prior to 1st mouse movement, InputManager returns (0,0) for cursor position

After my JME application starts but before I move my mouse, inputManager.getCursorPosition() always returns (0,0), even if the mouse cursor is nowhere near that corner of the screen. Meanwhile, LWJGL’s Mouse.getX() and Mouse.getY() return a more reasonable position.

As soon as my mouse moves, inputManager.getCursorPosition() starts returning reasonable positions that agree with LWJGL.

I see the same behavior with both 3.1.0-stable and 3.2.0-stable, so if this is a bug, it’s not a new one.

Here is my test app:

package mygame;

import com.jme3.app.SimpleApplication;
import com.jme3.font.BitmapText;
import com.jme3.math.Vector2f;
import org.lwjgl.input.Mouse;

public class Main extends SimpleApplication {

    BitmapText bitmapText;

    public static void main(String[] args) {
        Main app = new Main();
        app.start();
    }

    @Override
    public void simpleInitApp() {
        flyCam.setEnabled(false);
        inputManager.setCursorVisible(true);

        guiFont = assetManager.loadFont("Interface/Fonts/Default.fnt");
        bitmapText = new BitmapText(guiFont, false);
        bitmapText.setLocalTranslation(0, cam.getHeight(), 0);
        bitmapText.setSize(guiFont.getCharSet().getRenderedSize());
        guiNode.attachChild(bitmapText);
    }

    @Override
    public void simpleUpdate(float tpf) {
        float x = Mouse.getX();
        float y = Mouse.getY();

        Vector2f pos = inputManager.getCursorPosition();
        String message = String.format(
                "inputManager says %s     lwjgl says (%.1f, %.1f)",
                pos, x, y);
        bitmapText.setText(message);
    }
}

[tonihele]

My PR would solve this for LWJGL 3.

[stephengold]

I looked at LWJGL3, but I don’t understand it well enough to code a fix for it.