// Passes in the controller stick positions
public void SetStickPositions(Microsoft.Xna.Framework.Vector2 leftStick, Microsoft.Xna.Framework.Vector2 rightStick)
{
// move the center dot
_leftStickEllipse.Margin = new Thickness(leftStick.X * 100, leftStick.Y * -100, 0, 0);
int dialIndex, labelIndex;
dialIndex = labelIndex = -1;
// if the user hasn't pushed the left stick very far, don't do anything
if (leftStick.Length() > .8)
{
// Calculate the angle for the stick, then the index of the corresponding dial
double lAngle = Math.Atan2(-leftStick.Y, leftStick.X) + angleOffset + Math.PI * 2 + Math.PI / KeyboardWork.DIAL_AMT;
dialIndex = (int)(lAngle / (2 * Math.PI / KeyboardWork.DIAL_AMT));
dialIndex %= KeyboardWork.DIAL_AMT;
// if the user hasn't pushed the right stick very far, don't push a letter
if (rightStick.Length() > .8)
{
// Calculate the angle for the stick, then the corresponding label
double rAngle = Math.Atan2(-rightStick.Y, rightStick.X) + angleOffset + Math.PI * 2 + Math.PI / KeyboardWork.KEY_AMT;
labelIndex = (int)(rAngle / (2 * Math.PI / KeyboardWork.KEY_AMT));
labelIndex %= KeyboardWork.KEY_AMT;
if (_prevRStickMag < .8)
{
char key = (_keyLabels[labelIndex + KeyboardWork.DIAL_AMT * dialIndex].Content as String)[0];
InputRobot.KeyboardRobot.TypeCharacter(key);
}
}
}
// Reset the previously selected dial if it has changed
if (_prevDialIndex != dialIndex || _prevLabelIndex != labelIndex)
{
if (_prevDialIndex != -1)
{
SetDialSize(_prevDialIndex, 1.0, _prevLabelIndex, 1.0);
}
// Apply the dial size if we're pointing at a dial
if (dialIndex != -1)
{
SetDialSize(dialIndex, 1.1, labelIndex, 1.3);
}
// store the new dial data
_prevDialIndex = dialIndex;
_prevLabelIndex = labelIndex;
}
// store the previous length of the value
_prevRStickMag = rightStick.Length();
}
internal override bool SolvePositionConstraints(ref SolverData data)
{
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
Vector2 rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
Vector2 rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
Vector2 u = cB + rB - cA - rA;
float length = u.Length(); u.Normalize();
float C = length - MaxLength;
C = MathUtils.Clamp(C, 0.0f, Settings.MaxLinearCorrection);
float impulse = -_mass * C;
Vector2 P = impulse * u;
cA -= _invMassA * P;
aA -= _invIA * MathUtils.Cross(ref rA, ref P);
cB += _invMassB * P;
aB += _invIB * MathUtils.Cross(ref rB, ref P);
data.positions[_indexA].c = cA;
data.positions[_indexA].a = aA;
data.positions[_indexB].c = cB;
data.positions[_indexB].a = aB;
return(length - MaxLength < Settings.LinearSlop);
}
internal override void SolveVelocityConstraints(ref SolverData data)
{
Vector2 vA = data.velocities[_indexA].v;
float wA = data.velocities[_indexA].w;
// Cdot = v + cross(w, r)
Vector2 Cdot = vA + MathUtils.Cross(wA, ref _rA);
Vector2 impulse = MathUtils.Mul(ref _mass, -(Cdot + _C + _gamma * _impulse));
Vector2 oldImpulse = _impulse;
_impulse += impulse;
float maxImpulse = data.step.dt * MaxForce;
if (_impulse.LengthSquared() > maxImpulse * maxImpulse)
{
_impulse *= maxImpulse / _impulse.Length();
}
impulse = _impulse - oldImpulse;
vA += _invMassA * impulse;
wA += _invIA * MathUtils.Cross(ref _rA, ref impulse);
data.velocities[_indexA].v = vA;
data.velocities[_indexA].w = wA;
}
public void Update(float timeStep, float kSpring, float influenceRadius)
{
if (!Active)
{
return;
}
Vector2 dir = P1.Position - P0.Position;
float distance = dir.Length();
dir.Normalize();
// This is to avoid imploding simulation with really springy fluids
if (distance < 0.5f * influenceRadius)
{
Active = false;
return;
}
if (RestLength > influenceRadius)
{
Active = false;
return;
}
//Algorithm 3
float displacement = timeStep * timeStep * kSpring * (1.0f - RestLength / influenceRadius) * (RestLength - distance) * 0.5f;
dir *= displacement;
P0.Position -= dir;
P1.Position += dir;
}
public List <Microsoft.Xna.Framework.Vector3> DoEdges(List <Microsoft.Xna.Framework.Point> Nodes)
{
List <Geometry.Point> pts = new List <Geometry.Point>();
foreach (Microsoft.Xna.Framework.Point p in Nodes)
{
pts.Add(new Geometry.Point(p.X, p.Y));
}
List <Geometry.Triangle> tris = Triangulate(pts);
List <Microsoft.Xna.Framework.Vector3> Edges = new List <Microsoft.Xna.Framework.Vector3>();
Microsoft.Xna.Framework.Vector2 dist = new Microsoft.Xna.Framework.Vector2();
Microsoft.Xna.Framework.Vector3 curr = new Microsoft.Xna.Framework.Vector3();
foreach (Geometry.Triangle t in tris)
{
dist = Nodes[t.p1].ToVector2() - Nodes[t.p2].ToVector2();
curr = new Microsoft.Xna.Framework.Vector3(t.p1, t.p2, dist.Length());
if (!Edges.Contains(curr))
{
Edges.Add(curr);
}
dist = Nodes[t.p2].ToVector2() - Nodes[t.p3].ToVector2();
curr = new Microsoft.Xna.Framework.Vector3(t.p2, t.p3, dist.Length());
if (!Edges.Contains(curr))
{
Edges.Add(curr);
}
dist = Nodes[t.p3].ToVector2() - Nodes[t.p1].ToVector2();
curr = new Microsoft.Xna.Framework.Vector3(t.p3, t.p1, dist.Length());
if (!Edges.Contains(curr))
{
Edges.Add(curr);
}
}
return(Edges);
}
// Find the smallest correction we can apply to the first rectangle that
// makes it so the rectangles are no longer colliding.
public static PhysicalVector2 GetMinCorrection(
Rectangle rectangle1,
PhysicalVector2 position1,
Rectangle rectangle2,
PhysicalVector2 position2
)
{
var posRect1 = new PosRectangle(position1, rectangle1);
var posRect2 = new PosRectangle(position2, rectangle2);
var xCorrection = new PhysicalVector2(0, 0);
var yCorrection = new PhysicalVector2(0, 0);
// Check how far we have to push the rectangle out on the x direction.
if (position1.X <= position2.X)
{
xCorrection.X = posRect2.Left - posRect1.Right;
}
else
{
xCorrection.X = posRect2.Right - posRect1.Left;
}
// Check how far we have to push the rectangle out on the y direction.
if (position1.Y <= position2.Y)
{
yCorrection.Y = posRect2.Top - posRect1.Bottom;
}
else
{
yCorrection.Y = posRect2.Bottom - posRect1.Top;
}
// See which correction pushes the rectangle out the least and use that as our correction.
if (xCorrection.Length() < yCorrection.Length())
{
return(xCorrection);
}
else
{
return(yCorrection);
}
}
/// <summary>
/// tests if ray intersects AABB
/// </summary>
/// <param name="aabb"></param>
/// <returns></returns>
public static bool RayCastAABB(AABB aabb, Vector2 p1, Vector2 p2)
{
AABB segmentAABB = new AABB();
{
Vector2.Min(ref p1, ref p2, out segmentAABB.LowerBound);
Vector2.Max(ref p1, ref p2, out segmentAABB.UpperBound);
}
if (!AABB.TestOverlap(ref aabb, ref segmentAABB))
{
return(false);
}
Vector2 rayDir = p2 - p1;
Vector2 rayPos = p1;
Vector2 norm = new Vector2(-rayDir.Y, rayDir.X); //normal to ray
if (norm.Length() == 0.0f)
{
return(true); //if ray is just a point, return true (iff point is within aabb, as tested earlier)
}
norm.Normalize();
float dPos = Vector2.Dot(rayPos, norm);
var verts = aabb.Vertices;
float d0 = Vector2.Dot(verts[0], norm) - dPos;
for (int i = 1; i < 4; i++)
{
float d = Vector2.Dot(verts[i], norm) - dPos;
if (Math.Sign(d) != Math.Sign(d0))
{
//return true if the ray splits the vertices (ie: sign of dot products with normal are not all same)
return(true);
}
}
return(false);
}
/// <summary>
/// Constructor for RopeJoint.
/// </summary>
/// <param name="bodyA">The first body</param>
/// <param name="bodyB">The second body</param>
/// <param name="anchorA">The anchor on the first body</param>
/// <param name="anchorB">The anchor on the second body</param>
/// <param name="useWorldCoordinates">Set to true if you are using world coordinates as anchors.</param>
public RopeJoint(Body bodyA, Body bodyB, Vector2 anchorA, Vector2 anchorB, bool useWorldCoordinates = false)
: base(bodyA, bodyB)
{
JointType = JointType.Rope;
if (useWorldCoordinates)
{
LocalAnchorA = bodyA.GetLocalPoint(anchorA);
LocalAnchorB = bodyB.GetLocalPoint(anchorB);
}
else
{
LocalAnchorA = anchorA;
LocalAnchorB = anchorB;
}
//FPE feature: Setting default MaxLength
Vector2 d = WorldAnchorB - WorldAnchorA;
MaxLength = d.Length();
}
/// <summary>
/// Constructor for PulleyJoint.
/// </summary>
/// <param name="bodyA">The first body.</param>
/// <param name="bodyB">The second body.</param>
/// <param name="anchorA">The anchor on the first body.</param>
/// <param name="anchorB">The anchor on the second body.</param>
/// <param name="worldAnchorA">The world anchor for the first body.</param>
/// <param name="worldAnchorB">The world anchor for the second body.</param>
/// <param name="ratio">The ratio.</param>
/// <param name="useWorldCoordinates">Set to true if you are using world coordinates as anchors.</param>
public PulleyJoint(Body bodyA, Body bodyB, Vector2 anchorA, Vector2 anchorB, Vector2 worldAnchorA, Vector2 worldAnchorB, float ratio, bool useWorldCoordinates = false)
: base(bodyA, bodyB)
{
JointType = JointType.Pulley;
WorldAnchorA = worldAnchorA;
WorldAnchorB = worldAnchorB;
if (useWorldCoordinates)
{
LocalAnchorA = BodyA.GetLocalPoint(anchorA);
LocalAnchorB = BodyB.GetLocalPoint(anchorB);
Vector2 dA = anchorA - worldAnchorA;
LengthA = dA.Length();
Vector2 dB = anchorB - worldAnchorB;
LengthB = dB.Length();
}
else
{
LocalAnchorA = anchorA;
LocalAnchorB = anchorB;
Vector2 dA = anchorA - BodyA.GetLocalPoint(worldAnchorA);
LengthA = dA.Length();
Vector2 dB = anchorB - BodyB.GetLocalPoint(worldAnchorB);
LengthB = dB.Length();
}
Debug.Assert(ratio != 0.0f);
Debug.Assert(ratio > Settings.Epsilon);
Ratio = ratio;
Constant = LengthA + ratio * LengthB;
_impulse = 0.0f;
}
internal override void InitVelocityConstraints(ref SolverData data)
{
_indexA = BodyA.IslandIndex;
_indexB = BodyB.IslandIndex;
_localCenterA = BodyA._sweep.LocalCenter;
_localCenterB = BodyB._sweep.LocalCenter;
_invMassA = BodyA._invMass;
_invMassB = BodyB._invMass;
_invIA = BodyA._invI;
_invIB = BodyB._invI;
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 vA = data.velocities[_indexA].v;
float wA = data.velocities[_indexA].w;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
Vector2 vB = data.velocities[_indexB].v;
float wB = data.velocities[_indexB].w;
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
_rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
_rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
_u = cB + _rB - cA - _rA;
_length = _u.Length();
float C = _length - MaxLength;
if (C > 0.0f)
{
State = LimitState.AtUpper;
}
else
{
State = LimitState.Inactive;
}
if (_length > Settings.LinearSlop)
{
_u *= 1.0f / _length;
}
else
{
_u = Vector2.Zero;
_mass = 0.0f;
_impulse = 0.0f;
return;
}
// Compute effective mass.
float crA = MathUtils.Cross(ref _rA, ref _u);
float crB = MathUtils.Cross(ref _rB, ref _u);
float invMass = _invMassA + _invIA * crA * crA + _invMassB + _invIB * crB * crB;
_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f;
if (data.step.warmStarting)
{
// Scale the impulse to support a variable time step.
_impulse *= data.step.dtRatio;
Vector2 P = _impulse * _u;
vA -= _invMassA * P;
wA -= _invIA * MathUtils.Cross(ref _rA, ref P);
vB += _invMassB * P;
wB += _invIB * MathUtils.Cross(ref _rB, ref P);
}
else
{
_impulse = 0.0f;
}
data.velocities[_indexA].v = vA;
data.velocities[_indexA].w = wA;
data.velocities[_indexB].v = vB;
data.velocities[_indexB].w = wB;
}
public float Length()
{
return(_vector.Length());
}
internal override bool SolvePositionConstraints(ref SolverData data)
{
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
Vector2 rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
Vector2 rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
// Get the pulley axes.
Vector2 uA = cA + rA - WorldAnchorA;
Vector2 uB = cB + rB - WorldAnchorB;
float lengthA = uA.Length();
float lengthB = uB.Length();
if (lengthA > 10.0f * Settings.LinearSlop)
{
uA *= 1.0f / lengthA;
}
else
{
uA = Vector2.Zero;
}
if (lengthB > 10.0f * Settings.LinearSlop)
{
uB *= 1.0f / lengthB;
}
else
{
uB = Vector2.Zero;
}
// Compute effective mass.
float ruA = MathUtils.Cross(ref rA, ref uA);
float ruB = MathUtils.Cross(ref rB, ref uB);
float mA = _invMassA + _invIA * ruA * ruA;
float mB = _invMassB + _invIB * ruB * ruB;
float mass = mA + Ratio * Ratio * mB;
if (mass > 0.0f)
{
mass = 1.0f / mass;
}
float C = Constant - lengthA - Ratio * lengthB;
float linearError = Math.Abs(C);
float impulse = -mass * C;
Vector2 PA = -impulse * uA;
Vector2 PB = -Ratio * impulse * uB;
cA += _invMassA * PA;
aA += _invIA * MathUtils.Cross(ref rA, ref PA);
cB += _invMassB * PB;
aB += _invIB * MathUtils.Cross(ref rB, ref PB);
data.positions[_indexA].c = cA;
data.positions[_indexA].a = aA;
data.positions[_indexB].c = cB;
data.positions[_indexB].a = aB;
return(linearError < Settings.LinearSlop);
}
internal override void InitVelocityConstraints(ref SolverData data)
{
_indexA = BodyA.IslandIndex;
_indexB = BodyB.IslandIndex;
_localCenterA = BodyA._sweep.LocalCenter;
_localCenterB = BodyB._sweep.LocalCenter;
_invMassA = BodyA._invMass;
_invMassB = BodyB._invMass;
_invIA = BodyA._invI;
_invIB = BodyB._invI;
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 vA = data.velocities[_indexA].v;
float wA = data.velocities[_indexA].w;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
Vector2 vB = data.velocities[_indexB].v;
float wB = data.velocities[_indexB].w;
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
_rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
_rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
// Get the pulley axes.
_uA = cA + _rA - WorldAnchorA;
_uB = cB + _rB - WorldAnchorB;
float lengthA = _uA.Length();
float lengthB = _uB.Length();
if (lengthA > 10.0f * Settings.LinearSlop)
{
_uA *= 1.0f / lengthA;
}
else
{
_uA = Vector2.Zero;
}
if (lengthB > 10.0f * Settings.LinearSlop)
{
_uB *= 1.0f / lengthB;
}
else
{
_uB = Vector2.Zero;
}
// Compute effective mass.
float ruA = MathUtils.Cross(ref _rA, ref _uA);
float ruB = MathUtils.Cross(ref _rB, ref _uB);
float mA = _invMassA + _invIA * ruA * ruA;
float mB = _invMassB + _invIB * ruB * ruB;
_mass = mA + Ratio * Ratio * mB;
if (_mass > 0.0f)
{
_mass = 1.0f / _mass;
}
if (data.step.warmStarting)
{
// Scale impulses to support variable time steps.
_impulse *= data.step.dtRatio;
// Warm starting.
Vector2 PA = -(_impulse) * _uA;
Vector2 PB = (-Ratio * _impulse) * _uB;
vA += _invMassA * PA;
wA += _invIA * MathUtils.Cross(ref _rA, ref PA);
vB += _invMassB * PB;
wB += _invIB * MathUtils.Cross(ref _rB, ref PB);
}
else
{
_impulse = 0.0f;
}
data.velocities[_indexA].v = vA;
data.velocities[_indexA].w = wA;
data.velocities[_indexB].v = vB;
data.velocities[_indexB].w = wB;
}
internal override bool SolvePositionConstraints(ref SolverData data)
{
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
float angularError = 0.0f;
float positionError;
bool fixedRotation = (_invIA + _invIB == 0.0f);
// Solve angular limit constraint.
if (_enableLimit && _limitState != LimitState.Inactive && fixedRotation == false)
{
float angle = aB - aA - ReferenceAngle;
float limitImpulse = 0.0f;
if (_limitState == LimitState.Equal)
{
// Prevent large angular corrections
float C = MathUtils.Clamp(angle - _lowerAngle, -Settings.MaxAngularCorrection, Settings.MaxAngularCorrection);
limitImpulse = -_motorMass * C;
angularError = Math.Abs(C);
}
else if (_limitState == LimitState.AtLower)
{
float C = angle - _lowerAngle;
angularError = -C;
// Prevent large angular corrections and allow some slop.
C = MathUtils.Clamp(C + Settings.AngularSlop, -Settings.MaxAngularCorrection, 0.0f);
limitImpulse = -_motorMass * C;
}
else if (_limitState == LimitState.AtUpper)
{
float C = angle - _upperAngle;
angularError = C;
// Prevent large angular corrections and allow some slop.
C = MathUtils.Clamp(C - Settings.AngularSlop, 0.0f, Settings.MaxAngularCorrection);
limitImpulse = -_motorMass * C;
}
aA -= _invIA * limitImpulse;
aB += _invIB * limitImpulse;
}
// Solve point-to-point constraint.
{
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
Vector2 rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
Vector2 rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
Vector2 C = cB + rB - cA - rA;
positionError = C.Length();
float mA = _invMassA, mB = _invMassB;
float iA = _invIA, iB = _invIB;
Mat22 K = new Mat22();
K.ex.X = mA + mB + iA * rA.Y * rA.Y + iB * rB.Y * rB.Y;
K.ex.Y = -iA * rA.X * rA.Y - iB * rB.X * rB.Y;
K.ey.X = K.ex.Y;
K.ey.Y = mA + mB + iA * rA.X * rA.X + iB * rB.X * rB.X;
Vector2 impulse = -K.Solve(C);
cA -= mA * impulse;
aA -= iA * MathUtils.Cross(ref rA, ref impulse);
cB += mB * impulse;
aB += iB * MathUtils.Cross(ref rB, ref impulse);
}
data.positions[_indexA].c = cA;
data.positions[_indexA].a = aA;
data.positions[_indexB].c = cB;
data.positions[_indexB].a = aB;
return(positionError <= Settings.LinearSlop && angularError <= Settings.AngularSlop);
}
internal override void InitVelocityConstraints(ref SolverData data)
{
_indexA = BodyA.IslandIndex;
_indexB = BodyB.IslandIndex;
_localCenterA = BodyA._sweep.LocalCenter;
_localCenterB = BodyB._sweep.LocalCenter;
_invMassA = BodyA._invMass;
_invMassB = BodyB._invMass;
_invIA = BodyA._invI;
_invIB = BodyB._invI;
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 vA = data.velocities[_indexA].v;
float wA = data.velocities[_indexA].w;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
Vector2 vB = data.velocities[_indexB].v;
float wB = data.velocities[_indexB].w;
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
_rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
_rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
_u = cB + _rB - cA - _rA;
// Handle singularity.
float length = _u.Length();
if (length > Settings.LinearSlop)
{
_u *= 1.0f / length;
}
else
{
_u = Vector2.Zero;
}
float crAu = MathUtils.Cross(ref _rA, ref _u);
float crBu = MathUtils.Cross(ref _rB, ref _u);
float invMass = _invMassA + _invIA * crAu * crAu + _invMassB + _invIB * crBu * crBu;
// Compute the effective mass matrix.
_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f;
if (Frequency > 0.0f)
{
float C = length - Length;
// Frequency
float omega = Constant.Tau * Frequency;
// Damping coefficient
float d = 2.0f * _mass * DampingRatio * omega;
// Spring stiffness
float k = _mass * omega * omega;
// magic formulas
float h = data.step.dt;
_gamma = h * (d + h * k);
_gamma = _gamma != 0.0f ? 1.0f / _gamma : 0.0f;
_bias = C * h * k * _gamma;
invMass += _gamma;
_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f;
}
else
{
_gamma = 0.0f;
_bias = 0.0f;
}
if (data.step.warmStarting)
{
// Scale the impulse to support a variable time step.
_impulse *= data.step.dtRatio;
Vector2 P = _impulse * _u;
vA -= _invMassA * P;
wA -= _invIA * MathUtils.Cross(ref _rA, ref P);
vB += _invMassB * P;
wB += _invIB * MathUtils.Cross(ref _rB, ref P);
}
else
{
_impulse = 0.0f;
}
data.velocities[_indexA].v = vA;
data.velocities[_indexA].w = wA;
data.velocities[_indexB].v = vB;
data.velocities[_indexB].w = wB;
}
internal void Solve(ref TimeStep step, ref Vector2 gravity)
{
float h = step.dt;
// Integrate velocities and apply damping. Initialize the body state.
for (int i = 0; i < BodyCount; ++i)
{
Body b = Bodies[i];
Vector2 c = b._sweep.C;
float a = b._sweep.A;
Vector2 v = b._linearVelocity;
float w = b._angularVelocity;
// Store positions for continuous collision.
b._sweep.C0 = b._sweep.C;
b._sweep.A0 = b._sweep.A;
if (b.BodyType == BodyType.Dynamic)
{
// Integrate velocities.
// FPE: Only apply gravity if the body wants it.
if (b.IgnoreGravity)
{
v += h * (b._invMass * b._force);
}
else
{
v += h * (gravity + b._invMass * b._force);
}
w += h * b._invI * b._torque;
// Apply damping.
// ODE: dv/dt + c * v = 0
// Solution: v(t) = v0 * exp(-c * t)
// Time step: v(t + dt) = v0 * exp(-c * (t + dt)) = v0 * exp(-c * t) * exp(-c * dt) = v * exp(-c * dt)
// v2 = exp(-c * dt) * v1
// Taylor expansion:
// v2 = (1.0f - c * dt) * v1
v *= MathUtils.Clamp(1.0f - h * b.LinearDamping, 0.0f, 1.0f);
w *= MathUtils.Clamp(1.0f - h * b.AngularDamping, 0.0f, 1.0f);
}
_positions[i].c = c;
_positions[i].a = a;
_velocities[i].v = v;
_velocities[i].w = w;
}
// Solver data
SolverData solverData = new SolverData();
solverData.step = step;
solverData.positions = _positions;
solverData.velocities = _velocities;
solverData.locks = _locks;
_contactSolver.Reset(ref step, ContactCount, _contacts, _positions, _velocities,
_locks, _contactManager.VelocityConstraintsMultithreadThreshold, _contactManager.PositionConstraintsMultithreadThreshold);
_contactSolver.InitializeVelocityConstraints();
if (step.warmStarting)
{
_contactSolver.WarmStart();
}
if (Settings.EnableDiagnostics)
{
_watch.Start();
}
for (int i = 0; i < JointCount; ++i)
{
if (_joints[i].Enabled)
{
_joints[i].InitVelocityConstraints(ref solverData);
}
}
if (Settings.EnableDiagnostics)
{
_watch.Stop();
}
// Solve velocity constraints.
for (int i = 0; i < step.velocityIterations; ++i)
{
for (int j = 0; j < JointCount; ++j)
{
Joint joint = _joints[j];
if (!joint.Enabled)
{
continue;
}
if (Settings.EnableDiagnostics)
{
_watch.Start();
}
joint.SolveVelocityConstraints(ref solverData);
joint.Validate(step.inv_dt);
if (Settings.EnableDiagnostics)
{
_watch.Stop();
}
}
_contactSolver.SolveVelocityConstraints();
}
// Store impulses for warm starting.
_contactSolver.StoreImpulses();
// Integrate positions
for (int i = 0; i < BodyCount; ++i)
{
Vector2 c = _positions[i].c;
float a = _positions[i].a;
Vector2 v = _velocities[i].v;
float w = _velocities[i].w;
// Check for large velocities
Vector2 translation = h * v;
if (Vector2.Dot(translation, translation) > Settings.MaxTranslationSquared)
{
float ratio = Settings.MaxTranslation / translation.Length();
v *= ratio;
}
float rotation = h * w;
if (rotation * rotation > Settings.MaxRotationSquared)
{
float ratio = Settings.MaxRotation / Math.Abs(rotation);
w *= ratio;
}
// Integrate
c += h * v;
a += h * w;
_positions[i].c = c;
_positions[i].a = a;
_velocities[i].v = v;
_velocities[i].w = w;
}
// Solve position constraints
bool positionSolved = false;
for (int i = 0; i < step.positionIterations; ++i)
{
bool contactsOkay = _contactSolver.SolvePositionConstraints();
bool jointsOkay = true;
for (int j = 0; j < JointCount; ++j)
{
Joint joint = _joints[j];
if (!joint.Enabled)
{
continue;
}
if (Settings.EnableDiagnostics)
{
_watch.Start();
}
bool jointOkay = joint.SolvePositionConstraints(ref solverData);
if (Settings.EnableDiagnostics)
{
_watch.Stop();
}
jointsOkay = jointsOkay && jointOkay;
}
if (contactsOkay && jointsOkay)
{
// Exit early if the position errors are small.
positionSolved = true;
break;
}
}
if (Settings.EnableDiagnostics)
{
JointUpdateTime = TimeSpan.FromTicks(_watch.ElapsedTicks);
_watch.Reset();
}
// Copy state buffers back to the bodies
for (int i = 0; i < BodyCount; ++i)
{
Body body = Bodies[i];
body._sweep.C = _positions[i].c;
body._sweep.A = _positions[i].a;
body._linearVelocity = _velocities[i].v;
body._angularVelocity = _velocities[i].w;
body.SynchronizeTransform();
}
Report(_contactSolver._velocityConstraints);
if (Settings.AllowSleep)
{
float minSleepTime = Settings.MaxFloat;
for (int i = 0; i < BodyCount; ++i)
{
Body b = Bodies[i];
if (b.BodyType == BodyType.Static)
{
continue;
}
if (!b.SleepingAllowed || b._angularVelocity * b._angularVelocity > AngTolSqr || Vector2.Dot(b._linearVelocity, b._linearVelocity) > LinTolSqr)
{
b._sleepTime = 0.0f;
minSleepTime = 0.0f;
}
else
{
b._sleepTime += h;
minSleepTime = Math.Min(minSleepTime, b._sleepTime);
}
}
if (minSleepTime >= Settings.TimeToSleep && positionSolved)
{
for (int i = 0; i < BodyCount; ++i)
{
Body b = Bodies[i];
b.Awake = false;
}
}
}
}
internal void SolveTOI(ref TimeStep subStep, int toiIndexA, int toiIndexB)
{
Debug.Assert(toiIndexA < BodyCount);
Debug.Assert(toiIndexB < BodyCount);
// Initialize the body state.
for (int i = 0; i < BodyCount; ++i)
{
Body b = Bodies[i];
_positions[i].c = b._sweep.C;
_positions[i].a = b._sweep.A;
_velocities[i].v = b._linearVelocity;
_velocities[i].w = b._angularVelocity;
}
_contactSolver.Reset(ref subStep, ContactCount, _contacts, _positions, _velocities,
_locks, _contactManager.VelocityConstraintsMultithreadThreshold, _contactManager.PositionConstraintsMultithreadThreshold);
// Solve position constraints.
for (int i = 0; i < subStep.positionIterations; ++i)
{
bool contactsOkay = _contactSolver.SolveTOIPositionConstraints(toiIndexA, toiIndexB);
if (contactsOkay)
{
break;
}
}
// Leap of faith to new safe state.
Bodies[toiIndexA]._sweep.C0 = _positions[toiIndexA].c;
Bodies[toiIndexA]._sweep.A0 = _positions[toiIndexA].a;
Bodies[toiIndexB]._sweep.C0 = _positions[toiIndexB].c;
Bodies[toiIndexB]._sweep.A0 = _positions[toiIndexB].a;
// No warm starting is needed for TOI events because warm
// starting impulses were applied in the discrete solver.
_contactSolver.InitializeVelocityConstraints();
// Solve velocity constraints.
for (int i = 0; i < subStep.velocityIterations; ++i)
{
_contactSolver.SolveVelocityConstraints();
}
// Don't store the TOI contact forces for warm starting
// because they can be quite large.
float h = subStep.dt;
// Integrate positions.
for (int i = 0; i < BodyCount; ++i)
{
Vector2 c = _positions[i].c;
float a = _positions[i].a;
Vector2 v = _velocities[i].v;
float w = _velocities[i].w;
// Check for large velocities
Vector2 translation = h * v;
if (Vector2.Dot(translation, translation) > Settings.MaxTranslationSquared)
{
float ratio = Settings.MaxTranslation / translation.Length();
v *= ratio;
}
float rotation = h * w;
if (rotation * rotation > Settings.MaxRotationSquared)
{
float ratio = Settings.MaxRotation / Math.Abs(rotation);
w *= ratio;
}
// Integrate
c += h * v;
a += h * w;
_positions[i].c = c;
_positions[i].a = a;
_velocities[i].v = v;
_velocities[i].w = w;
// Sync bodies
Body body = Bodies[i];
body._sweep.C = c;
body._sweep.A = a;
body._linearVelocity = v;
body._angularVelocity = w;
body.SynchronizeTransform();
}
Report(_contactSolver._velocityConstraints);
}
internal override bool SolvePositionConstraints(ref SolverData data)
{
Vector2 cA = data.positions[_indexA].c;
float aA = data.positions[_indexA].a;
Vector2 cB = data.positions[_indexB].c;
float aB = data.positions[_indexB].a;
Complex qA = Complex.FromAngle(aA);
Complex qB = Complex.FromAngle(aB);
float mA = _invMassA, mB = _invMassB;
float iA = _invIA, iB = _invIB;
Vector2 rA = Complex.Multiply(LocalAnchorA - _localCenterA, ref qA);
Vector2 rB = Complex.Multiply(LocalAnchorB - _localCenterB, ref qB);
float positionError, angularError;
Mat33 K = new Mat33();
K.ex.X = mA + mB + rA.Y * rA.Y * iA + rB.Y * rB.Y * iB;
K.ey.X = -rA.Y * rA.X * iA - rB.Y * rB.X * iB;
K.ez.X = -rA.Y * iA - rB.Y * iB;
K.ex.Y = K.ey.X;
K.ey.Y = mA + mB + rA.X * rA.X * iA + rB.X * rB.X * iB;
K.ez.Y = rA.X * iA + rB.X * iB;
K.ex.Z = K.ez.X;
K.ey.Z = K.ez.Y;
K.ez.Z = iA + iB;
if (FrequencyHz > 0.0f)
{
Vector2 C1 = cB + rB - cA - rA;
positionError = C1.Length();
angularError = 0.0f;
Vector2 P = -K.Solve22(C1);
cA -= mA * P;
aA -= iA * MathUtils.Cross(ref rA, ref P);
cB += mB * P;
aB += iB * MathUtils.Cross(ref rB, ref P);
}
else
{
Vector2 C1 = cB + rB - cA - rA;
float C2 = aB - aA - ReferenceAngle;
positionError = C1.Length();
angularError = Math.Abs(C2);
Vector3 C = new Vector3(C1.X, C1.Y, C2);
Vector3 impulse;
if (K.ez.Z <= 0.0f)
{
Vector2 impulse2 = -K.Solve22(C1);
impulse = new Vector3(impulse2.X, impulse2.Y, 0.0f);
}
else
{
impulse = -K.Solve33(C);
}
Vector2 P = new Vector2(impulse.X, impulse.Y);
cA -= mA * P;
aA -= iA * (MathUtils.Cross(ref rA, ref P) + impulse.Z);
cB += mB * P;
aB += iB * (MathUtils.Cross(ref rB, ref P) + impulse.Z);
}
data.positions[_indexA].c = cA;
data.positions[_indexA].a = aA;
data.positions[_indexB].c = cB;
data.positions[_indexB].a = aB;
return(positionError <= Settings.LinearSlop && angularError <= Settings.AngularSlop);
}