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

Introduction

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

Prototype

public Transform(Vector2 position, float angle) 

Source Link

Document

Constructs a new Transform instance with the given position and angle

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 ww . ja 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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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;/*  www  .  ja  va 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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