public override void Step(b2TimeStep step)
{
float timestep = step.dt;
if (timestep <= float.MinValue)
{
return;
}
if (timestep > maxTimestep && maxTimestep > 0.0f)
{
timestep = maxTimestep;
}
for (b2ControllerEdge i = m_bodyList; i != null; i = i.nextBody)
{
b2Body body = i.body;
if (!body.IsAwake())
{
//Sleeping bodies are still - so have no damping
continue;
}
b2Vec2 damping =
body.GetWorldVector(
b2Math.MulMV(T,
body.GetLocalVector(
body.GetLinearVelocity()
)
)
);
body.SetLinearVelocity(new b2Vec2(
body.GetLinearVelocity().x + damping.x * timestep,
body.GetLinearVelocity().y + damping.y * timestep
));
}
}
public void AddBody(b2Body body)
{
b2ControllerEdge edge = new b2ControllerEdge();
edge.controller = this;
edge.body = body;
//
edge.nextBody = m_bodyList;
edge.prevBody = null;
m_bodyList = edge;
if (edge.nextBody != null)
{
edge.nextBody.prevBody = edge;
}
m_bodyCount++;
//
edge.nextController = body.m_controllerList;
edge.prevController = null;
body.m_controllerList = edge;
if (edge.nextController != null)
{
edge.nextController.prevController = edge;
}
body.m_controllerCount++;
}
public override void Step(b2TimeStep step)
{
for (b2ControllerEdge i = m_bodyList; i != null; i = i.nextBody)
{
b2Body body = i.body;
if (!body.IsAwake())
{
continue;
}
body.ApplyForce(F, body.GetWorldCenter());
}
}
public override void Step(b2TimeStep step)
{
b2Vec2 smallA = new b2Vec2(A.x * step.dt, A.y * step.dt);
for (b2ControllerEdge i = m_bodyList; i != null; i = i.nextBody)
{
b2Body body = i.body;
if (!body.IsAwake())
{
continue;
}
//Am being lazy here
body.SetLinearVelocity(new b2Vec2(
body.GetLinearVelocity().x + smallA.x,
body.GetLinearVelocity().y + smallA.y
));
}
}
public void RemoveBody(b2Body body)
{
b2ControllerEdge edge = body.m_controllerList;
while (edge != null && edge.controller != this)
{
edge = edge.nextController;
}
//Attempted to remove a body that was not attached?
//b2Settings.b2Assert(bEdge != null);
if (edge == null)
{
return; //add By kingBook 2019/3/15 11:48
}
if (edge.prevBody != null)
{
edge.prevBody.nextBody = edge.nextBody;
}
if (edge.nextBody != null)
{
edge.nextBody.prevBody = edge.prevBody;
}
if (edge.nextController != null)
{
edge.nextController.prevController = edge.prevController;
}
if (edge.prevController != null)
{
edge.prevController.nextController = edge.nextController;
}
if (m_bodyList == edge)
{
m_bodyList = edge.nextBody;
}
if (body.m_controllerList == edge)
{
body.m_controllerList = edge.nextController;
}
body.m_controllerCount--;
m_bodyCount--;
//b2Settings.b2Assert(body.m_controllerCount >= 0);
//b2Settings.b2Assert(m_bodyCount >= 0);
}
public override void Step(b2TimeStep step)
{
if (m_bodyList == null)
{
return;
}
if (useWorldGravity)
{
gravity = GetWorld().GetGravity().Copy();
}
for (b2ControllerEdge i = m_bodyList; i != null; i = i.nextBody)
{
b2Body body = i.body;
if (body.IsAwake() == false)
{
//Buoyancy force is just a function of position,
//so unlike most forces, it is safe to ignore sleeping bodes
continue;
}
b2Vec2 areac = new b2Vec2();
b2Vec2 massc = new b2Vec2();
float area = 0.0f;
float mass = 0.0f;
for (b2Fixture fixture = body.GetFixtureList(); fixture != null; fixture = fixture.GetNext())
{
b2Vec2 sc = new b2Vec2();
float sarea = fixture.GetShape().ComputeSubmergedArea(normal, offset, body.GetTransform(), sc);
area += sarea;
areac.x += sarea * sc.x;
areac.y += sarea * sc.y;
float shapeDensity;
if (useDensity)
{
//TODO: Figure out what to do now density is gone
shapeDensity = 1.0f;
}
else
{
shapeDensity = 1.0f;
}
mass += sarea * shapeDensity;
massc.x += sarea * sc.x * shapeDensity;
massc.y += sarea * sc.y * shapeDensity;
}
areac.x /= area;
areac.y /= area;
massc.x /= mass;
massc.y /= mass;
if (area < float.MinValue)
{
continue;
}
//Buoyancy
b2Vec2 buoyancyForce = gravity.GetNegative();
buoyancyForce.Multiply(density * area);
body.ApplyForce(buoyancyForce, massc);
//Linear drag
b2Vec2 dragForce = body.GetLinearVelocityFromWorldPoint(areac);
dragForce.Subtract(velocity);
dragForce.Multiply(-linearDrag * area);
body.ApplyForce(dragForce, areac);
//Angular drag
//TODO: Something that makes more physical sense?
body.ApplyTorque(-body.GetInertia() / body.GetMass() * area * body.GetAngularVelocity() * angularDrag);
}
}
public override void Step(b2TimeStep step)
{
//Inlined
b2ControllerEdge i = null;
b2Body body1 = null;
b2Vec2 p1 = null;
float mass1 = 0.0f;
b2ControllerEdge j = null;
b2Body body2 = null;
b2Vec2 p2 = null;
float dx = 0.0f;
float dy = 0.0f;
float r2 = 0.0f;
b2Vec2 f = null;
if (invSqr)
{
for (i = m_bodyList; i != null; i = i.nextBody)
{
body1 = i.body;
p1 = body1.GetWorldCenter();
mass1 = body1.GetMass();
for (j = m_bodyList; j != i; j = j.nextBody)
{
body2 = j.body;
p2 = body2.GetWorldCenter();
dx = p2.x - p1.x;
dy = p2.y - p1.y;
r2 = dx * dx + dy * dy;
if (r2 < float.MinValue)
{
continue;
}
f = new b2Vec2(dx, dy);
f.Multiply(G / r2 / Mathf.Sqrt(r2) * mass1 * body2.GetMass());
if (body1.IsAwake())
{
body1.ApplyForce(f, p1);
}
f.Multiply(-1.0f);
if (body2.IsAwake())
{
body2.ApplyForce(f, p2);
}
}
}
}
else
{
for (i = m_bodyList; i != null; i = i.nextBody)
{
body1 = i.body;
p1 = body1.GetWorldCenter();
mass1 = body1.GetMass();
for (j = m_bodyList; j != i; j = j.nextBody)
{
body2 = j.body;
p2 = body2.GetWorldCenter();
dx = p2.x - p1.x;
dy = p2.y - p1.y;
r2 = dx * dx + dy * dy;
if (r2 < float.MinValue)
{
continue;
}
f = new b2Vec2(dx, dy);
f.Multiply(G / r2 * mass1 * body2.GetMass());
if (body1.IsAwake())
{
body1.ApplyForce(f, p1);
}
f.Multiply(-1);
if (body2.IsAwake())
{
body2.ApplyForce(f, p2);
}
}
}
}
}