libGDX bullet position logic - libgdx

Question

My game has a update method which handles the fire ability of my chracter.
my problem is the logic of my game, the bullet should fire from the position of my chracter, upon game start(not moving the character) fire bullet come from the position of the character, but when i move my character the start position of bullet is not same with the position of character.
The direction of the bullet depends on the direction of the player.
private void update() {
Vector2 direction = new Vector2(0, 0);
if (Gdx.input.isKeyPressed(Keys.D)) {
direction.x = 1f ;
}
if (Gdx.input.isKeyPressed(Keys.A)) {
direction.x = -1f ;
}
if (Gdx.input.isKeyPressed(Keys.W)) {
direction.y = 1f ;
}
if (Gdx.input.isKeyPressed(Keys.S)) {
direction.y = -1f;
}
if (direction.x != 0 || direction.y != 0) {
playerDirection.set(direction);
System.out.println("player x: " +playerDirection.x + "\t" +"player y:"+playerDirection.y);
}
if (Gdx.input.isKeyPressed(Keys.F)) {
bulletPos = new Vector2(startPos);
bulletDirection.set(playerDirection);
}
if (bulletPos != null) {
bulletPos.x += direction.x;
bulletPos.y +=direction.y;
if (bulletPos.x < 0 || bulletPos.x > mapPixelWidth
|| bulletPos.y < 0 || bulletPos.y > mapPixelHeight) {
bulletPos = null;
}
}
}
can anyone knows the logic error, or anyone there can provide simple logic of shooting that fire on a direction?

Answer 1

From what i see, you're always firing button from players start position (startPos), and then, when the bullet is moving, you update its position according to player direction (direction.x, .y)? But when player changes direction, bullet is starting to move other way as well. Thats wrong.
After its created, bullet should be always moved independent from your player. So when you create it, it has to have own start position (taken from current player position), and own direction (based on current player position). Your player movement cannot change bullet position anymore.
Something like:
if (Gdx.input.isKeyPressed(Keys.F)) {
bulletPos.set(currentPlayerPosition);
bulletDirection.set(currentPlayerDirection);
}
//and then in update()
bulletPos.x+=bulletDirection.x;
bulletPos.y+=bulletDirection.y;
//until it goes out of screen, or passes given distance,
//or new bullet is created, or whatever condition you like