Android Open Source - Stickman A I Character

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From Project

Back to project page Stickman.

License

The source code is released under:

Apache License

Java Source Code

package com.wireframe.stickman;
//from   w  w  w .j  a va 2 s . c  om
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.math.Vector3;

public class AICharacter extends Character{
  protected Character target = null;
  
  protected float attackDelay = 0.5f; // Time between attacks
  protected float lastAttack = 0f;

  public AICharacter(String type, float x, float y, float z, float w, float h) {
    this(type, new Vector3(x,y,z), new Vector2(w,h));
  }

  public AICharacter(String type, Vector3 position, Vector2 size) {
    super(type, position, size);
  }

  public void update(){
    
    // Move Character
    super.update();

    // Make sure we are alive
    if( !isAlive() ) return;
    
    // Check delays
    if( lastAttack != 0f ){
      lastAttack += Gdx.graphics.getDeltaTime();
      if( lastAttack > attackDelay ){
        lastAttack = 0f;
      }
    }
    
    // Have a target?
    if( target == null ){
      searchForTarget();      
    }
    else if( !target.isAlive() ){
      target = null;
    }
    else if( canSee(target) ){
      if( canAttackTarget(target) ){
        stopMoving();
        setTargetToAttack(target);
        attackTarget();        
        return;
      }
      else{
        setTargetToAttack(null);
        moveTowardsTarget();
        return;
      }
    }
  }
  
  /**
   * Returns true if we had to change the direction that WE are facing
   * @return
   */
  protected boolean faceTarget(){
    
    // To the right of us
    if( target.getPosition().x > getPosition().x && !facingRight() ){
      flipFacingDirection();
      return true;
    }
    
    // To the left of us
    if( target.getPosition().x < getPosition().x && facingRight() ){
      flipFacingDirection();
      return true;
    }
    
    
    return false;
  }
  
  protected void moveTowardsTarget() {
    
    // Face the direction of the target
    if( faceTarget() ){
      return; 
    }
    
    // Move towards them
    if( target.getPosition().x > getPosition().x ){
      moveRight();
    }
    else if( target.getPosition().x < getPosition().x ){
      moveLeft();
    }
  }

  protected void attackTarget() {
    // Are we already attacking?
    if( isAttacking() ) return;
    
    // Attack Delay finished?
    if( lastAttack != 0f ) return;
      
    
    lastAttack += Gdx.graphics.getDeltaTime();
    attack();
  }

  protected void searchForTarget() {
    List<Character> enemies = null;
    if( getTeamNumber() == Character.TEAM_BLUE ) enemies = World.getEnemies();
    if( getTeamNumber() == Character.TEAM_RED ) enemies = World.getFriendlies();
    
    // Get all enemies in sight
    ArrayList<Character> nearbyEnemies = new ArrayList<Character>();
    for(int i = 0; i < enemies.size(); i++){
      Character enemy = enemies.get(i);
      if( canSee(enemy) && enemy.getTeamNumber() != this.getTeamNumber() ){        
        nearbyEnemies.add(enemy);
      }
    }
    
    // Find closest enemy
    if( !nearbyEnemies.isEmpty() ){
      Collections.sort(nearbyEnemies, new targetSearchPrioritiser(this));
      
      /*if ( this instanceof Enemy ){
        System.out.println("ENEMIES");
        for( Character c : nearbyEnemies ){
          System.out.println(c.getClass().getSimpleName() + " " + c.getPosition());
        }
      }*/
      target = nearbyEnemies.get(0);
    }
  }
  
  protected boolean canSee(Character character){
    
    // Not alive? Who cares
    if( !character.isAlive() ){
      return false;
    }
    
    // Check if the character is on the same Y
    if((int) character.getPosition().y < (int)getPosition().y-100 ||
        (int)character.getPosition().y > (int)getPosition().y+100){
      
      // Can't see target anymore
      target = null;
      return false;
    }
    
    // Check if he's within 200 pixels on X
    if((int) character.getPosition().x < (int)getPosition().x-200 ||
        (int)character.getPosition().x > (int)getPosition().x+200){
      
      // Can't see target anymore
      target = null;
            
      return false;
    }
    
    
    // Can see him
    return true;
  }
  
  private class targetSearchPrioritiser implements Comparator<Character>{
    private Character searcher;

    public targetSearchPrioritiser(AICharacter aiCharacter) {
      this.searcher = aiCharacter;
    }

    @Override
    public int compare(Character o1, Character o2) {
      
      // Distance between them
      float distance1 = o1.getPosition().dst(searcher.getPosition());
      float distance2 = o2.getPosition().dst(searcher.getPosition());
      return (int) Math.signum(distance1 - distance2);
    }
    
  }
}

Java Source Code List

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