com.dongbat.invasion.util.MovementUtil.java Source code

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Here is the source code for com.dongbat.invasion.util.MovementUtil.java

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package com.dongbat.invasion.util;

import com.artemis.Entity;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Body;
import com.dongbat.invasion.component.EnemyMovement;
import com.dongbat.invasion.component.Physics;

/**
 *
 * @author password
 */
public class MovementUtil {

    public static void moveTo(Entity entity, Vector2 destination) {
        Physics physicsComponent = EntityUtil.getComponent(entity, Physics.class);
        Body body = physicsComponent.getBody();
        float mass = body.getMass();
        Vector2 currentVelocity = body.getLinearVelocity();
        Vector2 position = body.getPosition();

        Vector2 desiredVelocity = destination.cpy().sub(position).nor().scl(physicsComponent.getMaxSpeed());

        Vector2 impulse = desiredVelocity.sub(currentVelocity).scl(mass);

        PhysicsUtil.applyImpulse(entity, impulse);
    }

    public static void moveEnemyTo(Entity entity, Vector2 destination) {
        if (!EntityUtil.isEnemy(entity)) {
            return;
        }

        Body body = EntityUtil.getComponent(entity, Physics.class).getBody();
        destination.y = body.getPosition().y;

        moveTo(entity, destination);
    }

    public static void chase(Entity chaser, Entity target) {
        chase(chaser, target, false);
    }

    public static void chase(Entity chaser, Entity target, boolean isHorizontal) {
        Body targetBody = EntityUtil.getComponent(target, Physics.class).getBody();

        if (isHorizontal) {
            moveEnemyTo(chaser, targetBody.getPosition());
        } else {
            moveTo(chaser, targetBody.getPosition());
        }
    }

    public static void evade(Entity evader, Entity threat, boolean isHorizontal) {
        // TODO
    }

    public static void evade(Entity evader, Vector2 position, boolean isHorizontal) {
        // TODO
    }

    public static void setTarget(Entity enemy, Vector2 target) {
        EnemyMovement movement = EntityUtil.getComponent(enemy, EnemyMovement.class);
        if (movement != null) {
            movement.setIntent(target);
        }
    }

    public static void drag(Entity enemy, Vector2 target, float force, int duration) {
        EnemyMovement movement = EntityUtil.getComponent(enemy, EnemyMovement.class);
        if (movement != null) {
            movement.setDraggedTo(target);
            movement.setDragForce(force);
            movement.setDragDuration(duration);
            movement.setStartDrag(TimeUtil.getGameTime());
            movement.setDraggedFrom(PhysicsUtil.getPosition(enemy));
        }
    }

    public static boolean hasArrived(Entity entity) {
        EnemyMovement enemyMovement = EntityUtil.getComponent(entity, EnemyMovement.class);
        Vector2 intent = enemyMovement.getIntent().cpy();
        Vector2 position = PhysicsUtil.getPosition(entity);
        intent.y = position.y;
        return position.epsilonEquals(intent, Constants.GAME.EPSILON);
    }
}