// Walk the perimiter of a wing looking for compatibly smooth connections. Returns true if any match was found, false if not.
static bool FindSoftEdgesRecursive(Vector3[] normals, WingedEdge wing, float angleThreshold, HashSet <Face> processed)
{
bool foundSmoothEdge = false;
using (var it = new WingedEdgeEnumerator(wing))
{
while (it.MoveNext())
{
var border = it.Current;
if (border.opposite == null)
{
continue;
}
if (border.opposite.face.smoothingGroup == Smoothing.smoothingGroupNone &&
IsSoftEdge(normals, border.edge, border.opposite.edge, angleThreshold))
{
if (processed.Add(border.opposite.face))
{
foundSmoothEdge = true;
border.opposite.face.smoothingGroup = wing.face.smoothingGroup;
FindSoftEdgesRecursive(normals, border.opposite, angleThreshold, processed);
}
}
}
}
return(foundSmoothEdge);
}
internal static void ApplySmoothingGroups(ProBuilderMesh mesh, IEnumerable <Face> faces, float angleThreshold, Vector3[] normals)
{
if (mesh == null || faces == null)
{
throw new System.ArgumentNullException("mesh");
}
// Reset the selected faces to no smoothing group
bool anySmoothed = false;
foreach (Face face in faces)
{
if (face.smoothingGroup != smoothingGroupNone)
{
anySmoothed = true;
}
face.smoothingGroup = Smoothing.smoothingGroupNone;
}
// if a set of normals was not supplied, get a new set of normals
// with no prior smoothing groups applied.
if (normals == null)
{
if (anySmoothed)
{
mesh.mesh.normals = null;
}
normals = mesh.GetNormals();
}
float threshold = Mathf.Abs(Mathf.Cos(Mathf.Clamp(angleThreshold, 0f, 89.999f) * Mathf.Deg2Rad));
HashSet <int> used = new HashSet <int>(mesh.facesInternal.Select(x => x.smoothingGroup));
int group = GetNextUnusedSmoothingGroup(1, used);
HashSet <Face> processed = new HashSet <Face>();
List <WingedEdge> wings = WingedEdge.GetWingedEdges(mesh, faces, true);
foreach (WingedEdge wing in wings)
{
// Already part of a group
if (!processed.Add(wing.face))
{
continue;
}
wing.face.smoothingGroup = group;
if (FindSoftEdgesRecursive(normals, wing, threshold, processed))
{
used.Add(group);
group = GetNextUnusedSmoothingGroup(group, used);
}
else
{
wing.face.smoothingGroup = Smoothing.smoothingGroupNone;
}
}
}
/// <summary>
/// Builds a list of predecessors from a given face index to all other faces
/// Uses the Djikstra pathfinding algorithm
/// </summary>
/// <param name="mesh">The mesh of the object</param>
/// <param name="start">The index of the starting face</param>
/// <returns>A list of predecessors from a face index to all other faces</returns>
private static int[] Dijkstra(ProBuilderMesh mesh, int start)
{
HashSet <int> visited = new HashSet <int>();
HashSet <int> toVisit = new HashSet <int>();
if (s_cachedMesh != mesh || s_cachedFacesCount != mesh.faceCount)
{
s_cachedWings = WingedEdge.GetWingedEdges(mesh, true);
s_cachedFacesIndex.Clear();
s_cachedFacesCount = mesh.faceCount;
for (int i = 0; i < mesh.facesInternal.Length; i++)
{
s_cachedFacesIndex.Add(mesh.facesInternal[i], i);
}
}
int wingCount = s_cachedWings.Count;
float[] weights = new float[wingCount];
int[] predecessors = new int[wingCount];
for (int i = 0; i < wingCount; i++)
{
weights[i] = float.MaxValue;
predecessors[i] = -1;
}
int current = start;
weights[current] = 0;
visited.Add(current);
// Construct the paths between the start face and every other faces
while (visited.Count < wingCount)
{
var currentWing = s_cachedWings[current];
var otherWing = currentWing;
// Update the weight array for each face next to the current one
do
{
var opposite = otherWing.opposite;
if (opposite == null)
{
otherWing = otherWing.next;
continue;
}
var idx = s_cachedFacesIndex[opposite.face];
var weight = GetWeight(current, idx, mesh);
// Change the predecessor and weight if the new path found if shorter
if (weights[current] + weight < weights[idx])
{
weights[idx] = weights[current] + weight;
predecessors[idx] = current;
}
// Add the face to the ones we can visit next, if not yet visited
if (!toVisit.Contains(idx) && !visited.Contains(idx))
{
toVisit.Add(idx);
}
otherWing = otherWing.next;
} while (otherWing != currentWing);
// This means there is an isolated face
if (toVisit.Count == 0)
{
return(predecessors);
}
// Look for the next face to visit, choosing the one with less weight
float min = float.MaxValue;
foreach (var i in toVisit)
{
if (weights[i] < min)
{
min = weights[i];
current = i;
}
}
visited.Add(current);
toVisit.Remove(current);
}
return(predecessors);
}
