Example usage for com.badlogic.gdx.physics.box2d Transform setPosition

Introduction

In this page you can find the example usage for com.badlogic.gdx.physics.box2d Transform setPosition.

Prototype

public void setPosition(Vector2 pos) 

Source Link

Document

Sets the position of this transform

Usage

From source file:com.badlogic.gdx.tests.box2d.ApplyForce.java

License:Apache License

@Override
protected void createWorld(World world) {
    world.setGravity(new Vector2(0, 0));

    float k_restitution = 0.4f;
    Body ground;//from w w w  . j  a v a2 s. c om

    {
        BodyDef bd = new BodyDef();
        bd.position.set(0, 20);
        ground = world.createBody(bd);

        EdgeShape shape = new EdgeShape();

        FixtureDef sd = new FixtureDef();
        sd.shape = shape;
        sd.density = 0;
        sd.restitution = k_restitution;

        shape.set(new Vector2(-20, -20), new Vector2(-20, 20));
        ground.createFixture(sd);

        shape.set(new Vector2(20, -20), new Vector2(20, 20));
        ground.createFixture(sd);

        shape.set(new Vector2(-20, 20), new Vector2(20, 20));
        ground.createFixture(sd);

        shape.set(new Vector2(-20, -20), new Vector2(20, -20));
        ground.createFixture(sd);

        shape.dispose();
    }

    {
        Transform xf1 = new Transform(new Vector2(), 0.3524f * (float) Math.PI);
        xf1.setPosition(xf1.mul(new Vector2(1, 0)));

        Vector2[] vertices = new Vector2[3];
        vertices[0] = xf1.mul(new Vector2(-1, 0));
        vertices[1] = xf1.mul(new Vector2(1, 0));
        vertices[2] = xf1.mul(new Vector2(0, 0.5f));

        PolygonShape poly1 = new PolygonShape();
        poly1.set(vertices);

        FixtureDef sd1 = new FixtureDef();
        sd1.shape = poly1;
        sd1.density = 4.0f;

        Transform xf2 = new Transform(new Vector2(), -0.3524f * (float) Math.PI);
        xf2.setPosition(xf2.mul(new Vector2(-1, 0)));

        vertices[0] = xf2.mul(new Vector2(-1, 0));
        vertices[1] = xf2.mul(new Vector2(1, 0));
        vertices[2] = xf2.mul(new Vector2(0, 0.5f));

        PolygonShape poly2 = new PolygonShape();
        poly2.set(vertices);

        FixtureDef sd2 = new FixtureDef();
        sd2.shape = poly2;
        sd2.density = 2.0f;

        BodyDef bd = new BodyDef();
        bd.type = BodyType.DynamicBody;
        bd.angularDamping = 5.0f;
        bd.linearDamping = 0.1f;

        bd.position.set(0, 2);
        bd.angle = (float) Math.PI;
        bd.allowSleep = false;
        m_body = world.createBody(bd);
        m_body.createFixture(sd1);
        m_body.createFixture(sd2);
        poly1.dispose();
        poly2.dispose();
    }

    {
        PolygonShape shape = new PolygonShape();
        shape.setAsBox(0.5f, 0.5f);

        FixtureDef fd = new FixtureDef();
        fd.shape = shape;
        fd.density = 1.0f;
        fd.friction = 0.3f;

        for (int i = 0; i < 10; i++) {
            BodyDef bd = new BodyDef();
            bd.type = BodyType.DynamicBody;

            bd.position.set(0, 5 + 1.54f * i);
            Body body = world.createBody(bd);

            body.createFixture(fd);

            float gravity = 10.0f;
            float I = body.getInertia();
            float mass = body.getMass();

            float radius = (float) Math.sqrt(2 * I / mass);

            FrictionJointDef jd = new FrictionJointDef();
            jd.localAnchorA.set(0, 0);
            jd.localAnchorB.set(0, 0);
            jd.bodyA = ground;
            jd.bodyB = body;
            jd.collideConnected = true;
            jd.maxForce = mass * gravity;
            jd.maxTorque = mass * radius * gravity;

            world.createJoint(jd);
        }

        shape.dispose();
    }
}

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From source file:zzz.box2dtest.ApplyForce.java

License:Apache License

@Override
protected void createWorld(World world) {
    world.setGravity(new Vector2(0, 0));
    Gdx.input.setInputProcessor(this);

    float k_restitution = 0.4f;
    Body ground;/*from w  w w  .  j a  v a  2 s .c o  m*/

    {
        BodyDef bd = new BodyDef();
        bd.position.set(0, 20);
        ground = world.createBody(bd);

        EdgeShape shape = new EdgeShape();

        FixtureDef sd = new FixtureDef();
        sd.shape = shape;
        sd.density = 0;
        sd.restitution = k_restitution;

        shape.set(new Vector2(-20, -20), new Vector2(-20, 20));
        ground.createFixture(sd);

        shape.set(new Vector2(20, -20), new Vector2(20, 20));
        ground.createFixture(sd);

        shape.set(new Vector2(-20, 20), new Vector2(20, 20));
        ground.createFixture(sd);

        shape.set(new Vector2(-20, -20), new Vector2(20, -20));
        ground.createFixture(sd);

        shape.dispose();
    }

    {
        Transform xf1 = new Transform(new Vector2(), 0.3524f * (float) Math.PI);
        xf1.setPosition(xf1.mul(new Vector2(1, 0)));

        Vector2[] vertices = new Vector2[3];
        vertices[0] = xf1.mul(new Vector2(-1, 0));
        vertices[1] = xf1.mul(new Vector2(1, 0));
        vertices[2] = xf1.mul(new Vector2(0, 0.5f));

        PolygonShape poly1 = new PolygonShape();
        poly1.set(vertices);

        FixtureDef sd1 = new FixtureDef();
        sd1.shape = poly1;
        sd1.density = 4.0f;

        Transform xf2 = new Transform(new Vector2(), -0.3524f * (float) Math.PI);
        xf2.setPosition(xf2.mul(new Vector2(-1, 0)));

        vertices[0] = xf2.mul(new Vector2(-1, 0));
        vertices[1] = xf2.mul(new Vector2(1, 0));
        vertices[2] = xf2.mul(new Vector2(0, 0.5f));

        PolygonShape poly2 = new PolygonShape();
        poly2.set(vertices);

        FixtureDef sd2 = new FixtureDef();
        sd2.shape = poly2;
        sd2.density = 2.0f;

        BodyDef bd = new BodyDef();
        bd.type = BodyType.DynamicBody;
        bd.angularDamping = 5.0f;
        bd.linearDamping = 0.1f;

        bd.position.set(0, 2);
        bd.angle = (float) Math.PI;
        bd.allowSleep = false;
        m_body = world.createBody(bd);
        m_body.createFixture(sd1);
        m_body.createFixture(sd2);
        poly1.dispose();
        poly2.dispose();
    }

    {
        PolygonShape shape = new PolygonShape();
        shape.setAsBox(0.5f, 0.5f);

        FixtureDef fd = new FixtureDef();
        fd.shape = shape;
        fd.density = 1.0f;
        fd.friction = 0.3f;

        for (int i = 0; i < 10; i++) {
            BodyDef bd = new BodyDef();
            bd.type = BodyType.DynamicBody;

            bd.position.set(0, 5 + 1.54f * i);
            Body body = world.createBody(bd);

            body.createFixture(fd);

            float gravity = 10.0f;
            float I = body.getInertia();
            float mass = body.getMass();

            float radius = (float) Math.sqrt(2 * I / mass);

            FrictionJointDef jd = new FrictionJointDef();
            jd.localAnchorA.set(0, 0);
            jd.localAnchorB.set(0, 0);
            jd.bodyA = ground;
            jd.bodyB = body;
            jd.collideConnected = true;
            jd.maxForce = mass * gravity;
            jd.maxTorque = mass * radius * gravity;

            world.createJoint(jd);
        }

        shape.dispose();
    }
}

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