Tweener

Tweener is a minimal Java/LibGDX library for animating any float property you can write an accessor for.

It uses LibGDX utility classes (like Array, Pool, etc.) under the hood, so it fits nicely with the LibGDX ecosystem.

Getting Started

In order to add this library to an existing LibGDX Gradle project, add the JitPack repository to your main build.gradle:

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Then, add the dependency to the core project:

project(":core") {
    ...

    dependencies {
        ...
        compile "com.github.dcampos:tweener:0.1.0"
    }
    ...
}

Usage

Define one or more accessors:

    public enum SpriteAccessor implements TweenAccessor<Sprite> {

        POS(2) {
            @Override
            public void get(Sprite object, float[] values) {
                values[0] = object.getX();
                values[1] = object.getY();
            }

            @Override
            public void set(Sprite object, float[] values) {
                object.setPosition(values[0], values[1]);
            }
        },
        
        // ...

        ALPHA(1) {
            @Override
            public void set(Sprite object, float[] values) {
                object.setAlpha(values[0]);
            }

            @Override
            public void get(Sprite object, float[] values) {
                values[0] = object.getColor().a;
            }
        };

        int count;

        SpriteAccessor(int count) {
            this.count = count;
        }

        @Override
        public int getCount() {
            return count;
        }
    }

Create a TweenManager:

    private TweenManager tweenManager = new TweenManager();

Add tweens to it:

    duration = 1.5f;
    
    tweenManager.add(
        Tweener.repeat().set(
            Tweener.sequence().add(Tweener.parallel()
                .add(Tweener.tween(sprite1, SpriteAccessor.ALPHA)
                    .to(0).duration(duration))
                .add(Tweener.tween(sprite1, SpriteAccessor.ROTATION)
                    .to(360).duration(duration))
                .add(Tweener.tween(sprite1, SpriteAccessor.SIZE)
                    .to(300, 300).duration(duration))
            ).add(Tweener.parallel()
                .add(Tweener.tween(sprite1, SpriteAccessor.ALPHA)
                    .to(1f).duration(duration))
                .add(Tweener.tween(sprite1, SpriteAccessor.ROTATION)
                    .to(0).duration(duration))
                .add(Tweener.tween(sprite1, SpriteAccessor.SIZE)
                    .to(200, 200).duration(duration))
           ).add(Tweener.delay(0.5f))
        );
    );

Update it:

tweenManager.update(deltaTime);

For a complete example, see the examples project.

Related projects

• Universal Tween Engine: this is the original tweening engine for Java, not just for LibGDX. Unfortunately, it hasn't been actively mantained since 2013.
• Tween Engine: an improved, actively mantained fork of the preceding one. It is a very good choice if you want a more mature library.
• gdx-tween: another tweening library for LibGDX.

License

This project is licensed under the MIT License - see the LICENSE.md file for details