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javaandroidioslibgdx

Libgdx computeGlyphAdvancesAndPositions doesn't exist


I'm doing text animation in Libgdx. Trying to do something like

font1 = new BitmapFont(Gdx.files.internal("fontLabel/fonty.fnt"), false);
font1.getRegion().getTexture()
        .setFilter(Texture.TextureFilter.Linear, Texture.TextureFilter.Linear);
touchPos = new Vector3();

listchar = new TextButton[pause.length()];
advances = new FloatArray();
post = new FloatArray();
font1.computeGlyphAdvancesAndPositions(pause, advances, post);

But computeGlyphAdvancesAndPositions doesn't exit anymore, what to do?

EDIT

I read this blog post which says to use GlyphLayout but I don't know how to do that? GlyphLayout doesn't take the parameters I want to give

I want to do something like the animation in this video, the old source code is here But as stated above, it doesn't work anymore because of the section I highlighted.

package com.tntstudio.texteffect;

import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL10;
import com.badlogic.gdx.graphics.Texture.TextureFilter;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.math.Interpolation;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.actions.Actions;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton.TextButtonStyle;
import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
import com.badlogic.gdx.utils.FloatArray;

public class TECore implements ApplicationListener {
    private Stage stage;
    private BitmapFont font;
    private TextButton[] listchar;
    private FloatArray post, advances;
    private String text;
    private static final float time = 0.5f, delay = 0.2f;
    private static final float x = 200f, y = 200f;

    @Override
    public void create() {
        stage = new Stage(800f, 480f, true);
        font = new BitmapFont(Gdx.files.internal("data/texteffect.fnt"));
        font.getRegion().getTexture()
                .setFilter(TextureFilter.Linear, TextureFilter.Linear);
        text = "manh phi libgdx";
        listchar = new TextButton[text.length()];
        advances = new FloatArray();
        post = new FloatArray();
        font.computeGlyphAdvancesAndPositions(text, advances, post);

        final TextButtonStyle style = new TextButtonStyle();
        style.font = font;

        /*-------- List Text --------*/
        for (int i = 0; i < text.length(); i++) {
            listchar[i] = new TextButton(String.valueOf(text.charAt(i)), style);
            listchar[i].setTransform(true);
            listchar[i].setPosition(x + post.get(i), y);
            listchar[i].setOrigin(advances.get(i) / 2,
                    listchar[i].getHeight() / 4);
            stage.addActor(listchar[i]);
        }

        Gdx.input.setInputProcessor(stage);

        /*-------- Drop Effect Adapter --------*/
        TextButton drop = new TextButton("drop", style);
        drop.setPosition(0, 10);
        drop.addListener(new ClickListener() {
            @Override
            public void clicked(InputEvent event, float x, float y) {
                dropText();
            }
        });
        stage.addActor(drop);

        /*-------- Spin effect Adapter --------*/
        TextButton spin = new TextButton("spin", style);
        spin.setPosition(0, 100f);
        spin.addListener(new ClickListener() {
            @Override
            public void clicked(InputEvent event, float x, float y) {
                spinText();
            }
        });
        stage.addActor(spin);
        /*-------- Appear effect Adapter --------*/
        TextButton appear = new TextButton("appear", style);
        appear.setPosition(0, 300f);
        appear.addListener(new ClickListener() {
            @Override
            public void clicked(InputEvent event, float x, float y) {
                appearText();
            }
        });
        stage.addActor(appear);

    }

    // ///////////////////////////////////////////////////////////////
    // Reset Param of a char in text
    // ///////////////////////////////////////////////////////////////
    private void resetText() {
        for (int i = 0; i < text.length(); i++) {
            listchar[i].setPosition(x + post.get(i), y);
            listchar[i].setOrigin(advances.get(i) / 2,
                    listchar[i].getHeight() / 4);
            listchar[i].setColor(0, 0, 0, 1);
            listchar[i].setScale(1f);
        }
    }

    private void dropText() {
        resetText();
        for (int i = 0; i < text.length(); i++) {
            listchar[i].setY(y + 200f);
            listchar[i].setColor(0, 0, 0, 0);
            listchar[i].addAction(Actions.delay(
                    delay * i,
                    Actions.parallel(Actions.alpha(1, time), Actions.moveTo(x
                            + post.get(i), y, time, Interpolation.bounceOut))));
        }
    }

    private void spinText() {
        resetText();
        for (int i = 0; i < text.length(); i++) {
            listchar[i].addAction(Actions.delay(delay * i,
                    Actions.rotateBy(360f, time * 5, Interpolation.elastic)));
        }
    }

    private void appearText(){
        resetText();
        for (int i=0; i<text.length(); i++){
            listchar[i].setScale(0f);
            listchar[i].setColor(0, 0, 0, 0);
            listchar[i].addAction(Actions.delay(delay*i, Actions.parallel(Actions.alpha(1, time), Actions.scaleTo(1, 1, time, Interpolation.swingOut))));
        }
    }

    @Override
    public void dispose() {
    }

    @Override
    public void render() {
        Gdx.gl.glClearColor(0, 0, 1, 1);
        Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
        stage.act(Gdx.graphics.getDeltaTime());
        stage.draw();
    }

    @Override
    public void resize(int width, int height) {
    }

    @Override
    public void pause() {
    }

    @Override
    public void resume() {
    }
}

Solution

  • Since version 1.5.6 of libGDX, the method BitmapFont.computeGlyphAdvancesAndPositions was removed in favor of GlyphLayout.

    BitmapFont.computeGlyphAdvancesAndPositions returned 2 arrays containing the advances and positions of the characters of the given CharSequence.

    To retrieve the same information using GlyphLayout:

    1. create a GlyphLayout object and set the desired font and text:

      GlyphLayout layout = new GlyphLayout();
      layout.setText(font, text);
      
    2. the provided text will be splitted into "runs" based on newlines; in case there are no newlines the whole text will be stored in the first run:

      GlyphRun run = layout.runs.get(0);
      
    3. GlyphRun contains xAdvances which is comparable to the advances array returned by BitmapFont.computeGlyphAdvancesAndPositions; the difference is that the first position of the array contains the X offset relative to the drawing position, while the actual advance width of the i-th character is in the i-th + 1 element of the array:

      float startingOffset = run.xAdvances.get(0);
      float ithAdvance = run.xAdvances.get(i + 1);
      
    4. unfortunately, the positions of the single characters of the text are not anymore readily available but we can obtain them by adding the advances of the previous characters:

      float[] positions = new float[text.length()];
      for (int i = 0; i < positions.length; i++) {
          if (i == 0) {
              // first position is the starting offset
              positions[0] = run.xAdvances.get(0);
          } else {
              // current position is the previous position plus its advance
              positions[i] = positions[i - 1] + run.xAdvances.get(i);  
          }         
      }
      

    In conclusion:

    • advances.get(i) is replaced by run.xAdvances.get(i + 1)
    • post.get(i) is replaced by positions[i], obtained as showed before (or in an equivalent manner)