public override bool Solve(ref idMatX o_m, ref idVecX o_x, ref idVecX o_b, ref idVecX o_lo, ref idVecX o_hi, int[] o_boxIndex)
{
// true when the matrix rows are 16 byte padded
padded = (((o_m.GetNumRows() + 3) & ~3) == o_m.GetNumColumns());
Debug.Assert(padded || o_m.GetNumRows() == o_m.GetNumColumns());
Debug.Assert(o_x.GetSize() == o_m.GetNumRows());
Debug.Assert(o_b.GetSize() == o_m.GetNumRows());
Debug.Assert(o_lo.GetSize() == o_m.GetNumRows());
Debug.Assert(o_hi.GetSize() == o_m.GetNumRows());
// allocate memory for permuted input
f.SetData(o_m.GetNumRows(), VECX_ALLOCA(o_m.GetNumRows()));
a.SetData(o_b.GetSize(), VECX_ALLOCA(o_b.GetSize()));
b.SetData(o_b.GetSize(), VECX_ALLOCA(o_b.GetSize()));
lo.SetData(o_lo.GetSize(), VECX_ALLOCA(o_lo.GetSize()));
hi.SetData(o_hi.GetSize(), VECX_ALLOCA(o_hi.GetSize()));
if (o_boxIndex != null)
{
boxIndex = new int[o_x.GetSize()];
Array.Copy(boxIndex, o_boxIndex, o_x.GetSize());
}
else
{
boxIndex = null;
}
// we override the const on o_m here but on exit the matrix is unchanged
m.SetData(o_m.GetNumRows(), o_m.GetNumColumns(), (float[])o_m[0]);
f.Zero();
a.Zero();
b = o_b;
lo = o_lo;
hi = o_hi;
// pointers to the rows of m
rowPtrs = new float[m.GetNumRows()][];
for (int i = 0; i < m.GetNumRows(); i++)
{
rowPtrs[i] = m[i];
}
// tells if a variable is at the low boundary, high boundary or inbetween
side = new int[m.GetNumRows()];
// index to keep track of the permutation
permuted = new int[m.GetNumRows()];
for (int i = 0; i < m.GetNumRows(); i++)
{
permuted[i] = i;
}
// permute input so all unbounded variables come first
numUnbounded = 0;
for (int i = 0; i < m.GetNumRows(); i++)
{
if (lo[i] == -float.NegativeInfinity && hi[i] == float.PositiveInfinity)
{
if (numUnbounded != i)
{
Swap(numUnbounded, i);
}
numUnbounded++;
}
}
// permute input so all variables using the boxIndex come last
int boxStartIndex = m.GetNumRows();
if (boxIndex != null)
{
for (int i = m.GetNumRows() - 1; i >= numUnbounded; i--)
{
if (boxIndex[i] >= 0 && (lo[i] != float.NegativeInfinity || hi[i] != float.PositiveInfinity))
{
boxStartIndex--;
if (boxStartIndex != i)
{
Swap(boxStartIndex, i);
}
}
}
}
// sub matrix for factorization
clamped.SetData(m.GetNumRows(), m.GetNumColumns(), MATX_ALLOCA(m.GetNumRows() * m.GetNumColumns()));
diagonal.SetData(m.GetNumRows(), VECX_ALLOCA(m.GetNumRows()));
// all unbounded variables are clamped
numClamped = numUnbounded;
// if there are unbounded variables
if (numUnbounded != 0)
{
// factor and solve for unbounded variables
if (!FactorClamped())
{
idLib.common.Printf("idLCP_Square::Solve: unbounded factorization failed\n");
return(false);
}
SolveClamped(f, b.ToArray());
// if there are no bounded variables we are done
if (numUnbounded == m.GetNumRows())
{
o_x = f; // the vector is not permuted
return(true);
}
}
#if IGNORE_UNSATISFIABLE_VARIABLES
int numIgnored = 0;
#endif
// allocate for delta force and delta acceleration
delta_f.SetData(m.GetNumRows(), VECX_ALLOCA(m.GetNumRows()));
delta_a.SetData(m.GetNumRows(), VECX_ALLOCA(m.GetNumRows()));
// // solve for bounded variables
string failed = null;
float dot;
for (int i = numUnbounded; i < m.GetNumRows(); i++)
{
// once we hit the box start index we can initialize the low and high boundaries of the variables using the box index
if (i == boxStartIndex)
{
for (int j = 0; j < boxStartIndex; j++)
{
o_x[permuted[j]] = f[j];
}
for (int j = boxStartIndex; j < m.GetNumRows(); j++)
{
float s = o_x[boxIndex[j]];
if (lo[j] != float.NegativeInfinity)
{
lo[j] = -idMath.Fabs(lo[j] * s);
}
if (hi[j] != float.PositiveInfinity)
{
hi[j] = idMath.Fabs(hi[j] * s);
}
}
}
// calculate acceleration for current variable
SIMDProcessor.Dot(out dot, rowPtrs[i], f.ToArray(), i);
a[i] = dot - b[i];
// if already at the low boundary
if (lo[i] >= -LCP_BOUND_EPSILON && a[i] >= -LCP_ACCEL_EPSILON)
{
side[i] = -1; continue;
}
// if already at the high boundary
if (hi[i] <= LCP_BOUND_EPSILON && a[i] <= LCP_ACCEL_EPSILON)
{
side[i] = 1; continue;
}
// if inside the clamped region
if (idMath.Fabs(a[i]) <= LCP_ACCEL_EPSILON)
{
side[i] = 0; AddClamped(i); continue;
}
// drive the current variable into a valid region
int n;
for (n = 0; n < maxIterations; n++)
{
// direction to move
float dir = (a[i] <= 0.0f ? 1.0f : -1.0f);
// calculate force delta
CalcForceDelta(i, dir);
// calculate acceleration delta: delta_a = m * delta_f;
CalcAccelDelta(i);
// maximum step we can take
float maxStep;
int limit;
int limitSide;
GetMaxStep(i, dir, out maxStep, out limit, out limitSide);
if (maxStep <= 0.0f)
{
#if IGNORE_UNSATISFIABLE_VARIABLES
// ignore the current variable completely
lo[i] = hi[i] = 0.0f;
f[i] = 0.0f;
side[i] = -1;
numIgnored++;
#else
failed = string.Format("invalid step size %.4f", maxStep);
#endif
break;
}
// change force
ChangeForce(i, maxStep);
// change acceleration
ChangeAccel(i, maxStep);
// clamp/unclamp the variable that limited this step
side[limit] = limitSide;
switch (limitSide)
{
case 0:
a[limit] = 0.0f;
AddClamped(limit);
break;
case -1:
f[limit] = lo[limit];
if (limit != i)
{
RemoveClamped(limit);
}
break;
case 1:
f[limit] = hi[limit];
if (limit != i)
{
RemoveClamped(limit);
}
break;
}
// if the current variable limited the step we can continue with the next variable
if (limit == i)
{
break;
}
}
if (n >= maxIterations)
{
failed = string.Format("max iterations %d", maxIterations);
break;
}
if (failed != null)
{
break;
}
}
#if IGNORE_UNSATISFIABLE_VARIABLES
if (numIgnored > 0)
{
if (lcp_showFailures.GetBool())
{
idLib.common.Printf("idLCP_Symmetric::Solve: %d of %d bounded variables ignored\n", numIgnored, m.GetNumRows() - numUnbounded);
}
}
#endif
// if failed clear remaining forces
if (failed != null)
{
if (lcp_showFailures.GetBool())
{
idLib.common.Printf("idLCP_Square::Solve: %s (%d of %d bounded variables ignored)\n", failed, m.GetNumRows() - i, m.GetNumRows() - numUnbounded);
}
for (int j = i; j < m.GetNumRows(); j++)
{
f[j] = 0.0f;
}
}
#if _DEBUG && false
if (failed == null)
{
// test whether or not the solution satisfies the complementarity conditions
for (int i = 0; i < m.GetNumRows(); i++)
{
a[i] = -b[i];
for (int j = 0; j < m.GetNumRows(); j++)
{
a[i] += rowPtrs[i][j] * f[j];
}
if (f[i] == lo[i])
{
if (lo[i] != hi[i] && a[i] < -LCP_ACCEL_EPSILON)
{
int bah1 = 1;
}
}
else if (f[i] == hi[i])
{
if (lo[i] != hi[i] && a[i] > LCP_ACCEL_EPSILON)
{
int bah2 = 1;
}
}
else if (f[i] < lo[i] || f[i] > hi[i] || idMath.Fabs(a[i]) > 1.0f)
{
int bah3 = 1;
}
}
}
#endif
// unpermute result
for (int i = 0; i < f.GetSize(); i++)
{
o_x[permuted[i]] = f[i];
}
// unpermute original matrix
for (int i = 0; i < m.GetNumRows(); i++)
{
for (int j = 0; j < m.GetNumRows(); j++)
{
if (permuted[j] == i)
{
break;
}
}
if (i != j)
{
m.SwapColumns(i, j);
idSwap(permuted[i], permuted[j]);
}
}
return(true);
}
