reeb.c

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Martin Poirier
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <math.h>
#include <string.h> // for memcpy
#include <stdio.h>
#include <stdlib.h> // for qsort
#include <float.h>

#include "DNA_scene_types.h"
#include "DNA_object_types.h"

#include "MEM_guardedalloc.h"

#include "BKE_context.h"

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "BLI_editVert.h"
#include "BLI_edgehash.h"
#include "BLI_ghash.h"
#include "BLI_heap.h"

//#include "BDR_editobject.h"

//#include "BIF_interface.h"
//#include "BIF_toolbox.h"
//#include "BIF_graphics.h"


//#include "blendef.h"

#include "ONL_opennl.h"

#include "reeb.h"

#if 0 /* UNUSED 2.5 */
static ReebGraph *GLOBAL_RG = NULL;
static ReebGraph *FILTERED_RG = NULL;
#endif

/*
 * Skeleton generation algorithm based on: 
 * "Harmonic Skeleton for Realistic Character Animation"
 * Gregoire Aujay, Franck Hetroy, Francis Lazarus and Christine Depraz
 * SIGGRAPH 2007
 * 
 * Reeb graph generation algorithm based on: 
 * "Robust On-line Computation of Reeb Graphs: Simplicity and Speed"
 * Valerio Pascucci, Giorgio Scorzelli, Peer-Timo Bremer and Ajith Mascarenhas
 * SIGGRAPH 2007
 * 
 * */
 
#define DEBUG_REEB
#define DEBUG_REEB_NODE

typedef struct VertexData
{
    float w; /* weight */
    int i; /* index */
    ReebNode *n;
} VertexData;

typedef struct EdgeIndex
{
    EditEdge **edges;
    int      *offset;
} EdgeIndex;

typedef enum {
    MERGE_LOWER,
    MERGE_HIGHER,
    MERGE_APPEND
} MergeDirection;

int mergeArcs(ReebGraph *rg, ReebArc *a0, ReebArc *a1);
void mergeArcEdges(ReebGraph *rg, ReebArc *aDst, ReebArc *aSrc, MergeDirection direction);
int mergeConnectedArcs(ReebGraph *rg, ReebArc *a0, ReebArc *a1);
EditEdge * NextEdgeForVert(EdgeIndex *indexed_edges, int index);
void mergeArcFaces(ReebGraph *rg, ReebArc *aDst, ReebArc *aSrc);
void addFacetoArc(ReebArc *arc, EditFace *efa);

void REEB_RadialSymmetry(BNode* root_node, RadialArc* ring, int count);
void REEB_AxialSymmetry(BNode* root_node, BNode* node1, BNode* node2, struct BArc* barc1, BArc* barc2);

void flipArcBuckets(ReebArc *arc);


/***************************************** UTILS **********************************************/

static VertexData *allocVertexData(EditMesh *em)
{
    VertexData *data;
    EditVert *eve;
    int totvert, index;
    
    totvert = BLI_countlist(&em->verts);
    
    data = MEM_callocN(sizeof(VertexData) * totvert, "VertexData");

    for(index = 0, eve = em->verts.first; eve; index++, eve = eve->next)
    {
        data[index].i = index;
        data[index].w = 0;
        eve->tmp.p = data + index;
    }
        
    return data;
}

static int indexData(EditVert *eve)
{
    return ((VertexData*)eve->tmp.p)->i;
}

static float weightData(EditVert *eve)
{
    return ((VertexData*)eve->tmp.p)->w;
}

static void weightSetData(EditVert *eve, float w)
{
    ((VertexData*)eve->tmp.p)->w = w;
}

static ReebNode* nodeData(EditVert *eve)
{
    return ((VertexData*)eve->tmp.p)->n;
}

static void nodeSetData(EditVert *eve, ReebNode *n)
{
    ((VertexData*)eve->tmp.p)->n = n;
}

void REEB_freeArc(BArc *barc)
{
    ReebArc *arc = (ReebArc*)barc;
    BLI_freelistN(&arc->edges);
    
    if (arc->buckets)
        MEM_freeN(arc->buckets);
        
    if (arc->faces)
        BLI_ghash_free(arc->faces, NULL, NULL);
    
    MEM_freeN(arc);
}

void REEB_freeGraph(ReebGraph *rg)
{
    ReebArc *arc;
    ReebNode *node;
    
    // free nodes
    for( node = rg->nodes.first; node; node = node->next )
    {
        BLI_freeNode((BGraph*)rg, (BNode*)node);
    }
    BLI_freelistN(&rg->nodes);
    
    // free arcs
    arc = rg->arcs.first;
    while( arc )
    {
        ReebArc *next = arc->next;
        REEB_freeArc((BArc*)arc);
        arc = next;
    }
    
    // free edge map
    BLI_edgehash_free(rg->emap, NULL);
    
    /* free linked graph */
    if (rg->link_up)
    {
        REEB_freeGraph(rg->link_up);
    }
    
    MEM_freeN(rg);
}

ReebGraph * newReebGraph(void)
{
    ReebGraph *rg;
    rg = MEM_callocN(sizeof(ReebGraph), "reeb graph");
    
    rg->totnodes = 0;
    rg->emap = BLI_edgehash_new();
    
    
    rg->free_arc = REEB_freeArc;
    rg->free_node = NULL;
    rg->radial_symmetry = REEB_RadialSymmetry;
    rg->axial_symmetry = REEB_AxialSymmetry;
    
    return rg;
}

void BIF_flagMultiArcs(ReebGraph *rg, int flag)
{
    for ( ; rg; rg = rg->link_up)
    {
        BLI_flagArcs((BGraph*)rg, flag);
    }
}

static ReebNode * addNode(ReebGraph *rg, EditVert *eve)
{
    float weight;
    ReebNode *node = NULL;
    
    weight = weightData(eve);
    
    node = MEM_callocN(sizeof(ReebNode), "reeb node");
    
    node->flag = 0; // clear flag on init
    node->symmetry_level = 0;
    node->arcs = NULL;
    node->degree = 0;
    node->weight = weight;
    node->index = rg->totnodes;
    VECCOPY(node->p, eve->co);  
    
    BLI_addtail(&rg->nodes, node);
    rg->totnodes++;
    
    nodeSetData(eve, node);
    
    return node;
}

static ReebNode * copyNode(ReebGraph *rg, ReebNode *node)
{
    ReebNode *cp_node = NULL;
    
    cp_node = MEM_callocN(sizeof(ReebNode), "reeb node copy");
    
    memcpy(cp_node, node, sizeof(ReebNode));
    
    cp_node->prev = NULL;
    cp_node->next = NULL;
    cp_node->arcs = NULL;
    
    cp_node->link_up = NULL;
    cp_node->link_down = NULL;
    
    BLI_addtail(&rg->nodes, cp_node);
    rg->totnodes++;
    
    return cp_node; 
}

static void relinkNodes(ReebGraph *low_rg, ReebGraph *high_rg)
{
    ReebNode *low_node, *high_node;
    
    if (low_rg == NULL || high_rg == NULL)
    {
        return;
    }
    
    for (low_node = low_rg->nodes.first; low_node; low_node = low_node->next)
    {
        for (high_node = high_rg->nodes.first; high_node; high_node = high_node->next)
        {
            if (low_node->index == high_node->index)
            {
                high_node->link_down = low_node;
                low_node->link_up = high_node;
                break;
            }
        }
    }
}

ReebNode *BIF_otherNodeFromIndex(ReebArc *arc, ReebNode *node)
{
    return (arc->head->index == node->index) ? arc->tail : arc->head;
}

ReebNode *BIF_NodeFromIndex(ReebArc *arc, ReebNode *node)
{
    return (arc->head->index == node->index) ? arc->head : arc->tail;
}

ReebNode *BIF_lowestLevelNode(ReebNode *node)
{
    while (node->link_down)
    {
        node = node->link_down;
    }
    
    return node;
}

static ReebArc * copyArc(ReebGraph *rg, ReebArc *arc)
{
    ReebArc *cp_arc;
    ReebNode *node;
    
    cp_arc = MEM_callocN(sizeof(ReebArc), "reeb arc copy");

    memcpy(cp_arc, arc, sizeof(ReebArc));
    
    cp_arc->link_up = arc;
    
    cp_arc->head = NULL;
    cp_arc->tail = NULL;

    cp_arc->prev = NULL;
    cp_arc->next = NULL;

    cp_arc->edges.first = NULL;
    cp_arc->edges.last = NULL;

    /* copy buckets */  
    cp_arc->buckets = MEM_callocN(sizeof(EmbedBucket) * cp_arc->bcount, "embed bucket");
    memcpy(cp_arc->buckets, arc->buckets, sizeof(EmbedBucket) * cp_arc->bcount);
    
    /* copy faces map */
    cp_arc->faces = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "copyArc gh");
    mergeArcFaces(rg, cp_arc, arc);
    
    /* find corresponding head and tail */
    for (node = rg->nodes.first; node && (cp_arc->head == NULL || cp_arc->tail == NULL); node = node->next)
    {
        if (node->index == arc->head->index)
        {
            cp_arc->head = node;
        }
        else if (node->index == arc->tail->index)
        {
            cp_arc->tail = node;
        }
    }
    
    BLI_addtail(&rg->arcs, cp_arc);
    
    return cp_arc;
}

static ReebGraph * copyReebGraph(ReebGraph *rg, int level)
{
    ReebNode *node;
    ReebArc *arc;
    ReebGraph *cp_rg = newReebGraph();
    
    cp_rg->resolution = rg->resolution;
    cp_rg->length = rg->length;
    cp_rg->link_up = rg;
    cp_rg->multi_level = level;

    /* Copy nodes */    
    for (node = rg->nodes.first; node; node = node->next)
    {
        ReebNode *cp_node = copyNode(cp_rg, node);
        cp_node->multi_level = level;
    }
    
    /* Copy arcs */
    for (arc = rg->arcs.first; arc; arc = arc->next)
    {
        copyArc(cp_rg, arc);
    }
    
    BLI_buildAdjacencyList((BGraph*)cp_rg);
    
    return cp_rg;
}

ReebGraph *BIF_graphForMultiNode(ReebGraph *rg, ReebNode *node)
{
    ReebGraph *multi_rg = rg;
    
    while(multi_rg && multi_rg->multi_level != node->multi_level)
    {
        multi_rg = multi_rg->link_up;
    }
    
    return multi_rg;
}

static ReebEdge * copyEdge(ReebEdge *edge)
{
    ReebEdge *newEdge = NULL;
    
    newEdge = MEM_callocN(sizeof(ReebEdge), "reeb edge");
    memcpy(newEdge, edge, sizeof(ReebEdge));
    
    newEdge->next = NULL;
    newEdge->prev = NULL;
    
    return newEdge;
}

static void printArc(ReebArc *arc)
{
    ReebEdge *edge;
    ReebNode *head = (ReebNode*)arc->head;
    ReebNode *tail = (ReebNode*)arc->tail;
    printf("arc: (%i) %f -> (%i) %f\n", head->index, head->weight, tail->index, tail->weight);
    
    for(edge = arc->edges.first; edge ; edge = edge->next)
    {
        printf("\tedge (%i, %i)\n", edge->v1->index, edge->v2->index);
    }
}

static void flipArc(ReebArc *arc)
{
    ReebNode *tmp;
    tmp = arc->head;
    arc->head = arc->tail;
    arc->tail = tmp;
    
    flipArcBuckets(arc);
}

#ifdef DEBUG_REEB_NODE
static void NodeDegreeDecrement(ReebGraph *UNUSED(rg), ReebNode *node)
{
    node->degree--;

//  if (node->degree == 0)
//  {
//      printf("would remove node %i\n", node->index);
//  }
}

static void NodeDegreeIncrement(ReebGraph *UNUSED(rg), ReebNode *node)
{
//  if (node->degree == 0)
//  {
//      printf("first connect node %i\n", node->index);
//  }

    node->degree++;
}

#else
#define NodeDegreeDecrement(rg, node) {node->degree--;}
#define NodeDegreeIncrement(rg, node) {node->degree++;}
#endif

void repositionNodes(ReebGraph *rg)
{
    BArc *arc = NULL;
    BNode *node = NULL;
    
    // Reset node positions
    for(node = rg->nodes.first; node; node = node->next)
    {
        node->p[0] = node->p[1] = node->p[2] = 0;
    }
    
    for(arc = rg->arcs.first; arc; arc = arc->next)
    {
        if (((ReebArc*)arc)->bcount > 0)
        {
            float p[3];
            
            VECCOPY(p, ((ReebArc*)arc)->buckets[0].p);
            mul_v3_fl(p, 1.0f / arc->head->degree);
            add_v3_v3(arc->head->p, p);
            
            VECCOPY(p, ((ReebArc*)arc)->buckets[((ReebArc*)arc)->bcount - 1].p);
            mul_v3_fl(p, 1.0f / arc->tail->degree);
            add_v3_v3(arc->tail->p, p);
        }
    }
}

void verifyNodeDegree(ReebGraph *rg)
{
#ifdef DEBUG_REEB
    ReebNode *node = NULL;
    ReebArc *arc = NULL;

    for(node = rg->nodes.first; node; node = node->next)
    {
        int count = 0;
        for(arc = rg->arcs.first; arc; arc = arc->next)
        {
            if (arc->head == node || arc->tail == node)
            {
                count++;
            }
        }
        if (count != node->degree)
        {
            printf("degree error in node %i: expected %i got %i\n", node->index, count, node->degree);
        }
        if (node->degree == 0)
        {
            printf("zero degree node %i with weight %f\n", node->index, node->weight);
        }
    }
#endif
}

static void verifyBucketsArc(ReebGraph *UNUSED(rg), ReebArc *arc)
{
    ReebNode *head = (ReebNode*)arc->head;
    ReebNode *tail = (ReebNode*)arc->tail;

    if (arc->bcount > 0)
    {
        int i;
        for(i = 0; i < arc->bcount; i++)
        {
            if (arc->buckets[i].nv == 0)
            {
                printArc(arc);
                printf("count error in bucket %i/%i\n", i+1, arc->bcount);
            }
        }
        
        if (ceilf(head->weight) != arc->buckets[0].val)
        {
            printArc(arc);
            printf("alloc error in first bucket: %f should be %f \n", arc->buckets[0].val, ceil(head->weight));
        }
        if (floorf(tail->weight) != arc->buckets[arc->bcount - 1].val)
        {
            printArc(arc);
            printf("alloc error in last bucket: %f should be %f \n", arc->buckets[arc->bcount - 1].val, floor(tail->weight));
        }
    }
}

void verifyBuckets(ReebGraph *rg)
{
#ifdef DEBUG_REEB
    ReebArc *arc = NULL;
    for(arc = rg->arcs.first; arc; arc = arc->next)
    {
        verifyBucketsArc(rg, arc);
    }
#endif
}

void verifyFaces(ReebGraph *rg)
{
#ifdef DEBUG_REEB
    int total = 0;
    ReebArc *arc = NULL;
    for(arc = rg->arcs.first; arc; arc = arc->next)
    {
        total += BLI_ghash_size(arc->faces);
    }
    
#endif
}

void verifyArcs(ReebGraph *rg)
{
    ReebArc *arc;
    
    for (arc = rg->arcs.first; arc; arc = arc->next)
    {
        if (arc->head->weight > arc->tail->weight)
        {
            printf("FLIPPED ARC!\n");
        }
    }
}

static void verifyMultiResolutionLinks(ReebGraph *rg, int level)
{
#ifdef DEBUG_REEB
    ReebGraph *lower_rg = rg->link_up;
    
    if (lower_rg)
    {
        ReebArc *arc;
        
        for (arc = rg->arcs.first; arc; arc = arc->next)
        {
            if (BLI_findindex(&lower_rg->arcs, arc->link_up) == -1)
            {
                printf("missing arc %p for level %i\n", (void *)arc->link_up, level);
                printf("Source arc was ---\n");
                printArc(arc);

                arc->link_up = NULL;
            }
        }
        
        
        verifyMultiResolutionLinks(lower_rg, level + 1);
    }
#endif
}
/***************************************** BUCKET UTILS **********************************************/

static void addVertToBucket(EmbedBucket *b, float co[3])
{
    b->nv++;
    interp_v3_v3v3(b->p, b->p, co, 1.0f / b->nv);
}

#if 0 /* UNUSED 2.5 */
static void removeVertFromBucket(EmbedBucket *b, float co[3])
{
    mul_v3_fl(b->p, (float)b->nv);
    sub_v3_v3(b->p, co);
    b->nv--;
    mul_v3_fl(b->p, 1.0f / (float)b->nv);
}
#endif

static void mergeBuckets(EmbedBucket *bDst, EmbedBucket *bSrc)
{
    if (bDst->nv > 0 && bSrc->nv > 0)
    {
        bDst->nv += bSrc->nv;
        interp_v3_v3v3(bDst->p, bDst->p, bSrc->p, (float)bSrc->nv / (float)(bDst->nv));
    }
    else if (bSrc->nv > 0)
    {
        bDst->nv = bSrc->nv;
        VECCOPY(bDst->p, bSrc->p);
    }
}

static void mergeArcBuckets(ReebArc *aDst, ReebArc *aSrc, float start, float end)
{
    if (aDst->bcount > 0 && aSrc->bcount > 0)
    {
        int indexDst = 0, indexSrc = 0;
        
        start = MAX3(start, aDst->buckets[0].val, aSrc->buckets[0].val);
        
        while(indexDst < aDst->bcount && aDst->buckets[indexDst].val < start)
        {
            indexDst++;
        }

        while(indexSrc < aSrc->bcount && aSrc->buckets[indexSrc].val < start)
        {
            indexSrc++;
        }
        
        for( ;  indexDst < aDst->bcount &&
                indexSrc < aSrc->bcount &&
                aDst->buckets[indexDst].val <= end &&
                aSrc->buckets[indexSrc].val <= end
                
             ;  indexDst++, indexSrc++)
        {
            mergeBuckets(aDst->buckets + indexDst, aSrc->buckets + indexSrc);
        }
    }
}

void flipArcBuckets(ReebArc *arc)
{
    int i, j;
    
    for (i = 0, j = arc->bcount - 1; i < j; i++, j--)
    {
        EmbedBucket tmp;
        
        tmp = arc->buckets[i];
        arc->buckets[i] = arc->buckets[j];
        arc->buckets[j] = tmp;
    }
}

static int countArcBuckets(ReebArc *arc)
{
    return (int)(floor(arc->tail->weight) - ceil(arc->head->weight)) + 1;
}

static void allocArcBuckets(ReebArc *arc)
{
    int i;
    float start = ceil(arc->head->weight);
    arc->bcount = countArcBuckets(arc);
    
    if (arc->bcount > 0)
    {
        arc->buckets = MEM_callocN(sizeof(EmbedBucket) * arc->bcount, "embed bucket");
        
        for(i = 0; i < arc->bcount; i++)
        {
            arc->buckets[i].val = start + i;
        }
    }
    else
    {
        arc->buckets = NULL;
    }
    
}

static void resizeArcBuckets(ReebArc *arc)
{
    EmbedBucket *oldBuckets = arc->buckets;
    int oldBCount = arc->bcount;
    
    if (countArcBuckets(arc) == oldBCount)
    {
        return;
    }
    
    allocArcBuckets(arc);
    
    if (oldBCount != 0 && arc->bcount != 0)
    {
        int oldStart = (int)oldBuckets[0].val;
        int oldEnd = (int)oldBuckets[oldBCount - 1].val;
        int newStart = (int)arc->buckets[0].val;
        int newEnd = (int)arc->buckets[arc->bcount - 1].val;
        int oldOffset = 0;
        int newOffset = 0;
        int len;
        
        if (oldStart < newStart)
        {
            oldOffset = newStart - oldStart;
        }
        else
        {
            newOffset = oldStart - newStart;
        }
        
        len = MIN2(oldEnd - (oldStart + oldOffset) + 1, newEnd - (newStart - newOffset) + 1);
        
        memcpy(arc->buckets + newOffset, oldBuckets + oldOffset, len * sizeof(EmbedBucket)); 
    }

    if (oldBuckets != NULL)
    {
        MEM_freeN(oldBuckets);
    }
}

static void reweightBuckets(ReebArc *arc)
{
    int i;
    float start = ceil((arc->head)->weight);
    
    if (arc->bcount > 0)
    {
        for(i = 0; i < arc->bcount; i++)
        {
            arc->buckets[i].val = start + i;
        }
    }
}

static void interpolateBuckets(ReebArc *arc, float *start_p, float *end_p, int start_index, int end_index)
{
    int total;
    int j;
    
    total = end_index - start_index + 2;
    
    for (j = start_index; j <= end_index; j++)
    {
        EmbedBucket *empty = arc->buckets + j;
        empty->nv = 1;
        interp_v3_v3v3(empty->p, start_p, end_p, (float)(j - start_index + 1) / total);
    }
}

static void fillArcEmptyBuckets(ReebArc *arc)
{
    float *start_p, *end_p;
    int start_index = 0, end_index = 0;
    int missing = 0;
    int i;
    
    start_p = arc->head->p;
    
    for(i = 0; i < arc->bcount; i++)
    {
        EmbedBucket *bucket = arc->buckets + i;
        
        if (missing)
        {
            if (bucket->nv > 0)
            {
                missing = 0;
                
                end_p = bucket->p;
                end_index = i - 1;
                
                interpolateBuckets(arc, start_p, end_p, start_index, end_index);
            }
        }
        else
        {
            if (bucket->nv == 0)
            {
                missing = 1;
                
                if (i > 0)
                {
                    start_p = arc->buckets[i - 1].p;
                }
                start_index = i;
            }
        }
    }
    
    if (missing)
    {
        end_p = arc->tail->p;
        end_index = arc->bcount - 1;
        
        interpolateBuckets(arc, start_p, end_p, start_index, end_index);
    }
}

static void ExtendArcBuckets(ReebArc *arc)
{
    ReebArcIterator arc_iter;
    BArcIterator *iter = (BArcIterator*)&arc_iter;
    EmbedBucket *last_bucket, *first_bucket;
    float *previous = NULL;
    float average_length = 0, length;
    int padding_head = 0, padding_tail = 0;
    
    if (arc->bcount == 0)
    {
        return; /* failsafe, shouldn't happen */
    }
    
    initArcIterator(iter, arc, arc->head);
    IT_next(iter);
    previous = iter->p;
    
    for (   IT_next(iter);
            IT_stopped(iter) == 0;
            previous = iter->p, IT_next(iter)
        )
    {
        average_length += len_v3v3(previous, iter->p);
    }
    average_length /= (arc->bcount - 1);
    
    first_bucket = arc->buckets;
    last_bucket = arc->buckets + (arc->bcount - 1);
    
    length = len_v3v3(first_bucket->p, arc->head->p);
    if (length > 2 * average_length)
    {
        padding_head = (int)floor(length / average_length);
    }

    length = len_v3v3(last_bucket->p, arc->tail->p);
    if (length > 2 * average_length)
    {
        padding_tail = (int)floor(length / average_length);
    }
    
    if (padding_head + padding_tail > 0)
    {
        EmbedBucket *old_buckets = arc->buckets;
        
        arc->buckets = MEM_callocN(sizeof(EmbedBucket) * (padding_head + arc->bcount + padding_tail), "embed bucket");
        memcpy(arc->buckets + padding_head, old_buckets, arc->bcount * sizeof(EmbedBucket));
        
        arc->bcount = padding_head + arc->bcount + padding_tail;
        
        MEM_freeN(old_buckets);
    }
    
    if (padding_head > 0)
    {
        interpolateBuckets(arc, arc->head->p, first_bucket->p, 0, padding_head);
    }
    
    if (padding_tail > 0)
    {
        interpolateBuckets(arc, last_bucket->p, arc->tail->p, arc->bcount - padding_tail, arc->bcount - 1);
    }
}

/* CALL THIS ONLY AFTER FILTERING, SINCE IT MESSES UP WEIGHT DISTRIBUTION */
static void extendGraphBuckets(ReebGraph *rg)
{
    ReebArc *arc;
    
    for (arc = rg->arcs.first; arc; arc = arc->next)
    {
        ExtendArcBuckets(arc);
    }
}

/**************************************** LENGTH CALCULATIONS ****************************************/

static void calculateArcLength(ReebArc *arc)
{
    ReebArcIterator arc_iter;
    BArcIterator *iter = (BArcIterator*)&arc_iter;
    float *vec0, *vec1;

    arc->length = 0;
    
    initArcIterator(iter, arc, arc->head);

    vec0 = arc->head->p;
    vec1 = arc->head->p; /* in case there's no embedding */

    while (IT_next(iter))   
    {
        vec1 = iter->p;
        
        arc->length += len_v3v3(vec0, vec1);
        
        vec0 = vec1;
    }
    
    arc->length += len_v3v3(arc->tail->p, vec1);    
}

static void calculateGraphLength(ReebGraph *rg)
{
    ReebArc *arc;
    
    for (arc = rg->arcs.first; arc; arc = arc->next)
    {
        calculateArcLength(arc);
    }
}

/**************************************** SYMMETRY HANDLING ******************************************/

void REEB_RadialSymmetry(BNode* root_node, RadialArc* ring, int count)
{
    ReebNode *node = (ReebNode*)root_node;
    float axis[3];
    int i;
    
    VECCOPY(axis, root_node->symmetry_axis);
    
    /* first pass, merge incrementally */
    for (i = 0; i < count - 1; i++)
    {
        ReebNode *node1, *node2;
        ReebArc *arc1, *arc2;
        float tangent[3];
        float normal[3];
        int j = i + 1;

        add_v3_v3v3(tangent, ring[i].n, ring[j].n);
        cross_v3_v3v3(normal, tangent, axis);
        
        node1 = (ReebNode*)BLI_otherNode(ring[i].arc, root_node);
        node2 = (ReebNode*)BLI_otherNode(ring[j].arc, root_node);
        
        arc1 = (ReebArc*)ring[i].arc;
        arc2 = (ReebArc*)ring[j].arc;

        /* mirror first node and mix with the second */
        BLI_mirrorAlongAxis(node1->p, root_node->p, normal);
        interp_v3_v3v3(node2->p, node2->p, node1->p, 1.0f / (j + 1));
        
        /* Merge buckets
         * there shouldn't be any null arcs here, but just to be safe 
         * */
        if (arc1->bcount > 0 && arc2->bcount > 0)
        {
            ReebArcIterator arc_iter1, arc_iter2;
            BArcIterator *iter1 = (BArcIterator*)&arc_iter1;
            BArcIterator *iter2 = (BArcIterator*)&arc_iter2;
            EmbedBucket *bucket1 = NULL, *bucket2 = NULL;
            
            initArcIterator(iter1, arc1, (ReebNode*)root_node);
            initArcIterator(iter2, arc2, (ReebNode*)root_node);
            
            bucket1 = IT_next(iter1);
            bucket2 = IT_next(iter2);
        
            /* Make sure they both start at the same value */   
            while(bucket1 && bucket2 && bucket1->val < bucket2->val)
            {
                bucket1 = IT_next(iter1);
            }
            
            while(bucket1 && bucket2 && bucket2->val < bucket1->val)
            {
                bucket2 = IT_next(iter2);
            }
    
    
            for ( ;bucket1 && bucket2; bucket1 = IT_next(iter1), bucket2 = IT_next(iter2))
            {
                bucket2->nv += bucket1->nv; /* add counts */
                
                /* mirror on axis */
                BLI_mirrorAlongAxis(bucket1->p, root_node->p, normal);
                /* add bucket2 in bucket1 */
                interp_v3_v3v3(bucket2->p, bucket2->p, bucket1->p, (float)bucket1->nv / (float)(bucket2->nv));
            }
        }
    }
    
    /* second pass, mirror back on previous arcs */
    for (i = count - 1; i > 0; i--)
    {
        ReebNode *node1, *node2;
        ReebArc *arc1, *arc2;
        float tangent[3];
        float normal[3];
        int j = i - 1;

        add_v3_v3v3(tangent, ring[i].n, ring[j].n);
        cross_v3_v3v3(normal, tangent, axis);
        
        node1 = (ReebNode*)BLI_otherNode(ring[i].arc, root_node);
        node2 = (ReebNode*)BLI_otherNode(ring[j].arc, root_node);
        
        arc1 = (ReebArc*)ring[i].arc;
        arc2 = (ReebArc*)ring[j].arc;

        /* copy first node than mirror */
        VECCOPY(node2->p, node1->p);
        BLI_mirrorAlongAxis(node2->p, root_node->p, normal);
        
        /* Copy buckets
         * there shouldn't be any null arcs here, but just to be safe 
         * */
        if (arc1->bcount > 0 && arc2->bcount > 0)
        {
            ReebArcIterator arc_iter1, arc_iter2;
            BArcIterator *iter1 = (BArcIterator*)&arc_iter1;
            BArcIterator *iter2 = (BArcIterator*)&arc_iter2;
            EmbedBucket *bucket1 = NULL, *bucket2 = NULL;
            
            initArcIterator(iter1, arc1, node);
            initArcIterator(iter2, arc2, node);
            
            bucket1 = IT_next(iter1);
            bucket2 = IT_next(iter2);
        
            /* Make sure they both start at the same value */   
            while(bucket1 && bucket1->val < bucket2->val)
            {
                bucket1 = IT_next(iter1);
            }
            
            while(bucket2 && bucket2->val < bucket1->val)
            {
                bucket2 = IT_next(iter2);
            }
    
    
            for ( ;bucket1 && bucket2; bucket1 = IT_next(iter1), bucket2 = IT_next(iter2))
            {
                /* copy and mirror back to bucket2 */           
                bucket2->nv = bucket1->nv;
                VECCOPY(bucket2->p, bucket1->p);
                BLI_mirrorAlongAxis(bucket2->p, node->p, normal);
            }
        }
    }
}

void REEB_AxialSymmetry(BNode* root_node, BNode* node1, BNode* node2, struct BArc* barc1, BArc* barc2)
{
    ReebArc *arc1, *arc2;
    float nor[3], p[3];

    arc1 = (ReebArc*)barc1;
    arc2 = (ReebArc*)barc2;

    VECCOPY(nor, root_node->symmetry_axis);
    
    /* mirror node2 along axis */
    VECCOPY(p, node2->p);
    BLI_mirrorAlongAxis(p, root_node->p, nor);

    /* average with node1 */
    add_v3_v3(node1->p, p);
    mul_v3_fl(node1->p, 0.5f);
    
    /* mirror back on node2 */
    VECCOPY(node2->p, node1->p);
    BLI_mirrorAlongAxis(node2->p, root_node->p, nor);
    
    /* Merge buckets
     * there shouldn't be any null arcs here, but just to be safe 
     * */
    if (arc1->bcount > 0 && arc2->bcount > 0)
    {
        ReebArcIterator arc_iter1, arc_iter2;
        BArcIterator *iter1 = (BArcIterator*)&arc_iter1;
        BArcIterator *iter2 = (BArcIterator*)&arc_iter2;
        EmbedBucket *bucket1 = NULL, *bucket2 = NULL;
        
        initArcIterator(iter1, arc1, (ReebNode*)root_node);
        initArcIterator(iter2, arc2, (ReebNode*)root_node);
        
        bucket1 = IT_next(iter1);
        bucket2 = IT_next(iter2);
    
        /* Make sure they both start at the same value */   
        while(bucket1 && bucket1->val < bucket2->val)
        {
            bucket1 = IT_next(iter1);
        }
        
        while(bucket2 && bucket2->val < bucket1->val)
        {
            bucket2 = IT_next(iter2);
        }


        for ( ;bucket1 && bucket2; bucket1 = IT_next(iter1), bucket2 = IT_next(iter2))
        {
            bucket1->nv += bucket2->nv; /* add counts */
            
            /* mirror on axis */
            BLI_mirrorAlongAxis(bucket2->p, root_node->p, nor);
            /* add bucket2 in bucket1 */
            interp_v3_v3v3(bucket1->p, bucket1->p, bucket2->p, (float)bucket2->nv / (float)(bucket1->nv));

            /* copy and mirror back to bucket2 */           
            bucket2->nv = bucket1->nv;
            VECCOPY(bucket2->p, bucket1->p);
            BLI_mirrorAlongAxis(bucket2->p, root_node->p, nor);
        }
    }
}

/************************************** ADJACENCY LIST *************************************************/


/****************************************** SMOOTHING **************************************************/

void postprocessGraph(ReebGraph *rg, char mode)
{
    ReebArc *arc;
    float fac1 = 0, fac2 = 1, fac3 = 0;

    switch(mode)
    {
    case SKGEN_AVERAGE:
        fac1 = fac2 = fac3 = 1.0f / 3.0f;
        break;
    case SKGEN_SMOOTH:
        fac1 = fac3 = 0.25f;
        fac2 = 0.5f;
        break;
    case SKGEN_SHARPEN:
        fac1 = fac2 = -0.25f;
        fac2 = 1.5f;
        break;
    default:
//      XXX
//      error("Unknown post processing mode");
        return;
    }
    
    for(arc = rg->arcs.first; arc; arc = arc->next)
    {
        EmbedBucket *buckets = arc->buckets;
        int bcount = arc->bcount;
        int index;

        for(index = 1; index < bcount - 1; index++)
        {
            interp_v3_v3v3(buckets[index].p, buckets[index].p, buckets[index - 1].p, fac1 / (fac1 + fac2));
            interp_v3_v3v3(buckets[index].p, buckets[index].p, buckets[index + 1].p, fac3 / (fac1 + fac2 + fac3));
        }
    }
}

/********************************************SORTING****************************************************/

static int compareNodesWeight(void *vnode1, void *vnode2)
{
    ReebNode *node1 = (ReebNode*)vnode1;
    ReebNode *node2 = (ReebNode*)vnode2;
    
    if (node1->weight < node2->weight)
    {
        return -1;
    }
    if (node1->weight > node2->weight)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

void sortNodes(ReebGraph *rg)
{
    BLI_sortlist(&rg->nodes, compareNodesWeight);
}

static int compareArcsWeight(void *varc1, void *varc2)
{
    ReebArc *arc1 = (ReebArc*)varc1;
    ReebArc *arc2 = (ReebArc*)varc2;
    ReebNode *node1 = (ReebNode*)arc1->head; 
    ReebNode *node2 = (ReebNode*)arc2->head; 
    
    if (node1->weight < node2->weight)
    {
        return -1;
    }
    if (node1->weight > node2->weight)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

void sortArcs(ReebGraph *rg)
{
    BLI_sortlist(&rg->arcs, compareArcsWeight);
}
/******************************************* JOINING ***************************************************/

static void reweightArc(ReebGraph *rg, ReebArc *arc, ReebNode *start_node, float start_weight)
{
    ReebNode *node;
    float old_weight;
    float end_weight = start_weight + ABS(arc->tail->weight - arc->head->weight);
    int i;
    
    node = (ReebNode*)BLI_otherNode((BArc*)arc, (BNode*)start_node);
    
    /* prevent backtracking */
    if (node->flag == 1)
    {
        return;
    }

    if (arc->tail == start_node)
    {
        flipArc(arc);
    }
    
    start_node->flag = 1;
    
    for (i = 0; i < node->degree; i++)
    {
        ReebArc *next_arc = node->arcs[i];
        
        reweightArc(rg, next_arc, node, end_weight);
    }

    /* update only if needed */ 
    if (arc->head->weight != start_weight || arc->tail->weight != end_weight)
    {
        old_weight = arc->head->weight; /* backup head weight, other arcs need it intact, it will be fixed by the source arc */
        
        arc->head->weight = start_weight;
        arc->tail->weight = end_weight;
        
        reweightBuckets(arc);
        resizeArcBuckets(arc);
        fillArcEmptyBuckets(arc);
        
        arc->head->weight = old_weight;
    }
} 

static void reweightSubgraph(ReebGraph *rg, ReebNode *start_node, float start_weight)
{
    int i;
        
    BLI_flagNodes((BGraph*)rg, 0);

    for (i = 0; i < start_node->degree; i++)
    {
        ReebArc *next_arc = start_node->arcs[i];
        
        reweightArc(rg, next_arc, start_node, start_weight);
    }
    start_node->weight = start_weight;
}

static int joinSubgraphsEnds(ReebGraph *rg, float threshold, int nb_subgraphs)
{
    int joined = 0;
    int subgraph;
    
    for (subgraph = 1; subgraph <= nb_subgraphs; subgraph++)
    {
        ReebNode *start_node, *end_node;
        ReebNode *min_node_start = NULL, *min_node_end = NULL;
        float min_distance = FLT_MAX;
        
        for (start_node = rg->nodes.first; start_node; start_node = start_node->next)
        {
            if (start_node->subgraph_index == subgraph && start_node->degree == 1)
            {
                
                for (end_node = rg->nodes.first; end_node; end_node = end_node->next)
                {
                    if (end_node->subgraph_index != subgraph)
                    {
                        float distance = len_v3v3(start_node->p, end_node->p);
                        
                        if (distance < threshold && distance < min_distance)
                        {
                            min_distance = distance;
                            min_node_end = end_node;
                            min_node_start = start_node;
                        }
                    }
                }
            }
        }
        
        end_node = min_node_end;
        start_node = min_node_start;
        
        if (end_node && start_node)
        {
            ReebArc *start_arc /* , *end_arc */ /* UNUSED */;
            int merging = 0;
            
            start_arc = start_node->arcs[0];
            /* end_arc = end_node->arcs[0]; */ /* UNUSED */
            
            if (start_arc->tail == start_node)
            {
                reweightSubgraph(rg, end_node, start_node->weight);
                
                start_arc->tail = end_node;
                
                merging = 1;
            }
            else if (start_arc->head == start_node)
            {
                reweightSubgraph(rg, start_node, end_node->weight);

                start_arc->head = end_node;

                merging = 2;
            }
            
            if (merging)
            {
                BLI_ReflagSubgraph((BGraph*)rg, end_node->flag, subgraph);
                                    
                resizeArcBuckets(start_arc);
                fillArcEmptyBuckets(start_arc);
                
                NodeDegreeIncrement(rg, end_node);
                BLI_rebuildAdjacencyListForNode((BGraph*)rg, (BNode*)end_node);
                
                BLI_removeNode((BGraph*)rg, (BNode*)start_node);
            }
            
            joined = 1;
        }       
    }
    
    return joined;
}

/* Reweight graph from smallest node, fix fliped arcs */
static void fixSubgraphsOrientation(ReebGraph *rg, int nb_subgraphs)
{
    int subgraph;
    
    for (subgraph = 1; subgraph <= nb_subgraphs; subgraph++)
    {
        ReebNode *node;
        ReebNode *start_node = NULL;
        
        for (node = rg->nodes.first; node; node = node->next)
        {
            if (node->subgraph_index == subgraph)
            {
                if (start_node == NULL || node->weight < start_node->weight)
                {
                    start_node = node;
                }
            }
        }
        
        if (start_node)
        {
            reweightSubgraph(rg, start_node, start_node->weight);
        }
    }
}

static int joinSubgraphs(ReebGraph *rg, float threshold)
{
    int nb_subgraphs;
    int joined = 0;
    
    BLI_buildAdjacencyList((BGraph*)rg);
    
    if (BLI_isGraphCyclic((BGraph*)rg))
    {
        /* don't deal with cyclic graphs YET */
        return 0;
    }
    
    /* sort nodes before flagging subgraphs to make sure root node is subgraph 0 */
    sortNodes(rg);
    
    nb_subgraphs = BLI_FlagSubgraphs((BGraph*)rg);
    
    /* Harmonic function can create flipped arcs, take the occasion to fix them */
//  XXX
//  if (G.scene->toolsettings->skgen_options & SKGEN_HARMONIC)
//  {
        fixSubgraphsOrientation(rg, nb_subgraphs);
//  }

    if (nb_subgraphs > 1)
    {
        joined |= joinSubgraphsEnds(rg, threshold, nb_subgraphs);
        
        if (joined)
        {
            removeNormalNodes(rg);
            BLI_buildAdjacencyList((BGraph*)rg);
        }
    }
    
    return joined;
}

/****************************************** FILTERING **************************************************/

static float lengthArc(ReebArc *arc)
{
#if 0
    ReebNode *head = (ReebNode*)arc->head;
    ReebNode *tail = (ReebNode*)arc->tail;
    
    return tail->weight - head->weight;
#else
    return arc->length;
#endif
}

static int compareArcs(void *varc1, void *varc2)
{
    ReebArc *arc1 = (ReebArc*)varc1;
    ReebArc *arc2 = (ReebArc*)varc2;
    float len1 = lengthArc(arc1);
    float len2 = lengthArc(arc2);
    
    if (len1 < len2)
    {
        return -1;
    }
    if (len1 > len2)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

static void filterArc(ReebGraph *rg, ReebNode *newNode, ReebNode *removedNode, ReebArc * srcArc, int merging)
{
    ReebArc *arc = NULL, *nextArc = NULL;

    if (merging)
    {
        /* first pass, merge buckets for arcs that spawned the two nodes into the source arc*/
        for(arc = rg->arcs.first; arc; arc = arc->next)
        {
            if (arc->head == srcArc->head && arc->tail == srcArc->tail && arc != srcArc)
            {
                ReebNode *head = srcArc->head;
                ReebNode *tail = srcArc->tail;
                mergeArcBuckets(srcArc, arc, head->weight, tail->weight);
            }
        }
    }

    /* second pass, replace removedNode by newNode, remove arcs that are collapsed in a loop */
    arc = rg->arcs.first;
    while(arc)
    {
        nextArc = arc->next;
        
        if (arc->head == removedNode || arc->tail == removedNode)
        {
            if (arc->head == removedNode)
            {
                arc->head = newNode;
            }
            else
            {
                arc->tail = newNode;
            }

            // Remove looped arcs           
            if (arc->head == arc->tail)
            {
                // v1 or v2 was already newNode, since we're removing an arc, decrement degree
                NodeDegreeDecrement(rg, newNode);
                
                // If it's srcArc, it'll be removed later, so keep it for now
                if (arc != srcArc)
                {
                    BLI_remlink(&rg->arcs, arc);
                    REEB_freeArc((BArc*)arc);
                }
            }
            else
            {
                /* flip arcs that flipped, can happen on diamond shapes, mostly on null arcs */
                if (arc->head->weight > arc->tail->weight)
                {
                    flipArc(arc);
                }
                //newNode->degree++; // incrementing degree since we're adding an arc
                NodeDegreeIncrement(rg, newNode);
                mergeArcFaces(rg, arc, srcArc);

                if (merging)
                {
                    ReebNode *head = arc->head;
                    ReebNode *tail = arc->tail;

                    // resize bucket list
                    resizeArcBuckets(arc);
                    mergeArcBuckets(arc, srcArc, head->weight, tail->weight);
                    
                    /* update length */
                    arc->length += srcArc->length;
                }
            }
        }
        
        arc = nextArc;
    }
}

void filterNullReebGraph(ReebGraph *rg)
{
    ReebArc *arc = NULL, *nextArc = NULL;
    
    arc = rg->arcs.first;
    while(arc)
    {
        nextArc = arc->next;
        // Only collapse arcs too short to have any embed bucket
        if (arc->bcount == 0)
        {
            ReebNode *newNode = (ReebNode*)arc->head;
            ReebNode *removedNode = (ReebNode*)arc->tail;
            float blend;
            
            blend = (float)newNode->degree / (float)(newNode->degree + removedNode->degree); // blending factors
            
            interp_v3_v3v3(newNode->p, removedNode->p, newNode->p, blend);
            
            filterArc(rg, newNode, removedNode, arc, 0);

            // Reset nextArc, it might have changed
            nextArc = arc->next;
            
            BLI_remlink(&rg->arcs, arc);
            REEB_freeArc((BArc*)arc);
            
            BLI_removeNode((BGraph*)rg, (BNode*)removedNode);
        }
        
        arc = nextArc;
    }
}

static int filterInternalExternalReebGraph(ReebGraph *rg, float threshold_internal, float threshold_external)
{
    ReebArc *arc = NULL, *nextArc = NULL;
    int value = 0;
    
    BLI_sortlist(&rg->arcs, compareArcs);
    
    for (arc = rg->arcs.first; arc; arc = nextArc)
    {
        nextArc = arc->next;

        // Only collapse non-terminal arcs that are shorter than threshold
        if (threshold_internal > 0 && arc->head->degree > 1 && arc->tail->degree > 1 && (lengthArc(arc) < threshold_internal))
        {
            ReebNode *newNode = NULL;
            ReebNode *removedNode = NULL;
            
            /* Always remove lower node, so arcs don't flip */
            newNode = arc->head;
            removedNode = arc->tail;

            filterArc(rg, newNode, removedNode, arc, 1);

            // Reset nextArc, it might have changed
            nextArc = arc->next;
            
            BLI_remlink(&rg->arcs, arc);
            REEB_freeArc((BArc*)arc);
            
            BLI_removeNode((BGraph*)rg, (BNode*)removedNode);
            value = 1;
        }
        
        // Only collapse terminal arcs that are shorter than threshold
        else if (threshold_external > 0 && (arc->head->degree == 1 || arc->tail->degree == 1) && (lengthArc(arc) < threshold_external))
        {
            ReebNode *terminalNode = NULL;
            ReebNode *middleNode = NULL;
            ReebNode *removedNode = NULL;
            
            // Assign terminal and middle nodes
            if (arc->head->degree == 1)
            {
                terminalNode = arc->head;
                middleNode = arc->tail;
            }
            else
            {
                terminalNode = arc->tail;
                middleNode = arc->head;
            }
            
            if (middleNode->degree == 2 && middleNode != rg->nodes.first)
            {
#if 1
                // If middle node is a normal node, it will be removed later
                // Only if middle node is not the root node
                /* USE THIS IF YOU WANT TO PROLONG ARCS TO THEIR TERMINAL NODES
                 * FOR HANDS, THIS IS NOT THE BEST RESULT 
                 * */
                continue;
#else
                removedNode = terminalNode;

                // removing arc, so we need to decrease the degree of the remaining node
                NodeDegreeDecrement(rg, middleNode);
#endif
            }
            // Otherwise, just plain remove of the arc
            else
            {
                removedNode = terminalNode;

                // removing arc, so we need to decrease the degree of the remaining node
                NodeDegreeDecrement(rg, middleNode);
            }

            // Reset nextArc, it might have changed
            nextArc = arc->next;
            
            BLI_remlink(&rg->arcs, arc);
            REEB_freeArc((BArc*)arc);
            
            BLI_removeNode((BGraph*)rg, (BNode*)removedNode);
            value = 1;
        }
    }
    
    return value;
}

static int filterCyclesReebGraph(ReebGraph *rg, float UNUSED(distance_threshold))
{
    ReebArc *arc1, *arc2;
    ReebArc *next2;
    int filtered = 0;
    
    for (arc1 = rg->arcs.first; arc1; arc1 = arc1->next)
    {
        for (arc2 = arc1->next; arc2; arc2 = next2)
        {
            next2 = arc2->next;
            if (arc1 != arc2 && arc1->head == arc2->head && arc1->tail == arc2->tail)
            {
                mergeArcEdges(rg, arc1, arc2, MERGE_APPEND);
                mergeArcFaces(rg, arc1, arc2);
                mergeArcBuckets(arc1, arc2, arc1->head->weight, arc1->tail->weight);

                NodeDegreeDecrement(rg, arc1->head);
                NodeDegreeDecrement(rg, arc1->tail);

                BLI_remlink(&rg->arcs, arc2);
                REEB_freeArc((BArc*)arc2);
                
                filtered = 1;
            }
        }
    }
    
    return filtered;
}

int filterSmartReebGraph(ReebGraph *UNUSED(rg), float UNUSED(threshold))
{
    int value = 0;
#if 0 //XXX
    ReebArc *arc = NULL, *nextArc = NULL;
    
    BLI_sortlist(&rg->arcs, compareArcs);

#ifdef DEBUG_REEB
    {   
        EditFace *efa;
        for(efa=G.editMesh->faces.first; efa; efa=efa->next) {
            efa->tmp.fp = -1;
        }
    }
#endif

    arc = rg->arcs.first;
    while(arc)
    {
        nextArc = arc->next;
        
        /* need correct normals and center */
        recalc_editnormals();

        // Only test terminal arcs
        if (arc->head->degree == 1 || arc->tail->degree == 1)
        {
            GHashIterator ghi;
            int merging = 0;
            int total = BLI_ghash_size(arc->faces);
            float avg_angle = 0;
            float avg_vec[3] = {0,0,0};
            
            for(BLI_ghashIterator_init(&ghi, arc->faces);
                !BLI_ghashIterator_isDone(&ghi);
                BLI_ghashIterator_step(&ghi))
            {
                EditFace *efa = BLI_ghashIterator_getValue(&ghi);

#if 0
                ReebArcIterator arc_iter;
                BArcIterator *iter = (BArcIterator*)&arc_iter;
                EmbedBucket *bucket = NULL;
                EmbedBucket *previous = NULL;
                float min_distance = -1;
                float angle = 0;
        
                initArcIterator(iter, arc, arc->head);
        
                bucket = nextBucket(iter);
                
                while (bucket != NULL)
                {
                    float *vec0 = NULL;
                    float *vec1 = bucket->p;
                    float midpoint[3], tangent[3];
                    float distance;
        
                    /* first bucket. Previous is head */
                    if (previous == NULL)
                    {
                        vec0 = arc->head->p;
                    }
                    /* Previous is a valid bucket */
                    else
                    {
                        vec0 = previous->p;
                    }
                    
                    VECCOPY(midpoint, vec1);
                    
                    distance = len_v3v3(midpoint, efa->cent);
                    
                    if (min_distance == -1 || distance < min_distance)
                    {
                        min_distance = distance;
                    
                        sub_v3_v3v3(tangent, vec1, vec0);
                        normalize_v3(tangent);
                        
                        angle = dot_v3v3(tangent, efa->n);
                    }
                    
                    previous = bucket;
                    bucket = nextBucket(iter);
                }
                
                avg_angle += saacos(fabs(angle));
#ifdef DEBUG_REEB
                efa->tmp.fp = saacos(fabs(angle));
#endif
#else
                add_v3_v3(avg_vec, efa->n);     
#endif
            }


#if 0           
            avg_angle /= total;
#else
            mul_v3_fl(avg_vec, 1.0 / total);
            avg_angle = dot_v3v3(avg_vec, avg_vec);
#endif
            
            arc->angle = avg_angle;
            
            if (avg_angle > threshold)
                merging = 1;
            
            if (merging)
            {
                ReebNode *terminalNode = NULL;
                ReebNode *middleNode = NULL;
                ReebNode *newNode = NULL;
                ReebNode *removedNode = NULL;
                int merging = 0;
                
                // Assign terminal and middle nodes
                if (arc->head->degree == 1)
                {
                    terminalNode = arc->head;
                    middleNode = arc->tail;
                }
                else
                {
                    terminalNode = arc->tail;
                    middleNode = arc->head;
                }
                
                // If middle node is a normal node, merge to terminal node
                if (middleNode->degree == 2)
                {
                    merging = 1;
                    newNode = terminalNode;
                    removedNode = middleNode;
                }
                // Otherwise, just plain remove of the arc
                else
                {
                    merging = 0;
                    newNode = middleNode;
                    removedNode = terminalNode;
                }
                
                // Merging arc
                if (merging)
                {
                    filterArc(rg, newNode, removedNode, arc, 1);
                }
                else
                {
                    // removing arc, so we need to decrease the degree of the remaining node
                    //newNode->degree--;
                    NodeDegreeDecrement(rg, newNode);
                }
    
                // Reset nextArc, it might have changed
                nextArc = arc->next;
                
                BLI_remlink(&rg->arcs, arc);
                REEB_freeArc((BArc*)arc);
                
                BLI_freelinkN(&rg->nodes, removedNode);
                value = 1;
            }
        }
        
        arc = nextArc;
    }
    
    #endif
    
    return value;
}

static void filterGraph(ReebGraph *rg, short options, float threshold_internal, float threshold_external)
{
    int done = 1;
    
    calculateGraphLength(rg);

    if ((options & SKGEN_FILTER_EXTERNAL) == 0)
    {
        threshold_external = 0;
    }

    if ((options & SKGEN_FILTER_INTERNAL) == 0)
    {
        threshold_internal = 0;
    }

    if (threshold_internal > 0 || threshold_external > 0)
    { 
        /* filter until there's nothing more to do */
        while (done == 1)
        {
            done = 0; /* no work done yet */
            
            done = filterInternalExternalReebGraph(rg, threshold_internal, threshold_external);
        }
    }

    if (options & SKGEN_FILTER_SMART)
    {
        filterSmartReebGraph(rg, 0.5);
        filterCyclesReebGraph(rg, 0.5);
    }

    repositionNodes(rg);

    /* Filtering might have created degree 2 nodes, so remove them */
    removeNormalNodes(rg);
}

static void finalizeGraph(ReebGraph *rg, char passes, char method)
{
    int i;
    
    BLI_buildAdjacencyList((BGraph*)rg);

    sortNodes(rg);
    
    sortArcs(rg);
    
    for(i = 0; i <  passes; i++)
    {
        postprocessGraph(rg, method);
    }
    
    extendGraphBuckets(rg);
}

/************************************** WEIGHT SPREADING ***********************************************/

static int compareVerts( const void* a, const void* b )
{
    EditVert *va = *(EditVert**)a;
    EditVert *vb = *(EditVert**)b;
    int value = 0;
    
    if (weightData(va) < weightData(vb))
    {
        value = -1;
    }
    else if (weightData(va) > weightData(vb))
    {
        value = 1;
    }

    return value;       
}

static void spreadWeight(EditMesh *em)
{
    EditVert **verts, *eve;
    float lastWeight = 0.0f;
    int totvert = BLI_countlist(&em->verts);
    int i;
    int work_needed = 1;
    
    verts = MEM_callocN(sizeof(EditVert*) * totvert, "verts array");
    
    for(eve = em->verts.first, i = 0; eve; eve = eve->next, i++)
    {
        verts[i] = eve;
    }
    
    while(work_needed == 1)
    {
        work_needed = 0;
        qsort(verts, totvert, sizeof(EditVert*), compareVerts);
        
        for(i = 0; i < totvert; i++)
        {
            eve = verts[i];
            
            if (i == 0 || (weightData(eve) - lastWeight) > FLT_EPSILON)
            {
                lastWeight = weightData(eve);
            }
            else
            {
                work_needed = 1;
                weightSetData(eve, lastWeight + FLT_EPSILON * 2);
                lastWeight = weightData(eve);
            }
        }
    }
    
    MEM_freeN(verts);
}

/******************************************** EXPORT ***************************************************/

static void exportNode(FILE *f, const char *text, ReebNode *node)
{
    fprintf(f, "%s i:%i w:%f d:%i %f %f %f\n", text, node->index, node->weight, node->degree, node->p[0], node->p[1], node->p[2]);
}

void REEB_exportGraph(ReebGraph *rg, int count)
{
    ReebArc *arc;
    char filename[128];
    FILE *f;
    
    if (count == -1)
    {
        strcpy(filename, "test.txt");
    }
    else {
        sprintf(filename, "test%05i.txt", count);
    }
    f = fopen(filename, "w");

    for(arc = rg->arcs.first; arc; arc = arc->next)
    {
        int i;
        float p[3];
        
        exportNode(f, "v1", arc->head);
        
        for(i = 0; i < arc->bcount; i++)
        {
            fprintf(f, "b nv:%i %f %f %f\n", arc->buckets[i].nv, arc->buckets[i].p[0], arc->buckets[i].p[1], arc->buckets[i].p[2]);
        }
        
        add_v3_v3v3(p, arc->tail->p, arc->head->p);
        mul_v3_fl(p, 0.5f);
        
        fprintf(f, "angle %0.3f %0.3f %0.3f %0.3f %i\n", p[0], p[1], p[2], arc->angle, BLI_ghash_size(arc->faces));
        exportNode(f, "v2", arc->tail);
    }   
    
    fclose(f);
}

/***************************************** MAIN ALGORITHM **********************************************/

/* edges alone will create zero degree nodes, use this function to remove them */
static void removeZeroNodes(ReebGraph *rg)
{
    ReebNode *node, *next_node;
    
    for (node = rg->nodes.first; node; node = next_node)
    {
        next_node = node->next;
        
        if (node->degree == 0)
        {
            BLI_removeNode((BGraph*)rg, (BNode*)node);
        }
    }
}

void removeNormalNodes(ReebGraph *rg)
{
    ReebArc *arc, *nextArc;
    
    // Merge degree 2 nodes
    for(arc = rg->arcs.first; arc; arc = nextArc)
    {
        nextArc = arc->next;
        
        while (arc->head->degree == 2 || arc->tail->degree == 2)
        {
            // merge at v1
            if (arc->head->degree == 2)
            {
                ReebArc *connectedArc = (ReebArc*)BLI_findConnectedArc((BGraph*)rg, (BArc*)arc, (BNode*)arc->head);

                /* If arcs are one after the other */
                if (arc->head == connectedArc->tail)
                {       
                    /* remove furthest arc */       
                    if (arc->tail->weight < connectedArc->head->weight)
                    {
                        mergeConnectedArcs(rg, arc, connectedArc);
                        nextArc = arc->next;
                    }
                    else
                    {
                        mergeConnectedArcs(rg, connectedArc, arc);
                        break; /* arc was removed, move to next */
                    }
                }
                /* Otherwise, arcs are side by side */
                else
                {
                    /* Don't do anything, we need to keep the lowest node, even if degree 2 */
                    break;
                }
            }
            
            // merge at v2
            if (arc->tail->degree == 2)
            {
                ReebArc *connectedArc = (ReebArc*)BLI_findConnectedArc((BGraph*)rg, (BArc*)arc, (BNode*)arc->tail);
                
                /* If arcs are one after the other */
                if (arc->tail == connectedArc->head)
                {               
                    /* remove furthest arc */       
                    if (arc->head->weight < connectedArc->tail->weight)
                    {
                        mergeConnectedArcs(rg, arc, connectedArc);
                        nextArc = arc->next;
                    }
                    else
                    {
                        mergeConnectedArcs(rg, connectedArc, arc);
                        break; /* arc was removed, move to next */
                    }
                }
                /* Otherwise, arcs are side by side */
                else
                {
                    /* Don't do anything, we need to keep the lowest node, even if degree 2 */
                    break;
                }
            }
        }
    }
    
}

static int edgeEquals(ReebEdge *e1, ReebEdge *e2)
{
    return (e1->v1 == e2->v1 && e1->v2 == e2->v2);
}

static ReebArc *nextArcMappedToEdge(ReebArc *arc, ReebEdge *e)
{
    ReebEdge *nextEdge = NULL;
    ReebEdge *edge = NULL;
    ReebArc *result = NULL;

    /* Find the ReebEdge in the edge list */
    for(edge = arc->edges.first; edge && !edgeEquals(edge, e); edge = edge->next)
    {   }
    
    nextEdge = edge->nextEdge;
    
    if (nextEdge != NULL)
    {
        result = nextEdge->arc;
    }

    return result;
}

void addFacetoArc(ReebArc *arc, EditFace *efa)
{
    BLI_ghash_insert(arc->faces, efa, efa);
}

void mergeArcFaces(ReebGraph *UNUSED(rg), ReebArc *aDst, ReebArc *aSrc)
{
    GHashIterator ghi;
    
    for(BLI_ghashIterator_init(&ghi, aSrc->faces);
        !BLI_ghashIterator_isDone(&ghi);
        BLI_ghashIterator_step(&ghi))
    {
        EditFace *efa = BLI_ghashIterator_getValue(&ghi);
        BLI_ghash_insert(aDst->faces, efa, efa);
    }
} 

void mergeArcEdges(ReebGraph *rg, ReebArc *aDst, ReebArc *aSrc, MergeDirection direction)
{
    ReebEdge *e = NULL;
    
    if (direction == MERGE_APPEND)
    {
        for(e = aSrc->edges.first; e; e = e->next)
        {
            e->arc = aDst; // Edge is stolen by new arc
        }
        
        BLI_movelisttolist(&aDst->edges , &aSrc->edges);
    }
    else
    {
        for(e = aSrc->edges.first; e; e = e->next)
        {
            ReebEdge *newEdge = copyEdge(e);

            newEdge->arc = aDst;
            
            BLI_addtail(&aDst->edges, newEdge);
            
            if (direction == MERGE_LOWER)
            {
                void **p = BLI_edgehash_lookup_p(rg->emap, e->v1->index, e->v2->index);
                
                newEdge->nextEdge = e;

                // if edge was the first in the list, point the edit edge to the new reeb edge instead.                         
                if (*p == e)
                {
                    *p = (void*)newEdge;
                }
                // otherwise, advance in the list until the predecessor is found then insert it there
                else
                {
                    ReebEdge *previous = (ReebEdge*)*p;
                    
                    while(previous->nextEdge != e)
                    {
                        previous = previous->nextEdge;
                    }
                    
                    previous->nextEdge = newEdge;
                }
            }
            else
            {
                newEdge->nextEdge = e->nextEdge;
                e->nextEdge = newEdge;
            }
        }
    }
} 

// return 1 on full merge
int mergeConnectedArcs(ReebGraph *rg, ReebArc *a0, ReebArc *a1)
{
    int result = 0;
    ReebNode *removedNode = NULL;
    
    a0->length += a1->length;
    
    mergeArcEdges(rg, a0, a1, MERGE_APPEND);
    mergeArcFaces(rg, a0, a1);
    
    // Bring a0 to the combine length of both arcs
    if (a0->tail == a1->head)
    {
        removedNode = a0->tail;
        a0->tail = a1->tail;
    }
    else if (a0->head == a1->tail)
    {
        removedNode = a0->head;
        a0->head = a1->head;
    }
    
    resizeArcBuckets(a0);
    // Merge a1 in a0
    mergeArcBuckets(a0, a1, a0->head->weight, a0->tail->weight);
    
    // remove a1 from graph
    BLI_remlink(&rg->arcs, a1);
    REEB_freeArc((BArc*)a1);
    
    BLI_removeNode((BGraph*)rg, (BNode*)removedNode);
    result = 1;
    
    return result;
}
// return 1 on full merge
int mergeArcs(ReebGraph *rg, ReebArc *a0, ReebArc *a1)
{
    int result = 0;
    // TRIANGLE POINTS DOWN
    if (a0->head->weight == a1->head->weight) // heads are the same
    {
        if (a0->tail->weight == a1->tail->weight) // tails also the same, arcs can be totally merge together
        {
            mergeArcEdges(rg, a0, a1, MERGE_APPEND);
            mergeArcFaces(rg, a0, a1);
            
            mergeArcBuckets(a0, a1, a0->head->weight, a0->tail->weight);
            
            // Adjust node degree
            //a1->head->degree--;
            NodeDegreeDecrement(rg, a1->head);
            //a1->tail->degree--;
            NodeDegreeDecrement(rg, a1->tail);
            
            // remove a1 from graph
            BLI_remlink(&rg->arcs, a1);
            
            REEB_freeArc((BArc*)a1);
            result = 1;
        }
        else if (a0->tail->weight > a1->tail->weight) // a1->tail->weight is in the middle
        {
            mergeArcEdges(rg, a1, a0, MERGE_LOWER);
            mergeArcFaces(rg, a1, a0);

            // Adjust node degree
            //a0->head->degree--;
            NodeDegreeDecrement(rg, a0->head);
            //a1->tail->degree++;
            NodeDegreeIncrement(rg, a1->tail);
            
            mergeArcBuckets(a1, a0, a1->head->weight, a1->tail->weight);
            a0->head = a1->tail;
            resizeArcBuckets(a0);
        }
        else // a0>n2 is in the middle
        {
            mergeArcEdges(rg, a0, a1, MERGE_LOWER);
            mergeArcFaces(rg, a0, a1);
            
            // Adjust node degree
            //a1->head->degree--;
            NodeDegreeDecrement(rg, a1->head);
            //a0->tail->degree++;
            NodeDegreeIncrement(rg, a0->tail);
            
            mergeArcBuckets(a0, a1, a0->head->weight, a0->tail->weight);
            a1->head = a0->tail;
            resizeArcBuckets(a1);
        }
    }
    // TRIANGLE POINTS UP
    else if (a0->tail->weight == a1->tail->weight) // tails are the same
    {
        if (a0->head->weight > a1->head->weight) // a0->head->weight is in the middle
        {
            mergeArcEdges(rg, a0, a1, MERGE_HIGHER);
            mergeArcFaces(rg, a0, a1);
            
            // Adjust node degree
            //a1->tail->degree--;
            NodeDegreeDecrement(rg, a1->tail);
            //a0->head->degree++;
            NodeDegreeIncrement(rg, a0->head);
            
            mergeArcBuckets(a0, a1, a0->head->weight, a0->tail->weight);
            a1->tail = a0->head;
            resizeArcBuckets(a1);
        }
        else // a1->head->weight is in the middle
        {
            mergeArcEdges(rg, a1, a0, MERGE_HIGHER);
            mergeArcFaces(rg, a1, a0);

            // Adjust node degree
            //a0->tail->degree--;
            NodeDegreeDecrement(rg, a0->tail);
            //a1->head->degree++;
            NodeDegreeIncrement(rg, a1->head);

            mergeArcBuckets(a1, a0, a1->head->weight, a1->tail->weight);
            a0->tail = a1->head;
            resizeArcBuckets(a0);
        }
    }
    else
    {
        // Need something here (OR NOT)
    }
    
    return result;
}

static void glueByMergeSort(ReebGraph *rg, ReebArc *a0, ReebArc *a1, ReebEdge *e0, ReebEdge *e1)
{
    int total = 0;
    while (total == 0 && a0 != a1 && a0 != NULL && a1 != NULL)
    {
        total = mergeArcs(rg, a0, a1);
        
        if (total == 0) // if it wasn't a total merge, go forward
        {
            if (a0->tail->weight < a1->tail->weight)
            {
                a0 = nextArcMappedToEdge(a0, e0);
            }
            else
            {
                a1 = nextArcMappedToEdge(a1, e1);
            }
        }
    }
}

static void mergePaths(ReebGraph *rg, ReebEdge *e0, ReebEdge *e1, ReebEdge *e2)
{
    ReebArc *a0, *a1, *a2;
    a0 = e0->arc;
    a1 = e1->arc;
    a2 = e2->arc;
    
    glueByMergeSort(rg, a0, a1, e0, e1);
    glueByMergeSort(rg, a0, a2, e0, e2);
} 

static ReebEdge * createArc(ReebGraph *rg, ReebNode *node1, ReebNode *node2)
{
    ReebEdge *edge;
    
    edge = BLI_edgehash_lookup(rg->emap, node1->index, node2->index);
    
    // Only add existing edges that haven't been added yet
    if (edge == NULL)
    {
        ReebArc *arc;
        ReebNode *v1, *v2;
        float len, offset;
        int i;
        
        arc = MEM_callocN(sizeof(ReebArc), "reeb arc");
        edge = MEM_callocN(sizeof(ReebEdge), "reeb edge");
        
        arc->flag = 0; // clear flag on init
        arc->symmetry_level = 0;
        arc->faces = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "createArc gh");
        
        if (node1->weight <= node2->weight)
        {
            v1 = node1; 
            v2 = node2; 
        }
        else
        {
            v1 = node2; 
            v2 = node1; 
        }
        
        arc->head = v1;
        arc->tail = v2;
        
        // increase node degree
        //v1->degree++;
        NodeDegreeIncrement(rg, v1);
        //v2->degree++;
        NodeDegreeIncrement(rg, v2);

        BLI_edgehash_insert(rg->emap, node1->index, node2->index, edge);
        
        edge->arc = arc;
        edge->nextEdge = NULL;
        edge->v1 = v1;
        edge->v2 = v2;
        
        BLI_addtail(&rg->arcs, arc);
        BLI_addtail(&arc->edges, edge);
        
        /* adding buckets for embedding */
        allocArcBuckets(arc);
        
        offset = arc->head->weight;
        len = arc->tail->weight - arc->head->weight;

#if 0
        /* This is the actual embedding filling described in the paper
         * the problem is that it only works with really dense meshes
         */
        if (arc->bcount > 0)
        {
            addVertToBucket(&(arc->buckets[0]), arc->head->co);
            addVertToBucket(&(arc->buckets[arc->bcount - 1]), arc->tail->co);
        }
#else
        for(i = 0; i < arc->bcount; i++)
        {
            float co[3];
            float f = (arc->buckets[i].val - offset) / len;
            
            interp_v3_v3v3(co, v1->p, v2->p, f);
            addVertToBucket(&(arc->buckets[i]), co);
        }
#endif

    }
    
    return edge;
}

static void addTriangleToGraph(ReebGraph *rg, ReebNode * n1, ReebNode * n2, ReebNode * n3, EditFace *efa)
{
    ReebEdge *re1, *re2, *re3;
    ReebEdge *e1, *e2, *e3;
    float len1, len2, len3;
    
    re1 = createArc(rg, n1, n2);
    re2 = createArc(rg, n2, n3);
    re3 = createArc(rg, n3, n1);
    
    addFacetoArc(re1->arc, efa);
    addFacetoArc(re2->arc, efa);
    addFacetoArc(re3->arc, efa);
    
    len1 = (float)fabs(n1->weight - n2->weight);
    len2 = (float)fabs(n2->weight - n3->weight);
    len3 = (float)fabs(n3->weight - n1->weight);
    
    /* The rest of the algorithm assumes that e1 is the longest edge */
    
    if (len1 >= len2 && len1 >= len3)
    {
        e1 = re1;
        e2 = re2;
        e3 = re3;
    }
    else if (len2 >= len1 && len2 >= len3)
    {
        e1 = re2;
        e2 = re1;
        e3 = re3;
    }
    else
    {
        e1 = re3;
        e2 = re2;
        e3 = re1;
    }
    
    /* And e2 is the lowest edge
     * If e3 is lower than e2, swap them
     */
    if (e3->v1->weight < e2->v1->weight)
    {
        ReebEdge *etmp = e2;
        e2 = e3;
        e3 = etmp;
    }
    
    
    mergePaths(rg, e1, e2, e3);
}

ReebGraph * generateReebGraph(EditMesh *em, int subdivisions)
{
    ReebGraph *rg;
    EditVert *eve;
    EditFace *efa;
    int index;
    /*int totvert;*/
    
#ifdef DEBUG_REEB
    int totfaces;
    int countfaces = 0;
#endif

    rg = newReebGraph();
    
    rg->resolution = subdivisions;
    
    /*totvert = BLI_countlist(&em->verts);*/ /*UNUSED*/
#ifdef DEBUG_REEB
    totfaces = BLI_countlist(&em->faces);
#endif
    
    renormalizeWeight(em, 1.0f);
    
    /* Spread weight to minimize errors */
    spreadWeight(em);

    renormalizeWeight(em, (float)rg->resolution);

    /* Adding vertice */
    for(index = 0, eve = em->verts.first; eve; eve = eve->next)
    {
        if (eve->h == 0)
        {
            addNode(rg, eve);
            eve->f2 = 0;
            index++;
        }
    }
    
    /* Adding face, edge per edge */
    for(efa = em->faces.first; efa; efa = efa->next)
    {
        if (efa->h == 0)
        {
            ReebNode *n1, *n2, *n3;
            
            n1 = nodeData(efa->v1);
            n2 = nodeData(efa->v2);
            n3 = nodeData(efa->v3);
            
            addTriangleToGraph(rg, n1, n2, n3, efa);
            
            if (efa->v4)
            {
                ReebNode *n4 = nodeData(efa->v4);
                addTriangleToGraph(rg, n1, n3, n4, efa);
            }
#ifdef DEBUG_REEB
            countfaces++;
            if (countfaces % 100 == 0)
            {
                printf("\rface %i of %i", countfaces, totfaces);
            }
#endif
        }
    }
    
    printf("\n");
    
    removeZeroNodes(rg);
    
    removeNormalNodes(rg);
    
    return rg;
}

/***************************************** WEIGHT UTILS **********************************************/

void renormalizeWeight(EditMesh *em, float newmax)
{
    EditVert *eve;
    float minimum, maximum, range;
    
    if (em == NULL || BLI_countlist(&em->verts) == 0)
        return;

    /* First pass, determine maximum and minimum */
    eve = em->verts.first;
    minimum = weightData(eve);
    maximum = minimum;
    for(; eve; eve = eve->next)
    {
        maximum = MAX2(maximum, weightData(eve));
        minimum = MIN2(minimum, weightData(eve));
    }
    
    range = maximum - minimum;

    /* Normalize weights */
    for(eve = em->verts.first; eve; eve = eve->next)
    {
        float weight = (weightData(eve) - minimum) / range * newmax;
        weightSetData(eve, weight);
    }
}


int weightFromLoc(EditMesh *em, int axis)
{
    EditVert *eve;
    
    if (em == NULL || BLI_countlist(&em->verts) == 0 || axis < 0 || axis > 2)
        return 0;

    /* Copy coordinate in weight */
    for(eve = em->verts.first; eve; eve = eve->next)
    {
        weightSetData(eve, eve->co[axis]);
    }

    return 1;
}

static float cotan_weight(float *v1, float *v2, float *v3)
{
    float a[3], b[3], c[3], clen;

    sub_v3_v3v3(a, v2, v1);
    sub_v3_v3v3(b, v3, v1);
    cross_v3_v3v3(c, a, b);

    clen = len_v3(c);

    if (clen == 0.0f)
        return 0.0f;
    
    return dot_v3v3(a, b)/clen;
}

static void addTriangle(EditVert *v1, EditVert *v2, EditVert *v3, int e1, int e2, int e3)
{
    /* Angle opposite e1 */
    float t1= cotan_weight(v1->co, v2->co, v3->co) / e2;
    
    /* Angle opposite e2 */
    float t2 = cotan_weight(v2->co, v3->co, v1->co) / e3;

    /* Angle opposite e3 */
    float t3 = cotan_weight(v3->co, v1->co, v2->co) / e1;
    
    int i1 = indexData(v1);
    int i2 = indexData(v2);
    int i3 = indexData(v3);
    
    nlMatrixAdd(i1, i1, t2+t3);
    nlMatrixAdd(i2, i2, t1+t3);
    nlMatrixAdd(i3, i3, t1+t2);

    nlMatrixAdd(i1, i2, -t3);
    nlMatrixAdd(i2, i1, -t3);

    nlMatrixAdd(i2, i3, -t1);
    nlMatrixAdd(i3, i2, -t1);

    nlMatrixAdd(i3, i1, -t2);
    nlMatrixAdd(i1, i3, -t2);
}

int weightToHarmonic(EditMesh *em, EdgeIndex *indexed_edges)
{
    NLboolean success;
    EditVert *eve;
    EditEdge *eed;
    EditFace *efa;
    int totvert = 0;
    int index;
    int rval;
    
    /* Find local extrema */
    for(eve = em->verts.first; eve; eve = eve->next)
    {
        totvert++;
    }

    /* Solve with openNL */
    
    nlNewContext();

    nlSolverParameteri(NL_NB_VARIABLES, totvert);

    nlBegin(NL_SYSTEM);
    
    /* Find local extrema */
    for(index = 0, eve = em->verts.first; eve; index++, eve = eve->next)
    {
        if (eve->h == 0)
        {
            EditEdge *eed;
            int maximum = 1;
            int minimum = 1;
            
            NextEdgeForVert(indexed_edges, -1); /* Reset next edge */
            for(eed = NextEdgeForVert(indexed_edges, index); eed && (maximum || minimum); eed = NextEdgeForVert(indexed_edges, index))
            {
                EditVert *eve2;
                
                if (eed->v1 == eve)
                {
                    eve2 = eed->v2;
                }
                else
                {
                    eve2 = eed->v1;
                }
                
                if (eve2->h == 0)
                {
                    /* Adjacent vertex is bigger, not a local maximum */
                    if (weightData(eve2) > weightData(eve))
                    {
                        maximum = 0;
                    }
                    /* Adjacent vertex is smaller, not a local minimum */
                    else if (weightData(eve2) < weightData(eve))
                    {
                        minimum = 0;
                    }
                }
            }
            
            if (maximum || minimum)
            {
                float w = weightData(eve);
                eve->f1 = 0;
                nlSetVariable(0, index, w);
                nlLockVariable(index);
            }
            else
            {
                eve->f1 = 1;
            }
        }
    }
    
    nlBegin(NL_MATRIX);

    /* Zero edge weight */
    for(eed = em->edges.first; eed; eed = eed->next)
    {
        eed->tmp.l = 0;
    }
    
    /* Add faces count to the edge weight */
    for(efa = em->faces.first; efa; efa = efa->next)
    {
        if (efa->h == 0)
        {
            efa->e1->tmp.l++;
            efa->e2->tmp.l++;
            efa->e3->tmp.l++;
            
            if (efa->e4)
            {
                efa->e4->tmp.l++;
            }
        }
    }

    /* Add faces angle to the edge weight */
    for(efa = em->faces.first; efa; efa = efa->next)
    {
        if (efa->h == 0)
        {
            if (efa->v4 == NULL)
            {
                addTriangle(efa->v1, efa->v2, efa->v3, efa->e1->tmp.l, efa->e2->tmp.l, efa->e3->tmp.l);
            }
            else
            {
                addTriangle(efa->v1, efa->v2, efa->v3, efa->e1->tmp.l, efa->e2->tmp.l, 2);
                addTriangle(efa->v3, efa->v4, efa->v1, efa->e3->tmp.l, efa->e4->tmp.l, 2);
            }
        }
    }
    
    nlEnd(NL_MATRIX);

    nlEnd(NL_SYSTEM);

    success = nlSolveAdvanced(NULL, NL_TRUE);

    if (success)
    {
        rval = 1;
        for(index = 0, eve = em->verts.first; eve; index++, eve = eve->next)
        {
            weightSetData(eve, nlGetVariable(0, index));
        }
    }
    else
    {
        rval = 0;
    }

    nlDeleteContext(nlGetCurrent());

    return rval;
}


EditEdge * NextEdgeForVert(EdgeIndex *indexed_edges, int index)
{
    static int offset = -1;
    
    /* Reset method, call with NULL mesh pointer */
    if (index == -1)
    {
        offset = -1;
        return NULL;
    }
    
    /* first pass, start at the head of the list */
    if (offset == -1)
    {
        offset = indexed_edges->offset[index];
    }
    /* subsequent passes, start on the next edge */
    else
    {
        offset++;
    }
    
    return indexed_edges->edges[offset];
}

static void shortestPathsFromVert(EditMesh *em, EditVert *starting_vert, EdgeIndex *indexed_edges)
{
    Heap     *edge_heap;
    EditVert *current_eve = NULL;
    EditEdge *eed = NULL;
    EditEdge *select_eed = NULL;
    
    edge_heap = BLI_heap_new();
    
    current_eve = starting_vert;
    
    /* insert guard in heap, when that is returned, no more edges */
    BLI_heap_insert(edge_heap, FLT_MAX, NULL);

    /* Initialize edge flag */
    for(eed= em->edges.first; eed; eed= eed->next)
    {
        eed->f1 = 0;
    }
    
    while (BLI_heap_size(edge_heap) > 0)
    {
        float current_weight;
        
        current_eve->f1 = 1; /* mark vertex as selected */
        
        /* Add all new edges connected to current_eve to the list */
        NextEdgeForVert(indexed_edges, -1); // Reset next edge
        for(eed = NextEdgeForVert(indexed_edges, indexData(current_eve)); eed; eed = NextEdgeForVert(indexed_edges, indexData(current_eve)))
        { 
            if (eed->f1 == 0)
            {
                BLI_heap_insert(edge_heap, weightData(current_eve) + eed->tmp.fp, eed);
                eed->f1 = 1;
            }
        }
        
        /* Find next shortest edge with unselected verts */
        do
        {
            current_weight = BLI_heap_node_value(BLI_heap_top(edge_heap));
            select_eed = BLI_heap_popmin(edge_heap);
        } while (select_eed != NULL && select_eed->v1->f1 != 0 && select_eed->v2->f1);
        
        if (select_eed != NULL)
        {
            select_eed->f1 = 2;
            
            if (select_eed->v1->f1 == 0) /* v1 is the new vertex */
            {
                current_eve = select_eed->v1;
            }
            else /* otherwise, it's v2 */
            {
                current_eve = select_eed->v2;
            }
            
            weightSetData(current_eve, current_weight);
        }
    }
    
    BLI_heap_free(edge_heap, NULL);
}

static void freeEdgeIndex(EdgeIndex *indexed_edges)
{
    MEM_freeN(indexed_edges->offset);
    MEM_freeN(indexed_edges->edges);
}

static void buildIndexedEdges(EditMesh *em, EdgeIndex *indexed_edges)
{
    EditVert *eve;
    EditEdge *eed;
    int totvert = 0;
    int tot_indexed = 0;
    int offset = 0;

    totvert = BLI_countlist(&em->verts);

    indexed_edges->offset = MEM_callocN(totvert * sizeof(int), "EdgeIndex offset");

    for(eed = em->edges.first; eed; eed = eed->next)
    {
        if (eed->v1->h == 0 && eed->v2->h == 0)
        {
            tot_indexed += 2;
            indexed_edges->offset[indexData(eed->v1)]++;
            indexed_edges->offset[indexData(eed->v2)]++;
        }
    }
    
    tot_indexed += totvert;

    indexed_edges->edges = MEM_callocN(tot_indexed * sizeof(EditEdge*), "EdgeIndex edges");

    /* setting vert offsets */
    for(eve = em->verts.first; eve; eve = eve->next)
    {
        if (eve->h == 0)
        {
            int d = indexed_edges->offset[indexData(eve)];
            indexed_edges->offset[indexData(eve)] = offset;
            offset += d + 1;
        }
    }

    /* adding edges in array */
    for(eed = em->edges.first; eed; eed= eed->next)
    {
        if (eed->v1->h == 0 && eed->v2->h == 0)
        {
            int i;
            for (i = indexed_edges->offset[indexData(eed->v1)]; i < tot_indexed; i++)
            {
                if (indexed_edges->edges[i] == NULL)
                {
                    indexed_edges->edges[i] = eed;
                    break;
                }
            }
            
            for (i = indexed_edges->offset[indexData(eed->v2)]; i < tot_indexed; i++)
            {
                if (indexed_edges->edges[i] == NULL)
                {
                    indexed_edges->edges[i] = eed;
                    break;
                }
            }
        }
    }
}

int weightFromDistance(EditMesh *em, EdgeIndex *indexed_edges)
{
    EditVert *eve;
    int totedge = 0;
    int totvert = 0;
    int vCount = 0;
    
    totvert = BLI_countlist(&em->verts);
    
    if (em == NULL || totvert == 0)
    {
        return 0;
    }
    
    totedge = BLI_countlist(&em->edges);
    
    if (totedge == 0)
    {
        return 0;
    }
    
    /* Initialize vertice flag and find at least one selected vertex */
    for(eve = em->verts.first; eve; eve = eve->next)
    {
        eve->f1 = 0;
        if (eve->f & SELECT)
        {
            vCount = 1;
        }
    }
    
    if (vCount == 0)
    {
        return 0; /* no selected vert, failure */
    }
    else
    {
        EditEdge *eed;
        int allDone = 0;

        /* Calculate edge weight */
        for(eed = em->edges.first; eed; eed= eed->next)
        {
            if (eed->v1->h == 0 && eed->v2->h == 0)
            {
                eed->tmp.fp = len_v3v3(eed->v1->co, eed->v2->co);
            }
        }

        /* Apply dijkstra spf for each selected vert */
        for(eve = em->verts.first; eve; eve = eve->next)
        {
            if (eve->f & SELECT)
            {
                shortestPathsFromVert(em, eve, indexed_edges);              
            }
        }
        
        /* connect unselected islands */
        while (allDone == 0)
        {
            EditVert *selected_eve = NULL;
            float selected_weight = 0;
            float min_distance = FLT_MAX;
            
            allDone = 1;
            
            for (eve = em->verts.first; eve; eve = eve->next)
            {
                /* for every vertex visible that hasn't been processed yet */
                if (eve->h == 0 && eve->f1 != 1)
                {
                    EditVert *closest_eve;
                    
                    /* find the closest processed vertex */
                    for (closest_eve = em->verts.first; closest_eve; closest_eve = closest_eve->next)
                    {
                        /* vertex is already processed and distance is smaller than current minimum */
                        if (closest_eve->f1 == 1)
                        {
                            float distance = len_v3v3(closest_eve->co, eve->co);
                            if (distance < min_distance)
                            {
                                min_distance = distance;
                                selected_eve = eve;
                                selected_weight = weightData(closest_eve);
                            }
                        }
                    }
                }
            }
            
            if (selected_eve)
            {
                allDone = 0;

                weightSetData(selected_eve, selected_weight + min_distance);
                shortestPathsFromVert(em, selected_eve, indexed_edges);
            }
        }
    }

    for(eve = em->verts.first; eve && vCount == 0; eve = eve->next)
    {
        if (eve->f1 == 0)
        {
            printf("vertex not reached\n");
            break;
        }
    }
    
    return 1;
}

/****************************************** BUCKET ITERATOR **************************************************/

static void* headNode(void *arg);
static void* tailNode(void *arg);
static void* nextBucket(void *arg);
static void* nextNBucket(void *arg, int n);
static void* peekBucket(void *arg, int n);
static void* previousBucket(void *arg);
static int   iteratorStopped(void *arg);

static void initIteratorFct(ReebArcIterator *iter)
{
    iter->head = headNode;
    iter->tail = tailNode;
    iter->peek = peekBucket;
    iter->next = nextBucket;
    iter->nextN = nextNBucket;
    iter->previous = previousBucket;
    iter->stopped = iteratorStopped;    
}

static void setIteratorValues(ReebArcIterator *iter, EmbedBucket *bucket)
{
    if (bucket)
    {
        iter->p = bucket->p;
        iter->no = bucket->no;
    }
    else
    {
        iter->p = NULL;
        iter->no = NULL;
    }
    iter->size = 0;
}

void initArcIterator(BArcIterator *arg, ReebArc *arc, ReebNode *head)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;

    initIteratorFct(iter);
    iter->arc = arc;
    
    if (head == arc->head)
    {
        iter->start = 0;
        iter->end = arc->bcount - 1;
        iter->stride = 1;
    }
    else
    {
        iter->start = arc->bcount - 1;
        iter->end = 0;
        iter->stride = -1;
    }
    
    iter->length = arc->bcount;
    
    iter->index = -1;
}

void initArcIteratorStart(BArcIterator *arg, struct ReebArc *arc, struct ReebNode *head, int start)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;

    initIteratorFct(iter);
    iter->arc = arc;
    
    if (head == arc->head)
    {
        iter->start = start;
        iter->end = arc->bcount - 1;
        iter->stride = 1;
    }
    else
    {
        iter->start = arc->bcount - 1 - start;
        iter->end = 0;
        iter->stride = -1;
    }
    
    iter->index = -1;
    
    iter->length = arc->bcount - start;

    if (start >= arc->bcount)
    {
        iter->start = iter->end; /* stop iterator since it's past its end */
    }
}

void initArcIterator2(BArcIterator *arg, ReebArc *arc, int start, int end)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;

    initIteratorFct(iter);
    iter->arc = arc;
    
    iter->start = start;
    iter->end = end;
    
    if (end > start)
    {
        iter->stride = 1;
    }
    else
    {
        iter->stride = -1;
    }

    iter->index = -1;

    iter->length = abs(iter->end - iter->start) + 1;
}

static void* headNode(void *arg)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;
    ReebNode *node;
    
    if (iter->start < iter->end)
    {
        node = iter->arc->head;
    }
    else
    {
        node = iter->arc->tail;
    }
    
    iter->p = node->p;
    iter->no = node->no;
    iter->size = 0;
    
    return node;
}

static void* tailNode(void *arg)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;
    ReebNode *node;
    
    if (iter->start < iter->end)
    {
        node = iter->arc->tail;
    }
    else
    {
        node = iter->arc->head;
    }
    
    iter->p = node->p;
    iter->no = node->no;
    iter->size = 0;
    
    return node;
}

static void* nextBucket(void *arg)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;
    EmbedBucket *result = NULL;
    
    iter->index++;
    
    if (iter->index < iter->length)
    {
        result = &(iter->arc->buckets[iter->start + (iter->stride * iter->index)]);
    }
    
    setIteratorValues(iter, result);
    return result;
}

static void* nextNBucket(void *arg, int n)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;
    EmbedBucket *result = NULL;
        
    iter->index += n;

    /* check if passed end */
    if (iter->index < iter->length)
    {
        result = &(iter->arc->buckets[iter->start + (iter->stride * iter->index)]);
    }
    
    setIteratorValues(iter, result);
    return result;
}

static void* peekBucket(void *arg, int n)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;
    EmbedBucket *result = NULL;
    int index = iter->index + n;

    /* check if passed end */
    if (index < iter->length)
    {
        result = &(iter->arc->buckets[iter->start + (iter->stride * index)]);
    }

    setIteratorValues(iter, result);
    return result;
}

static void* previousBucket(void *arg)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;
    EmbedBucket *result = NULL;
    
    if (iter->index > 0)
    {
        iter->index--;
        result = &(iter->arc->buckets[iter->start + (iter->stride * iter->index)]);
    }

    setIteratorValues(iter, result);
    return result;
}

static int iteratorStopped(void *arg)
{
    ReebArcIterator *iter = (ReebArcIterator*)arg;

    if (iter->index >= iter->length)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

/************************ PUBLIC FUNCTIONS *********************************************/

ReebGraph *BIF_ReebGraphMultiFromEditMesh(bContext *C)
{
    Scene *scene = CTX_data_scene(C);
    Object *obedit = CTX_data_edit_object(C);
    EditMesh *em =( (Mesh*)obedit->data)->edit_mesh;
    EdgeIndex indexed_edges;
    VertexData *data;
    ReebGraph *rg = NULL;
    ReebGraph *rgi, *previous;
    int i, nb_levels = REEB_MAX_MULTI_LEVEL;

    if (em == NULL)
        return NULL;
    
    data = allocVertexData(em);

    buildIndexedEdges(em, &indexed_edges);

    if (weightFromDistance(em, &indexed_edges) == 0)
    {
        // XXX error("No selected vertex\n");
        freeEdgeIndex(&indexed_edges);
        return NULL;
    }
    
    renormalizeWeight(em, 1.0f);

    if (scene->toolsettings->skgen_options & SKGEN_HARMONIC)
    {
        weightToHarmonic(em, &indexed_edges);
    }
    
    freeEdgeIndex(&indexed_edges);
    
    rg = generateReebGraph(em, scene->toolsettings->skgen_resolution);

    /* Remove arcs without embedding */
    filterNullReebGraph(rg);

    /* smart filter and loop filter on basic level */
    filterGraph(rg, SKGEN_FILTER_SMART, 0, 0);

    repositionNodes(rg);

    /* Filtering might have created degree 2 nodes, so remove them */
    removeNormalNodes(rg);
    
    joinSubgraphs(rg, 1.0);

    BLI_buildAdjacencyList((BGraph*)rg);
    
    /* calc length before copy, so we have same length on all levels */
    BLI_calcGraphLength((BGraph*)rg);

    previous = NULL;
    for (i = 0; i <= nb_levels; i++)
    {
        rgi = rg;
        
        /* don't filter last level */
        if (i > 0)
        {
            float internal_threshold;
            float external_threshold;

            /* filter internal progressively in second half only*/
            if (i > nb_levels / 2)
            {
                internal_threshold = rg->length * scene->toolsettings->skgen_threshold_internal;
            }
            else
            {
                internal_threshold = rg->length * scene->toolsettings->skgen_threshold_internal * (2 * i / (float)nb_levels);
            }
            
            external_threshold = rg->length * scene->toolsettings->skgen_threshold_external * (i / (float)nb_levels);

            filterGraph(rgi, scene->toolsettings->skgen_options, internal_threshold, external_threshold);
        }

        if (i < nb_levels)
        {
            rg = copyReebGraph(rgi, i + 1);
        }

        finalizeGraph(rgi, scene->toolsettings->skgen_postpro_passes, scene->toolsettings->skgen_postpro);

        BLI_markdownSymmetry((BGraph*)rgi, rgi->nodes.first, scene->toolsettings->skgen_symmetry_limit);
        
        if (previous != NULL)
        {
            relinkNodes(rgi, previous);
        }
        previous = rgi;
    }
    
    verifyMultiResolutionLinks(rg, 0);
    
    MEM_freeN(data);

    return rg;
}

#if 0

ReebGraph *BIF_ReebGraphFromEditMesh(void)
{
    EditMesh *em = G.editMesh;
    EdgeIndex indexed_edges;
    VertexData *data;
    ReebGraph *rg = NULL;
    
    if (em == NULL)
        return NULL;

    data = allocVertexData(em);

    buildIndexedEdges(em, &indexed_edges);
    
    if (weightFromDistance(em, &indexed_edges) == 0)
    {
        error("No selected vertex\n");
        freeEdgeIndex(&indexed_edges);
        freeEdgeIndex(&indexed_edges);
        return NULL;
    }
    
    renormalizeWeight(em, 1.0f);

    if (G.scene->toolsettings->skgen_options & SKGEN_HARMONIC)
    {
        weightToHarmonic(em, &indexed_edges);
    }
    
    freeEdgeIndex(&indexed_edges);
    
#ifdef DEBUG_REEB
    weightToVCol(em, 1);
#endif
    
    rg = generateReebGraph(em, G.scene->toolsettings->skgen_resolution);


    /* Remove arcs without embedding */
    filterNullReebGraph(rg);

    /* smart filter and loop filter on basic level */
    filterGraph(rg, SKGEN_FILTER_SMART, 0, 0);

    repositionNodes(rg);

    /* Filtering might have created degree 2 nodes, so remove them */
    removeNormalNodes(rg);
    
    joinSubgraphs(rg, 1.0);

    BLI_buildAdjacencyList((BGraph*)rg);
    
    /* calc length before copy, so we have same length on all levels */
    BLI_calcGraphLength((BGraph*)rg);
    
    filterGraph(rg, G.scene->toolsettings->skgen_options, G.scene->toolsettings->skgen_threshold_internal, G.scene->toolsettings->skgen_threshold_external);

    finalizeGraph(rg, G.scene->toolsettings->skgen_postpro_passes, G.scene->toolsettings->skgen_postpro);

#ifdef DEBUG_REEB
    REEB_exportGraph(rg, -1);
    
    arcToVCol(rg, em, 0);
    //angleToVCol(em, 1);
#endif

    printf("DONE\n");
    printf("%i subgraphs\n", BLI_FlagSubgraphs((BGraph*)rg));
    
    MEM_freeN(data);

    return rg;
}

void BIF_GlobalReebFree()
{
    if (GLOBAL_RG != NULL)
    {
        REEB_freeGraph(GLOBAL_RG);
        GLOBAL_RG = NULL;
    }
}

void BIF_GlobalReebGraphFromEditMesh(void)
{
    ReebGraph *rg;
    
    BIF_GlobalReebFree();
    
    rg = BIF_ReebGraphMultiFromEditMesh();

    GLOBAL_RG = rg;
}

void REEB_draw()
{
    ReebGraph *rg;
    ReebArc *arc;
    int i = 0;
    
    if (GLOBAL_RG == NULL)
    {
        return;
    }
    
    if (GLOBAL_RG->link_up && G.scene->toolsettings->skgen_options & SKGEN_DISP_ORIG)
    {
        for (rg = GLOBAL_RG; rg->link_up; rg = rg->link_up) ;
    }
    else
    {
        i = G.scene->toolsettings->skgen_multi_level;
        
        for (rg = GLOBAL_RG; rg->multi_level != i && rg->link_up; rg = rg->link_up) ;
    }
    
    glPointSize(BIF_GetThemeValuef(TH_VERTEX_SIZE));
    
    glDisable(GL_DEPTH_TEST);
    for (arc = rg->arcs.first; arc; arc = arc->next, i++)
    {
        ReebArcIterator arc_iter;
        BArcIterator *iter = (BArcIterator*)&arc_iter;
        float vec[3];
        char text[128];
        char *s = text;
        
        glLineWidth(BIF_GetThemeValuef(TH_VERTEX_SIZE) + 2);
        glColor3f(0, 0, 0);
        glBegin(GL_LINE_STRIP);
            glVertex3fv(arc->head->p);
            
            if (arc->bcount)
            {
                initArcIterator(iter, arc, arc->head);
                for (IT_next(iter); IT_stopped(iter) == 0; IT_next(iter))
                {
                    glVertex3fv(iter->p);
                }
            }
            
            glVertex3fv(arc->tail->p);
        glEnd();

        glLineWidth(BIF_GetThemeValuef(TH_VERTEX_SIZE));

        if (arc->symmetry_level == 1)
        {
            glColor3f(1, 0, 0);
        }
        else if (arc->symmetry_flag == SYM_SIDE_POSITIVE || arc->symmetry_flag == SYM_SIDE_NEGATIVE)
        {
            glColor3f(1, 0.5f, 0);
        }
        else if (arc->symmetry_flag >= SYM_SIDE_RADIAL)
        {
            glColor3f(0.5f, 1, 0);
        }
        else
        {
            glColor3f(1, 1, 0);
        }
        glBegin(GL_LINE_STRIP);
            glVertex3fv(arc->head->p);
            
            if (arc->bcount)
            {
                initArcIterator(iter, arc, arc->head);
                for (iter->next(iter); IT_stopped(iter) == 0; iter->next(iter))
                {
                    glVertex3fv(iter->p);
                }
            }
            
            glVertex3fv(arc->tail->p);
        glEnd();

        
        if (G.scene->toolsettings->skgen_options & SKGEN_DISP_EMBED)
        {
            glColor3f(1, 1, 1);             
            glBegin(GL_POINTS);
                glVertex3fv(arc->head->p);
                glVertex3fv(arc->tail->p);
                
                glColor3f(0.5f, 0.5f, 1);               
                if (arc->bcount)
                {
                    initArcIterator(iter, arc, arc->head);
                    for (iter->next(iter); IT_stopped(iter) == 0; iter->next(iter))
                    {
                        glVertex3fv(iter->p);
                    }
                }
            glEnd();
        }
        
        if (G.scene->toolsettings->skgen_options & SKGEN_DISP_INDEX)
        {
            mid_v3_v3v3(vec, arc->head->p, arc->tail->p);
            s += sprintf(s, "%i (%i-%i-%i) ", i, arc->symmetry_level, arc->symmetry_flag, arc->symmetry_group);
        
            if (G.scene->toolsettings->skgen_options & SKGEN_DISP_WEIGHT)
            {
                s += sprintf(s, "w:%0.3f ", arc->tail->weight - arc->head->weight);
            }
            
            if (G.scene->toolsettings->skgen_options & SKGEN_DISP_LENGTH)
            {
                s += sprintf(s, "l:%0.3f", arc->length);
            }
            
            glColor3f(0, 1, 0);
            glRasterPos3fv(vec);
            BMF_DrawString( G.fonts, text);
        }

        if (G.scene->toolsettings->skgen_options & SKGEN_DISP_INDEX)
        {
            sprintf(text, "  %i", arc->head->index);
            glRasterPos3fv(arc->head->p);
            BMF_DrawString( G.fonts, text);
    
            sprintf(text, "  %i", arc->tail->index);
            glRasterPos3fv(arc->tail->p);
            BMF_DrawString( G.fonts, text);
        }
    }
    glEnable(GL_DEPTH_TEST);
    
    glLineWidth(1.0);
    glPointSize(1.0);
}

#endif