Question

I am working on a first person game in Java, and I am trying to get the 3D movement working.

My problem is I would like to capture mouse movement, yet keep the mouse inside the window. After I capture the mouse movement, I figure the best way to keep the mouse in my window is to center the mouse in the window after moving, using Robot.moveMouse(x,y). This works fine, however the movement from the Robot triggers an event in my window which then gets interpreted as a normal event, and thus moves my character in the world.

I’ve tried various schemes of keeping state and ignoring movements until I am in the center, but they all seem finicky and don’t quite detect which events are user vs Robot controlled.

Is there an easy way to detect that a mouse movement came from the Robot?

Is there perhaps a simpler way to solve my problem that I am overlooking?

Answer 1

I solved this by switching to NEWT with JOGL 2.0 RC4. In particular, I use GLWindow and warpPointer instead of an AWT Frame with the Robot.mouseMove. With the switch, I instantly got smooth movements. Some sample code similar to what I’m doing (mileage may vary):

public class MyClass implements MouseListener {
    private GLWindow window;
    private int centeredX = -1;
    private int centeredY = -1;

    // ...

    public void mouseMoved(MouseEvent e) {
        if (centeredX == -1 || centeredY == -1) {
            center();
            return;
        }

        int deltaX = e.getX() - centeredX;
        int deltaY = e.getY() - centeredY;

        // ... Do something with the deltas

        centeredX = window.getWidth() / 2;
        centeredY = window.getHeight() / 2;
        window.warpPointer(centeredX, centeredY);
    }
}