public b2WheelJoint(b2WheelJointDef def)
: base(def)
{
m_localAnchorA = def.localAnchorA;
m_localAnchorB = def.localAnchorB;
m_localXAxisA = def.localAxisA;
m_localYAxisA = m_localXAxisA.NegUnitCross();
// m_localYAxisA = b2Math.b2Cross(1.0f, m_localXAxisA);
m_mass = 0.0f;
m_impulse = 0.0f;
m_motorMass = 0.0f;
m_motorImpulse = 0.0f;
m_springMass = 0.0f;
m_springImpulse = 0.0f;
m_maxMotorTorque = def.maxMotorTorque;
m_motorSpeed = def.motorSpeed;
m_enableMotor = def.enableMotor;
m_frequencyHz = def.frequencyHz;
m_dampingRatio = def.dampingRatio;
m_bias = 0.0f;
m_gamma = 0.0f;
m_ax.SetZero();
m_ay.SetZero();
}
public b2WheelJoint(b2WheelJointDef def)
: base(def)
{
m_localAnchorA = def.localAnchorA;
m_localAnchorB = def.localAnchorB;
m_localXAxisA = def.localAxisA;
m_localYAxisA = m_localXAxisA.NegUnitCross();
// m_localYAxisA = b2Math.b2Cross(1.0f, m_localXAxisA);
m_mass = 0.0f;
m_impulse = 0.0f;
m_motorMass = 0.0f;
m_motorImpulse = 0.0f;
m_springMass = 0.0f;
m_springImpulse = 0.0f;
m_maxMotorTorque = def.maxMotorTorque;
m_motorSpeed = def.motorSpeed;
m_enableMotor = def.enableMotor;
m_frequencyHz = def.frequencyHz;
m_dampingRatio = def.dampingRatio;
m_bias = 0.0f;
m_gamma = 0.0f;
m_ax.SetZero();
m_ay.SetZero();
}
public Car()
{
m_hz = 4.0f;
m_zeta = 0.7f;
m_speed = 50.0f;
b2Body ground = null;
{
b2BodyDef bd = new b2BodyDef();
ground = m_world.CreateBody(bd);
b2EdgeShape shape = new b2EdgeShape();
b2FixtureDef fd = new b2FixtureDef();
fd.shape = shape;
fd.density = 0.0f;
fd.friction = 0.6f;
shape.Set(new b2Vec2(-20.0f, 0.0f), new b2Vec2(20.0f, 0.0f));
ground.CreateFixture(fd);
float[] hs = {0.25f, 1.0f, 4.0f, 0.0f, 0.0f, -1.0f, -2.0f, -2.0f, -1.25f, 0.0f};
float x = 20.0f, y1 = 0.0f, dx = 5.0f;
for (int i = 0; i < 10; ++i)
{
float y2 = hs[i];
shape.Set(new b2Vec2(x, y1), new b2Vec2(x + dx, y2));
ground.CreateFixture(fd);
y1 = y2;
x += dx;
}
for (int i = 0; i < 10; ++i)
{
float y2 = hs[i];
shape.Set(new b2Vec2(x, y1), new b2Vec2(x + dx, y2));
ground.CreateFixture(fd);
y1 = y2;
x += dx;
}
shape.Set(new b2Vec2(x, 0.0f), new b2Vec2(x + 40.0f, 0.0f));
ground.CreateFixture(fd);
x += 80.0f;
shape.Set(new b2Vec2(x, 0.0f), new b2Vec2(x + 40.0f, 0.0f));
ground.CreateFixture(fd);
x += 40.0f;
shape.Set(new b2Vec2(x, 0.0f), new b2Vec2(x + 10.0f, 5.0f));
ground.CreateFixture(fd);
x += 20.0f;
shape.Set(new b2Vec2(x, 0.0f), new b2Vec2(x + 40.0f, 0.0f));
ground.CreateFixture(fd);
x += 40.0f;
shape.Set(new b2Vec2(x, 0.0f), new b2Vec2(x, 20.0f));
ground.CreateFixture(fd);
}
// Teeter
{
b2BodyDef bd = new b2BodyDef();
bd.position.Set(140.0f, 1.0f);
bd.type = b2BodyType.b2_dynamicBody;
b2Body body = m_world.CreateBody(bd);
b2PolygonShape box = new b2PolygonShape();
box.SetAsBox(10.0f, 0.25f);
body.CreateFixture(box, 1.0f);
b2RevoluteJointDef jd = new b2RevoluteJointDef();
jd.Initialize(ground, body, body.Position);
jd.lowerAngle = -8.0f * b2Settings.b2_pi / 180.0f;
jd.upperAngle = 8.0f * b2Settings.b2_pi / 180.0f;
jd.enableLimit = true;
m_world.CreateJoint(jd);
body.ApplyAngularImpulse(100.0f);
}
// Bridge
{
int N = 20;
b2PolygonShape shape = new b2PolygonShape();
shape.SetAsBox(1.0f, 0.125f);
b2FixtureDef fd = new b2FixtureDef();
fd.shape = shape;
fd.density = 1.0f;
fd.friction = 0.6f;
b2RevoluteJointDef jd = new b2RevoluteJointDef();
b2Body prevBody = ground;
for (int i = 0; i < N; ++i)
{
b2BodyDef bd = new b2BodyDef();
bd.type = b2BodyType.b2_dynamicBody;
bd.position.Set(161.0f + 2.0f * i, -0.125f);
b2Body body = m_world.CreateBody(bd);
body.CreateFixture(fd);
b2Vec2 anchor = new b2Vec2(160.0f + 2.0f * i, -0.125f);
jd.Initialize(prevBody, body, anchor);
m_world.CreateJoint(jd);
prevBody = body;
}
b2Vec2 anchor1 = new b2Vec2(160.0f + 2.0f * N, -0.125f);
jd.Initialize(prevBody, ground, anchor1);
m_world.CreateJoint(jd);
}
// Boxes
{
b2PolygonShape box = new b2PolygonShape();
box.SetAsBox(0.5f, 0.5f);
b2Body body = null;
b2BodyDef bd = new b2BodyDef();
bd.type = b2BodyType.b2_dynamicBody;
bd.position.Set(230.0f, 0.5f);
body = m_world.CreateBody(bd);
body.CreateFixture(box, 0.5f);
bd.position.Set(230.0f, 1.5f);
body = m_world.CreateBody(bd);
body.CreateFixture(box, 0.5f);
bd.position.Set(230.0f, 2.5f);
body = m_world.CreateBody(bd);
body.CreateFixture(box, 0.5f);
bd.position.Set(230.0f, 3.5f);
body = m_world.CreateBody(bd);
body.CreateFixture(box, 0.5f);
bd.position.Set(230.0f, 4.5f);
body = m_world.CreateBody(bd);
body.CreateFixture(box, 0.5f);
}
// Car
{
b2PolygonShape chassis = new b2PolygonShape();
b2Vec2[] vertices = new b2Vec2[8];
vertices[0].Set(-1.5f, -0.5f);
vertices[1].Set(1.5f, -0.5f);
vertices[2].Set(1.5f, 0.0f);
vertices[3].Set(0.0f, 0.9f);
vertices[4].Set(-1.15f, 0.9f);
vertices[5].Set(-1.5f, 0.2f);
chassis.Set(vertices, 6);
b2CircleShape circle = new b2CircleShape();
circle.Radius = 0.4f;
b2BodyDef bd = new b2BodyDef();
bd.type = b2BodyType.b2_dynamicBody;
bd.position.Set(0.0f, 1.0f);
m_car = m_world.CreateBody(bd);
m_car.CreateFixture(chassis, 1.0f);
b2FixtureDef fd = new b2FixtureDef();
fd.shape = circle;
fd.density = 1.0f;
fd.friction = 0.9f;
bd.position.Set(-1.0f, 0.35f);
m_wheel1 = m_world.CreateBody(bd);
m_wheel1.CreateFixture(fd);
bd.position.Set(1.0f, 0.4f);
m_wheel2 = m_world.CreateBody(bd);
m_wheel2.CreateFixture(fd);
b2WheelJointDef jd = new b2WheelJointDef();
b2Vec2 axis = new b2Vec2(0.0f, 1.0f);
jd.Initialize(m_car, m_wheel1, m_wheel1.Position, axis);
jd.motorSpeed = 0.0f;
jd.maxMotorTorque = 20.0f;
jd.enableMotor = true;
jd.frequencyHz = m_hz;
jd.dampingRatio = m_zeta;
m_spring1 = (b2WheelJoint) m_world.CreateJoint(jd);
jd.Initialize(m_car, m_wheel2, m_wheel2.Position, axis);
jd.motorSpeed = 0.0f;
jd.maxMotorTorque = 10.0f;
jd.enableMotor = false;
jd.frequencyHz = m_hz;
jd.dampingRatio = m_zeta;
m_spring2 = (b2WheelJoint) m_world.CreateJoint(jd);
}
}
