CODEWITHSUNDEEP
javalibgdxscene2d
CChapman01
CChapman01

Reputation: 31

Java/libGDX - issues with Actions.fadeIn() and Actions.fadeOut()

it's my first time posting and I'm self taught so be please gentle!

I've been building a bomberman replica game in libGDX using Game and Screen classes:

public class Main extends Game {
...

@Override
public void create() {
    levelScreen = new LevelScreen(playerCount, new int[playerCount]);
    levelScreen.level.addAction(Actions.sequence(Actions.alpha(0), Actions.fadeIn(2f)));
    this.setScreen(levelScreen);
}

However when the game launches there is no fade effect.

public class LevelScreen implements Screen {
...

@Override
public void render(float delta) {
    Gdx.gl.glClearColor(1, 0.1f, 0.5f, 0);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
    batch.begin();
    level.act();
    level.draw();
    batch.end();
}

I want this levelScreen to fade in from black but it just doesn't!

When the round is over I want to fadeOut of this levelScreen to black, then fadeIn to a trophyScreen from black:

(From Main Class)

@Override
public void render() {

    super.render();

        if (endRoundTimer <= 0) {
            trophyScreen = new TrophyScreen(playerCount, levelScreen.getScore());
            levelScreen.level.addAction(Actions.sequence(Actions.fadeOut(1), Actions.run(new Runnable() {
                @Override
                public void run() {
                    setScreen(trophyScreen);
                }
            })));
    }
}

And I've tried using the show() method in the TrophyScreen:

public class TrophyScreen implements Screen {
...
@Override
public void show()  {
    stage.addAction(Actions.sequence(Actions.alpha(0), Actions.fadeIn(1)));
}

I've done loads of searching and tried various things but no joy. I'm sure I'm missing something somewhere in a draw() or render() method that is preventing the fade Action from taking place.

UPDATE1

@Override public void draw() { 
super.draw();
if (roundOver) {
this.getBatch().begin(); String s = String.format("%s", message);
font_text.draw(this.getBatch(), s, (90 + (2 * 30)), (this.getHeight() / 2));
this.getBatch().end();
}

Upvotes: 2

Views: 1779

Answers (3)

BaldIdiot
BaldIdiot

Reputation: 1

A better way would be to just start by drawing a black image over everything, so you don't have to mess with every scene object's alpha. Use layering to do that. This post may be helpful.

Then you can control it's alpha channel, change it's rendering to 0 right before unpausing the game action to get it's drawing cycles back. Reactivate it on stage ending for your fade out effect.

Thank you cray, it's way better like this.

Upvotes: 0

Tenfour04
Tenfour04

Reputation: 93599

For fading to work on actors, they must properly apply their own color's alpha in the draw method. And for an entire hierarchy of objects to fade at once, they must all also apply the parentAlpha parameter from the draw method signature.

So your draw method in any custom Actor subclass should look like this:

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

If you are using a Sprite in your Actor instead of a TextureRegion (which I don't recommend due to redundancies) you must apply the color to the Sprite instead of Batch.

Note that this method of fading the whole game is not a "clean" fade. Any actors that are overlapping other actors will show through each other when the parent alpha is less than 1 during the fade. An alternative that would provide a clean-looking fade would be to draw a copy of your background (or black) over your entire scene and fade that instead.

Upvotes: 2

pr0gramista
pr0gramista

Reputation: 9008

I assume that level is an object of class that extends Stage and you are creating a control inside the stage, which is weird. You are not appling color to your font_text which I assume it is a BitmapFont

Solution, the weird way

If you want to do it in this way you will need something like that:

@Override public void draw() {
    super.draw();
    if (roundOver) {
        getBatch().begin();
        String s = String.format("%s", message);
        font_text.setColor(getRoot().getColor())
        font_text.draw(this.getBatch(), s, (90 + (2 * 30)), (this.getHeight() / 2));
        getBatch().end();
    }
}

getRoot() gets Group from Stage, we do it, because every action applied to Stage is actually applied to this Group root element. We get color (which has alpha channel) and we copy the color to the bitmapFont.

This solution is weird, because you are actually creating an Label inside Stage. It is pointless, actors plays on stage, not inside.

Solution, the good way

You want to draw text, right? So just use Label which is an actor, who shows a text. Actors do jobs for you:

stage = new Stage();
Label.LabelStyle labelStyle = new Label.LabelStyle(bitmapFont, Color.WHITE);
Label label = new Label("Hi, I am a label!", labelStyle);
stage.addActor(label);

Then you can apply actions and they will work fine (and every actor can have own actions applied).

stage.addAction(Actions.sequence(Actions.alpha(0), Actions.fadeIn(5)));
label.addAction(Actions.moveBy(0, 300, 15));

There is a lot of different actors like TextButton, Image, ScrollPane. They are customizable, easy to manage and they can be integrated in groups and tables.

Output:

Animated output

Upvotes: 1

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