public LinearProblemProperties BuildLCP(
JacobianConstraint[] constraints,
double timeStep)
{
LinearProblemBaseProperties baseProperties = new LinearProblemBaseProperties(constraints.Length);
Dictionary <HashSetStruct, List <DictionaryConstraintValue> > constraintsDictionary = new Dictionary <HashSetStruct, List <DictionaryConstraintValue> >();
for (int i = 0; i < constraints.Length; i++)
{
JacobianConstraint itemConstraint = constraints[i];
HashSetStruct hash = new HashSetStruct(itemConstraint.ObjectA.ID, itemConstraint.ObjectB.ID);
if (constraintsDictionary.TryGetValue(hash, out List <DictionaryConstraintValue> jc))
{
jc.Add(new DictionaryConstraintValue(itemConstraint, i));
}
else
{
constraintsDictionary.Add(hash, new List <DictionaryConstraintValue> {
new DictionaryConstraintValue(itemConstraint, i)
});
}
}
Graph graph = new Graph(constraints.Length);
var dictionaryArray = constraintsDictionary.ToArray();
var key_ID_A = constraintsDictionary.ToLookup(x => x.Key.ID_A);
var key_ID_B = constraintsDictionary.ToLookup(x => x.Key.ID_B);
var rangePartitioner = Partitioner.Create(
0,
dictionaryArray.Length,
Convert.ToInt32(dictionaryArray.Length / EngineParameters.MaxThreadNumber) + 1);
double timeFreq = 1.0 / timeStep;
Parallel.ForEach(
rangePartitioner,
new ParallelOptions {
MaxDegreeOfParallelism = EngineParameters.MaxThreadNumber
},
(range, loopState) =>
{
for (int i = range.Item1; i < range.Item2; i++)
{
var constraintValues = dictionaryArray[i];
var constraintValueKey = constraintValues.Key;
int contactA_ID_A = constraintValues.Key.ID_A;
int contactA_ID_B = constraintValues.Key.ID_B;
for (int w = 0; w < constraintValues.Value.Count; w++)
{
JacobianConstraint contactA = constraintValues.Value[w].Constraint;
List <int> index = new List <int>();
List <double> values = new List <double>();
int indexVal = constraintValues.Value[w].Index;
double correctionVal = contactA.CorrectionValue * timeFreq;
double correctionValue = (correctionVal) < 0 ?
Math.Max(correctionVal, -EngineParameters.MaxCorrectionValue) :
Math.Min(correctionVal, EngineParameters.MaxCorrectionValue);
baseProperties.B[indexVal] = correctionValue - contactA.JacobianVelocity - contactA.ConstraintValue;
baseProperties.ConstraintsArray[indexVal] = contactA.ContactReference;
baseProperties.ConstraintLimit[indexVal] = contactA.ConstraintLimit;
baseProperties.ConstraintType[indexVal] = contactA.Type;
//Diagonal value
double mValue = GetLCPDiagonalValue(contactA) +
(contactA.CFM * timeFreq) +
EngineParameters.CFM +
1E-40;
baseProperties.D[indexVal] = mValue;
baseProperties.InvD[indexVal] = 1.0 / mValue;
//contactA_ID_A == contactB_ID_A && contactA_ID_B == contactB_ID_B
for (int j = 0; j < constraintValues.Value.Count; j++)
{
int innerIndex = constraintValues.Value[j].Index;
if (innerIndex != indexVal)
{
JacobianConstraint contactB = constraintValues.Value[j].Constraint;
mValue = GetLCPMatrixValue(
contactA.LinearComponentA,
contactB.LinearComponentA,
contactA.AngularComponentA,
contactB.AngularComponentA,
contactA.ObjectA.MassInfo);
mValue += GetLCPMatrixValue(
contactA.LinearComponentB,
contactB.LinearComponentB,
contactA.AngularComponentB,
contactB.AngularComponentB,
contactA.ObjectB.MassInfo);
AddValues(ref index, ref values, mValue, innerIndex);
}
}
//contactA_ID_A == contactB_ID_B && contactA_ID_B == contactB_ID_A
var symmetricHashSet = new HashSetStruct(contactA_ID_B, contactA_ID_A);
if (constraintsDictionary.TryGetValue(symmetricHashSet, out List <DictionaryConstraintValue> symmetricList))
{
foreach (var item in symmetricList)
{
int innerIndex = item.Index;
if (innerIndex != indexVal)
{
JacobianConstraint contactB = item.Constraint;
mValue = GetLCPMatrixValue(
contactA.LinearComponentA,
contactB.LinearComponentB,
contactA.AngularComponentA,
contactB.AngularComponentB,
contactA.ObjectA.MassInfo);
mValue += GetLCPMatrixValue(
contactA.LinearComponentB,
contactB.LinearComponentA,
contactA.AngularComponentB,
contactB.AngularComponentA,
contactA.ObjectB.MassInfo);
AddValues(ref index, ref values, mValue, innerIndex);
}
}
}
//contactA_ID_A == contactB_ID_A
foreach (var constraintCheckItem in key_ID_A[contactA_ID_A])
{
AddLCPValues(
ref index,
ref values,
indexVal,
constraintCheckItem,
constraintValueKey,
symmetricHashSet,
contactA.LinearComponentA,
contactA.AngularComponentA,
contactA.ObjectA.MassInfo,
true);
}
//contactA_ID_A == contactB_ID_B
foreach (var constraintCheckItem in key_ID_B[contactA_ID_A])
{
AddLCPValues(
ref index,
ref values,
indexVal,
constraintCheckItem,
constraintValueKey,
symmetricHashSet,
contactA.LinearComponentA,
contactA.AngularComponentA,
contactA.ObjectA.MassInfo,
false);
}
//contactA_ID_B == contactB_ID_A
foreach (var constraintCheckItem in key_ID_A[contactA_ID_B])
{
AddLCPValues(
ref index,
ref values,
indexVal,
constraintCheckItem,
constraintValueKey,
symmetricHashSet,
contactA.LinearComponentB,
contactA.AngularComponentB,
contactA.ObjectB.MassInfo,
true);
}
//contactA_ID_B == contactB_ID_B
foreach (var constraintCheckItem in key_ID_B[contactA_ID_B])
{
AddLCPValues(
ref index,
ref values,
indexVal,
constraintCheckItem,
constraintValueKey,
symmetricHashSet,
contactA.LinearComponentB,
contactA.AngularComponentB,
contactA.ObjectB.MassInfo,
false);
}
//Sparse Matrix
baseProperties.M.Rows[indexVal] = new SparseVector(
values.ToArray(),
index.ToArray(),
baseProperties.M.m);
UpdateGraph(ref graph, index, indexVal);
}
}
});
var lp = new LinearProblemProperties(
baseProperties,
graph,
EngineParameters.FrictionDirections);
return(lp);
}
//TODO Refactor
public LinearProblemProperties GetLCPFrictionMatrix(LinearProblemProperties linearProblem)
{
var collisionIndexes = linearProblem.ConstraintType
.Select((constraint, index) => new { constraint, index })
.Where(x => x.constraint == ConstraintType.Collision).ToList();
if (collisionIndexes.Count > 0)
{
var numberOfCollision = collisionIndexes.Count;
var lcpMatrixDim = linearProblem.Count + numberOfCollision;
var frictionIndexes = linearProblem.ConstraintType
.Select((constraint, index) => new { constraint, index })
.Where(x => x.constraint == ConstraintType.Friction).ToList();
LinearProblemBaseProperties baseProperties = new LinearProblemBaseProperties(lcpMatrixDim);
var b = linearProblem.B.ToList();
var d = linearProblem.D.ToList();
var invD = linearProblem.InvD.ToList();
var constraintType = linearProblem.ConstraintType.ToList();
var constraintLimit = linearProblem.ConstraintLimit.ToList();
var m = linearProblem.GetOriginalSparseMatrix().Rows.ToList();
var constraintsArray = linearProblem.Constraints.ToList();
var startValue = linearProblem.StartImpulse.ToList();
var E_dim = numberOfCollision * EngineParameters.FrictionDirections;
var newRowLength = b.Count + numberOfCollision;
//Add fields to friction rows
for (int i = 0; i < numberOfCollision; i++)
{
var colIdx = collisionIndexes[i].index;
var fIndexes = constraintsArray.Select((constraint, index) => new { constraint, index })
.Where(x => x.constraint.HasValue && x.constraint.Value == colIdx).ToList();
//Add elements to matrix M, friction values
var rowIndexes = new List <int>()
{
collisionIndexes[i].index
};
var rowValues = new List <double>()
{
constraintLimit[frictionIndexes[0].index]
};
//Columns and rows update
for (int j = 0; j < fIndexes.Count; j++)
{
var idx = fIndexes[j].index;
var mIdx = m[idx];
var bufIndex = new List <int>(mIdx.Index);
var bufValue = new List <double>(mIdx.Value);
bufIndex.Add(mIdx.Length + i);
bufValue.Add(1.0);
m[idx] = new SparseVector(
bufValue.ToArray(),
bufIndex.ToArray(),
mIdx.Length + numberOfCollision);
rowIndexes.Add(idx);
rowValues.Add(-1.0);
}
//Rows Update
constraintType.Add(ConstraintType.FrictionValue);
b.Add(0.0);
d.Add(0.0);
invD.Add(0.0);
constraintLimit.Add(0.0);
startValue.Add(0.0);
var sparseElement = new SparseVector(
rowValues.ToArray(),
rowIndexes.ToArray(),
newRowLength);
m.Add(sparseElement);
}
for (int i = 0; i < m.Count; i++)
{
m[i] = new SparseVector(m[i].Value, m[i].Index, newRowLength);
b[i] *= -1.0;
}
baseProperties.B = b.ToArray();
baseProperties.D = d.ToArray();
baseProperties.InvD = invD.ToArray();
baseProperties.ConstraintType = constraintType.ToArray();
baseProperties.ConstraintLimit = constraintLimit.ToArray();
baseProperties.StartValue = startValue.ToArray();
baseProperties.M.Rows = m.ToArray();
var lcp = new LinearProblemProperties(baseProperties, null, EngineParameters.FrictionDirections);
//TODO Test
//var test = lcp.GetOriginalMatrix();
return(lcp);
}
return(linearProblem);
}