I have a (turn-based) tile-based game, in which you can shoot at entities.

You can move around with mouse and keyboard, it's all tile-based, except that bullets move "freely".

I've got it all working just fine except that when I move, and the creatures shoot towards the player, they shoot towards the previous tiles.. resulting in ugly looking "miss hits" or lag.

I think I need to implement some kind of predictive firing based on the bullet speed and the distance, but I don't quite know how to implement such a thing...

Here's a simplified snip of my firing code.

class Weapon {

public void fire(int x, int y) {
  ...
  ...
  ...
  Creature owner = getOwner();
  Tile targetTile = Zone.getTileAt(x, y);

  float dist = Vector.distance(owner.getCenterPosition(), targetTile.getCenterPosition());

  Bullet b = new Bullet();
  b.setPosition(owner.getCenterPosition());

  // Take dist into account in the duration to get constant speed regardless of distance
  float duration = dist / 600f;

  // Moves the bullet to the centre of the target tile in the given amount of time (in seconds)
  b.moveTo(targetTile.getCenterPosition(), duration);

  // This is what I'm after
  // Vector v = predict the position
  // b.moveTo(v, duration);

  Zone.add(bullet); // Now the bullet gets "ticked" and moveTo will be implemented
  }
}

Movement of creatures is as simple as setting the position variable.

If you need more information, just ask.