector logo] 3

License

UNLICENSE

This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or distribute this software, either in source code form or as a compiled binary, for any purpose, commercial or non-commercial, and by any means.

In jurisdictions that recognize copyright laws, the author or authors of this software dedicate any and all copyright interest in the software to the public domain. We make this dedication for the benefit of the public at large and to the detriment of our heirs and successors. We intend this dedication to be an overt act of relinquishment in perpetuity of all present and future rights to this software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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