protected static DB3D.IndexBuffer ToWireframeBuffer(Mesh mesh, out int linesCount)
{
linesCount = (mesh.Faces.Count * 3) + mesh.Faces.QuadCount;
if (linesCount > 0)
{
var ib = new DB3D.IndexBuffer(linesCount * DB3D.IndexLine.GetSizeInShortInts());
ib.Map(linesCount * DB3D.IndexLine.GetSizeInShortInts());
using (var istream = ib.GetIndexStreamLine())
{
foreach (var face in mesh.Faces)
{
istream.AddLine(new DB3D.IndexLine(face.A, face.B));
istream.AddLine(new DB3D.IndexLine(face.B, face.C));
istream.AddLine(new DB3D.IndexLine(face.C, face.D));
if (face.IsQuad)
{
istream.AddLine(new DB3D.IndexLine(face.D, face.A));
}
}
}
ib.Unmap();
return(ib);
}
return(null);
}
protected static DB3D.IndexBuffer ToTrianglesBuffer
(
Mesh mesh, Primitive.Part part,
out int triangleCount
)
{
triangleCount = part.FaceCount;
{
var faces = mesh.Faces;
for (int f = part.StartFaceIndex; f < part.EndFaceIndex; ++f)
{
if (faces[f].IsQuad)
{
triangleCount++;
}
}
}
if (triangleCount > 0)
{
var ib = new DB3D.IndexBuffer(triangleCount * DB3D.IndexTriangle.GetSizeInShortInts());
ib.Map(triangleCount * DB3D.IndexTriangle.GetSizeInShortInts());
using (var istream = ib.GetIndexStreamTriangle())
{
var faces = mesh.Faces;
for (int f = part.StartFaceIndex; f < part.EndFaceIndex; ++f)
{
var face = faces[f];
istream.AddTriangle(new DB3D.IndexTriangle(face.A - part.StartVertexIndex, face.B - part.StartVertexIndex, face.C - part.StartVertexIndex));
if (face.IsQuad)
{
istream.AddTriangle(new DB3D.IndexTriangle(face.C - part.StartVertexIndex, face.D - part.StartVertexIndex, face.A - part.StartVertexIndex));
}
}
}
ib.Unmap();
return(ib);
}
return(null);
}
static DB3D.IndexBuffer IndexPointsBuffer(int pointsCount)
{
Debug.Assert(pointsCount <= VertexThreshold);
if (indexPointsBuffer == null)
{
indexPointsBuffer = new DB3D.IndexBuffer(VertexThreshold * DB3D.IndexPoint.GetSizeInShortInts());
indexPointsBuffer.Map(VertexThreshold * DB3D.IndexPoint.GetSizeInShortInts());
using (var istream = indexPointsBuffer.GetIndexStreamPoint())
{
for (int vi = 0; vi < VertexThreshold; ++vi)
{
istream.AddPoint(new DB3D.IndexPoint(vi));
}
}
indexPointsBuffer.Unmap();
}
Debug.Assert(indexPointsBuffer.IsValid());
return(indexPointsBuffer);
}
protected static DB3D.IndexBuffer ToEdgeBuffer
(
Mesh mesh,
Primitive.Part part,
out int linesCount
)
{
if (part.VertexCount != mesh.Vertices.Count)
{
if (part.VertexCount > 0)
{
linesCount = -part.VertexCount;
return(IndexPointsBuffer(part.VertexCount));
}
linesCount = 0;
}
else
{
var edgeIndices = new List <IndexPair>();
if (mesh.Ngons.Count > 0)
{
foreach (var ngon in mesh.Ngons)
{
var boundary = ngon.BoundaryVertexIndexList();
if ((boundary?.Length ?? 0) > 1)
{
for (int b = 0; b < boundary.Length - 1; ++b)
{
edgeIndices.Add(new IndexPair((int)boundary[b], (int)boundary[b + 1]));
}
edgeIndices.Add(new IndexPair((int)boundary[boundary.Length - 1], (int)boundary[0]));
}
}
}
else
{
var vertices = mesh.TopologyVertices;
var edges = mesh.TopologyEdges;
var edgeCount = edges.Count;
for (int e = 0; e < edgeCount; ++e)
{
if (edges.IsEdgeUnwelded(e) || edges.GetConnectedFaces(e).Length < 2)
{
var pair = edges.GetTopologyVertices(e);
pair.I = vertices.MeshVertexIndices(pair.I)[0];
pair.J = vertices.MeshVertexIndices(pair.J)[0];
edgeIndices.Add(pair);
}
}
}
linesCount = edgeIndices.Count;
if (linesCount > 0)
{
var ib = new DB3D.IndexBuffer(linesCount * DB3D.IndexLine.GetSizeInShortInts());
ib.Map(linesCount * DB3D.IndexLine.GetSizeInShortInts());
using (var istream = ib.GetIndexStreamLine())
{
foreach (var edge in edgeIndices)
{
Debug.Assert(0 <= edge.I && edge.I < part.VertexCount);
Debug.Assert(0 <= edge.J && edge.J < part.VertexCount);
istream.AddLine(new DB3D.IndexLine(edge.I, edge.J));
}
}
ib.Unmap();
return(ib);
}
}
return(null);
}