Question

I want to use the canvas.drawText() method to draw some text frame after frame. When I run my game in Java, everything is fine. But when I run in html, the behaviour is different. I isolated the code (see below) and I get the same result.

package textbug.core;

import static playn.core.PlayN.*;

import playn.core.Canvas;
import playn.core.CanvasImage;
import playn.core.Game;
import playn.core.Image;
import playn.core.ImageLayer;

public class TextBugIsolated implements Game {

    Canvas canvas;
    int x = 20;

  @Override
  public void init() {
    // create and add background image layer
    Image bgImage = assetManager().getImage("images/bg.png");
    ImageLayer bgLayer = graphics().createImageLayer(bgImage);
    graphics().rootLayer().add(bgLayer);

    CanvasImage canvasImage = graphics().createImage(graphics().width(), graphics().height());

    ImageLayer imageLayer = graphics().createImageLayer();
    imageLayer.setImage(canvasImage);
    graphics().rootLayer().add(imageLayer);

    canvas = canvasImage.canvas();    
  }

  @Override
  public void paint(float alpha) {
    canvas.clear();
    canvas.drawText("PlayN is cool!", x++, 20);
    canvas.drawText("Hello World", 20, 100);
  }

  @Override
  public void update(float delta) {
  }

  @Override
  public int updateRate() {
    return 25;
  }
}

I would expect the text “PlayN is cool!” to move horizontally like in Java but it is not. I tried to debug but I cannot step in the native code.

Anyone has a clue? Am I trying something prohibited?

Answer 1

This is a known issue, as documented here. It only affects the HTML backend. That seems to be exactly what you’re seeing.