/// <summary>
/// Determine the boundary polygons of the lowest
/// horizontal planar face of the given solid.
/// </summary>
/// <param name="polygons">Return polygonal boundary
/// loops of lowest horizontal face, i.e. profile of
/// circumference and holes</param>
/// <param name="solid">Input solid</param>
/// <returns>False if no horizontal planar face was
/// found, else true</returns>
static bool GetBoundary(
List <List <XYZ> > polygons,
Solid solid)
{
PlanarFace lowest = null;
FaceArray faces = solid.Faces;
foreach (Face f in faces)
{
PlanarFace pf = f as PlanarFace;
if (null != pf && Util.IsHorizontal(pf))
{
if ((null == lowest) ||
(pf.Origin.Z < lowest.Origin.Z))
{
lowest = pf;
}
}
}
if (null != lowest)
{
XYZ p, q = XYZ.Zero;
bool first;
int i, n;
EdgeArrayArray loops = lowest.EdgeLoops;
foreach (EdgeArray loop in loops)
{
List <XYZ> vertices = new List <XYZ>();
first = true;
foreach (Edge e in loop)
{
IList <XYZ> points = e.Tessellate();
p = points[0];
if (!first)
{
Debug.Assert(p.IsAlmostEqualTo(q),
"expected subsequent start point"
+ " to equal previous end point");
}
n = points.Count;
q = points[n - 1];
for (i = 0; i < n - 1; ++i)
{
XYZ v = points[i];
v -= _offset * XYZ.BasisZ;
vertices.Add(v);
}
}
q -= _offset * XYZ.BasisZ;
Debug.Assert(q.IsAlmostEqualTo(vertices[0]),
"expected last end point to equal"
+ " first start point");
polygons.Add(vertices);
}
}
return(null != lowest);
}
/// <summary>
/// Return the uppermost horizontal face
/// of a given "horizontal" solid object
/// such as a floor slab. Currently only
/// supports planar faces.
/// </summary>
PlanarFace GetTopFace( Solid solid )
{
PlanarFace topFace = null;
FaceArray faces = solid.Faces;
foreach( Face f in faces )
{
PlanarFace pf = f as PlanarFace;
if( null != pf
&& Util.IsHorizontal( pf ) )
{
if( ( null == topFace )
|| ( topFace.Origin.Z < pf.Origin.Z ) )
{
topFace = pf;
}
}
}
return topFace;
}
