/*******************************************************************************
* Copyright (c) 2013, Daniel Murphy
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
******************************************************************************/
/**
* Created at 7:50:04 AM Jan 20, 2011
*/
package org.jbox2d.testbed.tests;
import org.jbox2d.collision.shapes.EdgeShape;
import org.jbox2d.collision.shapes.PolygonShape;
import org.jbox2d.common.MathUtils;
import org.jbox2d.common.Rot;
import org.jbox2d.common.Transform;
import org.jbox2d.common.Vec2;
import org.jbox2d.dynamics.Body;
import org.jbox2d.dynamics.BodyDef;
import org.jbox2d.dynamics.BodyType;
import org.jbox2d.dynamics.FixtureDef;
import org.jbox2d.dynamics.joints.FrictionJointDef;
import org.jbox2d.testbed.framework.TestbedSettings;
import org.jbox2d.testbed.framework.TestbedTest;
/**
* @author Daniel Murphy
*/
public class ApplyForce extends TestbedTest {
private static final long BODY_TAG = 12;
Body m_body;
@Override
public void initTest(boolean deserialized) {
if (deserialized) {
return;
}
getWorld().setGravity(new Vec2(0.0f, 0.0f));
final float k_restitution = 0.4f;
Body ground;
{
BodyDef bd = new BodyDef();
bd.position.set(0.0f, 20.0f);
ground = getWorld().createBody(bd);
EdgeShape shape = new EdgeShape();
FixtureDef sd = new FixtureDef();
sd.shape = shape;
sd.density = 0.0f;
sd.restitution = k_restitution;
// Left vertical
shape.set(new Vec2(-20.0f, -20.0f), new Vec2(-20.0f, 20.0f));
ground.createFixture(sd);
// Right vertical
shape.set(new Vec2(20.0f, -20.0f), new Vec2(20.0f, 20.0f));
ground.createFixture(sd);
// Top horizontal
shape.set(new Vec2(-20.0f, 20.0f), new Vec2(20.0f, 20.0f));
ground.createFixture(sd);
// Bottom horizontal
shape.set(new Vec2(-20.0f, -20.0f), new Vec2(20.0f, -20.0f));
ground.createFixture(sd);
}
{
Transform xf1 = new Transform();
xf1.q.set(0.3524f * MathUtils.PI);
Rot.mulToOutUnsafe(xf1.q, new Vec2(1.0f, 0.0f), xf1.p);
Vec2 vertices[] = new Vec2[3];
vertices[0] = Transform.mul(xf1, new Vec2(-1.0f, 0.0f));
vertices[1] = Transform.mul(xf1, new Vec2(1.0f, 0.0f));
vertices[2] = Transform.mul(xf1, new Vec2(0.0f, 0.5f));
PolygonShape poly1 = new PolygonShape();
poly1.set(vertices, 3);
FixtureDef sd1 = new FixtureDef();
sd1.shape = poly1;
sd1.density = 4.0f;
Transform xf2 = new Transform();
xf2.q.set(-0.3524f * MathUtils.PI);
Rot.mulToOut(xf2.q, new Vec2(-1.0f, 0.0f), xf2.p);
vertices[0] = Transform.mul(xf2, new Vec2(-1.0f, 0.0f));
vertices[1] = Transform.mul(xf2, new Vec2(1.0f, 0.0f));
vertices[2] = Transform.mul(xf2, new Vec2(0.0f, 0.5f));
PolygonShape poly2 = new PolygonShape();
poly2.set(vertices, 3);
FixtureDef sd2 = new FixtureDef();
sd2.shape = poly2;
sd2.density = 2.0f;
BodyDef bd = new BodyDef();
bd.type = BodyType.DYNAMIC;
bd.angularDamping = 2.0f;
bd.linearDamping = 0.5f;
bd.position.set(0.0f, 2.0f);
bd.angle = MathUtils.PI;
bd.allowSleep = false;
m_body = getWorld().createBody(bd);
m_body.createFixture(sd1);
m_body.createFixture(sd2);
}
{
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.DYNAMIC;
bd.position.set(0.0f, 5.0f + 1.54f * i);
Body body = getWorld().createBody(bd);
body.createFixture(fd);
float gravity = 10.0f;
float I = body.getInertia();
float mass = body.getMass();
// For a circle: I = 0.5 * m * r * r ==> r = sqrt(2 * I / m)
float radius = MathUtils.sqrt(2.0f * I / mass);
FrictionJointDef jd = new FrictionJointDef();
jd.localAnchorA.setZero();
jd.localAnchorB.setZero();
jd.bodyA = ground;
jd.bodyB = body;
jd.collideConnected = true;
jd.maxForce = mass * gravity;
jd.maxTorque = mass * radius * gravity;
getWorld().createJoint(jd);
}
}
}
@Override
public void keyPressed(char keyCar, int keyCode) {
// TODO Auto-generated method stub
super.keyPressed(keyCar, keyCode);
}
@Override
public void step(TestbedSettings settings) {
super.step(settings);
addTextLine("Use 'wasd' to move, 'e' and 's' drift.");
if (getModel().getKeys()['w']) {
Vec2 f = m_body.getWorldVector(new Vec2(0.0f, -30.0f));
Vec2 p = m_body.getWorldPoint(m_body.getLocalCenter().add(new Vec2(0.0f, 2.0f)));
m_body.applyForce(f, p);
} else if (getModel().getKeys()['q']) {
Vec2 f = m_body.getWorldVector(new Vec2(0.0f, -30.0f));
Vec2 p = m_body.getWorldPoint(m_body.getLocalCenter().add(new Vec2(-.2f, 0f)));
m_body.applyForce(f, p);
} else if (getModel().getKeys()['e']) {
Vec2 f = m_body.getWorldVector(new Vec2(0.0f, -30.0f));
Vec2 p = m_body.getWorldPoint(m_body.getLocalCenter().add(new Vec2(.2f, 0f)));
m_body.applyForce(f, p);
} else if (getModel().getKeys()['s']) {
Vec2 f = m_body.getWorldVector(new Vec2(0.0f, 30.0f));
Vec2 p = m_body.getWorldCenter();
m_body.applyForce(f, p);
}
if (getModel().getKeys()['a']) {
m_body.applyTorque(20.0f);
}
if (getModel().getKeys()['d']) {
m_body.applyTorque(-20.0f);
}
}
@Override
public boolean isSaveLoadEnabled() {
return true;
}
@Override
public Long getTag(Body body) {
if (body == m_body) {
return BODY_TAG;
}
return super.getTag(body);
}
@Override
public void processBody(Body body, Long tag) {
if (tag == BODY_TAG) {
m_body = body;
}
super.processBody(body, tag);
}
@Override
public String getTestName() {
return "Apply Force";
}
}