com.kotcrab.vis.runtime.system.physics.PhysicsSystem.java Source code

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Here is the source code for com.kotcrab.vis.runtime.system.physics.PhysicsSystem.java

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/*
 * Copyright 2014-2016 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.kotcrab.vis.runtime.system.physics;

import com.artemis.BaseSystem;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.World;
import com.kotcrab.vis.runtime.data.PhysicsSettings;

/**
 * Responsible for creating and updating physics world.
 * @author Kotcrab
 */
public class PhysicsSystem extends BaseSystem {
    private static final float TIME_STEP = 1f / 60f;
    private static final int VELOCITY_ITERATIONS = 6;
    private static final int POSITION_ITERATIONS = 2;

    private World box2dWorld;
    private float timeAccumulator;

    public PhysicsSystem(PhysicsSettings physicsSettings) {
        box2dWorld = new World(new Vector2(physicsSettings.gravityX, physicsSettings.gravityY),
                physicsSettings.allowSleep);
    }

    @Override
    protected void processSystem() {
        float frameTime = Math.min(world.delta, 0.25f);
        timeAccumulator += frameTime;
        while (timeAccumulator >= TIME_STEP) {
            box2dWorld.step(TIME_STEP, VELOCITY_ITERATIONS, POSITION_ITERATIONS);
            timeAccumulator -= TIME_STEP;
        }
    }

    @Override
    protected void dispose() {
        box2dWorld.dispose();
    }

    public World getPhysicsWorld() {
        return box2dWorld;
    }
}