CCGSubSurf.c

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#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "CCGSubSurf.h"

#include "MEM_guardedalloc.h"
#include "BLO_sys_types.h" // for intptr_t support

#ifdef _MSC_VER
#define CCG_INLINE __inline
#else
#define CCG_INLINE inline
#endif

/* copied from BKE_utildefines.h ugh */
#ifdef __GNUC__
#  define UNUSED(x) UNUSED_ ## x __attribute__((__unused__))
#else
#  define UNUSED(x) x
#endif

/* used for normalize_v3 in BLI_math_vector
 * float.h's FLT_EPSILON causes trouble with subsurf normals - campbell */
#define EPSILON (1.0e-35f)

/***/

typedef unsigned char   byte;

/***/

static int kHashSizes[] = {
    1, 3, 5, 11, 17, 37, 67, 131, 257, 521, 1031, 2053, 4099, 8209, 
    16411, 32771, 65537, 131101, 262147, 524309, 1048583, 2097169, 
    4194319, 8388617, 16777259, 33554467, 67108879, 134217757, 268435459
};

typedef struct _EHEntry EHEntry;
struct _EHEntry {
    EHEntry *next;
    void *key;
};
typedef struct _EHash {
    EHEntry **buckets;
    int numEntries, curSize, curSizeIdx;

    CCGAllocatorIFC allocatorIFC;
    CCGAllocatorHDL allocator;
} EHash;

#define EHASH_alloc(eh, nb)         ((eh)->allocatorIFC.alloc((eh)->allocator, nb))
#define EHASH_free(eh, ptr)         ((eh)->allocatorIFC.free((eh)->allocator, ptr))

#define EHASH_hash(eh, item)    (((uintptr_t) (item))%((unsigned int) (eh)->curSize))

static EHash *_ehash_new(int estimatedNumEntries, CCGAllocatorIFC *allocatorIFC, CCGAllocatorHDL allocator) {
    EHash *eh = allocatorIFC->alloc(allocator, sizeof(*eh));
    eh->allocatorIFC = *allocatorIFC;
    eh->allocator = allocator;
    eh->numEntries = 0;
    eh->curSizeIdx = 0;
    while (kHashSizes[eh->curSizeIdx]<estimatedNumEntries)
        eh->curSizeIdx++;
    eh->curSize = kHashSizes[eh->curSizeIdx];
    eh->buckets = EHASH_alloc(eh, eh->curSize*sizeof(*eh->buckets));
    memset(eh->buckets, 0, eh->curSize*sizeof(*eh->buckets));

    return eh;
}
typedef void (*EHEntryFreeFP)(EHEntry *, void *);
static void _ehash_free(EHash *eh, EHEntryFreeFP freeEntry, void *userData) {
    int numBuckets = eh->curSize;

    while (numBuckets--) {
        EHEntry *entry = eh->buckets[numBuckets];

        while (entry) {
            EHEntry *next = entry->next;

            freeEntry(entry, userData);

            entry = next;
        }
    }

    EHASH_free(eh, eh->buckets);
    EHASH_free(eh, eh);
}

static void _ehash_insert(EHash *eh, EHEntry *entry) {
    int numBuckets = eh->curSize;
    int hash = EHASH_hash(eh, entry->key);
    entry->next = eh->buckets[hash];
    eh->buckets[hash] = entry;
    eh->numEntries++;

    if (eh->numEntries > (numBuckets*3)) {
        EHEntry **oldBuckets = eh->buckets;
        eh->curSize = kHashSizes[++eh->curSizeIdx];
        
        eh->buckets = EHASH_alloc(eh, eh->curSize*sizeof(*eh->buckets));
        memset(eh->buckets, 0, eh->curSize*sizeof(*eh->buckets));

        while (numBuckets--) {
            for (entry = oldBuckets[numBuckets]; entry;) {
                EHEntry *next = entry->next;
                
                hash = EHASH_hash(eh, entry->key);
                entry->next = eh->buckets[hash];
                eh->buckets[hash] = entry;
                
                entry = next;
            }
        }

        EHASH_free(eh, oldBuckets);
    }
}

static void *_ehash_lookupWithPrev(EHash *eh, void *key, void ***prevp_r) {
    int hash = EHASH_hash(eh, key);
    void **prevp = (void**) &eh->buckets[hash];
    EHEntry *entry;
    
    for (; (entry = *prevp); prevp = (void**) &entry->next) {
        if (entry->key==key) {
            *prevp_r = (void**) prevp;
            return entry;
        }
    }
    
    return NULL;
}

static void *_ehash_lookup(EHash *eh, void *key) {
    int hash = EHASH_hash(eh, key);
    EHEntry *entry;
    
    for (entry = eh->buckets[hash]; entry; entry = entry->next)
        if (entry->key==key)
            break;
    
    return entry;
}



typedef struct _EHashIterator {
    EHash *eh;
    int curBucket;
    EHEntry *curEntry;
} EHashIterator;

static EHashIterator *_ehashIterator_new(EHash *eh) {
    EHashIterator *ehi = EHASH_alloc(eh, sizeof(*ehi));
    ehi->eh = eh;
    ehi->curEntry = NULL;
    ehi->curBucket = -1;
    while (!ehi->curEntry) {
        ehi->curBucket++;
        if (ehi->curBucket==ehi->eh->curSize)
            break;
        ehi->curEntry = ehi->eh->buckets[ehi->curBucket];
    }
    return ehi;
}
static void _ehashIterator_free(EHashIterator *ehi) {
    EHASH_free(ehi->eh, ehi);
}

static void *_ehashIterator_getCurrent(EHashIterator *ehi) {
    return ehi->curEntry;
}

static void _ehashIterator_next(EHashIterator *ehi) {
    if (ehi->curEntry) {
        ehi->curEntry = ehi->curEntry->next;
        while (!ehi->curEntry) {
            ehi->curBucket++;
            if (ehi->curBucket==ehi->eh->curSize)
                break;
            ehi->curEntry = ehi->eh->buckets[ehi->curBucket];
        }
    }
}
static int _ehashIterator_isStopped(EHashIterator *ehi) {
    return !ehi->curEntry;
}

/***/

static void *_stdAllocator_alloc(CCGAllocatorHDL UNUSED(a), int numBytes) {
    return malloc(numBytes);
}
static void *_stdAllocator_realloc(CCGAllocatorHDL UNUSED(a), void *ptr, int newSize, int UNUSED(oldSize)) {
    return realloc(ptr, newSize);
}
static void _stdAllocator_free(CCGAllocatorHDL UNUSED(a), void *ptr) {
    free(ptr);
}

static CCGAllocatorIFC *_getStandardAllocatorIFC(void) {
    static CCGAllocatorIFC ifc;

    ifc.alloc = _stdAllocator_alloc;
    ifc.realloc = _stdAllocator_realloc;
    ifc.free = _stdAllocator_free;
    ifc.release = NULL;

    return &ifc;
}

/***/

static int VertDataEqual(const float *a, const float *b) {
    return a[0]==b[0] && a[1]==b[1] && a[2]==b[2];
}
#define VertDataZero(av)                { float *_a = (float*) av; _a[0] = _a[1] = _a[2] = 0.0f; }
#define VertDataCopy(av, bv)            { float *_a = (float*) av, *_b = (float*) bv; _a[0] =_b[0]; _a[1] =_b[1]; _a[2] =_b[2]; }
#define VertDataAdd(av, bv)             { float *_a = (float*) av, *_b = (float*) bv; _a[0]+=_b[0]; _a[1]+=_b[1]; _a[2]+=_b[2]; }
#define VertDataSub(av, bv)             { float *_a = (float*) av, *_b = (float*) bv; _a[0]-=_b[0]; _a[1]-=_b[1]; _a[2]-=_b[2]; }
#define VertDataMulN(av, n)             { float *_a = (float*) av; _a[0]*=n; _a[1]*=n; _a[2]*=n; }
#define VertDataAvg4(tv, av, bv, cv, dv) \
    { \
        float *_t = (float*) tv, *_a = (float*) av, *_b = (float*) bv, *_c = (float*) cv, *_d = (float*) dv; \
        _t[0] = (_a[0]+_b[0]+_c[0]+_d[0])*.25f; \
        _t[1] = (_a[1]+_b[1]+_c[1]+_d[1])*.25f; \
        _t[2] = (_a[2]+_b[2]+_c[2]+_d[2])*.25f; \
    }
#define NormZero(av)                    { float *_a = (float*) av; _a[0] = _a[1] = _a[2] = 0.0f; }
#define NormCopy(av, bv)                { float *_a = (float*) av, *_b = (float*) bv; _a[0] =_b[0]; _a[1] =_b[1]; _a[2] =_b[2]; }
#define NormAdd(av, bv)                 { float *_a = (float*) av, *_b = (float*) bv; _a[0]+=_b[0]; _a[1]+=_b[1]; _a[2]+=_b[2]; }


static int _edge_isBoundary(const CCGEdge *e);

/***/

enum {
    Vert_eEffected=     (1<<0),
    Vert_eChanged=      (1<<1),
    Vert_eSeam=         (1<<2),
} /*VertFlags*/;
enum {
    Edge_eEffected=     (1<<0),
} /*CCGEdgeFlags*/;
enum {
    Face_eEffected=     (1<<0),
} /*FaceFlags*/;

struct _CCGVert {
    CCGVert     *next;  /* EHData.next */
    CCGVertHDL  vHDL;   /* EHData.key */

    short numEdges, numFaces, flags, pad;

    CCGEdge **edges;
    CCGFace **faces;
//  byte *levelData;
//  byte *userData;
};
#define VERT_getLevelData(v)        ((byte*) &(v)[1])

struct _CCGEdge {
    CCGEdge     *next;  /* EHData.next */
    CCGEdgeHDL  eHDL;   /* EHData.key */

    short numFaces, flags;
    float crease;

    CCGVert *v0,*v1;
    CCGFace **faces;

//  byte *levelData;
//  byte *userData;
};
#define EDGE_getLevelData(e)        ((byte*) &(e)[1])

struct _CCGFace {
    CCGFace     *next;  /* EHData.next */
    CCGFaceHDL  fHDL;   /* EHData.key */

    short numVerts, flags, pad1, pad2;

//  CCGVert **verts;
//  CCGEdge **edges;
//  byte *centerData;
//  byte **gridData;
//  byte *userData;
};
#define FACE_getVerts(f)        ((CCGVert**) &(f)[1])
#define FACE_getEdges(f)        ((CCGEdge**) &(FACE_getVerts(f)[(f)->numVerts]))
#define FACE_getCenterData(f)   ((byte*) &(FACE_getEdges(f)[(f)->numVerts]))

typedef enum {
    eSyncState_None = 0,
    eSyncState_Vert,
    eSyncState_Edge,
    eSyncState_Face,
    eSyncState_Partial,
} SyncState;

struct _CCGSubSurf {
    EHash *vMap;    /* map of CCGVertHDL -> Vert */
    EHash *eMap;    /* map of CCGEdgeHDL -> Edge */
    EHash *fMap;    /* map of CCGFaceHDL -> Face */

    CCGMeshIFC meshIFC;
    
    CCGAllocatorIFC allocatorIFC;
    CCGAllocatorHDL allocator;

    int subdivLevels;
    int numGrids;
    int allowEdgeCreation;
    float defaultCreaseValue;
    void *defaultEdgeUserData;

    void *q, *r;
        
        // data for calc vert normals
    int calcVertNormals;
    int normalDataOffset;

        // data for age'ing (to debug sync)
    int currentAge;
    int useAgeCounts;
    int vertUserAgeOffset;
    int edgeUserAgeOffset;
    int faceUserAgeOffset;

        // data used during syncing
    SyncState syncState;

    EHash *oldVMap, *oldEMap, *oldFMap;
    int lenTempArrays;
    CCGVert **tempVerts;
    CCGEdge **tempEdges;
};

#define CCGSUBSURF_alloc(ss, nb)            ((ss)->allocatorIFC.alloc((ss)->allocator, nb))
#define CCGSUBSURF_realloc(ss, ptr, nb, ob) ((ss)->allocatorIFC.realloc((ss)->allocator, ptr, nb, ob))
#define CCGSUBSURF_free(ss, ptr)            ((ss)->allocatorIFC.free((ss)->allocator, ptr))

/***/

static CCGVert *_vert_new(CCGVertHDL vHDL, CCGSubSurf *ss) {
    CCGVert *v = CCGSUBSURF_alloc(ss, sizeof(CCGVert) + ss->meshIFC.vertDataSize * (ss->subdivLevels+1) + ss->meshIFC.vertUserSize);
    byte *userData;

    v->vHDL = vHDL;
    v->edges = NULL;
    v->faces = NULL;
    v->numEdges = v->numFaces = 0;
    v->flags = 0;

    userData = ccgSubSurf_getVertUserData(ss, v);
    memset(userData, 0, ss->meshIFC.vertUserSize);
    if (ss->useAgeCounts) *((int*) &userData[ss->vertUserAgeOffset]) = ss->currentAge;

    return v;
}
static void _vert_remEdge(CCGVert *v, CCGEdge *e) {
    int i;
    for (i=0; i<v->numEdges; i++) {
        if (v->edges[i]==e) {
            v->edges[i] = v->edges[--v->numEdges];
            break;
        }
    }
}
static void _vert_remFace(CCGVert *v, CCGFace *f) {
    int i;
    for (i=0; i<v->numFaces; i++) {
        if (v->faces[i]==f) {
            v->faces[i] = v->faces[--v->numFaces];
            break;
        }
    }
}
static void _vert_addEdge(CCGVert *v, CCGEdge *e, CCGSubSurf *ss) {
    v->edges = CCGSUBSURF_realloc(ss, v->edges, (v->numEdges+1)*sizeof(*v->edges), v->numEdges*sizeof(*v->edges));
    v->edges[v->numEdges++] = e;
}
static void _vert_addFace(CCGVert *v, CCGFace *f, CCGSubSurf *ss) {
    v->faces = CCGSUBSURF_realloc(ss, v->faces, (v->numFaces+1)*sizeof(*v->faces), v->numFaces*sizeof(*v->faces));
    v->faces[v->numFaces++] = f;
}
static CCGEdge *_vert_findEdgeTo(const CCGVert *v, const CCGVert *vQ) {
    int i;
    for (i=0; i<v->numEdges; i++) {
        CCGEdge *e = v->edges[v->numEdges-1-i]; // XXX, note reverse
        if (    (e->v0==v && e->v1==vQ) ||
                (e->v1==v && e->v0==vQ))
            return e;
    }
    return NULL;
}
static int _vert_isBoundary(const CCGVert *v) {
    int i;
    for (i=0; i<v->numEdges; i++)
        if (_edge_isBoundary(v->edges[i]))
            return 1;
    return 0;
}

static void *_vert_getCo(CCGVert *v, int lvl, int dataSize) {
    return &VERT_getLevelData(v)[lvl*dataSize];
}
static float *_vert_getNo(CCGVert *v, int lvl, int dataSize, int normalDataOffset) {
    return (float*) &VERT_getLevelData(v)[lvl*dataSize + normalDataOffset];
}

static void _vert_free(CCGVert *v, CCGSubSurf *ss) {
    CCGSUBSURF_free(ss, v->edges);
    CCGSUBSURF_free(ss, v->faces);
    CCGSUBSURF_free(ss, v);
}

static int VERT_seam(const CCGVert *v) {
    return ((v->flags & Vert_eSeam) != 0);
}

/***/

static CCGEdge *_edge_new(CCGEdgeHDL eHDL, CCGVert *v0, CCGVert *v1, float crease, CCGSubSurf *ss) {
    CCGEdge *e = CCGSUBSURF_alloc(ss, sizeof(CCGEdge) + ss->meshIFC.vertDataSize *((ss->subdivLevels+1) + (1<<(ss->subdivLevels+1))-1) + ss->meshIFC.edgeUserSize);
    byte *userData;

    e->eHDL = eHDL;
    e->v0 = v0;
    e->v1 = v1;
    e->crease = crease;
    e->faces = NULL;
    e->numFaces = 0;
    e->flags = 0;
    _vert_addEdge(v0, e, ss);
    _vert_addEdge(v1, e, ss);

    userData = ccgSubSurf_getEdgeUserData(ss, e);
    memset(userData, 0, ss->meshIFC.edgeUserSize);
    if (ss->useAgeCounts) *((int*) &userData[ss->edgeUserAgeOffset]) = ss->currentAge;

    return e;
}
static void _edge_remFace(CCGEdge *e, CCGFace *f) {
    int i;
    for (i=0; i<e->numFaces; i++) {
        if (e->faces[i]==f) {
            e->faces[i] = e->faces[--e->numFaces];
            break;
        }
    }
}
static void _edge_addFace(CCGEdge *e, CCGFace *f, CCGSubSurf *ss) {
    e->faces = CCGSUBSURF_realloc(ss, e->faces, (e->numFaces+1)*sizeof(*e->faces), e->numFaces*sizeof(*e->faces));
    e->faces[e->numFaces++] = f;
}
static int _edge_isBoundary(const CCGEdge *e) {
    return e->numFaces<2;
}

static CCGVert *_edge_getOtherVert(CCGEdge *e, CCGVert *vQ) {
    if (vQ==e->v0) {
        return e->v1;
    } else {
        return e->v0;
    }
}

static void *_edge_getCo(CCGEdge *e, int lvl, int x, int dataSize) {
    int levelBase = lvl + (1<<lvl) - 1;
    return &EDGE_getLevelData(e)[dataSize*(levelBase + x)];
}
static float *_edge_getNo(CCGEdge *e, int lvl, int x, int dataSize, int normalDataOffset) {
    int levelBase = lvl + (1<<lvl) - 1;
    return (float*) &EDGE_getLevelData(e)[dataSize*(levelBase + x) + normalDataOffset];
}
static void *_edge_getCoVert(CCGEdge *e, CCGVert *v, int lvl, int x, int dataSize) {
    int levelBase = lvl + (1<<lvl) - 1;
    if (v==e->v0) {
        return &EDGE_getLevelData(e)[dataSize*(levelBase + x)];
    } else {
        return &EDGE_getLevelData(e)[dataSize*(levelBase + (1<<lvl) - x)];      
    }
}

static void _edge_free(CCGEdge *e, CCGSubSurf *ss) {
    CCGSUBSURF_free(ss, e->faces);
    CCGSUBSURF_free(ss, e);
}
static void _edge_unlinkMarkAndFree(CCGEdge *e, CCGSubSurf *ss) {
    _vert_remEdge(e->v0, e);
    _vert_remEdge(e->v1, e);
    e->v0->flags |= Vert_eEffected;
    e->v1->flags |= Vert_eEffected;
    _edge_free(e, ss);
}

static float EDGE_getSharpness(CCGEdge *e, int lvl) {
    if (!lvl)
        return e->crease;
    else if (!e->crease)
        return 0.0f;
    else if (e->crease - lvl < 0.0f)
        return 0.0f;
    else
        return e->crease - lvl;
}

static CCGFace *_face_new(CCGFaceHDL fHDL, CCGVert **verts, CCGEdge **edges, int numVerts, CCGSubSurf *ss) {
    int maxGridSize = 1 + (1<<(ss->subdivLevels-1));
    CCGFace *f = CCGSUBSURF_alloc(ss, sizeof(CCGFace) + sizeof(CCGVert*)*numVerts + sizeof(CCGEdge*)*numVerts + ss->meshIFC.vertDataSize *(1 + numVerts*maxGridSize + numVerts*maxGridSize*maxGridSize) + ss->meshIFC.faceUserSize);
    byte *userData;
    int i;

    f->numVerts = numVerts;
    f->fHDL = fHDL;
    f->flags = 0;

    for (i=0; i<numVerts; i++) {
        FACE_getVerts(f)[i] = verts[i];
        FACE_getEdges(f)[i] = edges[i];
        _vert_addFace(verts[i], f, ss);
        _edge_addFace(edges[i], f, ss);
    }

    userData = ccgSubSurf_getFaceUserData(ss, f);
    memset(userData, 0, ss->meshIFC.faceUserSize);
    if (ss->useAgeCounts) *((int*) &userData[ss->faceUserAgeOffset]) = ss->currentAge;

    return f;
}

static CCG_INLINE void *_face_getIECo(CCGFace *f, int lvl, int S, int x, int levels, int dataSize) {
    int maxGridSize = 1 + (1<<(levels-1));
    int spacing = 1<<(levels-lvl);
    byte *gridBase = FACE_getCenterData(f) + dataSize*(1 + S*(maxGridSize + maxGridSize*maxGridSize));
    return &gridBase[dataSize*x*spacing];
}
static CCG_INLINE void *_face_getIENo(CCGFace *f, int lvl, int S, int x, int levels, int dataSize, int normalDataOffset) {
    int maxGridSize = 1 + (1<<(levels-1));
    int spacing = 1<<(levels-lvl);
    byte *gridBase = FACE_getCenterData(f) + dataSize*(1 + S*(maxGridSize + maxGridSize*maxGridSize));
    return &gridBase[dataSize*x*spacing + normalDataOffset];
}
static CCG_INLINE void *_face_getIFCo(CCGFace *f, int lvl, int S, int x, int y, int levels, int dataSize) {
    int maxGridSize = 1 + (1<<(levels-1));
    int spacing = 1<<(levels-lvl);
    byte *gridBase = FACE_getCenterData(f) + dataSize*(1 + S*(maxGridSize + maxGridSize*maxGridSize));
    return &gridBase[dataSize*(maxGridSize + (y*maxGridSize + x)*spacing)];
}
static CCG_INLINE float *_face_getIFNo(CCGFace *f, int lvl, int S, int x, int y, int levels, int dataSize, int normalDataOffset) {
    int maxGridSize = 1 + (1<<(levels-1));
    int spacing = 1<<(levels-lvl);
    byte *gridBase = FACE_getCenterData(f) + dataSize*(1 + S*(maxGridSize + maxGridSize*maxGridSize));
    return (float*) &gridBase[dataSize*(maxGridSize + (y*maxGridSize + x)*spacing) + normalDataOffset];
}
static int _face_getVertIndex(CCGFace *f, CCGVert *v) {
    int i;
    for (i=0; i<f->numVerts; i++)
        if (FACE_getVerts(f)[i]==v)
            return i;
    return -1;
}
static CCG_INLINE void *_face_getIFCoEdge(CCGFace *f, CCGEdge *e, int lvl, int eX, int eY, int levels, int dataSize) {
    int maxGridSize = 1 + (1<<(levels-1));
    int spacing = 1<<(levels-lvl);
    int S, x, y, cx, cy;

    for (S=0; S<f->numVerts; S++)
        if (FACE_getEdges(f)[S]==e)
            break;

    eX = eX*spacing;
    eY = eY*spacing;
    if (e->v0!=FACE_getVerts(f)[S]) {
        eX = (maxGridSize*2 - 1)-1 - eX;
    }
    y = maxGridSize - 1 - eX;
    x = maxGridSize - 1 - eY;
    if (x<0) {
        S = (S+f->numVerts-1)%f->numVerts;
        cx = y;
        cy = -x;
    } else if (y<0) {
        S = (S+1)%f->numVerts;
        cx = -y;
        cy = x;
    } else {
        cx = x;
        cy = y;
    }
    return _face_getIFCo(f, levels, S, cx, cy, levels, dataSize);
}
static float *_face_getIFNoEdge(CCGFace *f, CCGEdge *e, int lvl, int eX, int eY, int levels, int dataSize, int normalDataOffset) {
    return (float*) ((byte*) _face_getIFCoEdge(f, e, lvl, eX, eY, levels, dataSize) + normalDataOffset);
}
static void _face_calcIFNo(CCGFace *f, int lvl, int S, int x, int y, float *no, int levels, int dataSize) {
    float *a = _face_getIFCo(f, lvl, S, x+0, y+0, levels, dataSize);
    float *b = _face_getIFCo(f, lvl, S, x+1, y+0, levels, dataSize);
    float *c = _face_getIFCo(f, lvl, S, x+1, y+1, levels, dataSize);
    float *d = _face_getIFCo(f, lvl, S, x+0, y+1, levels, dataSize);
    float a_cX = c[0]-a[0], a_cY = c[1]-a[1], a_cZ = c[2]-a[2];
    float b_dX = d[0]-b[0], b_dY = d[1]-b[1], b_dZ = d[2]-b[2];
    float length;

    no[0] = b_dY*a_cZ - b_dZ*a_cY;
    no[1] = b_dZ*a_cX - b_dX*a_cZ;
    no[2] = b_dX*a_cY - b_dY*a_cX;

    length = sqrt(no[0]*no[0] + no[1]*no[1] + no[2]*no[2]);

    if (length>EPSILON) {
        float invLength = 1.f/length;

        no[0] *= invLength;
        no[1] *= invLength;
        no[2] *= invLength;
    } else {
        NormZero(no);
    }
}

static void _face_free(CCGFace *f, CCGSubSurf *ss) {
    CCGSUBSURF_free(ss, f);
}
static void _face_unlinkMarkAndFree(CCGFace *f, CCGSubSurf *ss) {
    int j;
    for (j=0; j<f->numVerts; j++) {
        _vert_remFace(FACE_getVerts(f)[j], f);
        _edge_remFace(FACE_getEdges(f)[j], f);
        FACE_getVerts(f)[j]->flags |= Vert_eEffected;
    }
    _face_free(f, ss);
}

/***/

CCGSubSurf *ccgSubSurf_new(CCGMeshIFC *ifc, int subdivLevels, CCGAllocatorIFC *allocatorIFC, CCGAllocatorHDL allocator) {
    if (!allocatorIFC) {
        allocatorIFC = _getStandardAllocatorIFC();
        allocator = NULL;
    }

    if (subdivLevels<1) {
        return NULL;
    } else {
        CCGSubSurf *ss = allocatorIFC->alloc(allocator, sizeof(*ss));

        ss->allocatorIFC = *allocatorIFC;
        ss->allocator = allocator;

        ss->vMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
        ss->eMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
        ss->fMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);

        ss->meshIFC = *ifc;
        
        ss->subdivLevels = subdivLevels;
        ss->numGrids = 0;
        ss->allowEdgeCreation = 0;
        ss->defaultCreaseValue = 0;
        ss->defaultEdgeUserData = NULL;

        ss->useAgeCounts = 0;
        ss->vertUserAgeOffset = ss->edgeUserAgeOffset = ss->faceUserAgeOffset = 0;

        ss->calcVertNormals = 0;
        ss->normalDataOffset = 0;

        ss->q = CCGSUBSURF_alloc(ss, ss->meshIFC.vertDataSize);
        ss->r = CCGSUBSURF_alloc(ss, ss->meshIFC.vertDataSize);

        ss->currentAge = 0;

        ss->syncState = eSyncState_None;

        ss->oldVMap = ss->oldEMap = ss->oldFMap = NULL;
        ss->lenTempArrays = 0;
        ss->tempVerts = NULL;
        ss->tempEdges = NULL;   

        return ss;
    }
}

void ccgSubSurf_free(CCGSubSurf *ss) {
    CCGAllocatorIFC allocatorIFC = ss->allocatorIFC;
    CCGAllocatorHDL allocator = ss->allocator;

    if (ss->syncState) {
        _ehash_free(ss->oldFMap, (EHEntryFreeFP) _face_free, ss);
        _ehash_free(ss->oldEMap, (EHEntryFreeFP) _edge_free, ss);
        _ehash_free(ss->oldVMap, (EHEntryFreeFP) _vert_free, ss);

        MEM_freeN(ss->tempVerts);
        MEM_freeN(ss->tempEdges);
    }

    CCGSUBSURF_free(ss, ss->r);
    CCGSUBSURF_free(ss, ss->q);
    if (ss->defaultEdgeUserData) CCGSUBSURF_free(ss, ss->defaultEdgeUserData);

    _ehash_free(ss->fMap, (EHEntryFreeFP) _face_free, ss);
    _ehash_free(ss->eMap, (EHEntryFreeFP) _edge_free, ss);
    _ehash_free(ss->vMap, (EHEntryFreeFP) _vert_free, ss);

    CCGSUBSURF_free(ss, ss);

    if (allocatorIFC.release) {
        allocatorIFC.release(allocator);
    }
}

CCGError ccgSubSurf_setAllowEdgeCreation(CCGSubSurf *ss, int allowEdgeCreation, float defaultCreaseValue, void *defaultUserData) {
    if (ss->defaultEdgeUserData) {
        CCGSUBSURF_free(ss, ss->defaultEdgeUserData);
    }

    ss->allowEdgeCreation = !!allowEdgeCreation;
    ss->defaultCreaseValue = defaultCreaseValue;
    ss->defaultEdgeUserData = CCGSUBSURF_alloc(ss, ss->meshIFC.edgeUserSize);

    if (defaultUserData) {
        memcpy(ss->defaultEdgeUserData, defaultUserData, ss->meshIFC.edgeUserSize);
    } else {
        memset(ss->defaultEdgeUserData, 0, ss->meshIFC.edgeUserSize);
    }

    return eCCGError_None;
}
void ccgSubSurf_getAllowEdgeCreation(CCGSubSurf *ss, int *allowEdgeCreation_r, float *defaultCreaseValue_r, void *defaultUserData_r) {
    if (allowEdgeCreation_r) *allowEdgeCreation_r = ss->allowEdgeCreation;
    if (ss->allowEdgeCreation) {
        if (defaultCreaseValue_r) *defaultCreaseValue_r = ss->defaultCreaseValue;
        if (defaultUserData_r) memcpy(defaultUserData_r, ss->defaultEdgeUserData, ss->meshIFC.edgeUserSize);
    }
}

CCGError ccgSubSurf_setSubdivisionLevels(CCGSubSurf *ss, int subdivisionLevels) {
    if (subdivisionLevels<=0) {
        return eCCGError_InvalidValue;
    } else if (subdivisionLevels!=ss->subdivLevels) {
        ss->numGrids = 0;
        ss->subdivLevels = subdivisionLevels;
        _ehash_free(ss->vMap, (EHEntryFreeFP) _vert_free, ss);
        _ehash_free(ss->eMap, (EHEntryFreeFP) _edge_free, ss);
        _ehash_free(ss->fMap, (EHEntryFreeFP) _face_free, ss);
        ss->vMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
        ss->eMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
        ss->fMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
    }

    return eCCGError_None;
}

void ccgSubSurf_getUseAgeCounts(CCGSubSurf *ss, int *useAgeCounts_r, int *vertUserOffset_r, int *edgeUserOffset_r, int *faceUserOffset_r)
{
    *useAgeCounts_r = ss->useAgeCounts;

    if (vertUserOffset_r) *vertUserOffset_r = ss->vertUserAgeOffset;
    if (edgeUserOffset_r) *edgeUserOffset_r = ss->edgeUserAgeOffset;
    if (faceUserOffset_r) *faceUserOffset_r = ss->faceUserAgeOffset;
}

CCGError ccgSubSurf_setUseAgeCounts(CCGSubSurf *ss, int useAgeCounts, int vertUserOffset, int edgeUserOffset, int faceUserOffset) {
    if (useAgeCounts) {
        if (    (vertUserOffset+4>ss->meshIFC.vertUserSize) ||
                (edgeUserOffset+4>ss->meshIFC.edgeUserSize) ||
                (faceUserOffset+4>ss->meshIFC.faceUserSize)) {
            return eCCGError_InvalidValue;
        }  else {
            ss->useAgeCounts = 1;
            ss->vertUserAgeOffset = vertUserOffset;
            ss->edgeUserAgeOffset = edgeUserOffset;
            ss->faceUserAgeOffset = faceUserOffset;
        }
    } else {
        ss->useAgeCounts = 0;
        ss->vertUserAgeOffset = ss->edgeUserAgeOffset = ss->faceUserAgeOffset = 0;
    }

    return eCCGError_None;
}

CCGError ccgSubSurf_setCalcVertexNormals(CCGSubSurf *ss, int useVertNormals, int normalDataOffset) {
    if (useVertNormals) {
        if (normalDataOffset<0 || normalDataOffset+12>ss->meshIFC.vertDataSize) {
            return eCCGError_InvalidValue;
        } else {
            ss->calcVertNormals = 1;
            ss->normalDataOffset = normalDataOffset;
        }
    } else {
        ss->calcVertNormals = 0;
        ss->normalDataOffset = 0;
    }

    return eCCGError_None;
}

/***/

CCGError ccgSubSurf_initFullSync(CCGSubSurf *ss) {
    if (ss->syncState!=eSyncState_None) {
        return eCCGError_InvalidSyncState;
    }

    ss->currentAge++;

    ss->oldVMap = ss->vMap; 
    ss->oldEMap = ss->eMap; 
    ss->oldFMap = ss->fMap;

    ss->vMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
    ss->eMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);
    ss->fMap = _ehash_new(0, &ss->allocatorIFC, ss->allocator);

    ss->numGrids = 0;

    ss->lenTempArrays = 12;
    ss->tempVerts = MEM_mallocN(sizeof(*ss->tempVerts)*ss->lenTempArrays, "CCGSubsurf tempVerts");
    ss->tempEdges = MEM_mallocN(sizeof(*ss->tempEdges)*ss->lenTempArrays, "CCGSubsurf tempEdges");

    ss->syncState = eSyncState_Vert;

    return eCCGError_None;
}

CCGError ccgSubSurf_initPartialSync(CCGSubSurf *ss) {
    if (ss->syncState!=eSyncState_None) {
        return eCCGError_InvalidSyncState;
    }

    ss->currentAge++;

    ss->syncState = eSyncState_Partial;

    return eCCGError_None;
}

CCGError ccgSubSurf_syncVertDel(CCGSubSurf *ss, CCGVertHDL vHDL) {
    if (ss->syncState!=eSyncState_Partial) {
        return eCCGError_InvalidSyncState;
    } else {
        void **prevp;
        CCGVert *v = _ehash_lookupWithPrev(ss->vMap, vHDL, &prevp);

        if (!v || v->numFaces || v->numEdges) {
            return eCCGError_InvalidValue;
        } else {
            *prevp = v->next;
            _vert_free(v, ss);
        }
    }

    return eCCGError_None;
}

CCGError ccgSubSurf_syncEdgeDel(CCGSubSurf *ss, CCGEdgeHDL eHDL) {
    if (ss->syncState!=eSyncState_Partial) {
        return eCCGError_InvalidSyncState;
    } else {
        void **prevp;
        CCGEdge *e = _ehash_lookupWithPrev(ss->eMap, eHDL, &prevp);

        if (!e || e->numFaces) {
            return eCCGError_InvalidValue;
        } else {
            *prevp = e->next;
            _edge_unlinkMarkAndFree(e, ss);
        }
    }

    return eCCGError_None;
}

CCGError ccgSubSurf_syncFaceDel(CCGSubSurf *ss, CCGFaceHDL fHDL) {
    if (ss->syncState!=eSyncState_Partial) {
        return eCCGError_InvalidSyncState;
    } else {
        void **prevp;
        CCGFace *f = _ehash_lookupWithPrev(ss->fMap, fHDL, &prevp);

        if (!f) {
            return eCCGError_InvalidValue;
        } else {
            *prevp = f->next;
            _face_unlinkMarkAndFree(f, ss);
        }
    }

    return eCCGError_None;
}

CCGError ccgSubSurf_syncVert(CCGSubSurf *ss, CCGVertHDL vHDL, const void *vertData, int seam, CCGVert **v_r) {
    void **prevp;
    CCGVert *v = NULL;
    short seamflag = (seam)? Vert_eSeam: 0;
    
    if (ss->syncState==eSyncState_Partial) {
        v = _ehash_lookupWithPrev(ss->vMap, vHDL, &prevp);
        if (!v) {
            v = _vert_new(vHDL, ss);
            VertDataCopy(_vert_getCo(v,0,ss->meshIFC.vertDataSize), vertData);
            _ehash_insert(ss->vMap, (EHEntry*) v);
            v->flags = Vert_eEffected|seamflag;
        } else if (!VertDataEqual(vertData, _vert_getCo(v, 0, ss->meshIFC.vertDataSize)) || ((v->flags & Vert_eSeam) != seamflag)) {
            int i, j;

            VertDataCopy(_vert_getCo(v,0,ss->meshIFC.vertDataSize), vertData);
            v->flags = Vert_eEffected|seamflag;

            for (i=0; i<v->numEdges; i++) {
                CCGEdge *e = v->edges[i];
                e->v0->flags |= Vert_eEffected;
                e->v1->flags |= Vert_eEffected;
            }
            for (i=0; i<v->numFaces; i++) {
                CCGFace *f = v->faces[i];
                for (j=0; j<f->numVerts; j++) {
                    FACE_getVerts(f)[j]->flags |= Vert_eEffected;
                }
            }
        }
    } else {
        if (ss->syncState!=eSyncState_Vert) { 
            return eCCGError_InvalidSyncState;
        }

        v = _ehash_lookupWithPrev(ss->oldVMap, vHDL, &prevp);
        if (!v) {
            v = _vert_new(vHDL, ss);
            VertDataCopy(_vert_getCo(v,0,ss->meshIFC.vertDataSize), vertData);
            _ehash_insert(ss->vMap, (EHEntry*) v);
            v->flags = Vert_eEffected|seamflag;
        } else if (!VertDataEqual(vertData, _vert_getCo(v, 0, ss->meshIFC.vertDataSize)) || ((v->flags & Vert_eSeam) != seamflag)) {
            *prevp = v->next;
            _ehash_insert(ss->vMap, (EHEntry*) v);
            VertDataCopy(_vert_getCo(v,0,ss->meshIFC.vertDataSize), vertData);
            v->flags = Vert_eEffected|Vert_eChanged|seamflag;
        } else {
            *prevp = v->next;
            _ehash_insert(ss->vMap, (EHEntry*) v);
            v->flags = 0;
        }
    }

    if (v_r) *v_r = v;
    return eCCGError_None;
}

CCGError ccgSubSurf_syncEdge(CCGSubSurf *ss, CCGEdgeHDL eHDL, CCGVertHDL e_vHDL0, CCGVertHDL e_vHDL1, float crease, CCGEdge **e_r) {
    void **prevp;
    CCGEdge *e = NULL, *eNew;

    if (ss->syncState==eSyncState_Partial) {
        e = _ehash_lookupWithPrev(ss->eMap, eHDL, &prevp);
        if (!e || e->v0->vHDL!=e_vHDL0 || e->v1->vHDL!=e_vHDL1 || crease!=e->crease) {
            CCGVert *v0 = _ehash_lookup(ss->vMap, e_vHDL0);
            CCGVert *v1 = _ehash_lookup(ss->vMap, e_vHDL1);

            eNew = _edge_new(eHDL, v0, v1, crease, ss);

            if (e) {
                *prevp = eNew;
                eNew->next = e->next;

                _edge_unlinkMarkAndFree(e, ss);
            } else {
                _ehash_insert(ss->eMap, (EHEntry*) eNew);
            }

            eNew->v0->flags |= Vert_eEffected;
            eNew->v1->flags |= Vert_eEffected;
        }
    } else {
        if (ss->syncState==eSyncState_Vert) {
            ss->syncState = eSyncState_Edge;
        } else if (ss->syncState!=eSyncState_Edge) {
            return eCCGError_InvalidSyncState;
        }

        e = _ehash_lookupWithPrev(ss->oldEMap, eHDL, &prevp);
        if (!e || e->v0->vHDL!=e_vHDL0 || e->v1->vHDL!=e_vHDL1|| e->crease!=crease) {
            CCGVert *v0 = _ehash_lookup(ss->vMap, e_vHDL0);
            CCGVert *v1 = _ehash_lookup(ss->vMap, e_vHDL1);
            e = _edge_new(eHDL, v0, v1, crease, ss);
            _ehash_insert(ss->eMap, (EHEntry*) e);
            e->v0->flags |= Vert_eEffected;
            e->v1->flags |= Vert_eEffected;
        } else {
            *prevp = e->next;
            _ehash_insert(ss->eMap, (EHEntry*) e);
            e->flags = 0;
            if ((e->v0->flags|e->v1->flags)&Vert_eChanged) {
                e->v0->flags |= Vert_eEffected;
                e->v1->flags |= Vert_eEffected;
            }
        }
    }

    if (e_r) *e_r = e;
    return eCCGError_None;
}

CCGError ccgSubSurf_syncFace(CCGSubSurf *ss, CCGFaceHDL fHDL, int numVerts, CCGVertHDL *vHDLs, CCGFace **f_r) {
    void **prevp;
    CCGFace *f = NULL, *fNew;
    int j, k, topologyChanged = 0;

    if (numVerts>ss->lenTempArrays) {
        ss->lenTempArrays = (numVerts<ss->lenTempArrays*2)?ss->lenTempArrays*2:numVerts;
        ss->tempVerts = MEM_reallocN(ss->tempVerts, sizeof(*ss->tempVerts)*ss->lenTempArrays);
        ss->tempEdges = MEM_reallocN(ss->tempEdges, sizeof(*ss->tempEdges)*ss->lenTempArrays);
    }

    if (ss->syncState==eSyncState_Partial) {
        f = _ehash_lookupWithPrev(ss->fMap, fHDL, &prevp);

        for (k=0; k<numVerts; k++) {
            ss->tempVerts[k] = _ehash_lookup(ss->vMap, vHDLs[k]);
        }
        for (k=0; k<numVerts; k++) {
            ss->tempEdges[k] = _vert_findEdgeTo(ss->tempVerts[k], ss->tempVerts[(k+1)%numVerts]);
        }

        if (f) {
            if (    f->numVerts!=numVerts ||
                    memcmp(FACE_getVerts(f), ss->tempVerts, sizeof(*ss->tempVerts)*numVerts) ||
                    memcmp(FACE_getEdges(f), ss->tempEdges, sizeof(*ss->tempEdges)*numVerts))
                topologyChanged = 1;
        }

        if (!f || topologyChanged) {
            fNew = _face_new(fHDL, ss->tempVerts, ss->tempEdges, numVerts, ss);

            if (f) {
                ss->numGrids += numVerts - f->numVerts;

                *prevp = fNew;
                fNew->next = f->next;

                _face_unlinkMarkAndFree(f, ss);
            } else {
                ss->numGrids += numVerts;
                _ehash_insert(ss->fMap, (EHEntry*) fNew);
            }

            for (k=0; k<numVerts; k++)
                FACE_getVerts(fNew)[k]->flags |= Vert_eEffected;
        }
    } else {
        if (ss->syncState==eSyncState_Vert || ss->syncState==eSyncState_Edge) {
            ss->syncState = eSyncState_Face;
        } else if (ss->syncState!=eSyncState_Face) {
            return eCCGError_InvalidSyncState;
        }

        f = _ehash_lookupWithPrev(ss->oldFMap, fHDL, &prevp);

        for (k=0; k<numVerts; k++) {
            ss->tempVerts[k] = _ehash_lookup(ss->vMap, vHDLs[k]);

            if (!ss->tempVerts[k])
                return eCCGError_InvalidValue;
        }
        for (k=0; k<numVerts; k++) {
            ss->tempEdges[k] = _vert_findEdgeTo(ss->tempVerts[k], ss->tempVerts[(k+1)%numVerts]);

            if (!ss->tempEdges[k]) {
                if (ss->allowEdgeCreation) {
                    CCGEdge *e = ss->tempEdges[k] = _edge_new((CCGEdgeHDL) -1, ss->tempVerts[k], ss->tempVerts[(k+1)%numVerts], ss->defaultCreaseValue, ss);
                    _ehash_insert(ss->eMap, (EHEntry*) e);
                    e->v0->flags |= Vert_eEffected;
                    e->v1->flags |= Vert_eEffected;
                    if (ss->meshIFC.edgeUserSize) {
                        memcpy(ccgSubSurf_getEdgeUserData(ss, e), ss->defaultEdgeUserData, ss->meshIFC.edgeUserSize);
                    }
                } else {
                    return eCCGError_InvalidValue;
                }
            }
        }

        if (f) {
            if (    f->numVerts!=numVerts ||
                    memcmp(FACE_getVerts(f), ss->tempVerts, sizeof(*ss->tempVerts)*numVerts) ||
                    memcmp(FACE_getEdges(f), ss->tempEdges, sizeof(*ss->tempEdges)*numVerts))
                topologyChanged = 1;
        }

        if (!f || topologyChanged) {
            f = _face_new(fHDL, ss->tempVerts, ss->tempEdges, numVerts, ss);
            _ehash_insert(ss->fMap, (EHEntry*) f);
            ss->numGrids += numVerts;

            for (k=0; k<numVerts; k++)
                FACE_getVerts(f)[k]->flags |= Vert_eEffected;
        } else {
            *prevp = f->next;
            _ehash_insert(ss->fMap, (EHEntry*) f);
            f->flags = 0;
            ss->numGrids += f->numVerts;

            for (j=0; j<f->numVerts; j++) {
                if (FACE_getVerts(f)[j]->flags&Vert_eChanged) {
                    for (k=0; k<f->numVerts; k++)
                        FACE_getVerts(f)[k]->flags |= Vert_eEffected;
                    break;
                }
            }
        }
    }

    if (f_r) *f_r = f;
    return eCCGError_None;
}

static void ccgSubSurf__sync(CCGSubSurf *ss);
CCGError ccgSubSurf_processSync(CCGSubSurf *ss) {
    if (ss->syncState==eSyncState_Partial) {
        ss->syncState = eSyncState_None;

        ccgSubSurf__sync(ss);
    } else if (ss->syncState) {
        _ehash_free(ss->oldFMap, (EHEntryFreeFP) _face_unlinkMarkAndFree, ss);
        _ehash_free(ss->oldEMap, (EHEntryFreeFP) _edge_unlinkMarkAndFree, ss);
        _ehash_free(ss->oldVMap, (EHEntryFreeFP) _vert_free, ss);
        MEM_freeN(ss->tempEdges);
        MEM_freeN(ss->tempVerts);

        ss->lenTempArrays = 0;

        ss->oldFMap = ss->oldEMap = ss->oldVMap = NULL;
        ss->tempVerts = NULL;
        ss->tempEdges = NULL;

        ss->syncState = eSyncState_None;

        ccgSubSurf__sync(ss);
    } else {
        return eCCGError_InvalidSyncState;
    }

    return eCCGError_None;
}

#define VERT_getNo(e, lvl)                  _vert_getNo(e, lvl, vertDataSize, normalDataOffset)
#define EDGE_getNo(e, lvl, x)               _edge_getNo(e, lvl, x, vertDataSize, normalDataOffset)
#define FACE_getIFNo(f, lvl, S, x, y)       _face_getIFNo(f, lvl, S, x, y, subdivLevels, vertDataSize, normalDataOffset)
#define FACE_calcIFNo(f, lvl, S, x, y, no)  _face_calcIFNo(f, lvl, S, x, y, no, subdivLevels, vertDataSize)
#define FACE_getIENo(f, lvl, S, x)          _face_getIENo(f, lvl, S, x, subdivLevels, vertDataSize, normalDataOffset)
static void ccgSubSurf__calcVertNormals(CCGSubSurf *ss,
    CCGVert **effectedV, CCGEdge **effectedE, CCGFace **effectedF,
    int numEffectedV, int numEffectedE, int numEffectedF) {
    int i,ptrIdx;
    int subdivLevels = ss->subdivLevels;
    int lvl = ss->subdivLevels;
    int edgeSize = 1 + (1<<lvl);
    int gridSize = 1 + (1<<(lvl-1));
    int normalDataOffset = ss->normalDataOffset;
    int vertDataSize = ss->meshIFC.vertDataSize;

    #pragma omp parallel for private(ptrIdx) if(numEffectedF*edgeSize*edgeSize*4 >= CCG_OMP_LIMIT)
    for (ptrIdx=0; ptrIdx<numEffectedF; ptrIdx++) {
        CCGFace *f = (CCGFace*) effectedF[ptrIdx];
        int S, x, y;
        float no[3];

        for (S=0; S<f->numVerts; S++) {
            for (y=0; y<gridSize-1; y++)
                for (x=0; x<gridSize-1; x++)
                    NormZero(FACE_getIFNo(f, lvl, S, x, y));

            if (FACE_getEdges(f)[(S-1+f->numVerts)%f->numVerts]->flags&Edge_eEffected)
                for (x=0; x<gridSize-1; x++)
                    NormZero(FACE_getIFNo(f, lvl, S, x, gridSize-1));
            if (FACE_getEdges(f)[S]->flags&Edge_eEffected)
                for (y=0; y<gridSize-1; y++)
                    NormZero(FACE_getIFNo(f, lvl, S, gridSize-1, y));
            if (FACE_getVerts(f)[S]->flags&Vert_eEffected)
                NormZero(FACE_getIFNo(f, lvl, S, gridSize-1, gridSize-1));
        }

        for (S=0; S<f->numVerts; S++) {
            int yLimit = !(FACE_getEdges(f)[(S-1+f->numVerts)%f->numVerts]->flags&Edge_eEffected);
            int xLimit = !(FACE_getEdges(f)[S]->flags&Edge_eEffected);
            int yLimitNext = xLimit;
            int xLimitPrev = yLimit;
            
            for (y=0; y<gridSize - 1; y++) {
                for (x=0; x<gridSize - 1; x++) {
                    int xPlusOk = (!xLimit || x<gridSize-2);
                    int yPlusOk = (!yLimit || y<gridSize-2);

                    FACE_calcIFNo(f, lvl, S, x, y, no);

                    NormAdd(FACE_getIFNo(f, lvl, S, x+0, y+0), no);
                    if (xPlusOk)
                        NormAdd(FACE_getIFNo(f, lvl, S, x+1, y+0), no);
                    if (yPlusOk)
                        NormAdd(FACE_getIFNo(f, lvl, S, x+0, y+1), no);
                    if (xPlusOk && yPlusOk) {
                        if (x<gridSize-2 || y<gridSize-2 || FACE_getVerts(f)[S]->flags&Vert_eEffected) {
                            NormAdd(FACE_getIFNo(f, lvl, S, x+1, y+1), no);
                        }
                    }

                    if (x==0 && y==0) {
                        int K;

                        if (!yLimitNext || 1<gridSize-1)
                            NormAdd(FACE_getIFNo(f, lvl, (S+1)%f->numVerts, 0, 1), no);
                        if (!xLimitPrev || 1<gridSize-1)
                            NormAdd(FACE_getIFNo(f, lvl, (S-1+f->numVerts)%f->numVerts, 1, 0), no);

                        for (K=0; K<f->numVerts; K++) {
                            if (K!=S) {
                                NormAdd(FACE_getIFNo(f, lvl, K, 0, 0), no);
                            }
                        }
                    } else if (y==0) {
                        NormAdd(FACE_getIFNo(f, lvl, (S+1)%f->numVerts, 0, x), no);
                        if (!yLimitNext || x<gridSize-2)
                            NormAdd(FACE_getIFNo(f, lvl, (S+1)%f->numVerts, 0, x+1), no);
                    } else if (x==0) {
                        NormAdd(FACE_getIFNo(f, lvl, (S-1+f->numVerts)%f->numVerts, y, 0), no);
                        if (!xLimitPrev || y<gridSize-2)
                            NormAdd(FACE_getIFNo(f, lvl, (S-1+f->numVerts)%f->numVerts, y+1, 0), no);
                    }
                }
            }
        }
    }
        // XXX can I reduce the number of normalisations here?
    for (ptrIdx=0; ptrIdx<numEffectedV; ptrIdx++) {
        CCGVert *v = (CCGVert*) effectedV[ptrIdx];
        float length, *no = _vert_getNo(v, lvl, vertDataSize, normalDataOffset);

        NormZero(no);

        for (i=0; i<v->numFaces; i++) {
            CCGFace *f = v->faces[i];
            NormAdd(no, FACE_getIFNo(f, lvl, _face_getVertIndex(f,v), gridSize-1, gridSize-1));
        }

        length = sqrt(no[0]*no[0] + no[1]*no[1] + no[2]*no[2]);

        if (length>EPSILON) {
            float invLength = 1.0f/length;
            no[0] *= invLength;
            no[1] *= invLength;
            no[2] *= invLength;
        } else {
            NormZero(no);
        }

        for (i=0; i<v->numFaces; i++) {
            CCGFace *f = v->faces[i];
            NormCopy(FACE_getIFNo(f, lvl, _face_getVertIndex(f,v), gridSize-1, gridSize-1), no);
        }
    }
    for (ptrIdx=0; ptrIdx<numEffectedE; ptrIdx++) {
        CCGEdge *e = (CCGEdge*) effectedE[ptrIdx];

        if (e->numFaces) {
            CCGFace *fLast = e->faces[e->numFaces-1];
            int x;

            for (i=0; i<e->numFaces-1; i++) {
                CCGFace *f = e->faces[i];

                for (x=1; x<edgeSize-1; x++) {
                    NormAdd(_face_getIFNoEdge(fLast, e, lvl, x, 0, subdivLevels, vertDataSize, normalDataOffset),
                            _face_getIFNoEdge(f, e, lvl, x, 0, subdivLevels, vertDataSize, normalDataOffset));
                }
            }

            for (i=0; i<e->numFaces-1; i++) {
                CCGFace *f = e->faces[i];

                for (x=1; x<edgeSize-1; x++) {
                    NormCopy(_face_getIFNoEdge(f, e, lvl, x, 0, subdivLevels, vertDataSize, normalDataOffset),
                            _face_getIFNoEdge(fLast, e, lvl, x, 0, subdivLevels, vertDataSize, normalDataOffset));
                }
            }
        }
    }

    #pragma omp parallel for private(ptrIdx) if(numEffectedF*edgeSize*edgeSize*4 >= CCG_OMP_LIMIT)
    for (ptrIdx=0; ptrIdx<numEffectedF; ptrIdx++) {
        CCGFace *f = (CCGFace*) effectedF[ptrIdx];
        int S, x, y;

        for (S=0; S<f->numVerts; S++) {
            NormCopy(FACE_getIFNo(f, lvl, (S+1)%f->numVerts, 0, gridSize-1),
                     FACE_getIFNo(f, lvl, S, gridSize-1, 0));
        }

        for (S=0; S<f->numVerts; S++) {
            for (y=0; y<gridSize; y++) {
                for (x=0; x<gridSize; x++) {
                    float *no = FACE_getIFNo(f, lvl, S, x, y);
                    float length = sqrt(no[0]*no[0] + no[1]*no[1] + no[2]*no[2]);

                    if (length>EPSILON) {
                        float invLength = 1.0f/length;
                        no[0] *= invLength;
                        no[1] *= invLength;
                        no[2] *= invLength;
                    } else {
                        NormZero(no);
                    }
                }
            }

            VertDataCopy((float*)((byte*)FACE_getCenterData(f) + normalDataOffset),
                FACE_getIFNo(f, lvl, S, 0, 0));

            for (x=1; x<gridSize-1; x++)
                NormCopy(FACE_getIENo(f, lvl, S, x),
                    FACE_getIFNo(f, lvl, S, x, 0));
        }
    }

    for (ptrIdx=0; ptrIdx<numEffectedE; ptrIdx++) {
        CCGEdge *e = (CCGEdge*) effectedE[ptrIdx];

        if (e->numFaces) {
            CCGFace *f = e->faces[0];
            int x;

            for (x=0; x<edgeSize; x++)
                NormCopy(EDGE_getNo(e, lvl, x),
                    _face_getIFNoEdge(f, e, lvl, x, 0, subdivLevels, vertDataSize, normalDataOffset));
        }
        else {
            /* set to zero here otherwise the normals are uninitialized memory
             * render: tests/animation/knight.blend with valgrind.
             * we could be more clever and interpolate vertex normals but these are
             * most likely not used so just zero out. */
            int x;

            for (x=0; x<edgeSize; x++) {
                NormZero(EDGE_getNo(e, lvl, x));
            }
        }
    }
}
#undef FACE_getIFNo

#define VERT_getCo(v, lvl)              _vert_getCo(v, lvl, vertDataSize)
#define EDGE_getCo(e, lvl, x)           _edge_getCo(e, lvl, x, vertDataSize)
#define FACE_getIECo(f, lvl, S, x)      _face_getIECo(f, lvl, S, x, subdivLevels, vertDataSize)
#define FACE_getIFCo(f, lvl, S, x, y)   _face_getIFCo(f, lvl, S, x, y, subdivLevels, vertDataSize)
static void ccgSubSurf__calcSubdivLevel(CCGSubSurf *ss,
    CCGVert **effectedV, CCGEdge **effectedE, CCGFace **effectedF,
    int numEffectedV, int numEffectedE, int numEffectedF, int curLvl) {
    int subdivLevels = ss->subdivLevels;
    int edgeSize = 1 + (1<<curLvl);
    int gridSize = 1 + (1<<(curLvl-1));
    int nextLvl = curLvl+1;
    int ptrIdx, cornerIdx, i;
    int vertDataSize = ss->meshIFC.vertDataSize;
    void *q = ss->q, *r = ss->r;

    #pragma omp parallel for private(ptrIdx) if(numEffectedF*edgeSize*edgeSize*4 >= CCG_OMP_LIMIT)
    for (ptrIdx=0; ptrIdx<numEffectedF; ptrIdx++) {
        CCGFace *f = (CCGFace*) effectedF[ptrIdx];
        int S, x, y;

            /* interior face midpoints
             *  o old interior face points
             */
        for (S=0; S<f->numVerts; S++) {
            for (y=0; y<gridSize-1; y++) {
                for (x=0; x<gridSize-1; x++) {
                    int fx = 1 + 2*x;
                    int fy = 1 + 2*y;
                    void *co0 = FACE_getIFCo(f, curLvl, S, x+0, y+0);
                    void *co1 = FACE_getIFCo(f, curLvl, S, x+1, y+0);
                    void *co2 = FACE_getIFCo(f, curLvl, S, x+1, y+1);
                    void *co3 = FACE_getIFCo(f, curLvl, S, x+0, y+1);
                    void *co = FACE_getIFCo(f, nextLvl, S, fx, fy);

                    VertDataAvg4(co, co0, co1, co2, co3);
                }
            }
        }

            /* interior edge midpoints
             *  o old interior edge points
             *  o new interior face midpoints
             */
        for (S=0; S<f->numVerts; S++) {
            for (x=0; x<gridSize-1; x++) {
                int fx = x*2 + 1;
                void *co0 = FACE_getIECo(f, curLvl, S, x+0);
                void *co1 = FACE_getIECo(f, curLvl, S, x+1);
                void *co2 = FACE_getIFCo(f, nextLvl, (S+1)%f->numVerts, 1, fx);
                void *co3 = FACE_getIFCo(f, nextLvl, S, fx, 1);
                void *co = FACE_getIECo(f, nextLvl, S, fx);
                
                VertDataAvg4(co, co0, co1, co2, co3);
            }

                    /* interior face interior edge midpoints
                     *  o old interior face points
                     *  o new interior face midpoints
                     */

                /* vertical */
            for (x=1; x<gridSize-1; x++) {
                for (y=0; y<gridSize-1; y++) {
                    int fx = x*2;
                    int fy = y*2+1;
                    void *co0 = FACE_getIFCo(f, curLvl, S, x, y+0);
                    void *co1 = FACE_getIFCo(f, curLvl, S, x, y+1);
                    void *co2 = FACE_getIFCo(f, nextLvl, S, fx-1, fy);
                    void *co3 = FACE_getIFCo(f, nextLvl, S, fx+1, fy);
                    void *co = FACE_getIFCo(f, nextLvl, S, fx, fy);

                    VertDataAvg4(co, co0, co1, co2, co3);
                }
            }

                /* horizontal */
            for (y=1; y<gridSize-1; y++) {
                for (x=0; x<gridSize-1; x++) {
                    int fx = x*2+1;
                    int fy = y*2;
                    void *co0 = FACE_getIFCo(f, curLvl, S, x+0, y);
                    void *co1 = FACE_getIFCo(f, curLvl, S, x+1, y);
                    void *co2 = FACE_getIFCo(f, nextLvl, S, fx, fy-1);
                    void *co3 = FACE_getIFCo(f, nextLvl, S, fx, fy+1);
                    void *co = FACE_getIFCo(f, nextLvl, S, fx, fy);

                    VertDataAvg4(co, co0, co1, co2, co3);
                }
            }
        }
    }

        /* exterior edge midpoints
         *  o old exterior edge points
         *  o new interior face midpoints
         */
    for (ptrIdx=0; ptrIdx<numEffectedE; ptrIdx++) {
        CCGEdge *e = (CCGEdge*) effectedE[ptrIdx];
        float sharpness = EDGE_getSharpness(e, curLvl);
        int x, j;

        if (_edge_isBoundary(e) || sharpness > 1.0f) {
            for (x=0; x<edgeSize-1; x++) {
                int fx = x*2 + 1;
                void *co0 = EDGE_getCo(e, curLvl, x+0);
                void *co1 = EDGE_getCo(e, curLvl, x+1);
                void *co = EDGE_getCo(e, nextLvl, fx);

                VertDataCopy(co, co0);
                VertDataAdd(co, co1);
                VertDataMulN(co, 0.5f);
            }
        } else {
            for (x=0; x<edgeSize-1; x++) {
                int fx = x*2 + 1;
                void *co0 = EDGE_getCo(e, curLvl, x+0);
                void *co1 = EDGE_getCo(e, curLvl, x+1);
                void *co = EDGE_getCo(e, nextLvl, fx);
                int numFaces = 0;

                VertDataCopy(q, co0);
                VertDataAdd(q, co1);

                for (j=0; j<e->numFaces; j++) {
                    CCGFace *f = e->faces[j];
                    VertDataAdd(q, _face_getIFCoEdge(f, e, nextLvl, fx, 1, subdivLevels, vertDataSize));
                    numFaces++;
                }

                VertDataMulN(q, 1.0f/(2.0f+numFaces));

                VertDataCopy(r, co0);
                VertDataAdd(r, co1);
                VertDataMulN(r, 0.5f);

                VertDataCopy(co, q);
                VertDataSub(r, q);
                VertDataMulN(r, sharpness);
                VertDataAdd(co, r);
            }
        }
    }

        /* exterior vertex shift
         *  o old vertex points (shifting)
         *  o old exterior edge points
         *  o new interior face midpoints
         */
    for (ptrIdx=0; ptrIdx<numEffectedV; ptrIdx++) {
        CCGVert *v = (CCGVert*) effectedV[ptrIdx];
        void *co = VERT_getCo(v, curLvl);
        void *nCo = VERT_getCo(v, nextLvl);
        int sharpCount = 0, allSharp = 1;
        float avgSharpness = 0.0;
        int j, seam = VERT_seam(v), seamEdges = 0;

        for (j=0; j<v->numEdges; j++) {
            CCGEdge *e = v->edges[j];
            float sharpness = EDGE_getSharpness(e, curLvl);

            if (seam && _edge_isBoundary(e))
                seamEdges++;

            if (sharpness!=0.0f) {
                sharpCount++;
                avgSharpness += sharpness;
            } else {
                allSharp = 0;
            }
        }

        if(sharpCount) {
            avgSharpness /= sharpCount;
            if (avgSharpness > 1.0f) {
                avgSharpness = 1.0f;
            }
        }

        if (seamEdges < 2 || seamEdges != v->numEdges)
            seam = 0;

        if (!v->numEdges) {
            VertDataCopy(nCo, co);
        } else if (_vert_isBoundary(v)) {
            int numBoundary = 0;

            VertDataZero(r);
            for (j=0; j<v->numEdges; j++) {
                CCGEdge *e = v->edges[j];
                if (_edge_isBoundary(e)) {
                    VertDataAdd(r, _edge_getCoVert(e, v, curLvl, 1, vertDataSize));
                    numBoundary++;
                }
            }

            VertDataCopy(nCo, co);
            VertDataMulN(nCo, 0.75f);
            VertDataMulN(r, 0.25f/numBoundary);
            VertDataAdd(nCo, r);
        } else {
            int cornerIdx = (1 + (1<<(curLvl))) - 2;
            int numEdges = 0, numFaces = 0;

            VertDataZero(q);
            for (j=0; j<v->numFaces; j++) {
                CCGFace *f = v->faces[j];
                VertDataAdd(q, FACE_getIFCo(f, nextLvl, _face_getVertIndex(f,v), cornerIdx, cornerIdx));
                numFaces++;
            }
            VertDataMulN(q, 1.0f/numFaces);
            VertDataZero(r);
            for (j=0; j<v->numEdges; j++) {
                CCGEdge *e = v->edges[j];
                VertDataAdd(r, _edge_getCoVert(e, v, curLvl, 1,vertDataSize));
                numEdges++;
            }
            VertDataMulN(r, 1.0f/numEdges);

            VertDataCopy(nCo, co);
            VertDataMulN(nCo, numEdges-2.0f);
            VertDataAdd(nCo, q);
            VertDataAdd(nCo, r);
            VertDataMulN(nCo, 1.0f/numEdges);
        }

        if ((sharpCount>1 && v->numFaces) || seam) {
            VertDataZero(q);

            if (seam) {
                avgSharpness = 1.0f;
                sharpCount = seamEdges;
                allSharp = 1;
            }

            for (j=0; j<v->numEdges; j++) {
                CCGEdge *e = v->edges[j];
                float sharpness = EDGE_getSharpness(e, curLvl);

                if (seam) {
                    if (_edge_isBoundary(e))
                        VertDataAdd(q, _edge_getCoVert(e, v, curLvl, 1, vertDataSize));
                } else if (sharpness != 0.0f) {
                    VertDataAdd(q, _edge_getCoVert(e, v, curLvl, 1, vertDataSize));
                }
            }

            VertDataMulN(q, (float) 1/sharpCount);

            if (sharpCount!=2 || allSharp) {
                    // q = q + (co-q)*avgSharpness
                VertDataCopy(r, co);
                VertDataSub(r, q);
                VertDataMulN(r, avgSharpness);
                VertDataAdd(q, r);
            }

                // r = co*.75 + q*.25
            VertDataCopy(r, co);
            VertDataMulN(r, .75f);
            VertDataMulN(q, .25f);
            VertDataAdd(r, q);

                // nCo = nCo  + (r-nCo)*avgSharpness
            VertDataSub(r, nCo);
            VertDataMulN(r, avgSharpness);
            VertDataAdd(nCo, r);
        }
    }

        /* exterior edge interior shift
         *  o old exterior edge midpoints (shifting)
         *  o old exterior edge midpoints
         *  o new interior face midpoints
         */
    for (ptrIdx=0; ptrIdx<numEffectedE; ptrIdx++) {
        CCGEdge *e = (CCGEdge*) effectedE[ptrIdx];
        float sharpness = EDGE_getSharpness(e, curLvl);
        int sharpCount = 0;
        float avgSharpness = 0.0;
        int x, j;

        if (sharpness!=0.0f) {
            sharpCount = 2;
            avgSharpness += sharpness;

            if (avgSharpness > 1.0f) {
                avgSharpness = 1.0f;
            }
        } else {
            sharpCount = 0;
            avgSharpness = 0;
        }

        if (_edge_isBoundary(e) && (!e->numFaces || sharpCount<2)) {
            for (x=1; x<edgeSize-1; x++) {
                int fx = x*2;
                void *co = EDGE_getCo(e, curLvl, x);
                void *nCo = EDGE_getCo(e, nextLvl, fx);
                VertDataCopy(r, EDGE_getCo(e, curLvl, x-1));
                VertDataAdd(r, EDGE_getCo(e, curLvl, x+1));
                VertDataMulN(r, 0.5f);
                VertDataCopy(nCo, co);
                VertDataMulN(nCo, 0.75f);
                VertDataMulN(r, 0.25f);
                VertDataAdd(nCo, r);
            }
        } else {
            for (x=1; x<edgeSize-1; x++) {
                int fx = x*2;
                void *co = EDGE_getCo(e, curLvl, x);
                void *nCo = EDGE_getCo(e, nextLvl, fx);
                int numFaces = 0;

                VertDataZero(q);
                VertDataZero(r);
                VertDataAdd(r, EDGE_getCo(e, curLvl, x-1));
                VertDataAdd(r, EDGE_getCo(e, curLvl, x+1));
                for (j=0; j<e->numFaces; j++) {
                    CCGFace *f = e->faces[j];
                    VertDataAdd(q, _face_getIFCoEdge(f, e, nextLvl, fx-1, 1, subdivLevels, vertDataSize));
                    VertDataAdd(q, _face_getIFCoEdge(f, e, nextLvl, fx+1, 1, subdivLevels, vertDataSize));

                    VertDataAdd(r, _face_getIFCoEdge(f, e, curLvl, x, 1, subdivLevels, vertDataSize));
                    numFaces++;
                }
                VertDataMulN(q, 1.0f/(numFaces*2.0f));
                VertDataMulN(r, 1.0f/(2.0f + numFaces));

                VertDataCopy(nCo, co);
                VertDataMulN(nCo, (float) numFaces);
                VertDataAdd(nCo, q);
                VertDataAdd(nCo, r);
                VertDataMulN(nCo, 1.0f/(2+numFaces));

                if (sharpCount==2) {
                    VertDataCopy(q, co);
                    VertDataMulN(q, 6.0f);
                    VertDataAdd(q, EDGE_getCo(e, curLvl, x-1));
                    VertDataAdd(q, EDGE_getCo(e, curLvl, x+1));
                    VertDataMulN(q, 1/8.0f);

                    VertDataSub(q, nCo);
                    VertDataMulN(q, avgSharpness);
                    VertDataAdd(nCo, q);
                }
            }
        }
    }

    #pragma omp parallel private(ptrIdx) if(numEffectedF*edgeSize*edgeSize*4 >= CCG_OMP_LIMIT)
    {
        void *q, *r;

        #pragma omp critical
        {
            q = MEM_mallocN(ss->meshIFC.vertDataSize, "CCGSubsurf q");
            r = MEM_mallocN(ss->meshIFC.vertDataSize, "CCGSubsurf r");
        }

        #pragma omp for schedule(static)
        for (ptrIdx=0; ptrIdx<numEffectedF; ptrIdx++) {
            CCGFace *f = (CCGFace*) effectedF[ptrIdx];
            int S, x, y;

                /* interior center point shift
                 *  o old face center point (shifting)
                 *  o old interior edge points
                 *  o new interior face midpoints
                 */
            VertDataZero(q);
            for (S=0; S<f->numVerts; S++) {
                VertDataAdd(q, FACE_getIFCo(f, nextLvl, S, 1, 1));
            }
            VertDataMulN(q, 1.0f/f->numVerts);
            VertDataZero(r);
            for (S=0; S<f->numVerts; S++) {
                VertDataAdd(r, FACE_getIECo(f, curLvl, S, 1));
            }
            VertDataMulN(r, 1.0f/f->numVerts);

            VertDataMulN(FACE_getCenterData(f), f->numVerts-2.0f);
            VertDataAdd(FACE_getCenterData(f), q);
            VertDataAdd(FACE_getCenterData(f), r);
            VertDataMulN(FACE_getCenterData(f), 1.0f/f->numVerts);

            for (S=0; S<f->numVerts; S++) {
                    /* interior face shift
                     *  o old interior face point (shifting)
                     *  o new interior edge midpoints
                     *  o new interior face midpoints
                     */
                for (x=1; x<gridSize-1; x++) {
                    for (y=1; y<gridSize-1; y++) {
                        int fx = x*2;
                        int fy = y*2;
                        void *co = FACE_getIFCo(f, curLvl, S, x, y);
                        void *nCo = FACE_getIFCo(f, nextLvl, S, fx, fy);
                        
                        VertDataAvg4(q, FACE_getIFCo(f, nextLvl, S, fx-1, fy-1),
                            FACE_getIFCo(f, nextLvl, S, fx+1, fy-1),
                            FACE_getIFCo(f, nextLvl, S, fx+1, fy+1),
                            FACE_getIFCo(f, nextLvl, S, fx-1, fy+1));

                        VertDataAvg4(r, FACE_getIFCo(f, nextLvl, S, fx-1, fy+0),
                            FACE_getIFCo(f, nextLvl, S, fx+1, fy+0),
                            FACE_getIFCo(f, nextLvl, S, fx+0, fy-1),
                            FACE_getIFCo(f, nextLvl, S, fx+0, fy+1));

                        VertDataCopy(nCo, co);
                        VertDataSub(nCo, q);
                        VertDataMulN(nCo, 0.25f);
                        VertDataAdd(nCo, r);
                    }
                }

                    /* interior edge interior shift
                     *  o old interior edge point (shifting)
                     *  o new interior edge midpoints
                     *  o new interior face midpoints
                     */
                for (x=1; x<gridSize-1; x++) {
                    int fx = x*2;
                    void *co = FACE_getIECo(f, curLvl, S, x);
                    void *nCo = FACE_getIECo(f, nextLvl, S, fx);
                    
                    VertDataAvg4(q, FACE_getIFCo(f, nextLvl, (S+1)%f->numVerts, 1, fx-1),
                        FACE_getIFCo(f, nextLvl, (S+1)%f->numVerts, 1, fx+1),
                        FACE_getIFCo(f, nextLvl, S, fx+1, +1),
                        FACE_getIFCo(f, nextLvl, S, fx-1, +1));

                    VertDataAvg4(r, FACE_getIECo(f, nextLvl, S, fx-1),
                        FACE_getIECo(f, nextLvl, S, fx+1),
                        FACE_getIFCo(f, nextLvl, (S+1)%f->numVerts, 1, fx),
                        FACE_getIFCo(f, nextLvl, S, fx, 1));

                    VertDataCopy(nCo, co);
                    VertDataSub(nCo, q);
                    VertDataMulN(nCo, 0.25f);
                    VertDataAdd(nCo, r);
                }
            }
        }

        #pragma omp critical
        {
            MEM_freeN(q);
            MEM_freeN(r);
        }
    }

        /* copy down */
    edgeSize = 1 + (1<<(nextLvl));
    gridSize = 1 + (1<<((nextLvl)-1));
    cornerIdx = gridSize-1;

    #pragma omp parallel for private(i) if(numEffectedF*edgeSize*edgeSize*4 >= CCG_OMP_LIMIT)
    for (i=0; i<numEffectedE; i++) {
        CCGEdge *e = effectedE[i];
        VertDataCopy(EDGE_getCo(e, nextLvl, 0), VERT_getCo(e->v0, nextLvl));
        VertDataCopy(EDGE_getCo(e, nextLvl, edgeSize-1), VERT_getCo(e->v1, nextLvl));
    }

    #pragma omp parallel for private(i) if(numEffectedF*edgeSize*edgeSize*4 >= CCG_OMP_LIMIT)
    for (i=0; i<numEffectedF; i++) {
        CCGFace *f = effectedF[i];
        int S, x;

        for (S=0; S<f->numVerts; S++) {
            CCGEdge *e = FACE_getEdges(f)[S];
            CCGEdge *prevE = FACE_getEdges(f)[(S+f->numVerts-1)%f->numVerts];

            VertDataCopy(FACE_getIFCo(f, nextLvl, S, 0, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIECo(f, nextLvl, S, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIFCo(f, nextLvl, S, cornerIdx, cornerIdx), VERT_getCo(FACE_getVerts(f)[S], nextLvl));
            VertDataCopy(FACE_getIECo(f, nextLvl, S, cornerIdx), EDGE_getCo(FACE_getEdges(f)[S], nextLvl, cornerIdx));
            for (x=1; x<gridSize-1; x++) {
                void *co = FACE_getIECo(f, nextLvl, S, x);
                VertDataCopy(FACE_getIFCo(f, nextLvl, S, x, 0), co);
                VertDataCopy(FACE_getIFCo(f, nextLvl, (S+1)%f->numVerts, 0, x), co);
            }
            for (x=0; x<gridSize-1; x++) {
                int eI = gridSize-1-x;
                VertDataCopy(FACE_getIFCo(f, nextLvl, S, cornerIdx, x), _edge_getCoVert(e, FACE_getVerts(f)[S], nextLvl, eI,vertDataSize));
                VertDataCopy(FACE_getIFCo(f, nextLvl, S, x, cornerIdx), _edge_getCoVert(prevE, FACE_getVerts(f)[S], nextLvl, eI,vertDataSize));
            }
        }
    }
}


static void ccgSubSurf__sync(CCGSubSurf *ss) {
    CCGVert **effectedV;
    CCGEdge **effectedE;
    CCGFace **effectedF;
    int numEffectedV, numEffectedE, numEffectedF;
    int subdivLevels = ss->subdivLevels;
    int vertDataSize = ss->meshIFC.vertDataSize;
    int i, j, ptrIdx, S;
    int curLvl, nextLvl;
    void *q = ss->q, *r = ss->r;

    effectedV = MEM_mallocN(sizeof(*effectedV)*ss->vMap->numEntries, "CCGSubsurf effectedV");
    effectedE = MEM_mallocN(sizeof(*effectedE)*ss->eMap->numEntries, "CCGSubsurf effectedE");
    effectedF = MEM_mallocN(sizeof(*effectedF)*ss->fMap->numEntries, "CCGSubsurf effectedF");
    numEffectedV = numEffectedE = numEffectedF = 0;
    for (i=0; i<ss->vMap->curSize; i++) {
        CCGVert *v = (CCGVert*) ss->vMap->buckets[i];
        for (; v; v = v->next) {
            if (v->flags&Vert_eEffected) {
                effectedV[numEffectedV++] = v;

                for (j=0; j<v->numEdges; j++) {
                    CCGEdge *e = v->edges[j];
                    if (!(e->flags&Edge_eEffected)) {
                        effectedE[numEffectedE++] = e;
                        e->flags |= Edge_eEffected;
                    }
                }

                for (j=0; j<v->numFaces; j++) {
                    CCGFace *f = v->faces[j];
                    if (!(f->flags&Face_eEffected)) {
                        effectedF[numEffectedF++] = f;
                        f->flags |= Face_eEffected;
                    }
                }
            }
        }
    }

    curLvl = 0;
    nextLvl = curLvl+1;

    for (ptrIdx=0; ptrIdx<numEffectedF; ptrIdx++) {
        CCGFace *f = effectedF[ptrIdx];
        void *co = FACE_getCenterData(f);
        VertDataZero(co);
        for (i=0; i<f->numVerts; i++) {
            VertDataAdd(co, VERT_getCo(FACE_getVerts(f)[i], curLvl));
        }
        VertDataMulN(co, 1.0f/f->numVerts);

        f->flags = 0;
    }
    for (ptrIdx=0; ptrIdx<numEffectedE; ptrIdx++) {
        CCGEdge *e = effectedE[ptrIdx];
        void *co = EDGE_getCo(e, nextLvl, 1);
        float sharpness = EDGE_getSharpness(e, curLvl);

        if (_edge_isBoundary(e) || sharpness >= 1.0f) {
            VertDataCopy(co, VERT_getCo(e->v0, curLvl));
            VertDataAdd(co, VERT_getCo(e->v1, curLvl));
            VertDataMulN(co, 0.5f);
        } else {
            int numFaces = 0;
            VertDataCopy(q, VERT_getCo(e->v0, curLvl));
            VertDataAdd(q, VERT_getCo(e->v1, curLvl));
            for (i=0; i<e->numFaces; i++) {
                CCGFace *f = e->faces[i];
                VertDataAdd(q, FACE_getCenterData(f));
                numFaces++;
            }
            VertDataMulN(q, 1.0f/(2.0f+numFaces));

            VertDataCopy(r, VERT_getCo(e->v0, curLvl));
            VertDataAdd(r, VERT_getCo(e->v1, curLvl));
            VertDataMulN(r, 0.5f);

            VertDataCopy(co, q);
            VertDataSub(r, q);
            VertDataMulN(r, sharpness);
            VertDataAdd(co, r);
        }

        // edge flags cleared later
    }
    for (ptrIdx=0; ptrIdx<numEffectedV; ptrIdx++) {
        CCGVert *v = effectedV[ptrIdx];
        void *co = VERT_getCo(v, curLvl);
        void *nCo = VERT_getCo(v, nextLvl);
        int sharpCount = 0, allSharp = 1;
        float avgSharpness = 0.0;
        int seam = VERT_seam(v), seamEdges = 0;

        for (i=0; i<v->numEdges; i++) {
            CCGEdge *e = v->edges[i];
            float sharpness = EDGE_getSharpness(e, curLvl);

            if (seam && _edge_isBoundary(e))
                seamEdges++;

            if (sharpness!=0.0f) {
                sharpCount++;
                avgSharpness += sharpness;
            } else {
                allSharp = 0;
            }
        }

        if(sharpCount) {
            avgSharpness /= sharpCount;
            if (avgSharpness > 1.0f) {
                avgSharpness = 1.0f;
            }
        }

        if (seamEdges < 2 || seamEdges != v->numEdges)
            seam = 0;

        if (!v->numEdges) {
            VertDataCopy(nCo, co);
        } else if (_vert_isBoundary(v)) {
            int numBoundary = 0;

            VertDataZero(r);
            for (i=0; i<v->numEdges; i++) {
                CCGEdge *e = v->edges[i];
                if (_edge_isBoundary(e)) {
                    VertDataAdd(r, VERT_getCo(_edge_getOtherVert(e, v), curLvl));
                    numBoundary++;
                }
            }
            VertDataCopy(nCo, co);
            VertDataMulN(nCo, 0.75f);
            VertDataMulN(r, 0.25f/numBoundary);
            VertDataAdd(nCo, r);
        } else {
            int numEdges = 0, numFaces = 0;

            VertDataZero(q);
            for (i=0; i<v->numFaces; i++) {
                CCGFace *f = v->faces[i];
                VertDataAdd(q, FACE_getCenterData(f));
                numFaces++;
            }
            VertDataMulN(q, 1.0f/numFaces);
            VertDataZero(r);
            for (i=0; i<v->numEdges; i++) {
                CCGEdge *e = v->edges[i];
                VertDataAdd(r, VERT_getCo(_edge_getOtherVert(e, v), curLvl));
                numEdges++;
            }
            VertDataMulN(r, 1.0f/numEdges);

            VertDataCopy(nCo, co);
            VertDataMulN(nCo, numEdges-2.0f);
            VertDataAdd(nCo, q);
            VertDataAdd(nCo, r);
            VertDataMulN(nCo, 1.0f/numEdges);
        }

        if (sharpCount>1 || seam) {
            VertDataZero(q);

            if (seam) {
                avgSharpness = 1.0f;
                sharpCount = seamEdges;
                allSharp = 1;
            }

            for (i=0; i<v->numEdges; i++) {
                CCGEdge *e = v->edges[i];
                float sharpness = EDGE_getSharpness(e, curLvl);

                if (seam) {
                    if (_edge_isBoundary(e)) {
                        CCGVert *oV = _edge_getOtherVert(e, v);
                        VertDataAdd(q, VERT_getCo(oV, curLvl));
                    }
                } else if (sharpness != 0.0f) {
                    CCGVert *oV = _edge_getOtherVert(e, v);
                    VertDataAdd(q, VERT_getCo(oV, curLvl));
                }
            }

            VertDataMulN(q, (float) 1/sharpCount);

            if (sharpCount!=2 || allSharp) {
                    // q = q + (co-q)*avgSharpness
                VertDataCopy(r, co);
                VertDataSub(r, q);
                VertDataMulN(r, avgSharpness);
                VertDataAdd(q, r);
            }

                // r = co*.75 + q*.25
            VertDataCopy(r, co);
            VertDataMulN(r, 0.75f);
            VertDataMulN(q, 0.25f);
            VertDataAdd(r, q);

                // nCo = nCo  + (r-nCo)*avgSharpness
            VertDataSub(r, nCo);
            VertDataMulN(r, avgSharpness);
            VertDataAdd(nCo, r);
        }

        // vert flags cleared later
    }

    if (ss->useAgeCounts) {
        for (i=0; i<numEffectedV; i++) {
            CCGVert *v = effectedV[i];
            byte *userData = ccgSubSurf_getVertUserData(ss, v);
            *((int*) &userData[ss->vertUserAgeOffset]) = ss->currentAge;
        }

        for (i=0; i<numEffectedE; i++) {
            CCGEdge *e = effectedE[i];
            byte *userData = ccgSubSurf_getEdgeUserData(ss, e);
            *((int*) &userData[ss->edgeUserAgeOffset]) = ss->currentAge;
        }

        for (i=0; i<numEffectedF; i++) {
            CCGFace *f = effectedF[i];
            byte *userData = ccgSubSurf_getFaceUserData(ss, f);
            *((int*) &userData[ss->faceUserAgeOffset]) = ss->currentAge;
        }
    }

    for (i=0; i<numEffectedE; i++) {
        CCGEdge *e = effectedE[i];
        VertDataCopy(EDGE_getCo(e, nextLvl, 0), VERT_getCo(e->v0, nextLvl));
        VertDataCopy(EDGE_getCo(e, nextLvl, 2), VERT_getCo(e->v1, nextLvl));
    }
    for (i=0; i<numEffectedF; i++) {
        CCGFace *f = effectedF[i];
        for (S=0; S<f->numVerts; S++) {
            CCGEdge *e = FACE_getEdges(f)[S];
            CCGEdge *prevE = FACE_getEdges(f)[(S+f->numVerts-1)%f->numVerts];

            VertDataCopy(FACE_getIFCo(f, nextLvl, S, 0, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIECo(f, nextLvl, S, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIFCo(f, nextLvl, S, 1, 1), VERT_getCo(FACE_getVerts(f)[S], nextLvl));
            VertDataCopy(FACE_getIECo(f, nextLvl, S, 1), EDGE_getCo(FACE_getEdges(f)[S], nextLvl, 1));

            VertDataCopy(FACE_getIFCo(f, nextLvl, S, 1, 0), _edge_getCoVert(e, FACE_getVerts(f)[S], nextLvl, 1, vertDataSize));
            VertDataCopy(FACE_getIFCo(f, nextLvl, S, 0, 1), _edge_getCoVert(prevE, FACE_getVerts(f)[S], nextLvl, 1, vertDataSize));
        }
    }

    for (curLvl=1; curLvl<subdivLevels; curLvl++) {
        ccgSubSurf__calcSubdivLevel(ss,
            effectedV, effectedE, effectedF,
            numEffectedV, numEffectedE, numEffectedF, curLvl);
    }

    if (ss->calcVertNormals)
        ccgSubSurf__calcVertNormals(ss,
            effectedV, effectedE, effectedF,
            numEffectedV, numEffectedE, numEffectedF);

    for (ptrIdx=0; ptrIdx<numEffectedV; ptrIdx++) {
        CCGVert *v = effectedV[ptrIdx];
        v->flags = 0;
    }
    for (ptrIdx=0; ptrIdx<numEffectedE; ptrIdx++) {
        CCGEdge *e = effectedE[ptrIdx];
        e->flags = 0;
    }

    MEM_freeN(effectedF);
    MEM_freeN(effectedE);
    MEM_freeN(effectedV);
}

static void ccgSubSurf__allFaces(CCGSubSurf *ss, CCGFace ***faces, int *numFaces, int *freeFaces)
{
    CCGFace **array;
    int i, num;

    if(!*faces) {
        array = MEM_mallocN(sizeof(*array)*ss->fMap->numEntries, "CCGSubsurf allFaces");
        num = 0;
        for (i=0; i<ss->fMap->curSize; i++) {
            CCGFace *f = (CCGFace*) ss->fMap->buckets[i];

            for (; f; f = f->next)
                array[num++] = f;
        }

        *faces = array;
        *numFaces = num;
        *freeFaces= 1;
    }
    else
        *freeFaces= 0;
}

static void ccgSubSurf__effectedFaceNeighbours(CCGSubSurf *ss, CCGFace **faces, int numFaces, CCGVert ***verts, int *numVerts, CCGEdge ***edges, int *numEdges)
{
    CCGVert **arrayV;
    CCGEdge **arrayE;
    int numV, numE, i, j;

    arrayV = MEM_mallocN(sizeof(*arrayV)*ss->vMap->numEntries, "CCGSubsurf arrayV");
    arrayE = MEM_mallocN(sizeof(*arrayE)*ss->eMap->numEntries, "CCGSubsurf arrayV");
    numV = numE = 0;

    for (i=0; i<numFaces; i++) {
        CCGFace *f = faces[i];
        f->flags |= Face_eEffected;
    }

    for (i=0; i<ss->vMap->curSize; i++) {
        CCGVert *v = (CCGVert*) ss->vMap->buckets[i];

        for (; v; v = v->next) {
            for(j=0; j<v->numFaces; j++)
                if(!(v->faces[j]->flags & Face_eEffected))
                    break;
            
            if(j == v->numFaces) {
                arrayV[numV++] = v;
                v->flags |= Vert_eEffected;
            }
        }
    }

    for (i=0; i<ss->eMap->curSize; i++) {
        CCGEdge *e = (CCGEdge*) ss->eMap->buckets[i];

        for (; e; e = e->next) {
            for(j=0; j<e->numFaces; j++)
                if(!(e->faces[j]->flags & Face_eEffected))
                    break;
            
            if(j == e->numFaces) {
                e->flags |= Edge_eEffected;
                arrayE[numE++] = e;
            }
        }
    }

    *verts = arrayV;
    *numVerts = numV;
    *edges = arrayE;
    *numEdges = numE;
}

/* copy face grid coordinates to other places */
CCGError ccgSubSurf_updateFromFaces(CCGSubSurf *ss, int lvl, CCGFace **effectedF, int numEffectedF)
{
    int i, S, x, gridSize, cornerIdx, subdivLevels;
    int vertDataSize = ss->meshIFC.vertDataSize, freeF;

    subdivLevels = ss->subdivLevels;
    lvl = (lvl)? lvl: subdivLevels;
    gridSize = 1 + (1<<(lvl-1));
    cornerIdx = gridSize-1;

    ccgSubSurf__allFaces(ss, &effectedF, &numEffectedF, &freeF);

    for (i=0; i<numEffectedF; i++) {
        CCGFace *f = effectedF[i];

        for (S=0; S<f->numVerts; S++) {
            CCGEdge *e = FACE_getEdges(f)[S];
            CCGEdge *prevE = FACE_getEdges(f)[(S+f->numVerts-1)%f->numVerts];

            VertDataCopy(FACE_getCenterData(f), FACE_getIFCo(f, lvl, S, 0, 0));
            VertDataCopy(VERT_getCo(FACE_getVerts(f)[S], lvl), FACE_getIFCo(f, lvl, S, cornerIdx, cornerIdx));

            for (x=0; x<gridSize; x++)
                VertDataCopy(FACE_getIECo(f, lvl, S, x), FACE_getIFCo(f, lvl, S, x, 0));

            for (x=0; x<gridSize; x++) {
                int eI = gridSize-1-x;
                VertDataCopy(_edge_getCoVert(e, FACE_getVerts(f)[S], lvl, eI,vertDataSize), FACE_getIFCo(f, lvl, S, cornerIdx, x));
                VertDataCopy(_edge_getCoVert(prevE, FACE_getVerts(f)[S], lvl, eI,vertDataSize), FACE_getIFCo(f, lvl, S, x, cornerIdx));
            }
        }
    }

    if(freeF) MEM_freeN(effectedF);

    return eCCGError_None;
}

/* copy other places to face grid coordinates */
CCGError ccgSubSurf_updateToFaces(CCGSubSurf *ss, int lvl, CCGFace **effectedF, int numEffectedF)
{
    int i, S, x, gridSize, cornerIdx, subdivLevels;
    int vertDataSize = ss->meshIFC.vertDataSize, freeF;

    subdivLevels = ss->subdivLevels;
    lvl = (lvl)? lvl: subdivLevels;
    gridSize = 1 + (1<<(lvl-1));
    cornerIdx = gridSize-1;

    ccgSubSurf__allFaces(ss, &effectedF, &numEffectedF, &freeF);

    for (i=0; i<numEffectedF; i++) {
        CCGFace *f = effectedF[i];

        for (S=0; S<f->numVerts; S++) {
            int prevS = (S+f->numVerts-1)%f->numVerts;
            CCGEdge *e = FACE_getEdges(f)[S];
            CCGEdge *prevE = FACE_getEdges(f)[prevS];

            for (x=0; x<gridSize; x++) {
                int eI = gridSize-1-x;
                VertDataCopy(FACE_getIFCo(f, lvl, S, cornerIdx, x), _edge_getCoVert(e, FACE_getVerts(f)[S], lvl, eI,vertDataSize));
                VertDataCopy(FACE_getIFCo(f, lvl, S, x, cornerIdx), _edge_getCoVert(prevE, FACE_getVerts(f)[S], lvl, eI,vertDataSize));
            }

            for (x=1; x<gridSize-1; x++) {
                VertDataCopy(FACE_getIFCo(f, lvl, S, 0, x), FACE_getIECo(f, lvl, prevS, x));
                VertDataCopy(FACE_getIFCo(f, lvl, S, x, 0), FACE_getIECo(f, lvl, S, x));
            }

            VertDataCopy(FACE_getIFCo(f, lvl, S, 0, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIFCo(f, lvl, S, cornerIdx, cornerIdx), VERT_getCo(FACE_getVerts(f)[S], lvl));
        }
    }

    if(freeF) MEM_freeN(effectedF);

    return eCCGError_None;
}

/* stitch together face grids, averaging coordinates at edges
   and vertices, for multires displacements */
CCGError ccgSubSurf_stitchFaces(CCGSubSurf *ss, int lvl, CCGFace **effectedF, int numEffectedF)
{
    CCGVert **effectedV;
    CCGEdge **effectedE;
    int numEffectedV, numEffectedE, freeF;
    int i, S, x, gridSize, cornerIdx, subdivLevels, edgeSize;
    int vertDataSize = ss->meshIFC.vertDataSize;

    subdivLevels = ss->subdivLevels;
    lvl = (lvl)? lvl: subdivLevels;
    gridSize = 1 + (1<<(lvl-1));
    edgeSize = 1 + (1<<lvl);
    cornerIdx = gridSize-1;

    ccgSubSurf__allFaces(ss, &effectedF, &numEffectedF, &freeF);
    ccgSubSurf__effectedFaceNeighbours(ss, effectedF, numEffectedF,
        &effectedV, &numEffectedV, &effectedE, &numEffectedE);

    /* zero */
    for (i=0; i<numEffectedV; i++) {
        CCGVert *v = effectedV[i];
        if(v->numFaces)
            VertDataZero(VERT_getCo(v, lvl));
    }

    for (i=0; i<numEffectedE; i++) {
        CCGEdge *e = effectedE[i];

        if(e->numFaces)
            for (x=0; x<edgeSize; x++)
                VertDataZero(EDGE_getCo(e, lvl, x));
    }

    /* add */
    for (i=0; i<numEffectedF; i++) {
        CCGFace *f = effectedF[i];

        VertDataZero(FACE_getCenterData(f));

        for (S=0; S<f->numVerts; S++)
            for (x=0; x<gridSize; x++)
                VertDataZero(FACE_getIECo(f, lvl, S, x));

        for (S=0; S<f->numVerts; S++) {
            int prevS = (S+f->numVerts-1)%f->numVerts;
            CCGEdge *e = FACE_getEdges(f)[S];
            CCGEdge *prevE = FACE_getEdges(f)[prevS];

            VertDataAdd(FACE_getCenterData(f), FACE_getIFCo(f, lvl, S, 0, 0));
            if (FACE_getVerts(f)[S]->flags&Vert_eEffected)
                VertDataAdd(VERT_getCo(FACE_getVerts(f)[S], lvl), FACE_getIFCo(f, lvl, S, cornerIdx, cornerIdx));

            for (x=1; x<gridSize-1; x++) {
                VertDataAdd(FACE_getIECo(f, lvl, S, x), FACE_getIFCo(f, lvl, S, x, 0));
                VertDataAdd(FACE_getIECo(f, lvl, prevS, x), FACE_getIFCo(f, lvl, S, 0, x));
            }

            for (x=0; x<gridSize-1; x++) {
                int eI = gridSize-1-x;
                if (FACE_getEdges(f)[S]->flags&Edge_eEffected)
                    VertDataAdd(_edge_getCoVert(e, FACE_getVerts(f)[S], lvl, eI,vertDataSize), FACE_getIFCo(f, lvl, S, cornerIdx, x));
                if (FACE_getEdges(f)[prevS]->flags&Edge_eEffected)
                    if(x != 0)
                        VertDataAdd(_edge_getCoVert(prevE, FACE_getVerts(f)[S], lvl, eI,vertDataSize), FACE_getIFCo(f, lvl, S, x, cornerIdx));
            }
        }
    }

    /* average */
    for (i=0; i<numEffectedV; i++) {
        CCGVert *v = effectedV[i];
        if(v->numFaces)
            VertDataMulN(VERT_getCo(v, lvl), 1.0f/v->numFaces);
    }

    for (i=0; i<numEffectedE; i++) {
        CCGEdge *e = effectedE[i];

        VertDataCopy(EDGE_getCo(e, lvl, 0), VERT_getCo(e->v0, lvl));
        VertDataCopy(EDGE_getCo(e, lvl, edgeSize-1), VERT_getCo(e->v1, lvl));

        if(e->numFaces)
            for (x=1; x<edgeSize-1; x++)
                VertDataMulN(EDGE_getCo(e, lvl, x), 1.0f/e->numFaces);
    }

    /* copy */
    for (i=0; i<numEffectedF; i++) {
        CCGFace *f = effectedF[i];

        VertDataMulN(FACE_getCenterData(f), 1.0f/f->numVerts);

        for (S=0; S<f->numVerts; S++)
            for (x=1; x<gridSize-1; x++)
                VertDataMulN(FACE_getIECo(f, lvl, S, x), 0.5f);

        for (S=0; S<f->numVerts; S++) {
            int prevS = (S+f->numVerts-1)%f->numVerts;
            CCGEdge *e = FACE_getEdges(f)[S];
            CCGEdge *prevE = FACE_getEdges(f)[prevS];

            VertDataCopy(FACE_getIFCo(f, lvl, S, 0, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIFCo(f, lvl, S, cornerIdx, cornerIdx), VERT_getCo(FACE_getVerts(f)[S], lvl));

            for (x=1; x<gridSize-1; x++) {
                VertDataCopy(FACE_getIFCo(f, lvl, S, x, 0), FACE_getIECo(f, lvl, S, x));
                VertDataCopy(FACE_getIFCo(f, lvl, S, 0, x), FACE_getIECo(f, lvl, prevS, x));
            }

            for (x=0; x<gridSize-1; x++) {
                int eI = gridSize-1-x;
                VertDataCopy(FACE_getIFCo(f, lvl, S, cornerIdx, x), _edge_getCoVert(e, FACE_getVerts(f)[S], lvl, eI,vertDataSize));
                VertDataCopy(FACE_getIFCo(f, lvl, S, x, cornerIdx), _edge_getCoVert(prevE, FACE_getVerts(f)[S], lvl, eI,vertDataSize));
            }

            VertDataCopy(FACE_getIECo(f, lvl, S, 0), FACE_getCenterData(f));
            VertDataCopy(FACE_getIECo(f, lvl, S, gridSize-1), FACE_getIFCo(f, lvl, S, gridSize-1, 0));
        }
    }

    for (i=0; i<numEffectedV; i++)
        effectedV[i]->flags = 0;
    for (i=0; i<numEffectedE; i++)
        effectedE[i]->flags = 0;
    for (i=0; i<numEffectedF; i++)
        effectedF[i]->flags = 0;

    MEM_freeN(effectedE);
    MEM_freeN(effectedV);
    if(freeF) MEM_freeN(effectedF);

    return eCCGError_None;
}

/* update normals for specified faces */
CCGError ccgSubSurf_updateNormals(CCGSubSurf *ss, CCGFace **effectedF, int numEffectedF) {
    CCGVert **effectedV;
    CCGEdge **effectedE;
    int i, numEffectedV, numEffectedE, freeF;

    ccgSubSurf__allFaces(ss, &effectedF, &numEffectedF, &freeF);
    ccgSubSurf__effectedFaceNeighbours(ss, effectedF, numEffectedF,
        &effectedV, &numEffectedV, &effectedE, &numEffectedE);

    if (ss->calcVertNormals)
        ccgSubSurf__calcVertNormals(ss,
            effectedV, effectedE, effectedF,
            numEffectedV, numEffectedE, numEffectedF);

    for (i=0; i<numEffectedV; i++)
        effectedV[i]->flags = 0;
    for (i=0; i<numEffectedE; i++)
        effectedE[i]->flags = 0;
    for (i=0; i<numEffectedF; i++)
        effectedF[i]->flags = 0;

    MEM_freeN(effectedE);
    MEM_freeN(effectedV);
    if(freeF) MEM_freeN(effectedF);

    return eCCGError_None;
}

/* compute subdivision levels from a given starting point, used by
   multires subdivide/propagate, by filling in coordinates at a
   certain level, and then subdividing that up to the highest level */
CCGError ccgSubSurf_updateLevels(CCGSubSurf *ss, int lvl, CCGFace **effectedF, int numEffectedF)
{
    CCGVert **effectedV;
    CCGEdge **effectedE;
    int numEffectedV, numEffectedE, freeF, i;
    int curLvl, subdivLevels = ss->subdivLevels;

    ccgSubSurf__allFaces(ss, &effectedF, &numEffectedF, &freeF);
    ccgSubSurf__effectedFaceNeighbours(ss, effectedF, numEffectedF,
        &effectedV, &numEffectedV, &effectedE, &numEffectedE);

    for (curLvl=lvl; curLvl<subdivLevels; curLvl++) {
        ccgSubSurf__calcSubdivLevel(ss,
            effectedV, effectedE, effectedF,
            numEffectedV, numEffectedE, numEffectedF, curLvl);
    }

    for (i=0; i<numEffectedV; i++)
        effectedV[i]->flags = 0;
    for (i=0; i<numEffectedE; i++)
        effectedE[i]->flags = 0;
    for (i=0; i<numEffectedF; i++)
        effectedF[i]->flags = 0;

    MEM_freeN(effectedE);
    MEM_freeN(effectedV);
    if(freeF) MEM_freeN(effectedF);

    return eCCGError_None;
}

#undef VERT_getCo
#undef EDGE_getCo
#undef FACE_getIECo
#undef FACE_getIFCo

/*** External API accessor functions ***/

int ccgSubSurf_getNumVerts(const CCGSubSurf *ss) {
    return ss->vMap->numEntries;
}
int ccgSubSurf_getNumEdges(const CCGSubSurf *ss) {
    return ss->eMap->numEntries;
}
int ccgSubSurf_getNumFaces(const CCGSubSurf *ss) {
    return ss->fMap->numEntries;
}

CCGVert *ccgSubSurf_getVert(CCGSubSurf *ss, CCGVertHDL v) {
    return (CCGVert*) _ehash_lookup(ss->vMap, v);
}
CCGEdge *ccgSubSurf_getEdge(CCGSubSurf *ss, CCGEdgeHDL e) {
    return (CCGEdge*) _ehash_lookup(ss->eMap, e);
}
CCGFace *ccgSubSurf_getFace(CCGSubSurf *ss, CCGFaceHDL f) {
    return (CCGFace*) _ehash_lookup(ss->fMap, f);
}

int ccgSubSurf_getSubdivisionLevels(const CCGSubSurf *ss) {
    return ss->subdivLevels;
}
int ccgSubSurf_getEdgeSize(const CCGSubSurf *ss) {
    return ccgSubSurf_getEdgeLevelSize(ss, ss->subdivLevels);
}
int ccgSubSurf_getEdgeLevelSize(const CCGSubSurf *ss, int level) {
    if (level<1 || level>ss->subdivLevels) {
        return -1;
    } else {
        return 1 + (1<<level);
    }
}
int ccgSubSurf_getGridSize(const CCGSubSurf *ss) {
    return ccgSubSurf_getGridLevelSize(ss, ss->subdivLevels);
}
int ccgSubSurf_getGridLevelSize(const CCGSubSurf *ss, int level) {
    if (level<1 || level>ss->subdivLevels) {
        return -1;
    } else {
        return 1 + (1<<(level-1));
    }
}

/* Vert accessors */

CCGVertHDL ccgSubSurf_getVertVertHandle(CCGVert *v) {
    return v->vHDL;
}
int ccgSubSurf_getVertAge(CCGSubSurf *ss, CCGVert *v) {
    if (ss->useAgeCounts) {
        byte *userData = ccgSubSurf_getVertUserData(ss, v);
        return ss->currentAge - *((int*) &userData[ss->vertUserAgeOffset]);
    } else {
        return 0;
    }
}
void *ccgSubSurf_getVertUserData(CCGSubSurf *ss, CCGVert *v) {
    return VERT_getLevelData(v) + ss->meshIFC.vertDataSize*(ss->subdivLevels+1);
}
int ccgSubSurf_getVertNumFaces(CCGVert *v) {
    return v->numFaces;
}
CCGFace *ccgSubSurf_getVertFace(CCGVert *v, int index) {
    if (index<0 || index>=v->numFaces) {
        return NULL;
    } else {
        return v->faces[index];
    }
}
int ccgSubSurf_getVertNumEdges(CCGVert *v) {
    return v->numEdges;
}
CCGEdge *ccgSubSurf_getVertEdge(CCGVert *v, int index) {
    if (index<0 || index>=v->numEdges) {
        return NULL;
    } else {
        return v->edges[index];
    }
}
void *ccgSubSurf_getVertData(CCGSubSurf *ss, CCGVert *v) {
    return ccgSubSurf_getVertLevelData(ss, v, ss->subdivLevels);
}
void *ccgSubSurf_getVertLevelData(CCGSubSurf *ss, CCGVert *v, int level) {
    if (level<0 || level>ss->subdivLevels) {
        return NULL;
    } else {
        return _vert_getCo(v, level, ss->meshIFC.vertDataSize);
    }
}

/* Edge accessors */

CCGEdgeHDL ccgSubSurf_getEdgeEdgeHandle(CCGEdge *e) {
    return e->eHDL;
}
int ccgSubSurf_getEdgeAge(CCGSubSurf *ss, CCGEdge *e) {
    if (ss->useAgeCounts) {
        byte *userData = ccgSubSurf_getEdgeUserData(ss, e);
        return ss->currentAge - *((int*) &userData[ss->edgeUserAgeOffset]);
    } else {
        return 0;
    }
}
void *ccgSubSurf_getEdgeUserData(CCGSubSurf *ss, CCGEdge *e) {
    return EDGE_getLevelData(e) + ss->meshIFC.vertDataSize *((ss->subdivLevels+1) + (1<<(ss->subdivLevels+1))-1);
}
int ccgSubSurf_getEdgeNumFaces(CCGEdge *e) {
    return e->numFaces;
}
CCGFace *ccgSubSurf_getEdgeFace(CCGEdge *e, int index) {
    if (index<0 || index>=e->numFaces) {
        return NULL;
    } else {
        return e->faces[index];
    }
}
CCGVert *ccgSubSurf_getEdgeVert0(CCGEdge *e) {
    return e->v0;
}
CCGVert *ccgSubSurf_getEdgeVert1(CCGEdge *e) {
    return e->v1;
}
void *ccgSubSurf_getEdgeDataArray(CCGSubSurf *ss, CCGEdge *e) {
    return ccgSubSurf_getEdgeData(ss, e, 0);
}
void *ccgSubSurf_getEdgeData(CCGSubSurf *ss, CCGEdge *e, int x) {
    return ccgSubSurf_getEdgeLevelData(ss, e, x, ss->subdivLevels);
}
void *ccgSubSurf_getEdgeLevelData(CCGSubSurf *ss, CCGEdge *e, int x, int level) {
    if (level<0 || level>ss->subdivLevels) {
        return NULL;
    } else {
        return _edge_getCo(e, level, x, ss->meshIFC.vertDataSize);
    }
}
float ccgSubSurf_getEdgeCrease(CCGEdge *e) {
    return e->crease;
}

/* Face accessors */

CCGFaceHDL ccgSubSurf_getFaceFaceHandle(CCGSubSurf *UNUSED(ss), CCGFace *f) {
    return f->fHDL;
}
int ccgSubSurf_getFaceAge(CCGSubSurf *ss, CCGFace *f) {
    if (ss->useAgeCounts) {
        byte *userData = ccgSubSurf_getFaceUserData(ss, f);
        return ss->currentAge - *((int*) &userData[ss->faceUserAgeOffset]);
    } else {
        return 0;
    }
}
void *ccgSubSurf_getFaceUserData(CCGSubSurf *ss, CCGFace *f) {
    int maxGridSize = 1 + (1<<(ss->subdivLevels-1));
    return FACE_getCenterData(f) + ss->meshIFC.vertDataSize *(1 + f->numVerts*maxGridSize + f->numVerts*maxGridSize*maxGridSize);
}
int ccgSubSurf_getFaceNumVerts(CCGFace *f) {
    return f->numVerts;
}
CCGVert *ccgSubSurf_getFaceVert(CCGSubSurf *UNUSED(ss), CCGFace *f, int index) {
    if (index<0 || index>=f->numVerts) {
        return NULL;
    } else {
        return FACE_getVerts(f)[index];
    }
}
CCGEdge *ccgSubSurf_getFaceEdge(CCGSubSurf *UNUSED(ss), CCGFace *f, int index) {
    if (index<0 || index>=f->numVerts) {
        return NULL;
    } else {
        return FACE_getEdges(f)[index];
    }
}
int ccgSubSurf_getFaceEdgeIndex(CCGFace *f, CCGEdge *e) {
    int i;

    for (i=0; i<f->numVerts; i++)
        if (FACE_getEdges(f)[i]==e)
            return i;

    return -1;
}
void *ccgSubSurf_getFaceCenterData(CCGFace *f) {
    return FACE_getCenterData(f);
}
void *ccgSubSurf_getFaceGridEdgeDataArray(CCGSubSurf *ss, CCGFace *f, int gridIndex) {
    return ccgSubSurf_getFaceGridEdgeData(ss, f, gridIndex, 0);
}
void *ccgSubSurf_getFaceGridEdgeData(CCGSubSurf *ss, CCGFace *f, int gridIndex, int x) {
    return _face_getIECo(f, ss->subdivLevels, gridIndex, x, ss->subdivLevels, ss->meshIFC.vertDataSize);
}
void *ccgSubSurf_getFaceGridDataArray(CCGSubSurf *ss, CCGFace *f, int gridIndex) {
    return ccgSubSurf_getFaceGridData(ss, f, gridIndex, 0, 0);
}
void *ccgSubSurf_getFaceGridData(CCGSubSurf *ss, CCGFace *f, int gridIndex, int x, int y) {
    return _face_getIFCo(f, ss->subdivLevels, gridIndex, x, y, ss->subdivLevels, ss->meshIFC.vertDataSize);
}

/*** External API iterator functions ***/

CCGVertIterator *ccgSubSurf_getVertIterator(CCGSubSurf *ss) {
    return (CCGVertIterator*) _ehashIterator_new(ss->vMap);
}
CCGEdgeIterator *ccgSubSurf_getEdgeIterator(CCGSubSurf *ss) {
    return (CCGEdgeIterator*) _ehashIterator_new(ss->eMap);
}
CCGFaceIterator *ccgSubSurf_getFaceIterator(CCGSubSurf *ss) {
    return (CCGFaceIterator*) _ehashIterator_new(ss->fMap);
}

CCGVert *ccgVertIterator_getCurrent(CCGVertIterator *vi) {
    return (CCGVert*) _ehashIterator_getCurrent((EHashIterator*) vi);
}
int ccgVertIterator_isStopped(CCGVertIterator *vi) {
    return _ehashIterator_isStopped((EHashIterator*) vi);
}
void ccgVertIterator_next(CCGVertIterator *vi) {
    _ehashIterator_next((EHashIterator*) vi); 
}
void ccgVertIterator_free(CCGVertIterator *vi) {
    _ehashIterator_free((EHashIterator*) vi);
}

CCGEdge *ccgEdgeIterator_getCurrent(CCGEdgeIterator *vi) {
    return (CCGEdge*) _ehashIterator_getCurrent((EHashIterator*) vi);
}
int ccgEdgeIterator_isStopped(CCGEdgeIterator *vi) {
    return _ehashIterator_isStopped((EHashIterator*) vi);
}
void ccgEdgeIterator_next(CCGEdgeIterator *vi) {
    _ehashIterator_next((EHashIterator*) vi); 
}
void ccgEdgeIterator_free(CCGEdgeIterator *vi) {
    _ehashIterator_free((EHashIterator*) vi);
}

CCGFace *ccgFaceIterator_getCurrent(CCGFaceIterator *vi) {
    return (CCGFace*) _ehashIterator_getCurrent((EHashIterator*) vi);
}
int ccgFaceIterator_isStopped(CCGFaceIterator *vi) {
    return _ehashIterator_isStopped((EHashIterator*) vi);
}
void ccgFaceIterator_next(CCGFaceIterator *vi) {
    _ehashIterator_next((EHashIterator*) vi); 
}
void ccgFaceIterator_free(CCGFaceIterator *vi) {
    _ehashIterator_free((EHashIterator*) vi);
}

/*** Extern API final vert/edge/face interface ***/

int ccgSubSurf_getNumFinalVerts(const CCGSubSurf *ss) {
    int edgeSize = 1 + (1<<ss->subdivLevels);
    int gridSize = 1 + (1<<(ss->subdivLevels-1));
    int numFinalVerts = ss->vMap->numEntries + ss->eMap->numEntries*(edgeSize-2) + ss->fMap->numEntries + ss->numGrids*((gridSize-2) + ((gridSize-2)*(gridSize-2)));
    return numFinalVerts;
}
int ccgSubSurf_getNumFinalEdges(const CCGSubSurf *ss) {
    int edgeSize = 1 + (1<<ss->subdivLevels);
    int gridSize = 1 + (1<<(ss->subdivLevels-1));
    int numFinalEdges = ss->eMap->numEntries*(edgeSize-1) + ss->numGrids*((gridSize-1) + 2*((gridSize-2)*(gridSize-1)));
    return numFinalEdges;
}
int ccgSubSurf_getNumFinalFaces(const CCGSubSurf *ss) {
    int gridSize = 1 + (1<<(ss->subdivLevels-1));
    int numFinalFaces = ss->numGrids*((gridSize-1)*(gridSize-1));
    return numFinalFaces;
}