[LIBGDX学习]LibGDX代码详解（三十三）Bullet 连线

import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.graphics.g3d.Material;
import com.badlogic.gdx.graphics.g3d.Model;
import com.badlogic.gdx.graphics.g3d.attributes.ColorAttribute;
import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.physics.bullet.dynamics.btDynamicsWorld;
import com.badlogic.gdx.physics.bullet.dynamics.btPoint2PointConstraint;
import com.badlogic.gdx.physics.bullet.dynamics.btRigidBody;
import com.badlogic.gdx.physics.bullet.dynamics.btTypedConstraint;
import com.badlogic.gdx.utils.Array;

/** @author xoppa */
public class ConstraintsTest extends BaseBulletTest {

    final Array<btTypedConstraint> constraints = new Array<btTypedConstraint>();

    @Override
    public void create () {
        super.create();

        final Model barModel = modelBuilder.createBox(10f, 1f, 1f, new Material(new ColorAttribute(ColorAttribute.Diffuse,
                Color.WHITE)), Usage.Position | Usage.Normal);
        disposables.add(barModel);
        world.addConstructor("bar", new BulletConstructor(barModel, 0f)); // mass = 0: static body

        // Create the entities
        world.add("ground", 0f, 0f, 0f).setColor(0.25f + 0.5f * (float)Math.random(), 0.25f + 0.5f * (float)Math.random(),
                0.25f + 0.5f * (float)Math.random(), 1f);

        BulletEntity bar = world.add("bar", 0f, 7f, 0f);
        bar.setColor(0.75f + 0.25f * (float)Math.random(), 0.75f + 0.25f * (float)Math.random(),
                0.75f + 0.25f * (float)Math.random(), 1f);

        //BulletEntity box1 = world.add("box", -4.5f, 6f, 0f);
        BulletEntity box1 = world.add("box", -50.5f, 6f, 0f);
        box1.setColor(0.5f + 0.5f * (float)Math.random(), 0.5f + 0.5f * (float)Math.random(), 0.5f + 0.5f * (float)Math.random(),
                1f);
        btPoint2PointConstraint constraint = new btPoint2PointConstraint((btRigidBody)bar.body, (btRigidBody)box1.body,
                tmpV1.set(-7, -0.5f, -0.5f), tmpV2.set(-0.5f, 0.5f, -0.5f));
/*        btPoint2PointConstraint constraint = new btPoint2PointConstraint((btRigidBody)bar.body, (btRigidBody)box1.body,
                tmpV1.set(-5, -0.5f, -0.5f), tmpV2.set(-0.5f, 0.5f, -0.5f));*/
        ((btDynamicsWorld)world.collisionWorld).addConstraint(constraint, false);
        constraints.add(constraint);
        BulletEntity box2 = null;
        for (int i = 0; i < 10; i++) {
            if (i % 2 == 0) {
                box2 = world.add("box", -3.5f + (float)i, 6f, 0f);
                box2.setColor(0.5f + 0.5f * (float)Math.random(), 0.5f + 0.5f * (float)Math.random(),
                        0.5f + 0.5f * (float)Math.random(), 1f);
                constraint = new btPoint2PointConstraint((btRigidBody)box1.body, (btRigidBody)box2.body, tmpV1.set(0.5f, -0.5f,
                        0.5f), tmpV2.set(-0.5f, -0.5f, 0.5f));
            } else {
                box1 = world.add("box", -3.5f + (float)i, 6f, 0f);
                box1.setColor(0.5f + 0.5f * (float)Math.random(), 0.5f + 0.5f * (float)Math.random(),
                        0.5f + 0.5f * (float)Math.random(), 1f);
/*                constraint = new btPoint2PointConstraint((btRigidBody)box2.body, (btRigidBody)box1.body, tmpV1.set(0.5f, 0.5f,
                        -0.5f), tmpV2.set(-0.5f, 0.5f, -0.5f));*/
                constraint = new btPoint2PointConstraint((btRigidBody)box2.body, (btRigidBody)box1.body, tmpV1.set(2f, 0.5f,
                        -0.5f), tmpV2.set(-0.5f, 0.5f, -0.5f));
            }
            ((btDynamicsWorld)world.collisionWorld).addConstraint(constraint, false);
            constraints.add(constraint);
        }
        /*constraint = new btPoint2PointConstraint((btRigidBody)bar.body, (btRigidBody)box1.body, tmpV1.set(5f, -0.5f, -0.5f),
                tmpV2.set(0.5f, 0.5f, -0.5f));*/
        constraint = new btPoint2PointConstraint((btRigidBody)bar.body, (btRigidBody)box1.body, tmpV1.set(7f, -0.5f, -0.5f),
                tmpV2.set(0.5f, 0.5f, -0.5f));
        ((btDynamicsWorld)world.collisionWorld).addConstraint(constraint, false);
        constraints.add(constraint);
    }

    @Override
    public void dispose () {
        for (int i = 0; i < constraints.size; i++) {
            ((btDynamicsWorld)world.collisionWorld).removeConstraint(constraints.get(i));
            constraints.get(i).dispose();
        }
        constraints.clear();
        super.dispose();
    }

    @Override
    public boolean tap (float x, float y, int count, int button) {
        shoot(x, y);
        return true;
    }
}