/// <summary>
/// Loft operation:
/// This insets each face by 1/4 of its diagonal and adds a center face
/// </summary>
/// <param name="pMesh"></param>
/// <returns></returns>
public static PlanktonMesh Loft(this PlanktonMesh pMesh)
{
var lMesh = new PlanktonMesh();
// iterate over faces
for (int i = 0; i < pMesh.Faces.Count; i++)
{
// get face center
var center = pMesh.Faces.GetFaceCenter(i).ToPoint3d();
// get vertices for face
var vIndices = pMesh.Faces.GetFaceVertices(i);
var vertices = (from index in vIndices select pMesh.Vertices[index].ToPoint3d()).ToArray();
// get face vertex count
int vertexCount = vIndices.Length;
// calculate mid-Point between each face vertex and face center
Point3d[] midPoints = new Point3d[vertexCount];
for (int j = 0; j < vertexCount; j++)
{
midPoints[j] = new Line(center, vertices[j]).PointAt(0.5);
}
// Add original face vertices to new mesh
for (int j = 0; j < vertexCount; j++)
{
lMesh.Vertices.Add(vertices[j]);
}
// Add new face vertices to mesh
for (int j = 0; j < vertexCount; j++)
{
lMesh.Vertices.Add(midPoints[j]);
}
// Add new inset faces
int allVerticesCount = lMesh.Vertices.Count;
int startIndex = allVerticesCount - vertexCount * 2;
for (int j = 0; j < vertexCount; j++)
{
int a = j + startIndex;
int b = (j + 1) % vertexCount + startIndex;
int c = (j + 1) % vertexCount + startIndex + vertexCount;
int d = j + startIndex + vertexCount;
lMesh.Faces.AddFace(a, b, c, d);
}
// Add center face of inset
lMesh.Faces.AddFace(Enumerable.Range(startIndex + vertexCount, vertexCount));
}
// combine identical vertices,
// this is necessary because we added vertices by face
// ugly hack :(
lMesh = lMesh.CombineIdenticalVertices();
return(lMesh);
}
public static PlanktonMesh Quinto(this PlanktonMesh pMesh)
{
// new mesh to hold quinto result
var qMesh = new PlanktonMesh();
// iterate over faces
for (int i = 0; i < pMesh.Faces.Count; i++)
{
// get face vertices
var oldVertices =
(from index in pMesh.Faces.GetFaceVertices(i) select pMesh.Vertices[index].ToPoint3d()).ToArray();
var oldVertexCount = oldVertices.Length;
// empty array to hold all new face vertices
var vertexCount = oldVertices.Length * 3;
var vertices = new Point3d[vertexCount];
// add old vertices
for (int j = 0; j < oldVertexCount; j++)
{
vertices[j] = oldVertices[j];
}
// get mid points of face edges
for (int j = 0; j < oldVertexCount; j++)
{
int upperIndex = (j + 1) % oldVertexCount;
var midPoint = new Line(oldVertices[j], oldVertices[upperIndex]).PointAt(0.5);
// add to vertex array
vertices[j + oldVertexCount] = midPoint;
}
// get face center
var ptCenter = pMesh.Faces.GetFaceCenter(i).ToPoint3d();
// get mid point from edge mid-point to face center
for (int j = 0; j < oldVertexCount; j++)
{
var midPoint = new Line(vertices[j + oldVertexCount], ptCenter).PointAt(0.5);
// add to vertex array
vertices[j + 2 * oldVertexCount] = midPoint;
}
// Add vertices to new mesh
for (int j = 0; j < vertexCount; j++)
{
qMesh.Vertices.Add(vertices[j]);
}
// Add faces
int startIndex = qMesh.Vertices.Count - vertexCount;
for (int j = 0; j < oldVertexCount; j++)
{
int a = startIndex + j;
int b = startIndex + j + oldVertexCount;
int c = startIndex + j + 2 * oldVertexCount;
// don't know a sexy math formula for this behaviour right now :/
int d;
int e;
if (j == 0)
{
d = startIndex + vertexCount - 1;
e = startIndex + 2 * oldVertexCount - 1;
}
else
{
d = startIndex + j + 2 * oldVertexCount - 1;
e = startIndex + j + oldVertexCount - 1;
}
qMesh.Faces.AddFace(new[] { a, b, c, d, e });
}
// Add center face of inset
qMesh.Faces.AddFace(Enumerable.Range(startIndex + 2 * oldVertexCount, oldVertexCount));
}
// remove identical vertices which exist because we added by face
qMesh = qMesh.CombineIdenticalVertices();
// return
return(qMesh);
}
