/// <summary>
/// Recalculates the axis aligned bounding box and the inertia
/// values in world space.
/// </summary>
public virtual void Update()
{
if (isParticle)
{
this.inertia = FPMatrix.Zero;
this.invInertia = this.invInertiaWorld = FPMatrix.Zero;
this.invOrientation = this.orientation = FPMatrix.Identity;
this.boundingBox = shape.boundingBox;
FPVector.Add(ref boundingBox.min, ref this.position, out boundingBox.min);
FPVector.Add(ref boundingBox.max, ref this.position, out boundingBox.max);
angularVelocity.MakeZero();
}
else
{
// Given: Orientation, Inertia
FPMatrix.Transpose(ref orientation, out invOrientation);
this.Shape.GetBoundingBox(ref orientation, out boundingBox);
FPVector.Add(ref boundingBox.min, ref this.position, out boundingBox.min);
FPVector.Add(ref boundingBox.max, ref this.position, out boundingBox.max);
if (!isStatic)
{
FPMatrix.Multiply(ref invOrientation, ref invInertia, out invInertiaWorld);
FPMatrix.Multiply(ref invInertiaWorld, ref orientation, out invInertiaWorld);
}
}
}
/// <summary>
/// PrepareForIteration has to be called before <see cref="Iterate"/>.
/// </summary>
/// <param name="timestep">The timestep of the simulation.</param>
public void PrepareForIteration(FP timestep)
{
FP dvx, dvy, dvz;
dvx = (body2.angularVelocity.y * relativePos2.z) - (body2.angularVelocity.z * relativePos2.y) + body2.linearVelocity.x;
dvy = (body2.angularVelocity.z * relativePos2.x) - (body2.angularVelocity.x * relativePos2.z) + body2.linearVelocity.y;
dvz = (body2.angularVelocity.x * relativePos2.y) - (body2.angularVelocity.y * relativePos2.x) + body2.linearVelocity.z;
dvx = dvx - (body1.angularVelocity.y * relativePos1.z) + (body1.angularVelocity.z * relativePos1.y) - body1.linearVelocity.x;
dvy = dvy - (body1.angularVelocity.z * relativePos1.x) + (body1.angularVelocity.x * relativePos1.z) - body1.linearVelocity.y;
dvz = dvz - (body1.angularVelocity.x * relativePos1.y) + (body1.angularVelocity.y * relativePos1.x) - body1.linearVelocity.z;
FP kNormal = FP.Zero;
FPVector rantra = FPVector.zero;
if (!treatBody1AsStatic)
{
kNormal += body1.inverseMass;
if (!body1IsMassPoint)
{
// JVector.Cross(ref relativePos1, ref normal, out rantra);
rantra.x = (relativePos1.y * normal.z) - (relativePos1.z * normal.y);
rantra.y = (relativePos1.z * normal.x) - (relativePos1.x * normal.z);
rantra.z = (relativePos1.x * normal.y) - (relativePos1.y * normal.x);
// JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra);
FP num0 = ((rantra.x * body1.invInertiaWorld.M11) + (rantra.y * body1.invInertiaWorld.M21)) + (rantra.z * body1.invInertiaWorld.M31);
FP num1 = ((rantra.x * body1.invInertiaWorld.M12) + (rantra.y * body1.invInertiaWorld.M22)) + (rantra.z * body1.invInertiaWorld.M32);
FP num2 = ((rantra.x * body1.invInertiaWorld.M13) + (rantra.y * body1.invInertiaWorld.M23)) + (rantra.z * body1.invInertiaWorld.M33);
rantra.x = num0; rantra.y = num1; rantra.z = num2;
//JVector.Cross(ref rantra, ref relativePos1, out rantra);
num0 = (rantra.y * relativePos1.z) - (rantra.z * relativePos1.y);
num1 = (rantra.z * relativePos1.x) - (rantra.x * relativePos1.z);
num2 = (rantra.x * relativePos1.y) - (rantra.y * relativePos1.x);
rantra.x = num0; rantra.y = num1; rantra.z = num2;
}
}
FPVector rbntrb = FPVector.zero;
if (!treatBody2AsStatic)
{
kNormal += body2.inverseMass;
if (!body2IsMassPoint)
{
// JVector.Cross(ref relativePos1, ref normal, out rantra);
rbntrb.x = (relativePos2.y * normal.z) - (relativePos2.z * normal.y);
rbntrb.y = (relativePos2.z * normal.x) - (relativePos2.x * normal.z);
rbntrb.z = (relativePos2.x * normal.y) - (relativePos2.y * normal.x);
// JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra);
FP num0 = ((rbntrb.x * body2.invInertiaWorld.M11) + (rbntrb.y * body2.invInertiaWorld.M21)) + (rbntrb.z * body2.invInertiaWorld.M31);
FP num1 = ((rbntrb.x * body2.invInertiaWorld.M12) + (rbntrb.y * body2.invInertiaWorld.M22)) + (rbntrb.z * body2.invInertiaWorld.M32);
FP num2 = ((rbntrb.x * body2.invInertiaWorld.M13) + (rbntrb.y * body2.invInertiaWorld.M23)) + (rbntrb.z * body2.invInertiaWorld.M33);
rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2;
//JVector.Cross(ref rantra, ref relativePos1, out rantra);
num0 = (rbntrb.y * relativePos2.z) - (rbntrb.z * relativePos2.y);
num1 = (rbntrb.z * relativePos2.x) - (rbntrb.x * relativePos2.z);
num2 = (rbntrb.x * relativePos2.y) - (rbntrb.y * relativePos2.x);
rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2;
}
}
if (!treatBody1AsStatic)
{
kNormal += rantra.x * normal.x + rantra.y * normal.y + rantra.z * normal.z;
}
if (!treatBody2AsStatic)
{
kNormal += rbntrb.x * normal.x + rbntrb.y * normal.y + rbntrb.z * normal.z;
}
massNormal = FP.One / kNormal;
FP num = dvx * normal.x + dvy * normal.y + dvz * normal.z;
tangent.x = dvx - normal.x * num;
tangent.y = dvy - normal.y * num;
tangent.z = dvz - normal.z * num;
num = tangent.x * tangent.x + tangent.y * tangent.y + tangent.z * tangent.z;
if (num != FP.Zero)
{
num = FP.Sqrt(num);
tangent.x /= num;
tangent.y /= num;
tangent.z /= num;
}
FP kTangent = FP.Zero;
if (treatBody1AsStatic)
{
rantra.MakeZero();
}
else
{
kTangent += body1.inverseMass;
if (!body1IsMassPoint)
{
// JVector.Cross(ref relativePos1, ref normal, out rantra);
rantra.x = (relativePos1.y * tangent.z) - (relativePos1.z * tangent.y);
rantra.y = (relativePos1.z * tangent.x) - (relativePos1.x * tangent.z);
rantra.z = (relativePos1.x * tangent.y) - (relativePos1.y * tangent.x);
// JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra);
FP num0 = ((rantra.x * body1.invInertiaWorld.M11) + (rantra.y * body1.invInertiaWorld.M21)) + (rantra.z * body1.invInertiaWorld.M31);
FP num1 = ((rantra.x * body1.invInertiaWorld.M12) + (rantra.y * body1.invInertiaWorld.M22)) + (rantra.z * body1.invInertiaWorld.M32);
FP num2 = ((rantra.x * body1.invInertiaWorld.M13) + (rantra.y * body1.invInertiaWorld.M23)) + (rantra.z * body1.invInertiaWorld.M33);
rantra.x = num0; rantra.y = num1; rantra.z = num2;
//JVector.Cross(ref rantra, ref relativePos1, out rantra);
num0 = (rantra.y * relativePos1.z) - (rantra.z * relativePos1.y);
num1 = (rantra.z * relativePos1.x) - (rantra.x * relativePos1.z);
num2 = (rantra.x * relativePos1.y) - (rantra.y * relativePos1.x);
rantra.x = num0; rantra.y = num1; rantra.z = num2;
}
}
if (treatBody2AsStatic)
{
rbntrb.MakeZero();
}
else
{
kTangent += body2.inverseMass;
if (!body2IsMassPoint)
{
// JVector.Cross(ref relativePos1, ref normal, out rantra);
rbntrb.x = (relativePos2.y * tangent.z) - (relativePos2.z * tangent.y);
rbntrb.y = (relativePos2.z * tangent.x) - (relativePos2.x * tangent.z);
rbntrb.z = (relativePos2.x * tangent.y) - (relativePos2.y * tangent.x);
// JVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra);
FP num0 = ((rbntrb.x * body2.invInertiaWorld.M11) + (rbntrb.y * body2.invInertiaWorld.M21)) + (rbntrb.z * body2.invInertiaWorld.M31);
FP num1 = ((rbntrb.x * body2.invInertiaWorld.M12) + (rbntrb.y * body2.invInertiaWorld.M22)) + (rbntrb.z * body2.invInertiaWorld.M32);
FP num2 = ((rbntrb.x * body2.invInertiaWorld.M13) + (rbntrb.y * body2.invInertiaWorld.M23)) + (rbntrb.z * body2.invInertiaWorld.M33);
rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2;
//JVector.Cross(ref rantra, ref relativePos1, out rantra);
num0 = (rbntrb.y * relativePos2.z) - (rbntrb.z * relativePos2.y);
num1 = (rbntrb.z * relativePos2.x) - (rbntrb.x * relativePos2.z);
num2 = (rbntrb.x * relativePos2.y) - (rbntrb.y * relativePos2.x);
rbntrb.x = num0; rbntrb.y = num1; rbntrb.z = num2;
}
}
if (!treatBody1AsStatic)
{
kTangent += FPVector.Dot(ref rantra, ref tangent);
}
if (!treatBody2AsStatic)
{
kTangent += FPVector.Dot(ref rbntrb, ref tangent);
}
massTangent = FP.One / kTangent;
restitutionBias = lostSpeculativeBounce;
speculativeVelocity = FP.Zero;
FP relNormalVel = normal.x * dvx + normal.y * dvy + normal.z * dvz; //JVector.Dot(ref normal, ref dv);
if (Penetration > settings.allowedPenetration)
{
restitutionBias = settings.bias * (FP.One / timestep) * FPMath.Max(FP.Zero, Penetration - settings.allowedPenetration);
restitutionBias = FPMath.Clamp(restitutionBias, FP.Zero, settings.maximumBias);
// body1IsMassPoint = body2IsMassPoint = false;
}
FP timeStepRatio = timestep / lastTimeStep;
accumulatedNormalImpulse *= timeStepRatio;
accumulatedTangentImpulse *= timeStepRatio;
{
// Static/Dynamic friction
FP relTangentVel = -(tangent.x * dvx + tangent.y * dvy + tangent.z * dvz);
FP tangentImpulse = massTangent * relTangentVel;
FP maxTangentImpulse = -staticFriction * accumulatedNormalImpulse;
if (tangentImpulse < maxTangentImpulse)
{
friction = dynamicFriction;
}
else
{
friction = staticFriction;
}
}
FPVector impulse;
// Simultaneos solving and restitution is simply not possible
// so fake it a bit by just applying restitution impulse when there
// is a new contact.
/*if (relNormalVel < -FP.One && newContact)
* {
* restitutionBias = TSMath.Max(-restitution * relNormalVel, restitutionBias);
* }*/
restitutionBias = FPMath.Max(-restitution * relNormalVel, restitutionBias);
// Speculative Contacts!
// if the penetration is negative (which means the bodies are not already in contact, but they will
// be in the future) we store the current bounce bias in the variable 'lostSpeculativeBounce'
// and apply it the next frame, when the speculative contact was already solved.
if (penetration < -settings.allowedPenetration)
{
speculativeVelocity = penetration / timestep;
lostSpeculativeBounce = restitutionBias;
restitutionBias = FP.Zero;
}
else
{
lostSpeculativeBounce = FP.Zero;
}
impulse.x = normal.x * accumulatedNormalImpulse + tangent.x * accumulatedTangentImpulse;
impulse.y = normal.y * accumulatedNormalImpulse + tangent.y * accumulatedTangentImpulse;
impulse.z = normal.z * accumulatedNormalImpulse + tangent.z * accumulatedTangentImpulse;
if (!treatBody1AsStatic)
{
body1.linearVelocity.x -= (impulse.x * body1.inverseMass);
body1.linearVelocity.y -= (impulse.y * body1.inverseMass);
body1.linearVelocity.z -= (impulse.z * body1.inverseMass);
if (!body1IsMassPoint)
{
FP num0, num1, num2;
num0 = relativePos1.y * impulse.z - relativePos1.z * impulse.y;
num1 = relativePos1.z * impulse.x - relativePos1.x * impulse.z;
num2 = relativePos1.x * impulse.y - relativePos1.y * impulse.x;
FP num3 =
(((num0 * body1.invInertiaWorld.M11) +
(num1 * body1.invInertiaWorld.M21)) +
(num2 * body1.invInertiaWorld.M31));
FP num4 =
(((num0 * body1.invInertiaWorld.M12) +
(num1 * body1.invInertiaWorld.M22)) +
(num2 * body1.invInertiaWorld.M32));
FP num5 =
(((num0 * body1.invInertiaWorld.M13) +
(num1 * body1.invInertiaWorld.M23)) +
(num2 * body1.invInertiaWorld.M33));
body1.angularVelocity.x -= num3;
body1.angularVelocity.y -= num4;
body1.angularVelocity.z -= num5;
}
}
if (!treatBody2AsStatic)
{
body2.linearVelocity.x += (impulse.x * body2.inverseMass);
body2.linearVelocity.y += (impulse.y * body2.inverseMass);
body2.linearVelocity.z += (impulse.z * body2.inverseMass);
if (!body2IsMassPoint)
{
FP num0, num1, num2;
num0 = relativePos2.y * impulse.z - relativePos2.z * impulse.y;
num1 = relativePos2.z * impulse.x - relativePos2.x * impulse.z;
num2 = relativePos2.x * impulse.y - relativePos2.y * impulse.x;
FP num3 =
(((num0 * body2.invInertiaWorld.M11) +
(num1 * body2.invInertiaWorld.M21)) +
(num2 * body2.invInertiaWorld.M31));
FP num4 =
(((num0 * body2.invInertiaWorld.M12) +
(num1 * body2.invInertiaWorld.M22)) +
(num2 * body2.invInertiaWorld.M32));
FP num5 =
(((num0 * body2.invInertiaWorld.M13) +
(num1 * body2.invInertiaWorld.M23)) +
(num2 * body2.invInertiaWorld.M33));
body2.angularVelocity.x += num3;
body2.angularVelocity.y += num4;
body2.angularVelocity.z += num5;
}
}
lastTimeStep = timestep;
newContact = false;
}
/// <summary>
/// PrepareForIteration has to be called before <see cref="Iterate"/>.
/// </summary>
/// <param name="timestep">The timestep of the simulation.</param>
public void PrepareForIteration(FP timestep)
{
FPVector dv = CalculateRelativeVelocity();
FP kNormal = FP.Zero;
FPVector rantra = FPVector.zero;
if (!treatBody1AsStatic)
{
kNormal += body1.inverseMass;
if (!body1IsMassPoint)
{
FPVector.Cross(ref relativePos1, ref normal, out rantra);
FPVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra);
FPVector.Cross(ref rantra, ref relativePos1, out rantra);
}
}
FPVector rbntrb = FPVector.zero;
if (!treatBody2AsStatic)
{
kNormal += body2.inverseMass;
if (!body2IsMassPoint)
{
FPVector.Cross(ref relativePos2, ref normal, out rbntrb);
FPVector.Transform(ref rbntrb, ref body2.invInertiaWorld, out rbntrb);
FPVector.Cross(ref rbntrb, ref relativePos2, out rbntrb);
}
}
if (!treatBody1AsStatic)
{
kNormal += FPVector.Dot(ref rantra, ref normal);
}
if (!treatBody2AsStatic)
{
kNormal += FPVector.Dot(ref rbntrb, ref normal);
}
massNormal = FP.One / kNormal;
tangent = dv - FPVector.Dot(dv, normal) * normal;
tangent.Normalize();
FP kTangent = FP.Zero;
if (treatBody1AsStatic)
{
rantra.MakeZero();
}
else
{
kTangent += body1.inverseMass;
if (!body1IsMassPoint)
{
FPVector.Cross(ref relativePos1, ref normal, out rantra);
FPVector.Transform(ref rantra, ref body1.invInertiaWorld, out rantra);
FPVector.Cross(ref rantra, ref relativePos1, out rantra);
}
}
if (treatBody2AsStatic)
{
rbntrb.MakeZero();
}
else
{
kTangent += body2.inverseMass;
if (!body2IsMassPoint)
{
FPVector.Cross(ref relativePos2, ref tangent, out rbntrb);
FPVector.Transform(ref rbntrb, ref body2.invInertiaWorld, out rbntrb);
FPVector.Cross(ref rbntrb, ref relativePos2, out rbntrb);
}
}
if (!treatBody1AsStatic)
{
kTangent += FPVector.Dot(ref rantra, ref tangent);
}
if (!treatBody2AsStatic)
{
kTangent += FPVector.Dot(ref rbntrb, ref tangent);
}
massTangent = FP.One / kTangent;
restitutionBias = lostSpeculativeBounce;
speculativeVelocity = FP.Zero;
FP relNormalVel = FPVector.Dot(ref normal, ref dv);
if (Penetration > settings.allowedPenetration)
{
restitutionBias = settings.bias * (FP.One / timestep) * FPMath.Max(FP.Zero, Penetration - settings.allowedPenetration);
restitutionBias = FPMath.Clamp(restitutionBias, FP.Zero, settings.maximumBias);
// body1IsMassPoint = body2IsMassPoint = false;
}
FP timeStepRatio = timestep / lastTimeStep;
accumulatedNormalImpulse *= timeStepRatio;
accumulatedTangentImpulse *= timeStepRatio;
{
// Static/Dynamic friction
FP relTangentVel = -FPVector.Dot(ref tangent, ref dv);
FP tangentImpulse = massTangent * relTangentVel;
FP maxTangentImpulse = -staticFriction * accumulatedNormalImpulse;
if (tangentImpulse < maxTangentImpulse)
{
friction = dynamicFriction;
}
else
{
friction = staticFriction;
}
}
FPVector impulse;
// Simultaneos solving and restitution is simply not possible
// so fake it a bit by just applying restitution impulse when there
// is a new contact.
if (relNormalVel < -FP.One && newContact)
{
restitutionBias = FPMath.Max(-restitution * relNormalVel, restitutionBias);
}
// Speculative Contacts!
// if the penetration is negative (which means the bodies are not already in contact, but they will
// be in the future) we store the current bounce bias in the variable 'lostSpeculativeBounce'
// and apply it the next frame, when the speculative contact was already solved.
if (penetration < -settings.allowedPenetration)
{
speculativeVelocity = penetration / timestep;
lostSpeculativeBounce = restitutionBias;
restitutionBias = FP.Zero;
}
else
{
lostSpeculativeBounce = FP.Zero;
}
impulse = normal * accumulatedNormalImpulse + tangent * accumulatedTangentImpulse;
ApplyImpulse(ref impulse);
lastTimeStep = timestep;
newContact = false;
}