public void TestInvMul()
{
for (int i = 0; i < 100; ++i)
{
var xf = RandomTr((i % 2) == 0);
AssertAlmostEqual(TrTransform.InvMul(xf, xf), TrTransform.identity);
}
}
/// Returns xf_RS, relative to the passed line transform.
/// Applies m_LineDepth and ignores xf_RS.scale
/// TODO: see above.
TrTransform GetTransformForLine(Transform line, TrTransform xf_RS)
{
var xfRoomFromLine = Coords.AsRoom[line];
xf_RS.translation += xf_RS.forward * m_LineDepth;
xf_RS.scale = 1;
return(TrTransform.InvMul(xfRoomFromLine, xf_RS));
}
public TrTransform this[Transform target]
{
// Value being get/set is relative to m_parent; the fundamental invariant is:
// target.global = m_parent.global * value
get
{
// This works, but loses precision
// return AsGlobal[m_parent].inverse * AsGlobal[target];
if (target == m_parent)
{
return(TrTransform.identity);
}
// Concatenate up to the root, or to m_parent, whichever comes first.
var concatenated = AsLocal[target];
for (var ancestor = target.parent; ancestor != null; ancestor = ancestor.parent)
{
if (ancestor == m_parent)
{
return(concatenated);
}
else
{
concatenated = AsLocal[ancestor] * concatenated;
}
}
// And project down into m_parent's coordinate system
return(TrTransform.InvMul(AsGlobal[m_parent], concatenated));
}
set
{
// This works, but loses precision
// AsGlobal[target] = AsGlobal[m_parent] * value;
if (target == m_parent)
{
throw new System.InvalidOperationException("Can't set transform relative to self");
}
// Concatenate up to the root, or to m_parent, whichever comes first.
// Skip target's local transform, because we're replacing it
var concatenated = TrTransform.identity;
for (var ancestor = target.parent; ancestor != null; ancestor = ancestor.parent)
{
if (ancestor == m_parent)
{
AsLocal[target] = TrTransform.InvMul(concatenated, value);
return;
}
else
{
concatenated = AsLocal[ancestor] * concatenated;
}
}
AsLocal[target] = TrTransform.InvMul(concatenated, AsGlobal[m_parent] * value);
}
}