ParticleTypes.java

package org.jbox2d.testbed.tests;

import org.jbox2d.collision.shapes.CircleShape;
import org.jbox2d.collision.shapes.EdgeShape;
import org.jbox2d.collision.shapes.PolygonShape;
import org.jbox2d.common.Vec2;
import org.jbox2d.dynamics.Body;
import org.jbox2d.dynamics.BodyDef;
import org.jbox2d.dynamics.BodyType;
import org.jbox2d.particle.ParticleGroupDef;
import org.jbox2d.particle.ParticleType;
import org.jbox2d.testbed.framework.TestbedSettings;
import org.jbox2d.testbed.framework.TestbedTest;

public class ParticleTypes extends TestbedTest {

  Body circle;
  int flags = ParticleType.b2_tensileParticle;

  @Override
  public void initTest(boolean deserialized) {
    {
      BodyDef bd = new BodyDef();
      Body ground = m_world.createBody(bd);

      {
        PolygonShape shape = new PolygonShape();
        Vec2[] vertices =
            new Vec2[] {new Vec2(-40, -10), new Vec2(40, -10), new Vec2(40, 0), new Vec2(-40, 0)};
        shape.set(vertices, 4);
        ground.createFixture(shape, 0.0f);
      }

      {
        PolygonShape shape = new PolygonShape();
        Vec2[] vertices =
            new Vec2[] {new Vec2(-40, -1), new Vec2(-20, -1), new Vec2(-20, 20), new Vec2(-40, 30)};
        shape.set(vertices, 4);
        ground.createFixture(shape, 0.0f);
      }

      {
        PolygonShape shape = new PolygonShape();
        Vec2[] vertices =
            new Vec2[] {new Vec2(20, -1), new Vec2(40, -1), new Vec2(40, 30), new Vec2(20, 20)};
        shape.set(vertices, 4);
        ground.createFixture(shape, 0.0f);
      }
    }

    m_world.setParticleRadius(0.2f);
    {
      PolygonShape shape = new PolygonShape();
      shape.setAsBox(20, 10, new Vec2(0, 10), 0);
      ParticleGroupDef pd = new ParticleGroupDef();
      pd.flags = pd.flags;
      pd.shape = shape;
      m_world.createParticleGroup(pd);
    }

    {
      BodyDef bd = new BodyDef();
      bd.type = BodyType.KINEMATIC;
      Body body = m_world.createBody(bd);
      circle = body;
      CircleShape shape = new CircleShape();
      shape.m_p.set(0, 5);
      shape.m_radius = 1;
      body.createFixture(shape, 0.1f);
      body.setLinearVelocity(new Vec2(-6, 0.0f));
    }

    {
      BodyDef bd = new BodyDef();
      bd.type = BodyType.DYNAMIC;
      Body body = m_world.createBody(bd);
      PolygonShape shape = new PolygonShape();
      shape.setAsBox(1, 1, new Vec2(-10, 5), 0);
      body.createFixture(shape, 0.1f);
    }

    {
      BodyDef bd = new BodyDef();
      bd.type = BodyType.DYNAMIC;
      Body body = m_world.createBody(bd);
      PolygonShape shape = new PolygonShape();
      shape.setAsBox(1, 1, new Vec2(10, 5), 0.5f);
      body.createFixture(shape, 0.1f);
    }

    {
      BodyDef bd = new BodyDef();
      bd.type = BodyType.DYNAMIC;
      Body body = m_world.createBody(bd);
      EdgeShape shape = new EdgeShape();
      shape.set(new Vec2(0, 20), new Vec2(1, 21));
      body.createFixture(shape, 0.1f);
    }

    {
      BodyDef bd = new BodyDef();
      bd.type = BodyType.DYNAMIC;
      Body body = m_world.createBody(bd);
      EdgeShape shape = new EdgeShape();
      shape.set(new Vec2(3, 20), new Vec2(4, 21));
      body.createFixture(shape, 0.1f);
    }

    {
      BodyDef bd = new BodyDef();
      bd.type = BodyType.DYNAMIC;
      Body body = m_world.createBody(bd);
      EdgeShape shape = new EdgeShape();
      shape.set(new Vec2(-3, 21), new Vec2(-2, 20));
      body.createFixture(shape, 0.1f);
    }
  }

  @Override
  public void step(TestbedSettings settings) {
    super.step(settings);

    Vec2 p = circle.getTransform().p;
    Vec2 v = circle.getLinearVelocity();

    if ((p.x < -10.0f && v.x < 0.0f) || (p.x > 10.0f && v.x > 0.0f)) {
      v.x = -v.x;
      circle.setLinearVelocity(v);
    }
    int[] flagsBuffer = m_world.getParticleFlagsBuffer();
    for (int i = 0; i < m_world.getParticleCount(); i++) {
      flagsBuffer[i] = flags;
    }

    addTextLine("'a' Clear");
    addTextLine("'e' Elastic " + ((flags & ParticleType.b2_elasticParticle) != 0));
    addTextLine("'q' Powder  " + ((flags & ParticleType.b2_powderParticle) != 0));
    addTextLine("'t' Tensile " + ((flags & ParticleType.b2_tensileParticle) != 0));
    addTextLine("'v' Viscous " + ((flags & ParticleType.b2_viscousParticle) != 0));
  }

  @Override
  public void keyPressed(char keyCar, int keyCode) {
    super.keyPressed(keyCar, keyCode);
    int toggle = 0;
    switch (keyCar) {
      case 'a':
        flags = 0;
        break;
      case 'e':
        toggle = ParticleType.b2_elasticParticle;
        break;
      case 'q':
        toggle = ParticleType.b2_powderParticle;
        break;
      case 't':
        toggle = ParticleType.b2_tensileParticle;
        break;
      case 'v':
        toggle = ParticleType.b2_viscousParticle;
        break;
    }
    if (toggle != 0) {
      if ((flags & toggle) != 0) {
        flags = flags & ~toggle;
      } else {
        flags = flags | toggle;
      }
    }
  }

  @Override
  public String getTestName() {
    return "ParticleTypes";
  }
}