internal FrictionJoint(IWorldPool argWorldPool, FrictionJointDef def)
: base(argWorldPool, def)
{
m_localAnchorA = new Vec2(def.localAnchorA);
m_localAnchorB = new Vec2(def.localAnchorB);
m_linearImpulse = new Vec2();
m_angularImpulse = 0.0f;
m_maxForce = def.maxForce;
m_maxTorque = def.maxTorque;
}
public override void initTest(bool deserialized)
{
if (deserialized)
{
return;
}
getWorld().setGravity(new Vec2(0.0f, 0.0f));
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), ref 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), ref 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);
}
}
}
