com.badlogic.gdx.ai.tests.steer.box2d.Box2dFieldOfViewProximity.java Source code

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Here is the source code for com.badlogic.gdx.ai.tests.steer.box2d.Box2dFieldOfViewProximity.java

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/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.badlogic.gdx.ai.tests.steer.box2d;

import com.badlogic.gdx.ai.steer.Proximity;
import com.badlogic.gdx.ai.steer.Steerable;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Fixture;
import com.badlogic.gdx.physics.box2d.World;

/** A {@code Box2dFieldOfViewProximity} is a {@link Proximity} that queries the world for all fixtures that potentially overlap the
 * arc area of the circle having the specified detection radius and whose center is the owner position.
 * 
 * @author davebaol */
public class Box2dFieldOfViewProximity extends Box2dSquareAABBProximity {

    private static final Vector2 toSteerable = new Vector2();
    private static final Vector2 ownerOrientation = new Vector2();

    float angle;
    float coneThreshold;

    public Box2dFieldOfViewProximity(Steerable<Vector2> owner, World world, float detectionRadius, float angle) {
        super(owner, world, detectionRadius);
        setAngle(angle);
    }

    public float getAngle() {
        return angle;
    }

    public void setAngle(float angle) {
        this.angle = angle;
        this.coneThreshold = (float) Math.cos(angle * 0.5f);
    }

    @SuppressWarnings("unchecked")
    protected Steerable<Vector2> getSteerable(Fixture fixture) {
        return (Steerable<Vector2>) fixture.getBody().getUserData();
    }

    @Override
    protected void prepareAABB(AABB aabb) {
        super.prepareAABB(aabb);

        // Transform owner orientation to a Vector2
        owner.angleToVector(ownerOrientation, owner.getOrientation());
    }

    @Override
    protected boolean accept(Steerable<Vector2> steerable) {
        toSteerable.set(steerable.getPosition()).sub(owner.getPosition());

        // The bounding radius of the current body is taken into account
        // by adding it to the radius proximity
        float range = detectionRadius + steerable.getBoundingRadius();

        float toSteerableLen2 = toSteerable.len2();

        // Make sure the steerable is within the range.
        // Notice we're working in distance-squared space to avoid square root.
        if (toSteerableLen2 < range * range) {

            // Accept the steerable if it is within the field of view of the owner.
            return (ownerOrientation.dot(toSteerable) > coneThreshold);
        }

        // Reject the steerable
        return false;
    }

}