private static void RotateSoFacesAreParallelAndOpposite(IOrient s2, Face f1, Face f2, xyz rotpt)
{
// rotate s2 so the faces are facing in opposite directions
xyz n1 = f1.UnitNormal();
xyz n2 = f2.UnitNormal();
if (fp.eq_unitvec(n1, n2))
{
// we need to flip s2 180 degrees with respect to the plane of f2
xyz rotv = (f2.MainLoop[1].to - f2.MainLoop[0].to).normalize_in_place();
// cos(pi) is -1 and sin(pi) is 0
s2.Rotate(-1, 0, rotpt, rotv);
}
else if (fp.eq_unitvec(n1, -n2))
{
// do nothing. this is perfect.
}
else
{
double dot = xyz.dot(n1, n2);
xyz kp = xyz.cross(n2, n1).normalize_in_place();
s2.Rotate(-dot, -Math.Sqrt(1 - dot * dot), rotpt, kp);
}
}
public static void Edges(IOrient s2, Face f1, Face f2, HalfEdge he1, HalfEdge he2, EdgeAlignment align, double offset1, double offset2, bool reversed)
{
xyz v1;
xyz v2;
xyz uv1 = (he1.to - he1.from).normalize_in_place();
Debug.Assert(
(align == EdgeAlignment.Center) ||
(align == EdgeAlignment.Right) ||
(align == EdgeAlignment.Left)
);
// move the solid to match up two points
if (align == EdgeAlignment.Center)
{
v1 = he1.Center();
if (!fp.eq_inches(offset1, 0))
{
v1 += (offset1 * uv1);
}
v2 = he2.Center();
}
else if (align == EdgeAlignment.Right)
{
v1 = he1.to;
if (!fp.eq_inches(offset1, 0))
{
v1 -= (offset1 * uv1);
}
v2 = he2.from;
}
else // left
{
v1 = he1.from;
if (!fp.eq_inches(offset1, 0))
{
v1 += (offset1 * uv1);
}
v2 = he2.to;
}
if (!fp.eq_inches(offset2, 0))
{
xyz uv1perp = -(he1.GetInwardNormal());
v1 += (offset2 * uv1perp);
}
xyz tv = v1 - v2;
s2.Translate(tv.x, tv.y, tv.z);
if (reversed)
{
RotateSoFacesAreParallelAndSameDir(s2, f1, f2, v1);
}
else
{
RotateSoFacesAreParallelAndOpposite(s2, f1, f2, v1);
}
// now rotate around origin = f1.MainLoop[0].to and vector = n1 to align the other points
xyz q1 = he1.UnitVector();
xyz q2 = he2.UnitVector();
if (reversed)
{
q2 = -q2;
}
if (fp.eq_unitvec(q1, q2))
{
s2.Rotate(-1, 0, v1, f1.UnitNormal());
}
else if (fp.eq_unitvec(q1, -q2))
{
// do nothing. this is perfect.
}
else
{
double dot = xyz.dot(q1, q2);
xyz kp = xyz.cross(q2, q1).normalize_in_place();
s2.Rotate(-dot, -Math.Sqrt(1 - dot * dot), v1, kp);
}
}