CODEWITHSUNDEEP
androidlibgdxtweenscene2d
MAGS94
MAGS94

Reputation: 510

FadeOut Action in libgdx

I'm trying to animate all the actors in a stage but FadeOut Action doesn't work although the other actions work fine

I have the following code

getRoot().setPosition(Gdx.graphics.getWidth(), 0);
getRoot().getColor().a = 0;
SequenceAction sequenceAction = new SequenceAction();
sequenceAction.addAction(Actions.moveTo(0, 0, 3.0f));
sequenceAction.addAction(Actions.fadeOut(3.0f));
getRoot().addAction(sequenceAction);

I also tried another way to animate them by TweenEngine using class GroupAccessor implements TweenAccessor<Group> and All work fine except manipulating alpha value

public class GroupAccessor implements TweenAccessor<Group> {

    public static final int ALPHA = 0;
    public static final int POS_XY = 1;

    @Override
    public int getValues(Group target, int tweenType, float[] returnValues) {
        switch (tweenType) {
            case ALPHA :
                returnValues[0] = target.getColor().a;
                return 1;
            case POS_XY :
                returnValues[0] = target.getX();
                returnValues[1] = target.getY();
                return 2;
            default:
                assert false;
                return -1;
        }
    }

    @Override
    public void setValues(Group target, int tweenType, float[] newValues) {
        switch (tweenType) {
            case ALPHA :
                target.setColor(target.getColor().r, target.getColor().g, target.getColor().b,
                        newValues[0]);
                break;
            case POS_XY :
                target.setPosition(newValues[0], newValues[1]);
                break;
            default:
                assert false;
        }
    }
}

Animation using TweenEngine

Timeline.createSequence().
                push(Tween.set(getRoot(), GroupAccessor.POS_XY).target(Gdx.graphics.getWidth(),0))
                .push(Tween.to(getRoot(), GroupAccessor.POS_XY, 3.0f).target(0,0))
                .push(Tween.set(getRoot(), GroupAccessor.ALPHA).target(0))
                .push(Tween.to(getRoot(), GroupAccessor.ALPHA, 3.0f).target(1)).start(manager);

I have multiple actors and I made arrays of some of these actors. Here are 2 examples of draw() method of 2 actors

public void draw(Batch batch, float parentAlpha) {
        batch.draw(wallSprite, 0, 0, Constants.WIDTH, Constants.HEIGHT);
    }

public void draw(Batch batch, float parentAlpha) {
        batch.draw(gearSprite, getX(), getY(),
                gearSprite.getOriginX(), gearSprite.getOriginY(), gearSprite.getWidth(),
                gearSprite.getHeight(), gearSprite.getScaleX(), gearSprite.getScaleY()
                , gearSprite.getRotation());
        try {
            batch.draw(permittedCSprite, getX() + gearSprite.getWidth()/2
                            - permittedCSprite.getWidth()/2, getY() +
                            gearSprite.getHeight()/2 - permittedCSprite.getHeight()/2,
                    permittedCSprite.getWidth(), permittedCSprite.getHeight());
        }
        catch (NullPointerException e) {}
    }

Upvotes: 0

Views: 1060

Answers (1)

Tenfour04
Tenfour04

Reputation: 93599

The draw method of an Actor absolutely must set a color on the Batch. This is necessary to support fading. Even if you don't care about fading or changing the color of the actor, you would still need to change the color of the Batch to WHITE to ensure what color the actor is drawn with (because there is no guarantee of what color some other actor has left the batch at.

Typically, you would have something like this at the top of your draw method:

public void draw (Batch batch, float parentAlpha) {
    Color color = getColor();
    batch.setColor(color.r, color.g, color.b, color.a * parentAlpha);
    //...
}

However, if your Actor is drawing a Sprite instead of a TextureRegion, then you must set the color on the Sprite instead. This is because sprites have their own color which they pass on to the batch when you call sprite.draw.

If you are using a Sprite (which I don't recommend with Actors), your draw method should look something like this:

public void draw (Batch batch, float parentAlpha) {
    sprite.setColor(getColor());
    sprite.draw(batch, parentAlpha);
}

One "gotcha" is that Sprite is a subclass of TextureRegion. Sprite is a TextureRegion that holds information about color, size, orientation, position, etc, so it can be drawn a little bit faster (possibly) than a TextureRegion. It does this at the cost of using more memory. If you are using a Sprite, you should be calling sprite.draw not batch.draw(sprite ...), because the second option treats the sprite as a TextureRegion.

If you want to use Sprite, then you need to apply all the attributes you need to the sprite. For example:

public void draw (Batch batch, float parentAlpha) {
    sprite.setColor(getColor());
    sprite.setPosition(getX(), getY());
    sprite.setSize(getWidth(), getHeight());
    //etc. etc. etc. :(
    sprite.draw(batch, parentAlpha);
}

For this reason, it really doesn't make sense to use a Sprite in an Actor at all. Way too much redundancy. Just use TextureRegions.

Upvotes: 5

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