Test - GameState.java

package main;

import org.newdawn.slick.*;
import org.newdawn.slick.state.BasicGameState;
import org.newdawn.slick.state.StateBasedGame;

/**
 * User: Zsolt
 * Date: 2013.04.11.
 * Time: 19:14
 */

public class GameState extends BasicGameState {
    float x = 100, y = 100; // player's location (starts from 100 by 100)
    float targetX, targetY; // The targets for the player
    float mouseX, mouseY;   // The mouse locations
    Image player;           // The IMG file (player)

    @Override
    public int getID() {
        return 0; // This is used to jump between states ( stateBasedGame.enterState(GameState.getID()); )
    }

    @Override
    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {
        player = new Image("res/bg.png"); // Init the image
    }

    @Override
    public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {
        player.draw(x - 50, y - 50, 100, 100); // Draw a 100 by 100 sized player
    }

    @Override
    public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {
        Input input = gc.getInput(); // Store all inputs in this input object
        mouseX = input.getMouseX();  // Get mouseX from the input
        mouseY = input.getMouseY();  // Get mouseY from the input

        // 0 = left; 1 = right mouse button
        if (input.isMouseButtonDown(0)) {
            targetX = mouseX; // Set the target x to the mouseX
            targetY = mouseY; // Set the target Y to the mouseY
        }

        // Calculate the disrance between the current and the target locations
        float length = (float) Math.sqrt((targetX - x) * (targetX - x) + (targetY - y) * (targetY - y));
        float velocityX = (targetX - x) / length * delta * 1f;
        float velocityY = (targetY - y) / length * delta * 1f;

        x += velocityX; // Add distance_x to the current location
        y += velocityY; // Add distance_y to the current location
    }
}