public EdgeMesh(Mesh m)
{
this.Verticies = new List<Vector3>();
this.Faces = new List<EMFace>();
this.Edges = new List<EMEdge>();
foreach (var v in m.verticies) this.Verticies.Add(v.Position);
for (int i = 0; i < m.indicies.Length; i += 3)
{
var face = new EMFace(m.indicies[i + 0], m.indicies[i + 1], m.indicies[i + 2]);
foreach (var edge in face.edges)
face.Centroid += this.Verticies[edge.Verticies[0]];
face.Centroid /= face.edges.Count;
this.Faces.Add(face);
for (int e = 0; e < face.edges.Count; ++e)
{
var foundEdge = FindEdge(face.edges[e].Verticies[0], face.edges[e].Verticies[1]);
if (foundEdge != -1)
{
face.edges[e] = this.Edges[foundEdge];
face.edges[e].ParentFace.SetRecipricalNeighbor(face.edges[e], face);
}
else
this.Edges.Add(face.edges[e]);
}
}
}
private EMFace MergeFaces(EMFace A, EMFace B)
{
if (Object.ReferenceEquals(A, B))
{
throw new InvalidOperationException("Attempt to merge face with itself");
}
EMEdge sharedEdge = null;
foreach (var e in A.edges)
{
if (e.Neighbors.Contains(B))
{
sharedEdge = e;
}
}
if (sharedEdge == null)
{
throw new InvalidOperationException("Attempt to merge faces with no shared edge.");
}
var newFace = new EMFace();
newFace.edges = new List <EMEdge>(A.edges);
newFace.edges.InsertRange(0, B.edges);
newFace.edges.RemoveAll((e) => Object.ReferenceEquals(e, sharedEdge));
if (newFace.edges.Count <= 2)
{
throw new InvalidOperationException("Degenerate face generated");
}
return(newFace);
}
private EMFace OtherNeighbor(EMEdge e, EMFace f)
{
if (Object.ReferenceEquals(e.Neighbors[0], f))
{
return(e.Neighbors[1]);
}
else
{
return(e.Neighbors[0]);
}
}
private void VisitEdgePairsInSequence(EMFace face, Func <EMEdge, EMEdge, VEPISReturnCode> callback)
{
short?endpoint = null;
var currentEdge = face.edges[0];
var terminalCheck = false;
while (true)
{
if (!endpoint.HasValue)
{
endpoint = currentEdge.Verticies[1];
}
if (terminalCheck)
{
if (Object.ReferenceEquals(currentEdge, face.edges[0]))
{
break; //We've looped through the entire polygon
}
}
else
{
terminalCheck = true;
}
var nextEdge = FindNextEdgeInSequence(face, currentEdge, endpoint.Value);
short nextEndpoint = -1;
if (nextEdge.Verticies[0] == endpoint)
{
nextEndpoint = nextEdge.Verticies[1];
}
else
{
nextEndpoint = nextEdge.Verticies[0];
}
var callbackResult = callback(currentEdge, nextEdge);
if (callbackResult == VEPISReturnCode.Advance)
{
currentEdge = nextEdge;
}
else if (callbackResult == VEPISReturnCode.Abort)
{
break;
}
else
{
terminalCheck = false;
}
endpoint = nextEndpoint;
}
}
public static EMEdge FindSharedEdge(EMFace a, EMFace b)
{
foreach (var e in a.edges)
{
if (b.edges.Contains(e))
{
return(e);
}
}
return(null);
}
internal void SetRecipricalNeighbor(EMEdge edge, EMFace neighbor)
{
foreach (var e in edges)
{
if (Object.ReferenceEquals(e, edge))
{
e.Neighbors[1] = neighbor;
}
}
//for (int i = 0; i < 3; ++i)
// if (Object.ReferenceEquals(Edges[i],edge)) Neighbors[i] = neighbor;
}
public List<Vector3> ExtractPerimeter(EMFace face)
{
var r = new List<Vector3>();
VisitEdgePairsInSequence(face, (a, b) =>
{
//Record the un-shared end point of a.
if (b.Verticies.Contains(a.Verticies[0]))
r.Add(Verticies[a.Verticies[1]]);
else
r.Add(Verticies[a.Verticies[0]]);
return VEPISReturnCode.Advance;
});
return r;
}
private EMEdge FindNextEdgeInSequence(EMFace of, EMEdge after, short endpoint)
{
foreach (var e in of.edges)
{
if (Object.ReferenceEquals(e, after))
{
continue;
}
if (e.Verticies.Contains(endpoint))
{
return(e);
}
}
throw new InvalidOperationException("Malformed edge mesh");
}
public bool IsPointOnFace(Vector3 p, EMFace face)
{
var accumulatedAngle = 0.0f;
foreach (var edge in face.edges)
{
var v0 = Verticies[edge.Verticies[0]] - p;
var v1 = Verticies[edge.Verticies[1]] - p;
var angle = AngleBetweenVectors(v0, v1);
if (angle < 0) angle *= -1;
accumulatedAngle += angle;
}
return Gem.Math.Utility.NearlyEqual(accumulatedAngle, Gem.Math.Angle.PI2);
}
private Plane ConstructPlane(EMFace face)
{
Plane? r = null;
//Choose the first two edges of the face that are not colinear, and create a plane from them.
VisitEdgePairsInSequence(face, (A, B) =>
{
if (EdgesAreColinear(A, B)) return VEPISReturnCode.Advance;
var points = ExtractPointSequence(A, B);
r = new Plane(Verticies[points[0]], Verticies[points[1]], Verticies[points[2]]);
return VEPISReturnCode.Abort;
});
//If we made it here, there are no non-colinear edge pairs.
if (!r.HasValue) throw new InvalidOperationException("Attempt to construct plane from degenerate face");
return r.Value;
}
public bool IsPointOnFace(Vector3 p, EMFace face)
{
var accumulatedAngle = 0.0f;
foreach (var edge in face.edges)
{
var v0 = Verticies[edge.Verticies[0]] - p;
var v1 = Verticies[edge.Verticies[1]] - p;
var angle = AngleBetweenVectors(v0, v1);
if (angle < 0)
{
angle *= -1;
}
accumulatedAngle += angle;
}
return(Gem.Math.Utility.NearlyEqual(accumulatedAngle, Gem.Math.Angle.PI2));
}
public List <Vector3> ExtractPerimeter(EMFace face)
{
var r = new List <Vector3>();
VisitEdgePairsInSequence(face, (a, b) =>
{
//Record the un-shared end point of a.
if (b.Verticies.Contains(a.Verticies[0]))
{
r.Add(Verticies[a.Verticies[1]]);
}
else
{
r.Add(Verticies[a.Verticies[0]]);
}
return(VEPISReturnCode.Advance);
});
return(r);
}
public EdgeMesh(Mesh m)
{
this.Verticies = new List <Vector3>();
this.Faces = new List <EMFace>();
this.Edges = new List <EMEdge>();
foreach (var v in m.verticies)
{
this.Verticies.Add(v.Position);
}
for (int i = 0; i < m.indicies.Length; i += 3)
{
var face = new EMFace(m.indicies[i + 0], m.indicies[i + 1], m.indicies[i + 2]);
foreach (var edge in face.edges)
{
face.Centroid += this.Verticies[edge.Verticies[0]];
}
face.Centroid /= face.edges.Count;
this.Faces.Add(face);
for (int e = 0; e < face.edges.Count; ++e)
{
var foundEdge = FindEdge(face.edges[e].Verticies[0], face.edges[e].Verticies[1]);
if (foundEdge != -1)
{
face.edges[e] = this.Edges[foundEdge];
face.edges[e].ParentFace.SetRecipricalNeighbor(face.edges[e], face);
}
else
{
this.Edges.Add(face.edges[e]);
}
}
}
}
private bool IsConvex(EMFace face)
{
var accumulatedAngle = 0.0f;
VisitEdgePairsInSequence(face, (a, b) =>
{
var points = ExtractPointSequence(a, b);
var v0 = Verticies[points[0]] - Verticies[points[1]];
var v1 = Verticies[points[2]] - Verticies[points[1]];
var angle = AngleBetweenVectors(v0, v1);
accumulatedAngle += angle;
return(VEPISReturnCode.Advance);
});
if (accumulatedAngle < 0)
{
accumulatedAngle *= -1;
}
return(Gem.Math.Utility.NearlyEqual(accumulatedAngle, (face.edges.Count - 2) * Gem.Math.Angle.PI));
}
private Plane ConstructPlane(EMFace face)
{
Plane?r = null;
//Choose the first two edges of the face that are not colinear, and create a plane from them.
VisitEdgePairsInSequence(face, (A, B) =>
{
if (EdgesAreColinear(A, B))
{
return(VEPISReturnCode.Advance);
}
var points = ExtractPointSequence(A, B);
r = new Plane(Verticies[points[0]], Verticies[points[1]], Verticies[points[2]]);
return(VEPISReturnCode.Abort);
});
//If we made it here, there are no non-colinear edge pairs.
if (!r.HasValue)
{
throw new InvalidOperationException("Attempt to construct plane from degenerate face");
}
return(r.Value);
}
private void VisitEdgePairsInSequence(EMFace face, Func<EMEdge, EMEdge, VEPISReturnCode> callback)
{
short? endpoint = null;
var currentEdge = face.edges[0];
var terminalCheck = false;
while (true)
{
if (!endpoint.HasValue) endpoint = currentEdge.Verticies[1];
if (terminalCheck)
{
if (Object.ReferenceEquals(currentEdge, face.edges[0])) break; //We've looped through the entire polygon
}
else
terminalCheck = true;
var nextEdge = FindNextEdgeInSequence(face, currentEdge, endpoint.Value);
short nextEndpoint = -1;
if (nextEdge.Verticies[0] == endpoint) nextEndpoint = nextEdge.Verticies[1];
else nextEndpoint = nextEdge.Verticies[0];
var callbackResult = callback(currentEdge, nextEdge);
if (callbackResult == VEPISReturnCode.Advance)
currentEdge = nextEdge;
else if (callbackResult == VEPISReturnCode.Abort)
break;
else
terminalCheck = false;
endpoint = nextEndpoint;
}
}
public static EMEdge FindSharedEdge(EMFace a, EMFace b)
{
foreach (var e in a.edges)
if (b.edges.Contains(e)) return e;
return null;
}
private EMFace OtherNeighbor(EMEdge e, EMFace f)
{
if (Object.ReferenceEquals(e.Neighbors[0], f)) return e.Neighbors[1];
else return e.Neighbors[0];
}
private EMFace MergeFaces(EMFace A, EMFace B)
{
if (Object.ReferenceEquals(A, B))
throw new InvalidOperationException("Attempt to merge face with itself");
EMEdge sharedEdge = null;
foreach (var e in A.edges)
if (e.Neighbors.Contains(B)) sharedEdge = e;
if (sharedEdge == null)
throw new InvalidOperationException("Attempt to merge faces with no shared edge.");
var newFace = new EMFace();
newFace.edges = new List<EMEdge>(A.edges);
newFace.edges.InsertRange(0, B.edges);
newFace.edges.RemoveAll((e) => Object.ReferenceEquals(e, sharedEdge));
if (newFace.edges.Count <= 2)
throw new InvalidOperationException("Degenerate face generated");
return newFace;
}
private bool IsConvex(EMFace face)
{
var accumulatedAngle = 0.0f;
VisitEdgePairsInSequence(face, (a, b) =>
{
var points = ExtractPointSequence(a, b);
var v0 = Verticies[points[0]] - Verticies[points[1]];
var v1 = Verticies[points[2]] - Verticies[points[1]];
var angle = AngleBetweenVectors(v0, v1);
accumulatedAngle += angle;
return VEPISReturnCode.Advance;
});
if (accumulatedAngle < 0) accumulatedAngle *= -1;
return Gem.Math.Utility.NearlyEqual(accumulatedAngle, (face.edges.Count - 2) * Gem.Math.Angle.PI);
}
private EMEdge FindNextEdgeInSequence(EMFace of, EMEdge after, short endpoint)
{
foreach (var e in of.edges)
{
if (Object.ReferenceEquals(e, after)) continue;
if (e.Verticies.Contains(endpoint)) return e;
}
throw new InvalidOperationException("Malformed edge mesh");
}
internal void SetRecipricalNeighbor(EMEdge edge, EMFace neighbor)
{
foreach (var e in edges)
if (Object.ReferenceEquals(e, edge)) e.Neighbors[1] = neighbor;
//for (int i = 0; i < 3; ++i)
// if (Object.ReferenceEquals(Edges[i],edge)) Neighbors[i] = neighbor;
}
public bool FacesAreCoplanar(EMFace A, EMFace B)
{
return true; //In current test case, all faces that are connected are coplanar.
}
private void CalculateCentroid(EMFace face)
{
var perimeterPoints = ExtractPerimeter(face);
face.Centroid = Sum(perimeterPoints) / perimeterPoints.Count;
}
private void CalculateCentroid(EMFace face)
{
var perimeterPoints = ExtractPerimeter(face);
face.Centroid = Sum(perimeterPoints) / perimeterPoints.Count;
}
public bool FacesAreCoplanar(EMFace A, EMFace B)
{
return(true); //In current test case, all faces that are connected are coplanar.
}
