Drop unused thekla_atlas dependency

Since f12cb82 @reduz dropped the use of the thirdparty thekla_atlas
library, which is replaced by xatlas.

Fixes #28180.
Fixes #28182.

8 files changed, 0 insertions, 2374 deletions

diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Edge.cpp b/thirdparty/thekla_atlas/nvmesh/halfedge/Edge.cpp
deleted file mode 100644
index 671650296c..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Edge.cpp
+++ /dev/null
@@ -1,57 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#include "nvmesh.h" // pch
-
-#include "Edge.h"
-#include "Vertex.h"
-
-#include "nvmath/Vector.inl"
-
-using namespace nv;
-using namespace HalfEdge;
-
-Vector3 Edge::midPoint() const
-{
-    return (to()->pos + from()->pos) * 0.5f;
-}
-
-float Edge::length() const
-{
-    return ::length(to()->pos - from()->pos); 
-}
-
-// Return angle between this edge and the previous one.
-float Edge::angle() const {
-    Vector3 p = vertex->pos;
-    Vector3 a = prev->vertex->pos;
-    Vector3 b = next->vertex->pos;
-
-    Vector3 v0 = a - p;
-    Vector3 v1 = b - p;
-
-    return acosf(dot(v0, v1) / (nv::length(v0) * nv::length(v1)));
-}
-
-bool Edge::isValid() const
-{
-    // null face is OK.
-    if (next == NULL || prev == NULL || pair == NULL || vertex == NULL) return false;
-    if (next->prev != this) return false;
-    if (prev->next != this) return false;
-    if (pair->pair != this) return false;
-    return true;
-}
-
-/*
-Edge * Edge::nextBoundary() {
-    nvDebugCheck(this->m_pair == NULL);
-
-}
-
-Edge * Edge::prevBoundary() {
-    nvDebugCheck(this->m_pair == NULL);
-
-}
-*/
-
-
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Edge.h b/thirdparty/thekla_atlas/nvmesh/halfedge/Edge.h
deleted file mode 100644
index 25c47f4860..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Edge.h
+++ /dev/null
@@ -1,70 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#pragma once
-#ifndef NV_MESH_HALFEDGE_EDGE_H
-#define NV_MESH_HALFEDGE_EDGE_H
-
-#include "nvmath/Vector.h"
-
-namespace nv
-{
-    namespace HalfEdge { class Vertex; class Face; class Edge; }
-
-    /// Half edge edge. 
-    class HalfEdge::Edge
-    {
-        NV_FORBID_COPY(Edge);
-    public:
-
-        uint id;
-
-        Edge * next;
-        Edge * prev;	// This is not strictly half-edge, but makes algorithms easier and faster.
-        Edge * pair;
-        Vertex * vertex;
-        Face * face;
-
-
-        // Default constructor.
-        Edge(uint id) : id(id), next(NULL), prev(NULL), pair(NULL), vertex(NULL), face(NULL)
-        {
-        }
-
-
-        // Vertex queries.
-        const Vertex * from() const { return vertex; }
-        Vertex * from() { return vertex; }
-
-        const Vertex * to() const { return pair->vertex; }  // This used to be 'next->vertex', but that changed often when the connectivity of the mesh changes.
-        Vertex * to() { return pair->vertex; }
-
-
-        // Edge queries.
-        void setNext(Edge * e) { next = e; if (e != NULL) e->prev = this; }
-        void setPrev(Edge * e) { prev = e; if (e != NULL) e->next = this; }
-
-        // @@ Add these helpers:
-        //Edge * nextBoundary();
-        //Edge * prevBoundary();
-
-
-        // @@ It would be more simple to only check m_pair == NULL
-        // Face queries.
-        bool isBoundary() const { return !(face && pair->face); }
-
-        // @@ This is not exactly accurate, we should compare the texture coordinates...
-        bool isSeam() const { return vertex != pair->next->vertex || next->vertex != pair->vertex; }
-
-        bool isValid() const;
-
-        // Geometric queries.
-        Vector3 midPoint() const;
-        float length() const;
-        float angle() const;
-
-    };
-
-} // nv namespace
-
-
-#endif // NV_MESH_HALFEDGE_EDGE_H
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Face.cpp b/thirdparty/thekla_atlas/nvmesh/halfedge/Face.cpp
deleted file mode 100644
index 9f6987154e..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Face.cpp
+++ /dev/null
@@ -1,268 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#include "nvmesh.h" // pch
-
-#include "Face.h"
-#include "Vertex.h"
-
-#include "nvmath/Fitting.h"
-#include "nvmath/Plane.h"
-#include "nvmath/Vector.inl"
-
-#include "nvcore/Array.h"
-
-
-using namespace nv;
-using namespace HalfEdge;
-
-/// Get face area.
-float Face::area() const
-{
-    float area = 0;
-    const Vector3 & v0 = edge->from()->pos;
-
-    for (ConstEdgeIterator it(edges(edge->next)); it.current() != edge->prev; it.advance())
-    {
-        const Edge * e = it.current();
-
-        const Vector3 & v1 = e->vertex->pos;
-        const Vector3 & v2 = e->next->vertex->pos; 
-
-        area += length(cross(v1-v0, v2-v0));
-    }
-
-    return area * 0.5f;
-}
-
-float Face::parametricArea() const
-{
-    float area = 0;
-    const Vector2 & v0 = edge->from()->tex;
-
-    for (ConstEdgeIterator it(edges(edge->next)); it.current() != edge->prev; it.advance())
-    {
-        const Edge * e = it.current();
-
-        const Vector2 & v1 = e->vertex->tex;
-        const Vector2 & v2 = e->next->vertex->tex;
-
-        area += triangleArea(v0, v1, v2);
-    }
-
-    return area * 0.5f;
-}
-
-
-/// Get boundary length.
-float Face::boundaryLength() const
-{
-    float bl = 0;
-
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        bl += edge->length();
-    }
-
-    return bl;
-}
-
-
-/// Get face normal.
-Vector3 Face::normal() const
-{
-    Vector3 n(0);
-
-    const Vertex * vertex0 = NULL;
-
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        nvCheck(edge != NULL);
-
-        if (vertex0 == NULL)
-        {
-            vertex0 = edge->vertex;
-        }
-        else if (edge->next->vertex != vertex0)
-        {
-            const HalfEdge::Vertex * vertex1 = edge->from();
-            const HalfEdge::Vertex * vertex2 = edge->to();
-
-            const Vector3 & p0 = vertex0->pos;
-            const Vector3 & p1 = vertex1->pos;
-            const Vector3 & p2 = vertex2->pos;
-
-            Vector3 v10 = p1 - p0;
-            Vector3 v20 = p2 - p0;
-
-            n += cross(v10, v20);
-        }
-    }
-
-    return normalizeSafe(n, Vector3(0, 0, 1), 0.0f);
-
-
-    // Get face points eliminating duplicates.
-    /*Array<Vector3> points(4);
-
-    points.append(m_edge->prev()->from()->pos);
-
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        nvDebugCheck(edge != NULL);
-
-        const Vector3 & p = edge->from()->pos;
-        if (points.back() != p)
-        {
-            points.append(edge->from()->pos);
-        }
-    }
-
-    points.popBack();
-
-    if (points.count() < 3)
-    {
-        // Invalid normal.
-        return Vector3(0.0f);
-    }
-    else
-    {
-        // Compute regular normal.
-        Vector3 normal = normalizeSafe(cross(points[1] - points[0], points[2] - points[0]), Vector3(0.0f), 0.0f);
-
-#pragma NV_MESSAGE("TODO: make sure these three points are not colinear")
-
-        if (points.count() > 3)
-        {
-            // Compute best fitting plane to the points.
-            Plane plane = Fit::bestPlane(points.count(), points.buffer());
-
-            // Adjust normal orientation.
-            if (dot(normal, plane.vector()) > 0) {
-                normal = plane.vector();
-            }
-            else {
-                normal = -plane.vector();
-            }
-        }
-
-        nvDebugCheck(isNormalized(normal));
-        return normal;
-    }*/
-}
-
-Vector3 Face::centroid() const
-{
-    Vector3 sum(0.0f);
-    uint count = 0;
-
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        sum += edge->from()->pos;
-        count++;
-    }
-
-    return sum / float(count);
-}
-
-
-bool Face::isValid() const
-{
-    uint count = 0;
-
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        if (edge->face != this) return false;
-        if (!edge->isValid()) return false;
-        if (!edge->pair->isValid()) return false;
-        count++;
-    }
-
-    if (count < 3) return false;
-
-    return true;
-}
-
-
-// Determine if this face contains the given edge.
-bool Face::contains(const Edge * e) const
-{
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        if(it.current() == e) return true;
-    }
-    return false;
-}
-
-// Returns index in this face of the given edge.
-uint Face::edgeIndex(const Edge * e) const
-{
-    int i = 0;
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance(), i++)
-    {
-        if(it.current() == e) return i;
-    }
-    return NIL;
-}
-
-
-Edge * Face::edgeAt(uint idx)
-{ 
-    int i = 0;
-    for(EdgeIterator it(edges()); !it.isDone(); it.advance(), i++) {
-        if (i == idx) return it.current();
-    }
-    return NULL;
-}
-const Edge * Face::edgeAt(uint idx) const 
-{
-    int i = 0;
-    for(ConstEdgeIterator it(edges()); !it.isDone(); it.advance(), i++) {
-        if (i == idx) return it.current();
-    }
-    return NULL;
-}
-
-
-// Count the number of edges in this face.
-uint Face::edgeCount() const
-{
-    uint count = 0;
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance()) { ++count; }
-    return count;
-}
-
-// Determine if this is a boundary face.
-bool Face::isBoundary() const
-{
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        nvDebugCheck(edge->pair != NULL);
-
-        if (edge->pair->face == NULL) {
-            return true;
-        }
-    }
-    return false;
-}
-
-// Count the number of boundary edges in the face.
-uint Face::boundaryCount() const
-{
-    uint count = 0;
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance())
-    {
-        const Edge * edge = it.current();
-        nvDebugCheck(edge->pair != NULL);
-
-        if (edge->pair->face == NULL) {
-            count++;
-        }
-    }
-    return count;
-}
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Face.h b/thirdparty/thekla_atlas/nvmesh/halfedge/Face.h
deleted file mode 100644
index 677f8666f0..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Face.h
+++ /dev/null
@@ -1,106 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#pragma once
-#ifndef NV_MESH_HALFEDGE_FACE_H
-#define NV_MESH_HALFEDGE_FACE_H
-
-#include <nvmesh/halfedge/Edge.h>
-
-namespace nv
-{
-    namespace HalfEdge { class Vertex; class Face; class Edge; }
-
-    /// Face of a half-edge mesh.
-    class HalfEdge::Face
-    {
-        NV_FORBID_COPY(Face);
-    public:
-
-        uint id;
-        uint16 group;
-        uint16 material;
-        Edge * edge;
-
-
-        Face(uint id) : id(id), group(~0), material(~0), edge(NULL) {}
-
-        float area() const;
-        float parametricArea() const;
-        float boundaryLength() const;
-        Vector3 normal() const;
-        Vector3 centroid() const;
-
-        bool isValid() const;
-
-        bool contains(const Edge * e) const;
-        uint edgeIndex(const Edge * e) const;
-        
-        Edge * edgeAt(uint idx);
-        const Edge * edgeAt(uint idx) const;
-
-        uint edgeCount() const;
-        bool isBoundary() const;
-        uint boundaryCount() const;
-
-
-        // The iterator that visits the edges of this face in clockwise order.
-        class EdgeIterator //: public Iterator<Edge *>
-        {
-        public:
-            EdgeIterator(Edge * e) : m_end(NULL), m_current(e) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->next;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual Edge * current() const { return m_current; }
-            Vertex * vertex() const { return m_current->vertex; }
-
-        private:
-            Edge * m_end;
-            Edge * m_current;
-        };
-
-        EdgeIterator edges() { return EdgeIterator(edge); }
-        EdgeIterator edges(Edge * e)
-        { 
-            nvDebugCheck(contains(e));
-            return EdgeIterator(e); 
-        }
-
-        // The iterator that visits the edges of this face in clockwise order.
-        class ConstEdgeIterator //: public Iterator<const Edge *>
-        {
-        public:
-            ConstEdgeIterator(const Edge * e) : m_end(NULL), m_current(e) { }
-            ConstEdgeIterator(const EdgeIterator & it) : m_end(NULL), m_current(it.current()) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->next;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual const Edge * current() const { return m_current; }
-            const Vertex * vertex() const { return m_current->vertex; }
-
-        private:
-            const Edge * m_end;
-            const Edge * m_current;
-        };
-
-        ConstEdgeIterator edges() const { return ConstEdgeIterator(edge); }
-        ConstEdgeIterator edges(const Edge * e) const
-        { 
-            nvDebugCheck(contains(e));
-            return ConstEdgeIterator(e); 
-        }
-    };
-
-} // nv namespace
-
-#endif // NV_MESH_HALFEDGE_FACE_H
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Mesh.cpp b/thirdparty/thekla_atlas/nvmesh/halfedge/Mesh.cpp
deleted file mode 100644
index 0012513bce..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Mesh.cpp
+++ /dev/null
@@ -1,1284 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#include "nvmesh.h" // pch
-
-#include "Mesh.h"
-#include "Edge.h"
-#include "Vertex.h"
-#include "Face.h"
-
-#include "nvmesh/TriMesh.h"
-#include "nvmesh/QuadTriMesh.h"
-#include "nvmesh/MeshBuilder.h"
-
-#include "nvmath/Vector.inl"
-#include "nvcore/Array.inl"
-#include "nvcore/HashMap.inl"
-
-
-using namespace nv;
-using namespace HalfEdge;
-
-Mesh::Mesh() : m_colocalVertexCount(0)
-{
-    errorCount = 0;
-}
-
-Mesh::Mesh(const Mesh * mesh)
-{
-    errorCount = 0;
-
-    // Copy mesh vertices.
-    const uint vertexCount = mesh->vertexCount();
-    m_vertexArray.resize(vertexCount);
-
-    for (uint v = 0; v < vertexCount; v++)
-    {
-        const Vertex * vertex = mesh->vertexAt(v);
-        nvDebugCheck(vertex->id == v);
-
-        m_vertexArray[v] = new Vertex(v);
-        m_vertexArray[v]->pos = vertex->pos;
-        m_vertexArray[v]->nor = vertex->nor;
-        m_vertexArray[v]->tex = vertex->tex;
-    }
-
-    m_colocalVertexCount = vertexCount;
-
-
-    // Copy mesh faces.
-    const uint faceCount = mesh->faceCount();
-
-    Array<uint> indexArray(3);
-
-    for (uint f = 0; f < faceCount; f++)
-    {
-        const Face * face = mesh->faceAt(f);
-
-        for(Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance()) {
-            const Vertex * vertex = it.current()->from();
-            indexArray.append(vertex->id);
-        }
-
-        addFace(indexArray);
-        indexArray.clear();
-    }
-}
-
-Mesh::~Mesh()
-{
-    clear();
-}
-
-
-void Mesh::clear()
-{
-    deleteAll(m_vertexArray); 
-    m_vertexArray.clear();
-
-    foreach(i, m_edgeMap)
-    {
-        delete m_edgeMap[i].value;
-    }
-    //deleteAll(m_edgeArray);	// edgeArray only contains 1/2 of the edges!
-    m_edgeArray.clear();
-    m_edgeMap.clear();
-
-    deleteAll(m_faceArray);
-    m_faceArray.clear();
-}
-
-
-Vertex * Mesh::addVertex(const Vector3 & pos)
-{
-    nvDebugCheck(isFinite(pos));
-
-    Vertex * v = new Vertex(m_vertexArray.count());
-    v->pos = pos;
-    m_vertexArray.append(v);
-
-    return v;
-
-//    return addVertex(m_vertexArray.count(), pos);
-}
-
-/*Vertex * Mesh::addVertex(uint id, const Vector3 & pos)
-{
-    nvDebugCheck(isFinite(pos));
-
-    Vertex * v = new Vertex(id);
-    v->pos = pos;
-    m_vertexArray.append(v);
-
-    return v;
-}*/
-
-/*void Mesh::addVertices(const Mesh * mesh)
-{
-nvCheck(mesh != NULL);
-
-// Add mesh vertices
-for (uint v = 0; v < vertexCount; v++)
-{
-const Vertex * vertex = mesh->vertexAt(v);
-nvDebugCheck(vertex != NULL);
-
-Vertex * v = addVertex(vertex->pos());
-nvDebugCheck(v != NULL);
-
-v->setNor(vertex->nor());
-v->setTex(vertex->tex());
-}
-}*/
-
-
-/// Link colocal vertices based on geometric location only.
-void Mesh::linkColocals()
-{
-    nvDebug("--- Linking colocals:\n");
-
-    const uint vertexCount = this->vertexCount();
-    HashMap<Vector3, Vertex *> vertexMap(vertexCount);
-
-    for (uint v = 0; v < vertexCount; v++)
-    {
-        Vertex * vertex = vertexAt(v);
-
-        Vertex * colocal;
-        if (vertexMap.get(vertex->pos, &colocal))
-        {
-            colocal->linkColocal(vertex);
-        }
-        else
-        {
-            vertexMap.add(vertex->pos, vertex);
-        }
-    }
-
-    m_colocalVertexCount = vertexMap.count();
-
-    nvDebug("---   %d vertex positions.\n", m_colocalVertexCount);
-
-    // @@ Remove duplicated vertices? or just leave them as colocals?
-}
-
-void Mesh::linkColocalsWithCanonicalMap(const Array<uint> & canonicalMap)
-{
-    nvDebug("--- Linking colocals:\n");
-
-    uint vertexMapSize = 0;
-    foreach(i, canonicalMap) {
-        vertexMapSize = max(vertexMapSize, canonicalMap[i] + 1);
-    }
-    
-    Array<Vertex *> vertexMap;
-    vertexMap.resize(vertexMapSize, NULL);
-
-    m_colocalVertexCount = 0;
-
-    const uint vertexCount = this->vertexCount();
-    for (uint v = 0; v < vertexCount; v++)
-    {
-        Vertex * vertex = vertexAt(v);
-
-        Vertex * colocal = vertexMap[canonicalMap[v]];
-        if (colocal != NULL)
-        {
-            nvDebugCheck(vertex->pos == colocal->pos);
-            colocal->linkColocal(vertex);
-        }
-        else
-        {
-            vertexMap[canonicalMap[v]] = vertex;
-            m_colocalVertexCount++;
-        }
-    }
-
-    nvDebug("---   %d vertex positions.\n", m_colocalVertexCount);
-}
-
-
-Face * Mesh::addFace()
-{
-    Face * f = new Face(m_faceArray.count());
-    m_faceArray.append(f);
-    return f;
-}
-
-Face * Mesh::addFace(uint v0, uint v1, uint v2)
-{
-    Array<uint> indexArray(3);
-    indexArray << v0 << v1 << v2;
-    return addFace(indexArray, 0, 3);
-}
-
-Face * Mesh::addFace(uint v0, uint v1, uint v2, uint v3)
-{
-    Array<uint> indexArray(4);
-    indexArray << v0 << v1 << v2 << v3;
-    return addFace(indexArray, 0, 4);
-}
-
-Face * Mesh::addFace(const Array<uint> & indexArray)
-{
-    return addFace(indexArray, 0, indexArray.count());
-}
-
-
-Face * Mesh::addFace(const Array<uint> & indexArray, uint first, uint num)
-{
-    nvDebugCheck(first < indexArray.count());
-    nvDebugCheck(num <= indexArray.count()-first);
-    nvDebugCheck(num > 2);
-
-    if (!canAddFace(indexArray, first, num)) {
-        errorCount++;
-        return NULL;
-    }
-
-    Face * f = new Face(m_faceArray.count());
-
-    Edge * firstEdge = NULL;
-    Edge * last = NULL;
-    Edge * current = NULL;
-
-    for(uint i = 0; i < num-1; i++)
-    {
-        current = addEdge(indexArray[first+i], indexArray[first+i+1]);
-        nvCheck(current != NULL && current->face == NULL);
-
-        current->face = f;
-
-        if (last != NULL) last->setNext(current);
-        else firstEdge = current;
-
-        last = current;
-    }
-
-    current = addEdge(indexArray[first+num-1], indexArray[first]);
-    nvCheck(current != NULL && current->face == NULL);
-
-    current->face = f;
-
-    last->setNext(current);
-    current->setNext(firstEdge);
-
-    f->edge = firstEdge;
-    m_faceArray.append(f);
-
-    return f;
-}
-
-/*void Mesh::addFaces(const Mesh * mesh)
-{
-nvCheck(mesh != NULL);
-
-Array indexArray;
-// Add faces
-
-}*/
-
-
-// Return true if the face can be added to the manifold mesh.
-bool Mesh::canAddFace(const Array<uint> & indexArray, uint first, uint num) const
-{
-    for (uint j = num - 1, i = 0; i < num; j = i++) {
-        if (!canAddEdge(indexArray[first+j], indexArray[first+i])) {
-            errorIndex0 = indexArray[first+j];
-            errorIndex1 = indexArray[first+i];
-            return false;
-        }
-    }
-
-    // We also have to make sure the face does not have any duplicate edge!
-    for (uint i = 0; i < num; i++) {
-
-        int i0 = indexArray[first + i + 0];
-        int i1 = indexArray[first + (i + 1)%num];
-
-        for (uint j = i + 1; j < num; j++) {
-            int j0 = indexArray[first + j + 0];
-            int j1 = indexArray[first + (j + 1)%num];
-
-            if (i0 == j0 && i1 == j1) {
-                return false;
-            }
-        }
-    }
-
-    return true;
-}
-
-// Return true if the edge doesn't exist or doesn't have any adjacent face. 
-bool Mesh::canAddEdge(uint i, uint j) const
-{
-    if (i == j) {
-        // Skip degenerate edges.
-        return false;
-    }
-
-    // Same check, but taking into account colocal vertices.
-    const Vertex * v0 = vertexAt(i);
-    const Vertex * v1 = vertexAt(j);
-
-    for(Vertex::ConstVertexIterator it(v0->colocals()); !it.isDone(); it.advance())
-    {
-        if (it.current() == v1)
-        {
-            // Skip degenerate edges.
-            return false;
-        }
-    }
-
-    // Make sure edge has not been added yet.
-    Edge * edge = findEdge(i, j);
-
-    return edge == NULL || edge->face == NULL; // We ignore edges that don't have an adjacent face yet, since this face could become the edge's face.
-}
-
-Edge * Mesh::addEdge(uint i, uint j)
-{
-    nvCheck(i != j);
-
-    Edge * edge = findEdge(i, j);
-
-    if (edge != NULL) {
-        // Edge may already exist, but its face must not be set.
-        nvDebugCheck(edge->face == NULL);
-
-        // Nothing else to do!
-
-    }
-    else {
-        // Add new edge.
-
-        // Lookup pair.
-        Edge * pair = findEdge(j, i);
-
-        if (pair != NULL)
-        {
-            // Create edge with same id.
-            edge = new Edge(pair->id + 1);
-
-            // Link edge pairs.
-            edge->pair = pair;
-            pair->pair = edge;
-
-            // @@ I'm not sure this is necessary!
-            pair->vertex->setEdge(pair);
-        }
-        else
-        {
-            // Create edge.
-            edge = new Edge(2*m_edgeArray.count());
-
-            // Add only unpaired edges.
-            m_edgeArray.append(edge);
-        }
-
-        edge->vertex = m_vertexArray[i];
-        m_edgeMap.add(Key(i,j), edge);
-    }
-
-    // Face and Next are set by addFace.
-
-    return edge;
-}
-
-
-/// Find edge, test all colocals.
-Edge * Mesh::findEdge(uint i, uint j) const
-{
-    Edge * edge = NULL;
-
-    const Vertex * v0 = vertexAt(i);
-    const Vertex * v1 = vertexAt(j);
-
-    // Test all colocal pairs.
-    for(Vertex::ConstVertexIterator it0(v0->colocals()); !it0.isDone(); it0.advance())
-    {
-        for(Vertex::ConstVertexIterator it1(v1->colocals()); !it1.isDone(); it1.advance())
-        {
-            Key key(it0.current()->id, it1.current()->id);
-
-            if (edge == NULL) {
-                m_edgeMap.get(key, &edge);
-#if !defined(_DEBUG)
-                if (edge != NULL) return edge;
-#endif
-            }
-            else {
-                // Make sure that only one edge is found.
-                nvDebugCheck(!m_edgeMap.get(key));
-            }
-        }
-    }
-
-    return edge;
-}
-
-/// Link boundary edges once the mesh has been created.
-void Mesh::linkBoundary()
-{
-    nvDebug("--- Linking boundaries:\n");
-
-    int num = 0;
-
-    // Create boundary edges.
-    uint edgeCount = this->edgeCount();
-    for(uint e = 0; e < edgeCount; e++)
-    {
-        Edge * edge = edgeAt(e);
-        if (edge != NULL && edge->pair == NULL) {
-            Edge * pair = new Edge(edge->id + 1);
-
-            uint i = edge->from()->id;
-            uint j = edge->next->from()->id;
-
-            Key key(j,i);
-            nvCheck(!m_edgeMap.get(key));
-
-            pair->vertex = m_vertexArray[j];
-            m_edgeMap.add(key, pair);
-
-            edge->pair = pair;
-            pair->pair = edge;
-
-            num++;
-        }
-    }
-
-    // Link boundary edges.
-    for (uint e = 0; e < edgeCount; e++) {
-        Edge * edge = edgeAt(e);
-        if (edge != NULL && edge->pair->face == NULL) {
-            linkBoundaryEdge(edge->pair);
-        }
-    }
-
-    nvDebug("---   %d boundary edges.\n", num);
-}
-
-/// Link this boundary edge.
-void Mesh::linkBoundaryEdge(Edge * edge)
-{
-    nvCheck(edge->face == NULL);
-
-    // Make sure next pointer has not been set. @@ We want to be able to relink boundary edges after mesh changes.
-    //nvCheck(edge->next() == NULL);
-
-    Edge * next = edge;
-    while(next->pair->face != NULL) {
-        // Get pair prev
-        Edge * e = next->pair->next;
-        while (e->next != next->pair) {
-            e = e->next;
-        }
-        next = e;
-    }
-    edge->setNext(next->pair);
-
-    // Adjust vertex edge, so that it's the boundary edge. (required for isBoundary())
-    if (edge->vertex->edge != edge)
-    {
-        // Multiple boundaries in the same edge.
-        //nvCheck( edge->vertex()->edge() == NULL || edge->vertex()->edge()->face() != NULL );
-        edge->vertex->edge = edge;
-    }
-}
-
-
-/// Convert to tri mesh.
-TriMesh * Mesh::toTriMesh() const
-{
-    uint triangleCount = 0;
-
-    // Count triangle faces.
-    const uint faceCount = this->faceCount();
-    for(uint f = 0; f < faceCount; f++)
-    {
-        const Face * face = faceAt(f);
-        triangleCount += face->edgeCount() - 2;
-    }
-
-    TriMesh * triMesh = new TriMesh(triangleCount, vertexCount());
-
-    // Add vertices.
-    Array<TriMesh::Vertex> & vertices = triMesh->vertices();
-
-    const uint vertexCount = this->vertexCount();
-    for(uint v = 0; v < vertexCount; v++)
-    {
-        const Vertex * vertex = vertexAt(v);
-
-        TriMesh::Vertex triVertex;
-        triVertex.id = vertices.count();
-        triVertex.pos = vertex->pos;
-        triVertex.nor = vertex->nor;
-        triVertex.tex = vertex->tex;
-
-        vertices.append(triVertex);
-    }
-
-    // Add triangles.
-    Array<TriMesh::Face> & triangles = triMesh->faces();
-
-    for(uint f = 0; f < faceCount; f++)
-    {
-        const Face * face = faceAt(f);
-
-        // @@ Triangulate arbitrary polygons correctly.
-        const uint v0 = face->edge->vertex->id;
-        uint v1 = face->edge->next->vertex->id;
-
-        for(Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
-        {
-            uint v2 = it.current()->vertex->id;
-
-            // Skip the first two vertices.
-            if (v2 == v0 || v2 == v1) continue;
-
-            TriMesh::Face triangle;
-            triangle.id = triangles.count();
-            triangle.v[0] = v0;
-            triangle.v[1] = v1;
-            triangle.v[2] = v2;
-
-            v1 = v2;
-
-            triangles.append(triangle);
-        }
-    }
-
-    return triMesh;
-}
-
-QuadTriMesh * Mesh::toQuadTriMesh() const
-{
-    MeshBuilder builder;
-
-    const uint vertexCount = this->vertexCount();
-    builder.hintVertexCount(vertexCount);
-
-    for(uint v = 0; v < vertexCount; v++)
-    {
-        const Vertex * vertex = vertexAt(v);
-
-        builder.addPosition(vertex->pos);
-        builder.addNormal(vertex->nor);
-        builder.addTexCoord(vertex->tex);
-    }
-
-    const uint faceCount = this->faceCount();
-    builder.hintTriangleCount(faceCount);
-
-    for(uint f = 0; f < faceCount; f++)
-    {
-        const Face * face = faceAt(f);
-
-        builder.beginPolygon();
-
-        for(Face::ConstEdgeIterator it(face->edges()); !it.isDone(); it.advance())
-        {
-            uint v = it.current()->vertex->id;
-            builder.addVertex(v, v, v);
-        }
-
-        builder.endPolygon();
-    }
-
-    builder.done();
-
-    return builder.buildQuadTriMesh();
-}
-
-
-// Triangulate in place.
-void Mesh::triangulate() {
-
-    bool all_triangles = true;
-
-    const uint faceCount = m_faceArray.count();
-    for (uint f = 0; f < faceCount; f++) {
-        Face * face = m_faceArray[f];
-        if (face->edgeCount() != 3) {
-            all_triangles = false;
-            break;
-        }
-    }
-
-    if (all_triangles) {
-        return;
-    }
-
-
-    // Do not touch vertices, but rebuild edges and faces.
-    Array<Edge *> edgeArray;
-    Array<Face *> faceArray;
-
-    swap(edgeArray, m_edgeArray);
-    swap(faceArray, m_faceArray);
-    m_edgeMap.clear();
-
-    for (uint f = 0; f < faceCount; f++) {
-        Face * face = faceArray[f];
-
-        // Trivial fan-like triangulation.
-        const uint v0 = face->edge->vertex->id;
-        uint v2, v1 = -1;
-
-        for (Face::EdgeIterator it(face->edges()); !it.isDone(); it.advance()) {
-            Edge * edge = it.current();
-            v2 = edge->to()->id;
-            if (v2 == v0) break;
-            if (v1 != -1) addFace(v0, v1, v2);
-            v1 = v2;
-        }
-    }
-
-    nvDebugCheck(m_faceArray.count() > faceCount); // triangle count > face count
-
-    linkBoundary();
-
-    deleteAll(edgeArray);
-    deleteAll(faceArray);
-}
-
-
-/*
-Fixing T-junctions.
-
-- Find T-junctions. Find  vertices that are on an edge. 
-    - This test is approximate.
-    - Insert edges on a spatial index to speedup queries.
-    - Consider only open edges, that is edges that have no pairs.
-    - Consider only vertices on boundaries.
-- Close T-junction.
-    - Split edge.
-
-*/
-bool Mesh::splitBoundaryEdges() {
-    
-    Array<Vertex *> boundaryVertices;
-
-    foreach(i, m_vertexArray) {
-        Vertex * v = m_vertexArray[i];
-        if (v->isBoundary()) {
-            boundaryVertices.append(v);
-        }
-    }
-
-    nvDebug("Fixing T-junctions:\n");
-
-    int splitCount = 0;
-
-    foreach(v, boundaryVertices) {
-        Vertex * vertex = boundaryVertices[v];
-
-        Vector3 x0 = vertex->pos;
-
-        // Find edges that this vertex overlaps with.
-        foreach(e, m_edgeArray) {
-        //for (uint e = 0; e < m_edgeArray.count(); e++) {
-            Edge * edge = m_edgeArray[e];
-            if (edge != NULL && edge->isBoundary()) {
-
-                if (edge->from() == vertex || edge->to() == vertex) {
-                    continue;
-                }
-
-                Vector3 x1 = edge->from()->pos;
-                Vector3 x2 = edge->to()->pos;
-
-                Vector3 v01 = x0 - x1;
-                Vector3 v21 = x2 - x1;
-
-                float l = length(v21);
-                float d = length(cross(v01, v21)) / l;
-
-                if (isZero(d)) {
-                    float t = dot(v01, v21) / (l * l);
-
-                    // @@ Snap x0 to x1 or x2, if too close? No, do vertex snapping elsewhere.
-                    /*if (equal(t, 0.0f, 0.01f)) {
-                        //vertex->setPos(x1);
-                    }
-                    else if (equal(t, 1.0f, 0.01f)) {
-                        //vertex->setPos(x2);
-                    }
-                    else*/
-                    if (t > 0.0f + NV_EPSILON && t < 1.0f - NV_EPSILON) {
-                        nvDebugCheck(equal(lerp(x1, x2, t), x0));
-
-                        Vertex * splitVertex = splitBoundaryEdge(edge, t, x0);
-                        vertex->linkColocal(splitVertex);   // @@ Should we do this here?
-                        splitCount++;
-                    }
-                }
-            }
-        }
-    }
-
-    nvDebug(" - %d edges split.\n", splitCount);
-
-    nvDebugCheck(isValid());
-
-    return splitCount != 0;
-}
-
-
-// For this to be effective, we have to fix the boundary junctions first.
-Edge * Mesh::sewBoundary(Edge * startEdge) {
-    nvDebugCheck(startEdge->face == NULL);
-
-    // @@ We may want to be more conservative linking colocals in order to preserve the input topology. One way of doing that is by linking colocals only 
-    // if the vertices next to them are linked as well. That is, by sewing boundaries after detecting them. If any pair of consecutive edges have their first
-    // and last vertex in the same position, then it can be linked.
-
-    Edge * lastBoundarySeen = startEdge;
-
-    nvDebug("Sewing Boundary:\n");
-
-    int count = 0;
-    int sewnCount = 0;
-
-    Edge * edge = startEdge;
-    do {
-        nvDebugCheck(edge->face == NULL);
-
-        Edge * edge_a = edge;
-        Edge * edge_b = edge->prev;
-
-        Edge * pair_a = edge_a->pair;
-        Edge * pair_b = edge_b->pair;
-
-        Vertex * v0a = edge_a->to();
-        Vertex * v0b = edge_b->from();
-        Vertex * v1a = edge_a->from();
-        Vertex * v1b = edge_b->to();
-
-        nvDebugCheck(v1a->isColocal(v1b));
-
-        /*
-        v0b +      _+ v0a
-             \     /
-            b \   / a
-               \|/
-            v1b + v1a
-        */
-
-        // @@ This should not happen while sewing, but it may be produced somewhere else.
-        nvDebugCheck(edge_a != edge_b);
-
-        if (v0a->pos == v0b->pos) {
-
-            // Link vertices.
-            v0a->linkColocal(v0b);
-            
-            // Remove edges to be collapsed.
-            disconnect(edge_a);
-            disconnect(edge_b);
-            disconnect(pair_a);
-            disconnect(pair_b);
-
-            // Link new boundary edges.
-            Edge * prevBoundary = edge_b->prev;
-            Edge * nextBoundary = edge_a->next;
-            if (nextBoundary != NULL) {
-                nvDebugCheck(nextBoundary->face == NULL);
-                nvDebugCheck(prevBoundary->face == NULL);
-                nextBoundary->setPrev(prevBoundary);
-            
-                // Make sure boundary vertex points to boundary edge.
-                v0a->setEdge(nextBoundary); // This updates all colocals.
-            }
-            lastBoundarySeen = prevBoundary;
-
-            // Creat new edge.
-            Edge * newEdge_a = addEdge(v0a->id, v1a->id);   // pair_a->from()->id, pair_a->to()->id
-            Edge * newEdge_b = addEdge(v1b->id, v0b->id);
-
-            newEdge_a->pair = newEdge_b;
-            newEdge_b->pair = newEdge_a;
-
-            newEdge_a->face = pair_a->face;
-            newEdge_b->face = pair_b->face;
-
-            newEdge_a->setNext(pair_a->next);
-            newEdge_a->setPrev(pair_a->prev);
-
-            newEdge_b->setNext(pair_b->next);
-            newEdge_b->setPrev(pair_b->prev);
-
-            delete edge_a;
-            delete edge_b;
-            delete pair_a;
-            delete pair_b;
-
-            edge = nextBoundary;    // If nextBoundary is NULL we have closed the loop.
-            sewnCount++;
-        }
-        else {
-            edge = edge->next;
-        }
-        
-        count++;
-    } while(edge != NULL && edge != lastBoundarySeen);
-
-    nvDebug(" - Sewn %d out of %d.\n", sewnCount, count);
-
-    if (lastBoundarySeen != NULL) {
-        nvDebugCheck(lastBoundarySeen->face == NULL);
-    }
-
-    return lastBoundarySeen;
-}
-
-
-// @@ We must always disconnect edge pairs simultaneously.
-void Mesh::disconnect(Edge * edge) {
-    nvDebugCheck(edge != NULL);
-
-    // Remove from edge list.
-    if ((edge->id & 1) == 0) {
-        nvDebugCheck(m_edgeArray[edge->id / 2] == edge);
-        m_edgeArray[edge->id / 2] = NULL;
-    }
-
-    // Remove edge from map. @@ Store map key inside edge?
-    nvDebugCheck(edge->from() != NULL && edge->to() != NULL);
-    bool removed = m_edgeMap.remove(Key(edge->from()->id, edge->to()->id));
-    nvDebugCheck(removed == true);
-
-    // Disconnect from vertex.
-    if (edge->vertex != NULL) {
-        if (edge->vertex->edge == edge) {
-            if (edge->prev && edge->prev->pair) {
-                edge->vertex->edge = edge->prev->pair;
-            }
-            else if (edge->pair && edge->pair->next) {
-                edge->vertex->edge = edge->pair->next;
-            }
-            else {
-                edge->vertex->edge = NULL;
-                // @@ Remove disconnected vertex?
-            }
-        }
-        //edge->setVertex(NULL);
-    }
-
-    // Disconnect from face.
-    if (edge->face != NULL) {
-        if (edge->face->edge == edge) {
-            if (edge->next != NULL && edge->next != edge) {
-                edge->face->edge = edge->next;
-            }
-            else if (edge->prev != NULL && edge->prev != edge) {
-                edge->face->edge = edge->prev;
-            }
-            else {
-                edge->face->edge = NULL;
-                // @@ Remove disconnected face?
-            }
-        }
-        //edge->setFace(NULL);
-    }
-
-    // @@ Hack, we don't disconnect from pair, because pair needs us to remove itself from the map.
-    // Disconect from pair.
-    /*if (edge->pair != NULL) {
-        if (edge->pair->pair == edge) {
-            edge->pair->setPair(NULL);
-        }
-        //edge->setPair(NULL);
-    }*/
-
-    // Disconnect from previous.
-    if (edge->prev) {
-        if (edge->prev->next == edge) {
-            edge->prev->setNext(NULL);
-        }
-        //edge->setPrev(NULL);
-    }
-
-    // Disconnect from next.
-    if (edge->next) {
-        if (edge->next->prev == edge) {
-            edge->next->setPrev(NULL);
-        }
-        //edge->setNext(NULL);
-    }
-}
-
-
-void Mesh::remove(Edge * edge) {
-    nvDebugCheck(edge != NULL);
-
-    disconnect(edge);
-
-    delete edge;
-}
-
-void Mesh::remove(Vertex * vertex) {
-    nvDebugCheck(vertex != NULL);
-
-    // Remove from vertex list.
-    m_vertexArray[vertex->id] = NULL;
-
-    // Disconnect from colocals.
-    vertex->unlinkColocal();
-
-    // Disconnect from edges.
-    if (vertex->edge != NULL) {
-        // @@ Removing a connected vertex is asking for trouble...
-        if (vertex->edge->vertex == vertex) {
-            // @@ Connect edge to a colocal?
-            vertex->edge->vertex = NULL;
-        }
-
-        vertex->setEdge(NULL);
-    }
-
-    delete vertex;
-}
-
-void Mesh::remove(Face * face) {
-    nvDebugCheck(face != NULL);
-
-    // Remove from face list.
-    m_faceArray[face->id] = NULL;
-
-    // Disconnect from edges.
-    if (face->edge != NULL) {
-        nvDebugCheck(face->edge->face == face);
-
-        face->edge->face = NULL;
-
-        face->edge = NULL;
-    }
-
-    delete face;
-}
-
-
-void Mesh::compactEdges() {
-    const uint edgeCount = m_edgeArray.count();
-
-    uint c = 0;
-    for (uint i = 0; i < edgeCount; i++) {
-        if (m_edgeArray[i] != NULL) {
-            if (i != c) {
-                m_edgeArray[c] = m_edgeArray[i];
-                m_edgeArray[c]->id = 2 * c;
-                if (m_edgeArray[c]->pair != NULL) {
-                    m_edgeArray[c]->pair->id = 2 * c + 1;
-                }
-            }
-            c++;
-        }
-    }
-
-    m_edgeArray.resize(c);
-}
-
-
-void Mesh::compactVertices() {
-    const uint vertexCount = m_vertexArray.count();
-
-    uint c = 0;
-    for (uint i = 0; i < vertexCount; i++) {
-        if (m_vertexArray[i] != NULL) {
-            if (i != c) {
-                m_vertexArray[c] = m_vertexArray[i];
-                m_vertexArray[c]->id = c;
-            }
-            c++;
-        }
-    }
-
-    m_vertexArray.resize(c);
-
-    // @@ Generate xref array for external attributes.
-}
-
-
-void Mesh::compactFaces() {
-    const uint faceCount = m_faceArray.count();
-
-    uint c = 0;
-    for (uint i = 0; i < faceCount; i++) {
-        if (m_faceArray[i] != NULL) {
-            if (i != c) {
-                m_faceArray[c] = m_faceArray[i];
-                m_faceArray[c]->id = c;
-            }
-            c++;
-        }
-    }
-
-    m_faceArray.resize(c);
-}
-
-
-Vertex * Mesh::splitBoundaryEdge(Edge * edge, float t, const Vector3 & pos) {
-
-    /*
-      We want to go from this configuration:
-           
-            +   +
-            |   ^
-       edge |<->|  pair
-            v   |
-            +   +
-      
-      To this one:
-
-            +   +
-            |   ^
-         e0 |<->| p0
-            v   |
-     vertex +   + 
-            |   ^
-         e1 |<->| p1
-            v   |
-            +   +
-
-    */
-
-
-    Edge * pair = edge->pair;
-
-    // Make sure boundaries are linked.
-    nvDebugCheck(pair != NULL); 
-
-    // Make sure edge is a boundary edge.
-    nvDebugCheck(pair->face == NULL);
-
-    // Add new vertex.
-    Vertex * vertex = addVertex(pos);
-    vertex->nor = lerp(edge->from()->nor, edge->to()->nor, t);
-    vertex->tex = lerp(edge->from()->tex, edge->to()->tex, t);
-    vertex->col = lerp(edge->from()->col, edge->to()->col, t);
-
-    disconnect(edge);
-    disconnect(pair);
-
-    // Add edges.
-    Edge * e0 = addEdge(edge->from()->id, vertex->id);
-    Edge * p0 = addEdge(vertex->id, pair->to()->id);
-
-    Edge * e1 = addEdge(vertex->id, edge->to()->id);
-    Edge * p1 = addEdge(pair->from()->id, vertex->id);
-
-    // Link edges.
-    e0->setNext(e1);
-    p1->setNext(p0);
-
-    e0->setPrev(edge->prev);
-    e1->setNext(edge->next);
-
-    p1->setPrev(pair->prev);
-    p0->setNext(pair->next);
-
-    nvDebugCheck(e0->next == e1);
-    nvDebugCheck(e1->prev == e0);
-
-    nvDebugCheck(p1->next == p0);
-    nvDebugCheck(p0->prev == p1);
-
-    nvDebugCheck(p0->pair == e0);
-    nvDebugCheck(e0->pair == p0);
-
-    nvDebugCheck(p1->pair == e1);
-    nvDebugCheck(e1->pair == p1);
-
-    // Link faces.
-    e0->face = edge->face;
-    e1->face = edge->face;
-
-    // Link vertices.
-    edge->from()->setEdge(e0);
-    vertex->setEdge(e1);
-
-    delete edge;
-    delete pair;
-
-    return vertex;
-}
-
-#if 0
-// Without introducing new vertices.
-void Mesh::splitBoundaryEdge(Edge * edge, Vertex * vertex) {
-
-    /*
-      We want to go from this configuration:
-
-            |   | pn
-            +   +
-            |   ^
-            |   |
-       edge |<->| pair
-            |   |
-            v   |
-            +   +
-            |   | pp
-      
-      To this one:
-          \       /
-           \     /
-            +   +
-            |   ^
-         e0 |<->| p0
-            v   |
-     vertex +   + 
-            |   ^
-         e1 |<->| p1
-            v   |
-            +   +
-           /     \
-          /       \
-    */
-
-
-    Edge * pair = edge->pair;
-    Edge * pn = pair->next();
-    Edge * pp = pair->prev();
-
-    // Make sure boundaries are linked.
-    nvDebugCheck(pair != NULL);
-
-    // Make sure edge is a boundary edge.
-    nvDebugCheck(pair->face() == NULL);
-
-    nvDebugCheck(edge->isValid());
-    nvDebugCheck(pair->isValid());
-
-    disconnect(edge);
-    disconnect(pair);
-
-    // Add edges.
-    Edge * e0 = addEdge(edge->from()->id(), vertex->id());
-    Edge * e1 = addEdge(vertex->id(), edge->to()->id());
-
-    // Link faces.
-    e0->setFace(edge->face());
-    e1->setFace(edge->face());
-
-    // Link pairs.
-    Edge * p0 = findEdge(vertex->id(), pair->to()->id());
-    if (p0 == NULL) {
-        p0 = addEdge(vertex->id(), pair->to()->id());
-        pn->setPrev(p0);
-    }
-    else {
-        nvDebugCheck(p0->face() != NULL);
-        if (e0->prev() != NULL) {
-            pn->setPrev(e0->prev());
-        }
-        else {
-            nvDebugCheck(pn == e0);
-        }
-    }
-    
-    Edge * p1 = findEdge(pair->from()->id(), vertex->id());
-    if (p1 == NULL) {
-        p1 = addEdge(pair->from()->id(), vertex->id());
-        pp->setNext(p1);
-    }
-    else {
-        nvDebugCheck(p1->face() != NULL);
-        if (e1->next() != NULL) {
-            pp->setPrev(e1->next());
-        }
-        else {
-            nvDebugCheck(pp == e1);
-        }
-    }
-
-    // Link edges.
-    e0->setNext(e1); // e1->setPrev(e0)
-
-    if (p0->face() == p1->face()) { // can be null
-        p1->setNext(p0); // p0->setPrev(p1)
-    }
-    else {
-        //if (p1->face() == NULL) p1->setNext(
-    }
-    
-
-    e0->setPrev(edge->prev());
-    e1->setNext(edge->next());
-
-    nvDebugCheck(e0->pair == p0);
-    nvDebugCheck(e1->pair == p1);
-    nvDebugCheck(p0->pair == e0);
-    nvDebugCheck(p1->pair == e1);
-
-    nvDebugCheck(e0->isValid());
-    nvDebugCheck(e1->isValid());
-    nvDebugCheck(pp->isValid());
-    nvDebugCheck(pn->isValid());
-
-    nvDebugCheck(e0->pair->isValid());
-    nvDebugCheck(e1->pair->isValid());
-    nvDebugCheck(pp->pair->isValid());
-    nvDebugCheck(pn->pair->isValid());
-
-    nvDebugCheck(edge->face->isValid());
-
-    if (pn->pair->face != NULL) {
-        nvDebugCheck(pn->pair->face->isValid());
-    }
-
-    if (pp->pair->face() != NULL) {
-        nvDebugCheck(pn->pair->face->isValid());
-    }
-
-    if (p0->face != NULL) {
-        nvDebugCheck(p0->face->isValid());
-    }
-
-    if (p1->face() != NULL) {
-        nvDebugCheck(p1->face()->isValid());
-    }
-
-    nvDebugCheck(isValid()); // Only for extreme debugging.
-
-    // Link vertices.
-    edge->from()->setEdge(e0);
-    vertex->setEdge(p0);
-
-    delete edge;
-    delete pair;
-}
-#endif
-
-bool Mesh::isValid() const
-{
-    // Make sure all edges are valid.
-    const uint edgeCount = m_edgeArray.count();
-    for (uint e = 0; e < edgeCount; e++) {
-        Edge * edge = m_edgeArray[e];
-        if (edge != NULL) {
-            if (edge->id != 2*e) {
-                return false;
-            }
-            if (!edge->isValid()) {
-                return false;
-            }
-
-            if (edge->pair->id != 2*e+1) {
-                return false;
-            }
-            if (!edge->pair->isValid()) {
-                return false;
-            }
-        }
-    }
-
-    // @@ Make sure all faces are valid.
-
-    // @@ Make sure all vertices are valid.
-
-    return true;
-}
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Mesh.h b/thirdparty/thekla_atlas/nvmesh/halfedge/Mesh.h
deleted file mode 100644
index c202c2ef9a..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Mesh.h
+++ /dev/null
@@ -1,274 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#pragma once
-#ifndef NV_MESH_HALFEDGE_MESH_H
-#define NV_MESH_HALFEDGE_MESH_H
-
-#include "nvmesh/nvmesh.h"
-#include "nvcore/Array.h"
-#include "nvcore/HashMap.h"
-
-/*
-If I were to redo this again, there are a number of things that I would do differently.
-- Edge map is only useful when importing a mesh to guarantee the result is two-manifold. However, when manipulating the mesh
-  it's a pain to maintain the map up to date.
-- Edge array only points to the even vertices. There's no good reason for that. The map becomes required to traverse all edges
-  or you have to make sure edges are properly paired.
-- Linked boundaries. It's cleaner to assume a NULL pair means a boundary edge. Makes easier to seal boundaries. The only reason
-  why we link boundaries is to simplify traversal, but that could be done with two helper functions (nextBoundary, prevBoundary).
-- Minimize the amount of state that needs to be set in a certain way:
-    - boundary vertices point to boundary edge.
-- Remove parenthesis! Make some members public.
-- Remove member functions with side effects:
-    - e->setNext(n) modifies e->next and n->prev, instead use "link(e, n)", or "e->next = n, n->prev = e"
-*/
-
-
-namespace nv
-{
-    class Vector3;
-    class TriMesh;
-    class QuadTriMesh;
-    //template <typename T> struct Hash<Mesh::Key>;
-
-    namespace HalfEdge
-    {
-        class Edge;
-        class Face;
-        class Vertex;
-
-        /// Simple half edge mesh designed for dynamic mesh manipulation.
-        class Mesh
-        {
-        public:
-
-            Mesh();
-            Mesh(const Mesh * mesh);
-            ~Mesh();
-
-            void clear();
-
-            Vertex * addVertex(const Vector3 & pos);
-            //Vertex * addVertex(uint id, const Vector3 & pos);
-            //void addVertices(const Mesh * mesh);
-
-            void linkColocals();
-            void linkColocalsWithCanonicalMap(const Array<uint> & canonicalMap);
-            void resetColocalLinks();
-
-            Face * addFace();
-            Face * addFace(uint v0, uint v1, uint v2);
-            Face * addFace(uint v0, uint v1, uint v2, uint v3);
-            Face * addFace(const Array<uint> & indexArray);
-            Face * addFace(const Array<uint> & indexArray, uint first, uint num);
-            //void addFaces(const Mesh * mesh);
-
-            // These functions disconnect the given element from the mesh and delete it.
-            void disconnect(Edge * edge);
-            void disconnectPair(Edge * edge);
-            void disconnect(Vertex * vertex);
-            void disconnect(Face * face);
-
-            void remove(Edge * edge);
-            void remove(Vertex * vertex);
-            void remove(Face * face);
-
-            // Remove holes from arrays and reassign indices.
-            void compactEdges();
-            void compactVertices();
-            void compactFaces();
-
-            void triangulate();
-
-            void linkBoundary();
-            
-            bool splitBoundaryEdges(); // Returns true if any split was made.
-
-            // Sew the boundary that starts at the given edge, returns one edge that still belongs to boundary, or NULL if boundary closed.
-            HalfEdge::Edge * sewBoundary(Edge * startEdge);
-
-
-            // Vertices
-            uint vertexCount() const { return m_vertexArray.count(); }
-            const Vertex * vertexAt(int i) const { return m_vertexArray[i]; }
-            Vertex * vertexAt(int i) { return m_vertexArray[i]; }
-
-            uint colocalVertexCount() const { return m_colocalVertexCount; }
-
-            // Faces
-            uint faceCount() const { return m_faceArray.count(); }
-            const Face * faceAt(int i) const { return m_faceArray[i]; }
-            Face * faceAt(int i) { return m_faceArray[i]; }
-
-            // Edges
-            uint edgeCount() const { return m_edgeArray.count();  }
-            const Edge * edgeAt(int i) const { return m_edgeArray[i]; }
-            Edge * edgeAt(int i) { return m_edgeArray[i]; }
-
-            class ConstVertexIterator;
-
-            class VertexIterator
-            {
-                friend class ConstVertexIterator;
-            public:
-                VertexIterator(Mesh * mesh) : m_mesh(mesh), m_current(0) { }
-
-                virtual void advance() { m_current++; }
-                virtual bool isDone() const { return m_current == m_mesh->vertexCount(); }
-                virtual Vertex * current() const { return m_mesh->vertexAt(m_current); }
-
-            private:
-                HalfEdge::Mesh * m_mesh;
-                uint m_current;
-            };
-            VertexIterator vertices() { return VertexIterator(this); }
-
-            class ConstVertexIterator
-            {
-            public:
-                ConstVertexIterator(const Mesh * mesh) : m_mesh(mesh), m_current(0) { }
-                ConstVertexIterator(class VertexIterator & it) : m_mesh(it.m_mesh), m_current(it.m_current) { }
-
-                virtual void advance() { m_current++; }
-                virtual bool isDone() const { return m_current == m_mesh->vertexCount(); }
-                virtual const Vertex * current() const { return m_mesh->vertexAt(m_current); }
-
-            private:
-                const HalfEdge::Mesh * m_mesh;
-                uint m_current;
-            };
-            ConstVertexIterator vertices() const { return ConstVertexIterator(this); }
-
-            class ConstFaceIterator;
-
-            class FaceIterator
-            {
-                friend class ConstFaceIterator;
-            public:
-                FaceIterator(Mesh * mesh) : m_mesh(mesh), m_current(0) { }
-
-                virtual void advance() { m_current++; }
-                virtual bool isDone() const { return m_current == m_mesh->faceCount(); }
-                virtual Face * current() const { return m_mesh->faceAt(m_current); }
-
-            private:
-                HalfEdge::Mesh * m_mesh;
-                uint m_current;
-            };
-            FaceIterator faces() { return FaceIterator(this); }
-
-            class ConstFaceIterator
-            {
-            public:
-                ConstFaceIterator(const Mesh * mesh) : m_mesh(mesh), m_current(0) { }
-                ConstFaceIterator(const FaceIterator & it) : m_mesh(it.m_mesh), m_current(it.m_current) { }
-
-                virtual void advance() { m_current++; }
-                virtual bool isDone() const { return m_current == m_mesh->faceCount(); }
-                virtual const Face * current() const { return m_mesh->faceAt(m_current); }
-
-            private:
-                const HalfEdge::Mesh * m_mesh;
-                uint m_current;
-            };
-            ConstFaceIterator faces() const { return ConstFaceIterator(this); }
-
-            class ConstEdgeIterator;
-
-            class EdgeIterator
-            {
-                friend class ConstEdgeIterator;
-            public:
-                EdgeIterator(Mesh * mesh) : m_mesh(mesh), m_current(0) { }
-
-                virtual void advance() { m_current++; }
-                virtual bool isDone() const { return m_current == m_mesh->edgeCount(); }
-                virtual Edge * current() const { return m_mesh->edgeAt(m_current); }
-
-            private:
-                HalfEdge::Mesh * m_mesh;
-                uint m_current;
-            };
-            EdgeIterator edges() { return EdgeIterator(this); }
-
-            class ConstEdgeIterator
-            {
-            public:
-                ConstEdgeIterator(const Mesh * mesh) : m_mesh(mesh), m_current(0) { }
-                ConstEdgeIterator(const EdgeIterator & it) : m_mesh(it.m_mesh), m_current(it.m_current) { }
-
-                virtual void advance() { m_current++; }
-                virtual bool isDone() const { return m_current == m_mesh->edgeCount(); }
-                virtual const Edge * current() const { return m_mesh->edgeAt(m_current); }
-
-            private:
-                const HalfEdge::Mesh * m_mesh;
-                uint m_current;
-            };
-            ConstEdgeIterator edges() const { return ConstEdgeIterator(this); }
-
-            // @@ Add half-edge iterator.
-
-
-
-            // Convert to tri mesh.
-            TriMesh * toTriMesh() const;
-            QuadTriMesh * toQuadTriMesh() const;
-
-            bool isValid() const;
-
-        public:
-
-            // Error status:
-            mutable uint errorCount;
-            mutable uint errorIndex0;
-            mutable uint errorIndex1;
-
-        private:
-
-            bool canAddFace(const Array<uint> & indexArray, uint first, uint num) const;
-            bool canAddEdge(uint i, uint j) const;
-            Edge * addEdge(uint i, uint j);
-
-            Edge * findEdge(uint i, uint j) const;
-
-            void linkBoundaryEdge(Edge * edge);
-            Vertex * splitBoundaryEdge(Edge * edge, float t, const Vector3 & pos);
-            void splitBoundaryEdge(Edge * edge, Vertex * vertex);
-
-        private:
-
-            Array<Vertex *> m_vertexArray;
-            Array<Edge *> m_edgeArray;
-            Array<Face *> m_faceArray;
-
-            struct Key {
-                Key() {}
-                Key(const Key & k) : p0(k.p0), p1(k.p1) {}
-                Key(uint v0, uint v1) : p0(v0), p1(v1) {}
-                void operator=(const Key & k) { p0 = k.p0; p1 = k.p1; }
-                bool operator==(const Key & k) const { return p0 == k.p0 && p1 == k.p1; }
-
-                uint p0;
-                uint p1;
-            };
-            friend struct Hash<Mesh::Key>;
-
-            HashMap<Key, Edge *> m_edgeMap;
-
-            uint m_colocalVertexCount;
-
-        };
-        /*
-        // This is a much better hash than the default and greatly improves performance!
-        template <> struct hash<Mesh::Key>
-        {
-        uint operator()(const Mesh::Key & k) const { return k.p0 + k.p1; }
-        };
-        */
-
-    } // HalfEdge namespace
-
-} // nv namespace
-
-#endif // NV_MESH_HALFEDGE_MESH_H
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Vertex.cpp b/thirdparty/thekla_atlas/nvmesh/halfedge/Vertex.cpp
deleted file mode 100644
index 66dad69f8a..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Vertex.cpp
+++ /dev/null
@@ -1,94 +0,0 @@
-// This code is in the public domain -- castano@gmail.com
-
-#include "nvmesh.h" // pch
-
-#include "Vertex.h"
-
-#include "nvmath/Vector.inl"
-
-using namespace nv;
-using namespace HalfEdge;
-
-
-// Set first edge of all colocals.
-void Vertex::setEdge(Edge * e)
-{
-    for (VertexIterator it(colocals()); !it.isDone(); it.advance()) { 
-        it.current()->edge = e;
-    }
-}
-
-// Update position of all colocals.
-void Vertex::setPos(const Vector3 & p)
-{
-    for (VertexIterator it(colocals()); !it.isDone(); it.advance()) {
-        it.current()->pos = p;
-    }
-}
-
-
-uint HalfEdge::Vertex::colocalCount() const
-{
-    uint count = 0;
-    for (ConstVertexIterator it(colocals()); !it.isDone(); it.advance()) { ++count; }
-    return count;
-}
-
-uint HalfEdge::Vertex::valence() const
-{
-    uint count = 0;
-    for (ConstEdgeIterator it(edges()); !it.isDone(); it.advance()) { ++count; }
-    return count;
-}
-
-const HalfEdge::Vertex * HalfEdge::Vertex::firstColocal() const
-{
-    uint firstId = id;
-    const Vertex * vertex = this;
-
-    for (ConstVertexIterator it(colocals()); !it.isDone(); it.advance())
-    {
-        if (it.current()->id < firstId) {
-            firstId = vertex->id;
-            vertex = it.current();
-        }
-    }
-
-    return vertex;
-}
-
-HalfEdge::Vertex * HalfEdge::Vertex::firstColocal()
-{
-    Vertex * vertex = this;
-    uint firstId = id;
-
-    for (VertexIterator it(colocals()); !it.isDone(); it.advance())
-    {
-        if (it.current()->id < firstId) {
-            firstId = vertex->id;
-            vertex = it.current();
-        }
-    }
-
-    return vertex;
-}
-
-bool HalfEdge::Vertex::isFirstColocal() const
-{
-    return firstColocal() == this;
-}
-
-bool HalfEdge::Vertex::isColocal(const Vertex * v) const {
-    if (this == v) return true;
-    if (pos != v->pos) return false;
-
-    for (ConstVertexIterator it(colocals()); !it.isDone(); it.advance())
-    {
-        if (v == it.current()) {
-            return true;
-        }
-    }
-
-    return false;
-}
-
diff --git a/thirdparty/thekla_atlas/nvmesh/halfedge/Vertex.h b/thirdparty/thekla_atlas/nvmesh/halfedge/Vertex.h
deleted file mode 100644
index 1c5c8d7141..0000000000
--- a/thirdparty/thekla_atlas/nvmesh/halfedge/Vertex.h
+++ /dev/null
@@ -1,221 +0,0 @@
-// This code is in the public domain -- castanyo@yahoo.es
-
-#pragma once
-#ifndef NV_MESH_HALFEDGE_VERTEX_H
-#define NV_MESH_HALFEDGE_VERTEX_H
-
-#include "nvmesh/halfedge/Edge.h"
-
-namespace nv
-{
-    namespace HalfEdge { class Vertex; class Face; class Edge; }
-
-    // Half edge vertex.
-    class HalfEdge::Vertex
-    {
-        NV_FORBID_COPY(Vertex);
-    public:
-
-        uint id;
-
-        Edge * edge;
-        Vertex * next;
-        Vertex * prev;
-
-        Vector3 pos;
-        Vector3 nor;
-        Vector2 tex;
-        Vector4 col;
-
-
-        Vertex(uint id) : id(id), edge(NULL), pos(0.0f), nor(0.0f), tex(0.0f), col(0.0f) {
-            next = this;
-            prev = this;
-        }
-
-
-        void setEdge(Edge * e);
-        void setPos(const Vector3 & p);
-
-        uint colocalCount() const;
-        uint valence() const;
-        bool isFirstColocal() const;
-        const Vertex * firstColocal() const;
-        Vertex * firstColocal();
-
-        bool isColocal(const Vertex * v) const;
-
-        
-        void linkColocal(Vertex * v) {
-            next->prev = v;
-            v->next = next; 
-            next = v;
-            v->prev = this;
-        }
-        void unlinkColocal() {
-            next->prev = prev;
-            prev->next = next;
-            next = this;
-            prev = this;
-        }
-
-
-        // @@ Note: This only works if linkBoundary has been called.
-        bool isBoundary() const {
-            return (edge && !edge->face);
-        }
-
-
-        //	for(EdgeIterator it(iterator()); !it.isDone(); it.advance()) { ... }
-        //
-        //	EdgeIterator it(iterator());
-        //	while(!it.isDone()) {
-        //		...
-        //		id.advance(); 
-        //	}
-
-        // Iterator that visits the edges around this vertex in counterclockwise order.
-        class EdgeIterator //: public Iterator<Edge *>
-        {
-        public:
-            EdgeIterator(Edge * e) : m_end(NULL), m_current(e) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->pair->next;
-                //m_current = m_current->prev->pair;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual Edge * current() const { return m_current; }
-            Vertex * vertex() const { return m_current->vertex; }
-
-        private:
-            Edge * m_end;
-            Edge * m_current;
-        };
-
-        EdgeIterator edges() { return EdgeIterator(edge); }
-        EdgeIterator edges(Edge * e) { return EdgeIterator(e); }
-
-        // Iterator that visits the edges around this vertex in counterclockwise order.
-        class ConstEdgeIterator //: public Iterator<Edge *>
-        {
-        public:
-            ConstEdgeIterator(const Edge * e) : m_end(NULL), m_current(e) { }
-            ConstEdgeIterator(EdgeIterator it) : m_end(NULL), m_current(it.current()) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->pair->next;
-                //m_current = m_current->prev->pair;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual const Edge * current() const { return m_current; }
-            const Vertex * vertex() const { return m_current->to(); }
-
-        private:
-            const Edge * m_end;
-            const Edge * m_current;
-        };
-
-        ConstEdgeIterator edges() const { return ConstEdgeIterator(edge); }
-        ConstEdgeIterator edges(const Edge * e) const { return ConstEdgeIterator(e); }
-
-
-        // Iterator that visits the edges around this vertex in counterclockwise order.
-        class ReverseEdgeIterator //: public Iterator<Edge *>
-        {
-        public:
-            ReverseEdgeIterator(Edge * e) : m_end(NULL), m_current(e) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->prev->pair;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual Edge * current() const { return m_current; }
-            Vertex * vertex() const { return m_current->vertex; }
-
-        private:
-            Edge * m_end;
-            Edge * m_current;
-        };
-
-        // Iterator that visits the edges around this vertex in counterclockwise order.
-        class ReverseConstEdgeIterator //: public Iterator<Edge *>
-        {
-        public:
-            ReverseConstEdgeIterator(const Edge * e) : m_end(NULL), m_current(e) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->prev->pair;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual const Edge * current() const { return m_current; }
-            const Vertex * vertex() const { return m_current->to(); }
-
-        private:
-            const Edge * m_end;
-            const Edge * m_current;
-        };
-
-
-
-        // Iterator that visits all the colocal vertices.
-        class VertexIterator //: public Iterator<Edge *>
-        {
-        public:
-            VertexIterator(Vertex * v) : m_end(NULL), m_current(v) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->next;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual Vertex * current() const { return m_current; }
-
-        private:
-            Vertex * m_end;
-            Vertex * m_current;
-        };
-
-        VertexIterator colocals() { return VertexIterator(this); }
-
-        // Iterator that visits all the colocal vertices.
-        class ConstVertexIterator //: public Iterator<Edge *>
-        {
-        public:
-            ConstVertexIterator(const Vertex * v) : m_end(NULL), m_current(v) { }
-
-            virtual void advance()
-            {
-                if (m_end == NULL) m_end = m_current;
-                m_current = m_current->next;
-            }
-
-            virtual bool isDone() const { return m_end == m_current; }
-            virtual const Vertex * current() const { return m_current; }
-
-        private:
-            const Vertex * m_end;
-            const Vertex * m_current;
-        };
-
-        ConstVertexIterator colocals() const { return ConstVertexIterator(this); }
-
-    };
-
-} // nv namespace
-
-#endif // NV_MESH_HALFEDGE_VERTEX_H