curve.c

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

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

#include "MEM_guardedalloc.h"

#include "BLI_bpath.h"
#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"
#include "BLI_ghash.h"

#include "DNA_curve_types.h"  
#include "DNA_material_types.h"  

/* for dereferencing pointers */
#include "DNA_key_types.h"  
#include "DNA_scene_types.h"  
#include "DNA_vfont_types.h"  
#include "DNA_object_types.h"

#include "BKE_animsys.h"
#include "BKE_anim.h"  
#include "BKE_curve.h"  
#include "BKE_displist.h"  
#include "BKE_font.h" 
#include "BKE_global.h" 
#include "BKE_key.h"  
#include "BKE_library.h"  
#include "BKE_main.h"  
#include "BKE_object.h"
#include "BKE_material.h"

/* globals */

/* local */
static int cu_isectLL(float *v1, float *v2, float *v3, float *v4, 
                      short cox, short coy,
                      float *labda, float *mu, float *vec);

void unlink_curve(Curve *cu)
{
    int a;
    
    for(a=0; a<cu->totcol; a++) {
        if(cu->mat[a]) cu->mat[a]->id.us--;
        cu->mat[a]= NULL;
    }
    if(cu->vfont) cu->vfont->id.us--; 
    cu->vfont= NULL;

    if(cu->vfontb) cu->vfontb->id.us--; 
    cu->vfontb= NULL;

    if(cu->vfonti) cu->vfonti->id.us--; 
    cu->vfonti= NULL;

    if(cu->vfontbi) cu->vfontbi->id.us--; 
    cu->vfontbi= NULL;
    
    if(cu->key) cu->key->id.us--;
    cu->key= NULL;
}

/* frees editcurve entirely */
void BKE_free_editfont(Curve *cu)
{
    if(cu->editfont) {
        EditFont *ef= cu->editfont;
        
        if(ef->oldstr) MEM_freeN(ef->oldstr);
        if(ef->oldstrinfo) MEM_freeN(ef->oldstrinfo);
        if(ef->textbuf) MEM_freeN(ef->textbuf);
        if(ef->textbufinfo) MEM_freeN(ef->textbufinfo);
        if(ef->copybuf) MEM_freeN(ef->copybuf);
        if(ef->copybufinfo) MEM_freeN(ef->copybufinfo);
        
        MEM_freeN(ef);
        cu->editfont= NULL;
    }
}

void free_curve_editNurb_keyIndex(EditNurb *editnurb)
{
    if (!editnurb->keyindex) {
        return;
    }
    BLI_ghash_free(editnurb->keyindex, NULL, (GHashValFreeFP)MEM_freeN);
    editnurb->keyindex= NULL;
}

void free_curve_editNurb (Curve *cu)
{
    if(cu->editnurb) {
        freeNurblist(&cu->editnurb->nurbs);
        free_curve_editNurb_keyIndex(cu->editnurb);
        MEM_freeN(cu->editnurb);
        cu->editnurb= NULL;
    }
}

/* don't free curve itself */
void free_curve(Curve *cu)
{
    freeNurblist(&cu->nurb);
    BLI_freelistN(&cu->bev);
    freedisplist(&cu->disp);
    BKE_free_editfont(cu);

    free_curve_editNurb(cu);
    unlink_curve(cu);
    BKE_free_animdata((ID *)cu);
    
    if(cu->mat) MEM_freeN(cu->mat);
    if(cu->str) MEM_freeN(cu->str);
    if(cu->strinfo) MEM_freeN(cu->strinfo);
    if(cu->bb) MEM_freeN(cu->bb);
    if(cu->path) free_path(cu->path);
    if(cu->tb) MEM_freeN(cu->tb);
}

Curve *add_curve(const char *name, int type)
{
    Curve *cu;

    cu= alloc_libblock(&G.main->curve, ID_CU, name);
    
    cu->size[0]= cu->size[1]= cu->size[2]= 1.0;
    cu->flag= CU_FRONT|CU_BACK|CU_DEFORM_BOUNDS_OFF|CU_PATH_RADIUS;
    cu->pathlen= 100;
    cu->resolu= cu->resolv= (type == OB_SURF) ? 4 : 12;
    cu->width= 1.0;
    cu->wordspace = 1.0;
    cu->spacing= cu->linedist= 1.0;
    cu->fsize= 1.0;
    cu->ulheight = 0.05;    
    cu->texflag= CU_AUTOSPACE;
    cu->smallcaps_scale= 0.75f;
    cu->twist_mode= CU_TWIST_MINIMUM;   // XXX: this one seems to be the best one in most cases, at least for curve deform...
    cu->type= type;
    
    cu->bb= unit_boundbox();
    
    if(type==OB_FONT) {
        cu->vfont= cu->vfontb= cu->vfonti= cu->vfontbi= get_builtin_font();
        cu->vfont->id.us+=4;
        cu->str= MEM_mallocN(12, "str");
        BLI_strncpy(cu->str, "Text", 12);
        cu->len= cu->pos= 4;
        cu->strinfo= MEM_callocN(12*sizeof(CharInfo), "strinfo new");
        cu->totbox= cu->actbox= 1;
        cu->tb= MEM_callocN(MAXTEXTBOX*sizeof(TextBox), "textbox");
        cu->tb[0].w = cu->tb[0].h = 0.0;
    }
    
    return cu;
}

Curve *copy_curve(Curve *cu)
{
    Curve *cun;
    int a;
    
    cun= copy_libblock(&cu->id);
    cun->nurb.first= cun->nurb.last= NULL;
    duplicateNurblist( &(cun->nurb), &(cu->nurb));

    cun->mat= MEM_dupallocN(cu->mat);
    for(a=0; a<cun->totcol; a++) {
        id_us_plus((ID *)cun->mat[a]);
    }
    
    cun->str= MEM_dupallocN(cu->str);
    cun->strinfo= MEM_dupallocN(cu->strinfo);   
    cun->tb= MEM_dupallocN(cu->tb);
    cun->bb= MEM_dupallocN(cu->bb);
    
    cun->key= copy_key(cu->key);
    if(cun->key) cun->key->from= (ID *)cun;
    
    cun->disp.first= cun->disp.last= NULL;
    cun->bev.first= cun->bev.last= NULL;
    cun->path= NULL;

    cun->editnurb= NULL;
    cun->editfont= NULL;
    cun->selboxes= NULL;

#if 0   // XXX old animation system
    /* single user ipo too */
    if(cun->ipo) cun->ipo= copy_ipo(cun->ipo);
#endif // XXX old animation system

    id_us_plus((ID *)cun->vfont);
    id_us_plus((ID *)cun->vfontb);  
    id_us_plus((ID *)cun->vfonti);
    id_us_plus((ID *)cun->vfontbi);
    
    return cun;
}

static void extern_local_curve(Curve *cu)
{   
    id_lib_extern((ID *)cu->vfont);
    id_lib_extern((ID *)cu->vfontb);    
    id_lib_extern((ID *)cu->vfonti);
    id_lib_extern((ID *)cu->vfontbi);
    
    if(cu->mat) {
        extern_local_matarar(cu->mat, cu->totcol);
    }
}

void make_local_curve(Curve *cu)
{
    Main *bmain= G.main;
    Object *ob;
    int is_local= FALSE, is_lib= FALSE;
    
    /* - when there are only lib users: don't do
     * - when there are only local users: set flag
     * - mixed: do a copy
     */
    
    if(cu->id.lib==NULL) return;

    if(cu->id.us==1) {
        id_clear_lib_data(bmain, &cu->id);
        extern_local_curve(cu);
        return;
    }

    for(ob= bmain->object.first; ob && ELEM(0, is_lib, is_local); ob= ob->id.next) {
        if(ob->data == cu) {
            if(ob->id.lib) is_lib= TRUE;
            else is_local= TRUE;
        }
    }

    if(is_local && is_lib == FALSE) {
        id_clear_lib_data(bmain, &cu->id);
        extern_local_curve(cu);
    }
    else if(is_local && is_lib) {
        Curve *cu_new= copy_curve(cu);
        cu_new->id.us= 0;

        BKE_id_lib_local_paths(bmain, cu->id.lib, &cu_new->id);

        for(ob= bmain->object.first; ob; ob= ob->id.next) {
            if(ob->data==cu) {
                if(ob->id.lib==NULL) {
                    ob->data= cu_new;
                    cu_new->id.us++;
                    cu->id.us--;
                }
            }
        }
    }
}

/* Get list of nurbs from editnurbs structure */
ListBase *curve_editnurbs(Curve *cu)
{
    if (cu->editnurb) {
        return &cu->editnurb->nurbs;
    }

    return NULL;
}

short curve_type(Curve *cu)
{
    Nurb *nu;
    int type= cu->type;

    if(cu->vfont) {
        return OB_FONT;
    }

    if(!cu->type) {
        type= OB_CURVE;

        for (nu= cu->nurb.first; nu; nu= nu->next) {
            if(nu->pntsv>1) {
                type= OB_SURF;
            }
        }
    }

    return type;
}

void update_curve_dimension(Curve *cu)
{
    ListBase *nurbs= BKE_curve_nurbs(cu);
    Nurb *nu= nurbs->first;

    if(cu->flag&CU_3D) {
        for( ; nu; nu= nu->next) {
            nu->flag &= ~CU_2D;
        }
    }
    else {
        for( ; nu; nu= nu->next) {
            nu->flag |= CU_2D;
            test2DNurb(nu);

            /* since the handles are moved they need to be auto-located again */
            if(nu->type == CU_BEZIER)
                calchandlesNurb(nu);
        }
    }
}

void test_curve_type(Object *ob)
{
    ob->type= curve_type(ob->data);

    if(ob->type==OB_CURVE)
        update_curve_dimension((Curve *)ob->data);
}

void tex_space_curve(Curve *cu)
{
    DispList *dl;
    BoundBox *bb;
    float *fp, min[3], max[3];
    int tot, doit= 0;
    
    if(cu->bb==NULL) cu->bb= MEM_callocN(sizeof(BoundBox), "boundbox");
    bb= cu->bb;
    
    INIT_MINMAX(min, max);

    dl= cu->disp.first;
    while(dl) {
        
        if(dl->type==DL_INDEX3 || dl->type==DL_INDEX3) tot= dl->nr;
        else tot= dl->nr*dl->parts;
        
        if(tot) doit= 1;
        fp= dl->verts;
        while(tot--) {
            DO_MINMAX(fp, min, max);
            fp += 3;
        }
        dl= dl->next;
    }

    if(!doit) {
        min[0] = min[1] = min[2] = -1.0f;
        max[0] = max[1] = max[2] = 1.0f;
    }

    boundbox_set_from_min_max(bb, min, max);

    if(cu->texflag & CU_AUTOSPACE) {
        mid_v3_v3v3(cu->loc, min, max);
        cu->size[0]= (max[0]-min[0])/2.0f;
        cu->size[1]= (max[1]-min[1])/2.0f;
        cu->size[2]= (max[2]-min[2])/2.0f;

        cu->rot[0]= cu->rot[1]= cu->rot[2]= 0.0f;

        if(cu->size[0]==0.0f) cu->size[0]= 1.0f;
        else if(cu->size[0]>0.0f && cu->size[0]<0.00001f) cu->size[0]= 0.00001f;
        else if(cu->size[0]<0.0f && cu->size[0]> -0.00001f) cu->size[0]= -0.00001f;
    
        if(cu->size[1]==0.0f) cu->size[1]= 1.0f;
        else if(cu->size[1]>0.0f && cu->size[1]<0.00001f) cu->size[1]= 0.00001f;
        else if(cu->size[1]<0.0f && cu->size[1]> -0.00001f) cu->size[1]= -0.00001f;
    
        if(cu->size[2]==0.0f) cu->size[2]= 1.0f;
        else if(cu->size[2]>0.0f && cu->size[2]<0.00001f) cu->size[2]= 0.00001f;
        else if(cu->size[2]<0.0f && cu->size[2]> -0.00001f) cu->size[2]= -0.00001f;

    }
}

int count_curveverts(ListBase *nurb)
{
    Nurb *nu;
    int tot=0;
    
    nu= nurb->first;
    while(nu) {
        if(nu->bezt) tot+= 3*nu->pntsu;
        else if(nu->bp) tot+= nu->pntsu*nu->pntsv;
        
        nu= nu->next;
    }
    return tot;
}

int count_curveverts_without_handles(ListBase *nurb)
{
    Nurb *nu;
    int tot=0;
    
    nu= nurb->first;
    while(nu) {
        if(nu->bezt) tot+= nu->pntsu;
        else if(nu->bp) tot+= nu->pntsu*nu->pntsv;
        
        nu= nu->next;
    }
    return tot;
}

/* **************** NURBS ROUTINES ******************** */

void freeNurb(Nurb *nu)
{

    if(nu==NULL) return;

    if(nu->bezt) MEM_freeN(nu->bezt);
    nu->bezt= NULL;
    if(nu->bp) MEM_freeN(nu->bp);
    nu->bp= NULL;
    if(nu->knotsu) MEM_freeN(nu->knotsu);
    nu->knotsu= NULL;
    if(nu->knotsv) MEM_freeN(nu->knotsv);
    nu->knotsv= NULL;
    /* if(nu->trim.first) freeNurblist(&(nu->trim)); */

    MEM_freeN(nu);

}


void freeNurblist(ListBase *lb)
{
    Nurb *nu, *next;

    if(lb==NULL) return;

    nu= lb->first;
    while(nu) {
        next= nu->next;
        freeNurb(nu);
        nu= next;
    }
    lb->first= lb->last= NULL;
}

Nurb *duplicateNurb(Nurb *nu)
{
    Nurb *newnu;
    int len;

    newnu= (Nurb*)MEM_mallocN(sizeof(Nurb),"duplicateNurb");
    if(newnu==NULL) return NULL;
    memcpy(newnu, nu, sizeof(Nurb));

    if(nu->bezt) {
        newnu->bezt=
            (BezTriple*)MEM_mallocN((nu->pntsu)* sizeof(BezTriple),"duplicateNurb2");
        memcpy(newnu->bezt, nu->bezt, nu->pntsu*sizeof(BezTriple));
    }
    else {
        len= nu->pntsu*nu->pntsv;
        newnu->bp=
            (BPoint*)MEM_mallocN((len)* sizeof(BPoint),"duplicateNurb3");
        memcpy(newnu->bp, nu->bp, len*sizeof(BPoint));
        
        newnu->knotsu= newnu->knotsv= NULL;
        
        if(nu->knotsu) {
            len= KNOTSU(nu);
            if(len) {
                newnu->knotsu= MEM_mallocN(len*sizeof(float), "duplicateNurb4");
                memcpy(newnu->knotsu, nu->knotsu, sizeof(float)*len);
            }
        }
        if(nu->pntsv>1 && nu->knotsv) {
            len= KNOTSV(nu);
            if(len) {
                newnu->knotsv= MEM_mallocN(len*sizeof(float), "duplicateNurb5");
                memcpy(newnu->knotsv, nu->knotsv, sizeof(float)*len);
            }
        }
    }
    return newnu;
}

void duplicateNurblist(ListBase *lb1, ListBase *lb2)
{
    Nurb *nu, *nun;
    
    freeNurblist(lb1);
    
    nu= lb2->first;
    while(nu) {
        nun= duplicateNurb(nu);
        BLI_addtail(lb1, nun);
        
        nu= nu->next;
    }
}

void test2DNurb(Nurb *nu)
{
    BezTriple *bezt;
    BPoint *bp;
    int a;
    
    if((nu->flag & CU_2D)==0)
        return;

    if(nu->type == CU_BEZIER) {
        a= nu->pntsu;
        bezt= nu->bezt;
        while(a--) {
            bezt->vec[0][2]= 0.0; 
            bezt->vec[1][2]= 0.0; 
            bezt->vec[2][2]= 0.0;
            bezt++;
        }
    }
    else {
        a= nu->pntsu*nu->pntsv;
        bp= nu->bp;
        while(a--) {
            bp->vec[2]= 0.0;
            bp++;
        }
    }
}

void minmaxNurb(Nurb *nu, float *min, float *max)
{
    BezTriple *bezt;
    BPoint *bp;
    int a;

    if(nu->type == CU_BEZIER) {
        a= nu->pntsu;
        bezt= nu->bezt;
        while(a--) {
            DO_MINMAX(bezt->vec[0], min, max);
            DO_MINMAX(bezt->vec[1], min, max);
            DO_MINMAX(bezt->vec[2], min, max);
            bezt++;
        }
    }
    else {
        a= nu->pntsu*nu->pntsv;
        bp= nu->bp;
        while(a--) {
            DO_MINMAX(bp->vec, min, max);
            bp++;
        }
    }
}

/* be sure to call makeknots after this */
void addNurbPoints(Nurb *nu, int number)
{
    BPoint *tmp= nu->bp;
    int i;
    nu->bp= (BPoint *)MEM_mallocN((nu->pntsu + number) * sizeof(BPoint), "rna_Curve_spline_points_add");

    if(tmp) {
        memmove(nu->bp, tmp, nu->pntsu * sizeof(BPoint));
        MEM_freeN(tmp);
    }

    memset(nu->bp + nu->pntsu, 0, number * sizeof(BPoint));

    for(i=0, tmp= nu->bp + nu->pntsu; i < number; i++, tmp++) {
        tmp->radius= 1.0f;
    }

    nu->pntsu += number;
}

void addNurbPointsBezier(Nurb *nu, int number)
{
    BezTriple *tmp= nu->bezt;
    int i;
    nu->bezt= (BezTriple *)MEM_mallocN((nu->pntsu + number) * sizeof(BezTriple), "rna_Curve_spline_points_add");

    if(tmp) {
        memmove(nu->bezt, tmp, nu->pntsu * sizeof(BezTriple));
        MEM_freeN(tmp);
    }

    memset(nu->bezt + nu->pntsu, 0, number * sizeof(BezTriple));

    for(i=0, tmp= nu->bezt + nu->pntsu; i < number; i++, tmp++) {
        tmp->radius= 1.0f;
    }

    nu->pntsu += number;
}

/* ~~~~~~~~~~~~~~~~~~~~Non Uniform Rational B Spline calculations ~~~~~~~~~~~ */


static void calcknots(float *knots, const short pnts, const short order, const short flag)
{
    /* knots: number of pnts NOT corrected for cyclic */
    const int pnts_order= pnts + order;
    float k;
    int a;

    switch(flag & (CU_NURB_ENDPOINT|CU_NURB_BEZIER)) {
    case CU_NURB_ENDPOINT:
        k= 0.0;
        for(a=1; a <= pnts_order; a++) {
            knots[a-1]= k;
            if(a >= order && a <= pnts) k+= 1.0f;
        }
        break;
    case CU_NURB_BEZIER:
        /* Warning, the order MUST be 2 or 4,
         * if this is not enforced, the displist will be corrupt */
        if(order==4) {
            k= 0.34;
            for(a=0; a < pnts_order; a++) {
                knots[a]= floorf(k);
                k+= (1.0f/3.0f);
            }
        }
        else if(order==3) {
            k= 0.6f;
            for(a=0; a < pnts_order; a++) {
                if(a >= order && a <= pnts) k+= 0.5f;
                knots[a]= floorf(k);
            }
        }
        else {
            printf("bez nurb curve order is not 3 or 4, should never happen\n");
        }
        break;
    default:
        for(a=0; a < pnts_order; a++) {
            knots[a]= (float)a;
        }
        break;
    }
}

static void makecyclicknots(float *knots, short pnts, short order)
/* pnts, order: number of pnts NOT corrected for cyclic */
{
    int a, b, order2, c;

    if(knots==NULL) return;

    order2=order-1;

    /* do first long rows (order -1), remove identical knots at endpoints */
    if(order>2) {
        b= pnts+order2;
        for(a=1; a<order2; a++) {
            if(knots[b]!= knots[b-a]) break;
        }
        if(a==order2) knots[pnts+order-2]+= 1.0f;
    }

    b= order;
        c=pnts + order + order2;
    for(a=pnts+order2; a<c; a++) {
        knots[a]= knots[a-1]+ (knots[b]-knots[b-1]);
        b--;
    }
}



static void makeknots(Nurb *nu, short uv)
{
    if(nu->type == CU_NURBS) {
        if(uv == 1) {
            if(nu->knotsu) MEM_freeN(nu->knotsu);
            if(check_valid_nurb_u(nu)) {
                nu->knotsu= MEM_callocN(4+sizeof(float)*KNOTSU(nu), "makeknots");
                if(nu->flagu & CU_NURB_CYCLIC) {
                    calcknots(nu->knotsu, nu->pntsu, nu->orderu, 0);  /* cyclic should be uniform */
                    makecyclicknots(nu->knotsu, nu->pntsu, nu->orderu);
                } else {
                    calcknots(nu->knotsu, nu->pntsu, nu->orderu, nu->flagu);
                }
            }
            else nu->knotsu= NULL;
        
        } else if(uv == 2) {
            if(nu->knotsv) MEM_freeN(nu->knotsv);
            if(check_valid_nurb_v(nu)) {
                nu->knotsv= MEM_callocN(4+sizeof(float)*KNOTSV(nu), "makeknots");
                if(nu->flagv & CU_NURB_CYCLIC) {
                    calcknots(nu->knotsv, nu->pntsv, nu->orderv, 0);  /* cyclic should be uniform */
                    makecyclicknots(nu->knotsv, nu->pntsv, nu->orderv);
                } else {
                    calcknots(nu->knotsv, nu->pntsv, nu->orderv, nu->flagv);
                }
            }
            else nu->knotsv= NULL;
        }
    }
}

void nurbs_knot_calc_u(Nurb *nu)
{
    makeknots(nu, 1);
}

void nurbs_knot_calc_v(Nurb *nu)
{
    makeknots(nu, 2);
}

static void basisNurb(float t, short order, short pnts, float *knots, float *basis, int *start, int *end)
{
    float d, e;
    int i, i1 = 0, i2 = 0 ,j, orderpluspnts, opp2, o2;

    orderpluspnts= order+pnts;
        opp2 = orderpluspnts-1;

    /* this is for float inaccuracy */
    if(t < knots[0]) t= knots[0];
    else if(t > knots[opp2]) t= knots[opp2];

    /* this part is order '1' */
        o2 = order + 1;
    for(i=0;i<opp2;i++) {
        if(knots[i]!=knots[i+1] && t>= knots[i] && t<=knots[i+1]) {
            basis[i]= 1.0;
            i1= i-o2;
            if(i1<0) i1= 0;
            i2= i;
            i++;
            while(i<opp2) {
                basis[i]= 0.0;
                i++;
            }
            break;
        }
        else basis[i]= 0.0;
    }
    basis[i]= 0.0;
    
    /* this is order 2,3,... */
    for(j=2; j<=order; j++) {

        if(i2+j>= orderpluspnts) i2= opp2-j;

        for(i= i1; i<=i2; i++) {
            if(basis[i]!=0.0f)
                d= ((t-knots[i])*basis[i]) / (knots[i+j-1]-knots[i]);
            else
                d= 0.0f;

            if(basis[i+1] != 0.0f)
                e= ((knots[i+j]-t)*basis[i+1]) / (knots[i+j]-knots[i+1]);
            else
                e= 0.0;

            basis[i]= d+e;
        }
    }

    *start= 1000;
    *end= 0;

    for(i=i1; i<=i2; i++) {
        if(basis[i] > 0.0f) {
            *end= i;
            if(*start==1000) *start= i;
        }
    }
}


void makeNurbfaces(Nurb *nu, float *coord_array, int rowstride, int resolu, int resolv)
/* coord_array  has to be 3*4*resolu*resolv in size, and zero-ed */
{
    BPoint *bp;
    float *basisu, *basis, *basisv, *sum, *fp, *in;
    float u, v, ustart, uend, ustep, vstart, vend, vstep, sumdiv;
    int i, j, iofs, jofs, cycl, len, curu, curv;
    int istart, iend, jsta, jen, *jstart, *jend, ratcomp;
    
    int totu = nu->pntsu*resolu, totv = nu->pntsv*resolv;
    
    if(nu->knotsu==NULL || nu->knotsv==NULL) return;
    if(nu->orderu>nu->pntsu) return;
    if(nu->orderv>nu->pntsv) return;
    if(coord_array==NULL) return;
    
    /* allocate and initialize */
    len = totu * totv;
    if(len==0) return;
    

    
    sum= (float *)MEM_callocN(sizeof(float)*len, "makeNurbfaces1");
    
    len= totu*totv;
    if(len==0) {
        MEM_freeN(sum);
        return;
    }

    bp= nu->bp;
    i= nu->pntsu*nu->pntsv;
    ratcomp=0;
    while(i--) {
        if(bp->vec[3] != 1.0f) {
            ratcomp= 1;
            break;
        }
        bp++;
    }
    
    fp= nu->knotsu;
    ustart= fp[nu->orderu-1];
    if(nu->flagu & CU_NURB_CYCLIC) uend= fp[nu->pntsu+nu->orderu-1];
    else uend= fp[nu->pntsu];
    ustep= (uend-ustart)/((nu->flagu & CU_NURB_CYCLIC) ? totu : totu - 1);
    
    basisu= (float *)MEM_mallocN(sizeof(float)*KNOTSU(nu), "makeNurbfaces3");

    fp= nu->knotsv;
    vstart= fp[nu->orderv-1];
    
    if(nu->flagv & CU_NURB_CYCLIC) vend= fp[nu->pntsv+nu->orderv-1];
    else vend= fp[nu->pntsv];
    vstep= (vend-vstart)/((nu->flagv & CU_NURB_CYCLIC) ? totv : totv - 1);
    
    len= KNOTSV(nu);
    basisv= (float *)MEM_mallocN(sizeof(float)*len*totv, "makeNurbfaces3");
    jstart= (int *)MEM_mallocN(sizeof(float)*totv, "makeNurbfaces4");
    jend= (int *)MEM_mallocN(sizeof(float)*totv, "makeNurbfaces5");

    /* precalculation of basisv and jstart,jend */
    if(nu->flagv & CU_NURB_CYCLIC) cycl= nu->orderv-1; 
    else cycl= 0;
    v= vstart;
    basis= basisv;
    curv= totv;
    while(curv--) {
        basisNurb(v, nu->orderv, (short)(nu->pntsv+cycl), nu->knotsv, basis, jstart+curv, jend+curv);
        basis+= KNOTSV(nu);
        v+= vstep;
    }

    if(nu->flagu & CU_NURB_CYCLIC) cycl= nu->orderu-1; 
    else cycl= 0;
    in= coord_array;
    u= ustart;
    curu= totu;
    while(curu--) {

        basisNurb(u, nu->orderu, (short)(nu->pntsu+cycl), nu->knotsu, basisu, &istart, &iend);

        basis= basisv;
        curv= totv;
        while(curv--) {

            jsta= jstart[curv];
            jen= jend[curv];

            /* calculate sum */
            sumdiv= 0.0;
            fp= sum;

            for(j= jsta; j<=jen; j++) {

                if(j>=nu->pntsv) jofs= (j - nu->pntsv);
                else jofs= j;
                bp= nu->bp+ nu->pntsu*jofs+istart-1;

                for(i= istart; i<=iend; i++, fp++) {

                    if(i>= nu->pntsu) {
                        iofs= i- nu->pntsu;
                        bp= nu->bp+ nu->pntsu*jofs+iofs;
                    }
                    else bp++;

                    if(ratcomp) {
                        *fp= basisu[i]*basis[j]*bp->vec[3];
                        sumdiv+= *fp;
                    }
                    else *fp= basisu[i]*basis[j];
                }
            }
        
            if(ratcomp) {
                fp= sum;
                for(j= jsta; j<=jen; j++) {
                    for(i= istart; i<=iend; i++, fp++) {
                        *fp/= sumdiv;
                    }
                }
            }

            /* one! (1.0) real point now */
            fp= sum;
            for(j= jsta; j<=jen; j++) {

                if(j>=nu->pntsv) jofs= (j - nu->pntsv);
                else jofs= j;
                bp= nu->bp+ nu->pntsu*jofs+istart-1;

                for(i= istart; i<=iend; i++, fp++) {

                    if(i>= nu->pntsu) {
                        iofs= i- nu->pntsu;
                        bp= nu->bp+ nu->pntsu*jofs+iofs;
                    }
                    else bp++;

                    if(*fp != 0.0f) {
                        in[0]+= (*fp) * bp->vec[0];
                        in[1]+= (*fp) * bp->vec[1];
                        in[2]+= (*fp) * bp->vec[2];
                    }
                }
            }

            in+=3;
            basis+= KNOTSV(nu);
        }
        u+= ustep;
        if (rowstride!=0) in = (float*) (((unsigned char*) in) + (rowstride - 3*totv*sizeof(*in)));
    }

    /* free */
    MEM_freeN(sum);
    MEM_freeN(basisu);
    MEM_freeN(basisv);
    MEM_freeN(jstart);
    MEM_freeN(jend);
}

void makeNurbcurve(Nurb *nu, float *coord_array, float *tilt_array, float *radius_array, float *weight_array, int resolu, int stride)
/* coord_array has to be 3*4*pntsu*resolu in size and zero-ed
 * tilt_array and radius_array will be written to if valid */
{
    BPoint *bp;
    float u, ustart, uend, ustep, sumdiv;
    float *basisu, *sum, *fp;
    float *coord_fp= coord_array, *tilt_fp= tilt_array, *radius_fp= radius_array, *weight_fp= weight_array;
    int i, len, istart, iend, cycl;

    if(nu->knotsu==NULL) return;
    if(nu->orderu>nu->pntsu) return;
    if(coord_array==NULL) return;

    /* allocate and initialize */
    len= nu->pntsu;
    if(len==0) return;
    sum= (float *)MEM_callocN(sizeof(float)*len, "makeNurbcurve1");
    
    resolu= (resolu*SEGMENTSU(nu));
    
    if(resolu==0) {
        MEM_freeN(sum);
        return;
    }

    fp= nu->knotsu;
    ustart= fp[nu->orderu-1];
    if(nu->flagu & CU_NURB_CYCLIC) uend= fp[nu->pntsu+nu->orderu-1];
    else uend= fp[nu->pntsu];
    ustep= (uend-ustart)/(resolu - ((nu->flagu & CU_NURB_CYCLIC) ? 0 : 1));
    
    basisu= (float *)MEM_mallocN(sizeof(float)*KNOTSU(nu), "makeNurbcurve3");

    if(nu->flagu & CU_NURB_CYCLIC) cycl= nu->orderu-1; 
    else cycl= 0;

    u= ustart;
    while(resolu--) {

        basisNurb(u, nu->orderu, (short)(nu->pntsu+cycl), nu->knotsu, basisu, &istart, &iend);
        /* calc sum */
        sumdiv= 0.0;
        fp= sum;
        bp= nu->bp+ istart-1;
        for(i= istart; i<=iend; i++, fp++) {

            if(i>=nu->pntsu) bp= nu->bp+(i - nu->pntsu);
            else bp++;

            *fp= basisu[i]*bp->vec[3];
            sumdiv+= *fp;
        }
        if(sumdiv != 0.0f) if(sumdiv < 0.999f || sumdiv > 1.001f) {
            /* is normalizing needed? */
            fp= sum;
            for(i= istart; i<=iend; i++, fp++) {
                *fp/= sumdiv;
            }
        }

        /* one! (1.0) real point */
        fp= sum;
        bp= nu->bp+ istart-1;
        for(i= istart; i<=iend; i++, fp++) {

            if(i>=nu->pntsu) bp= nu->bp+(i - nu->pntsu);
            else bp++;

            if(*fp != 0.0f) {
                
                coord_fp[0]+= (*fp) * bp->vec[0];
                coord_fp[1]+= (*fp) * bp->vec[1];
                coord_fp[2]+= (*fp) * bp->vec[2];
                
                if (tilt_fp)
                    (*tilt_fp) += (*fp) * bp->alfa;
                
                if (radius_fp)
                    (*radius_fp) += (*fp) * bp->radius;

                if (weight_fp)
                    (*weight_fp) += (*fp) * bp->weight;
                
            }
        }

        coord_fp = (float *)(((char *)coord_fp) + stride);
        
        if (tilt_fp)    tilt_fp = (float *)(((char *)tilt_fp) + stride);
        if (radius_fp)  radius_fp = (float *)(((char *)radius_fp) + stride);
        if (weight_fp)  weight_fp = (float *)(((char *)weight_fp) + stride);
        
        u+= ustep;
    }

    /* free */
    MEM_freeN(sum);
    MEM_freeN(basisu);
}

/* forward differencing method for bezier curve */
void forward_diff_bezier(float q0, float q1, float q2, float q3, float *p, int it, int stride)
{
    float rt0,rt1,rt2,rt3,f;
    int a;

    f= (float)it;
    rt0= q0;
    rt1= 3.0f*(q1-q0)/f;
    f*= f;
    rt2= 3.0f*(q0-2.0f*q1+q2)/f;
    f*= it;
    rt3= (q3-q0+3.0f*(q1-q2))/f;

    q0= rt0;
    q1= rt1+rt2+rt3;
    q2= 2*rt2+6*rt3;
    q3= 6*rt3;

    for(a=0; a<=it; a++) {
        *p= q0;
        p = (float *)(((char *)p)+stride);
        q0+= q1;
        q1+= q2;
        q2+= q3;
    }
}

static void forward_diff_bezier_cotangent(float *p0, float *p1, float *p2, float *p3, float *p, int it, int stride)
{
    /* note that these are not purpendicular to the curve
     * they need to be rotated for this,
     *
     * This could also be optimized like forward_diff_bezier */
    int a;
    for(a=0; a<=it; a++) {
        float t = (float)a / (float)it;

        int i;
        for(i=0; i<3; i++) {
            p[i]= (-6*t + 6)*p0[i] + (18*t - 12)*p1[i] + (-18*t + 6)*p2[i] + (6*t)*p3[i];
        }
        normalize_v3(p);
        p = (float *)(((char *)p)+stride);
    }
}

/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */

float *make_orco_surf(Object *ob)
{
    /* Note: this function is used in convertblender only atm, so
     * suppose nonzero curve's render resolution should always be used */
    Curve *cu= ob->data;
    Nurb *nu;
    int a, b, tot=0;
    int sizeu, sizev;
    int resolu, resolv;
    float *fp, *coord_array;
    
    /* first calculate the size of the datablock */
    nu= cu->nurb.first;
    while(nu) {
        /* as we want to avoid the seam in a cyclic nurbs
        texture wrapping, reserve extra orco data space to save these extra needed
        vertex based UV coordinates for the meridian vertices.
        Vertices on the 0/2pi boundary are not duplicated inside the displist but later in
        the renderface/vert construction.
        
        See also convertblender.c: init_render_surf()
        */

        resolu= cu->resolu_ren ? cu->resolu_ren : nu->resolu;
        resolv= cu->resolv_ren ? cu->resolv_ren : nu->resolv;
        
        sizeu = nu->pntsu*resolu;
        sizev = nu->pntsv*resolv;
        if (nu->flagu & CU_NURB_CYCLIC) sizeu++;
        if (nu->flagv & CU_NURB_CYCLIC) sizev++;
        if(nu->pntsv>1) tot+= sizeu * sizev;
        
        nu= nu->next;
    }
    /* makeNurbfaces wants zeros */
    fp= coord_array= MEM_callocN(3*sizeof(float)*tot, "make_orco");
    
    nu= cu->nurb.first;
    while(nu) {
        resolu= cu->resolu_ren ? cu->resolu_ren : nu->resolu;
        resolv= cu->resolv_ren ? cu->resolv_ren : nu->resolv;

        if(nu->pntsv>1) {
            sizeu = nu->pntsu*resolu;
            sizev = nu->pntsv*resolv;
            if (nu->flagu & CU_NURB_CYCLIC) sizeu++;
            if (nu->flagv & CU_NURB_CYCLIC) sizev++;
            
            if(cu->flag & CU_UV_ORCO) {
                for(b=0; b< sizeu; b++) {
                    for(a=0; a< sizev; a++) {
                        
                        if(sizev <2) fp[0]= 0.0f;
                        else fp[0]= -1.0f + 2.0f*((float)a)/(sizev - 1);
                        
                        if(sizeu <2) fp[1]= 0.0f;
                        else fp[1]= -1.0f + 2.0f*((float)b)/(sizeu - 1);
                        
                        fp[2]= 0.0;
                        
                        fp+= 3;
                    }
                }
            }
            else {
                float *_tdata= MEM_callocN((nu->pntsu*resolu) * (nu->pntsv*resolv) *3*sizeof(float), "temp data");
                float *tdata= _tdata;
                
                makeNurbfaces(nu, tdata, 0, resolu, resolv);
                
                for(b=0; b<sizeu; b++) {
                    int use_b= b;
                    if (b==sizeu-1 && (nu->flagu & CU_NURB_CYCLIC))
                        use_b= 0;
                    
                    for(a=0; a<sizev; a++) {
                        int use_a= a;
                        if (a==sizev-1 && (nu->flagv & CU_NURB_CYCLIC))
                            use_a= 0;
                        
                        tdata = _tdata + 3 * (use_b * (nu->pntsv*resolv) + use_a);
                        
                        fp[0]= (tdata[0]-cu->loc[0])/cu->size[0];
                        fp[1]= (tdata[1]-cu->loc[1])/cu->size[1];
                        fp[2]= (tdata[2]-cu->loc[2])/cu->size[2];
                        fp+= 3;
                    }
                }
                
                MEM_freeN(_tdata);
            }
        }
        nu= nu->next;
    }
    
    return coord_array;
}


    /* NOTE: This routine is tied to the order of vertex
     * built by displist and as passed to the renderer.
     */
float *make_orco_curve(Scene *scene, Object *ob)
{
    Curve *cu = ob->data;
    DispList *dl;
    int u, v, numVerts;
    float *fp, *coord_array;
    ListBase disp = {NULL, NULL};

    makeDispListCurveTypes_forOrco(scene, ob, &disp);

    numVerts = 0;
    for (dl=disp.first; dl; dl=dl->next) {
        if (dl->type==DL_INDEX3) {
            numVerts += dl->nr;
        } else if (dl->type==DL_SURF) {
            /* convertblender.c uses the Surface code for creating renderfaces when cyclic U only (closed circle beveling) */
            if (dl->flag & DL_CYCL_U) {
                if (dl->flag & DL_CYCL_V)
                    numVerts += (dl->parts+1)*(dl->nr+1);
                else
                    numVerts += dl->parts*(dl->nr+1);
            }
            else
                numVerts += dl->parts*dl->nr;
        }
    }

    fp= coord_array= MEM_mallocN(3*sizeof(float)*numVerts, "cu_orco");
    for (dl=disp.first; dl; dl=dl->next) {
        if (dl->type==DL_INDEX3) {
            for (u=0; u<dl->nr; u++, fp+=3) {
                if (cu->flag & CU_UV_ORCO) {
                    fp[0]= 2.0f*u/(dl->nr-1) - 1.0f;
                    fp[1]= 0.0;
                    fp[2]= 0.0;
                } else {
                    copy_v3_v3(fp, &dl->verts[u*3]);

                    fp[0]= (fp[0]-cu->loc[0])/cu->size[0];
                    fp[1]= (fp[1]-cu->loc[1])/cu->size[1];
                    fp[2]= (fp[2]-cu->loc[2])/cu->size[2];
                }
            }
        } else if (dl->type==DL_SURF) {
            int sizeu= dl->nr, sizev= dl->parts;
            
            /* exception as handled in convertblender.c too */
            if (dl->flag & DL_CYCL_U) {
                sizeu++;
                if (dl->flag & DL_CYCL_V)
                    sizev++;
            }
            
            for (u=0; u<sizev; u++) {
                for (v=0; v<sizeu; v++,fp+=3) {
                    if (cu->flag & CU_UV_ORCO) {
                        fp[0]= 2.0f*u/(sizev - 1) - 1.0f;
                        fp[1]= 2.0f*v/(sizeu - 1) - 1.0f;
                        fp[2]= 0.0;
                    } else {
                        float *vert;
                        int realv= v % dl->nr;
                        int realu= u % dl->parts;
                        
                        vert= dl->verts + 3*(dl->nr*realu + realv);
                        copy_v3_v3(fp, vert);

                        fp[0]= (fp[0]-cu->loc[0])/cu->size[0];
                        fp[1]= (fp[1]-cu->loc[1])/cu->size[1];
                        fp[2]= (fp[2]-cu->loc[2])/cu->size[2];
                    }
                }
            }
        }
    }

    freedisplist(&disp);

    return coord_array;
}


/* ***************** BEVEL ****************** */

void makebevelcurve(Scene *scene, Object *ob, ListBase *disp, int forRender)
{
    DispList *dl, *dlnew;
    Curve *bevcu, *cu;
    float *fp, facx, facy, angle, dangle;
    int nr, a;

    cu= ob->data;
    disp->first = disp->last = NULL;

    /* if a font object is being edited, then do nothing */
// XXX  if( ob == obedit && ob->type == OB_FONT ) return;

    if(cu->bevobj) {
        if (cu->bevobj->type!=OB_CURVE) return;

        bevcu= cu->bevobj->data;
        if(bevcu->ext1==0.0f && bevcu->ext2==0.0f) {
            ListBase bevdisp= {NULL, NULL};
            facx= cu->bevobj->size[0];
            facy= cu->bevobj->size[1];

            if (forRender) {
                makeDispListCurveTypes_forRender(scene, cu->bevobj, &bevdisp, NULL, 0);
                dl= bevdisp.first;
            } else {
                dl= cu->bevobj->disp.first;
                if(dl==NULL) {
                    makeDispListCurveTypes(scene, cu->bevobj, 0);
                    dl= cu->bevobj->disp.first;
                }
            }

            while(dl) {
                if ELEM(dl->type, DL_POLY, DL_SEGM) {
                    dlnew= MEM_mallocN(sizeof(DispList), "makebevelcurve1");
                    *dlnew= *dl;
                    dlnew->verts= MEM_mallocN(3*sizeof(float)*dl->parts*dl->nr, "makebevelcurve1");
                    memcpy(dlnew->verts, dl->verts, 3*sizeof(float)*dl->parts*dl->nr);

                    if(dlnew->type==DL_SEGM) dlnew->flag |= (DL_FRONT_CURVE|DL_BACK_CURVE);

                    BLI_addtail(disp, dlnew);
                    fp= dlnew->verts;
                    nr= dlnew->parts*dlnew->nr;
                    while(nr--) {
                        fp[2]= fp[1]*facy;
                        fp[1]= -fp[0]*facx;
                        fp[0]= 0.0;
                        fp+= 3;
                    }
                }
                dl= dl->next;
            }

            freedisplist(&bevdisp);
        }
    }
    else if(cu->ext1==0.0f && cu->ext2==0.0f) {
        ;
    }
    else if(cu->ext2==0.0f) {
        dl= MEM_callocN(sizeof(DispList), "makebevelcurve2");
        dl->verts= MEM_mallocN(2*3*sizeof(float), "makebevelcurve2");
        BLI_addtail(disp, dl);
        dl->type= DL_SEGM;
        dl->parts= 1;
        dl->flag= DL_FRONT_CURVE|DL_BACK_CURVE;
        dl->nr= 2;
        
        fp= dl->verts;
        fp[0]= fp[1]= 0.0;
        fp[2]= -cu->ext1;
        fp[3]= fp[4]= 0.0;
        fp[5]= cu->ext1;
    }
    else if( (cu->flag & (CU_FRONT|CU_BACK))==0 && cu->ext1==0.0f)  { // we make a full round bevel in that case
        
        nr= 4+ 2*cu->bevresol;
           
        dl= MEM_callocN(sizeof(DispList), "makebevelcurve p1");
        dl->verts= MEM_mallocN(nr*3*sizeof(float), "makebevelcurve p1");
        BLI_addtail(disp, dl);
        dl->type= DL_POLY;
        dl->parts= 1;
        dl->flag= DL_BACK_CURVE;
        dl->nr= nr;

        /* a circle */
        fp= dl->verts;
        dangle= (2.0f*(float)M_PI/(nr));
        angle= -(nr-1)*dangle;
        
        for(a=0; a<nr; a++) {
            fp[0]= 0.0;
            fp[1]= (cosf(angle)*(cu->ext2));
            fp[2]= (sinf(angle)*(cu->ext2)) - cu->ext1;
            angle+= dangle;
            fp+= 3;
        }
    }
    else {
        short dnr;
        
        /* bevel now in three parts, for proper vertex normals */
        /* part 1, back */

        if((cu->flag & CU_BACK) || !(cu->flag & CU_FRONT)) {
            dnr= nr= 2+ cu->bevresol;
            if( (cu->flag & (CU_FRONT|CU_BACK))==0)
                nr= 3+ 2*cu->bevresol;

            dl= MEM_callocN(sizeof(DispList), "makebevelcurve p1");
            dl->verts= MEM_mallocN(nr*3*sizeof(float), "makebevelcurve p1");
            BLI_addtail(disp, dl);
            dl->type= DL_SEGM;
            dl->parts= 1;
            dl->flag= DL_BACK_CURVE;
            dl->nr= nr;

            /* half a circle */
            fp= dl->verts;
            dangle= (0.5*M_PI/(dnr-1));
            angle= -(nr-1)*dangle;

            for(a=0; a<nr; a++) {
                fp[0]= 0.0;
                fp[1]= (float)(cosf(angle)*(cu->ext2));
                fp[2]= (float)(sinf(angle)*(cu->ext2)) - cu->ext1;
                angle+= dangle;
                fp+= 3;
            }
        }
        
        /* part 2, sidefaces */
        if(cu->ext1!=0.0f) {
            nr= 2;
            
            dl= MEM_callocN(sizeof(DispList), "makebevelcurve p2");
            dl->verts= MEM_callocN(nr*3*sizeof(float), "makebevelcurve p2");
            BLI_addtail(disp, dl);
            dl->type= DL_SEGM;
            dl->parts= 1;
            dl->nr= nr;
            
            fp= dl->verts;
            fp[1]= cu->ext2;
            fp[2]= -cu->ext1;
            fp[4]= cu->ext2;
            fp[5]= cu->ext1;
            
            if( (cu->flag & (CU_FRONT|CU_BACK))==0) {
                dl= MEM_dupallocN(dl);
                dl->verts= MEM_dupallocN(dl->verts);
                BLI_addtail(disp, dl);
                
                fp= dl->verts;
                fp[1]= -fp[1];
                fp[2]= -fp[2];
                fp[4]= -fp[4];
                fp[5]= -fp[5];
            }
        }
        
        /* part 3, front */
        if((cu->flag & CU_FRONT) || !(cu->flag & CU_BACK)) {
            dnr= nr= 2+ cu->bevresol;
            if( (cu->flag & (CU_FRONT|CU_BACK))==0)
                nr= 3+ 2*cu->bevresol;

            dl= MEM_callocN(sizeof(DispList), "makebevelcurve p3");
            dl->verts= MEM_mallocN(nr*3*sizeof(float), "makebevelcurve p3");
            BLI_addtail(disp, dl);
            dl->type= DL_SEGM;
            dl->flag= DL_FRONT_CURVE;
            dl->parts= 1;
            dl->nr= nr;

            /* half a circle */
            fp= dl->verts;
            angle= 0.0;
            dangle= (0.5*M_PI/(dnr-1));

            for(a=0; a<nr; a++) {
                fp[0]= 0.0;
                fp[1]= (float)(cosf(angle)*(cu->ext2));
                fp[2]= (float)(sinf(angle)*(cu->ext2)) + cu->ext1;
                angle+= dangle;
                fp+= 3;
            }
        }
    }
}

static int cu_isectLL(float *v1, float *v2, float *v3, float *v4, short cox, short coy, float *labda, float *mu, float *vec)
{
    /* return:
        -1: colliniar
         0: no intersection of segments
         1: exact intersection of segments
         2: cross-intersection of segments
    */
    float deler;

    deler= (v1[cox]-v2[cox])*(v3[coy]-v4[coy])-(v3[cox]-v4[cox])*(v1[coy]-v2[coy]);
    if(deler==0.0f) return -1;

    *labda= (v1[coy]-v3[coy])*(v3[cox]-v4[cox])-(v1[cox]-v3[cox])*(v3[coy]-v4[coy]);
    *labda= -(*labda/deler);

    deler= v3[coy]-v4[coy];
    if(deler==0) {
        deler=v3[cox]-v4[cox];
        *mu= -(*labda*(v2[cox]-v1[cox])+v1[cox]-v3[cox])/deler;
    } else {
        *mu= -(*labda*(v2[coy]-v1[coy])+v1[coy]-v3[coy])/deler;
    }
    vec[cox]= *labda*(v2[cox]-v1[cox])+v1[cox];
    vec[coy]= *labda*(v2[coy]-v1[coy])+v1[coy];

    if(*labda>=0.0f && *labda<=1.0f && *mu>=0.0f && *mu<=1.0f) {
        if(*labda==0.0f || *labda==1.0f || *mu==0.0f || *mu==1.0f) return 1;
        return 2;
    }
    return 0;
}


static short bevelinside(BevList *bl1,BevList *bl2)
{
    /* is bl2 INSIDE bl1 ? with left-right method and "labda's" */
    /* returns '1' if correct hole  */
    BevPoint *bevp, *prevbevp;
    float min,max,vec[3],hvec1[3],hvec2[3],lab,mu;
    int nr, links=0,rechts=0,mode;

    /* take first vertex of possible hole */

    bevp= (BevPoint *)(bl2+1);
    hvec1[0]= bevp->vec[0]; 
    hvec1[1]= bevp->vec[1]; 
    hvec1[2]= 0.0;
    copy_v3_v3(hvec2,hvec1);
    hvec2[0]+=1000;

    /* test it with all edges of potential surounding poly */
    /* count number of transitions left-right  */

    bevp= (BevPoint *)(bl1+1);
    nr= bl1->nr;
    prevbevp= bevp+(nr-1);

    while(nr--) {
        min= prevbevp->vec[1];
        max= bevp->vec[1];
        if(max<min) {
            min= max;
            max= prevbevp->vec[1];
        }
        if(min!=max) {
            if(min<=hvec1[1] && max>=hvec1[1]) {
                /* there's a transition, calc intersection point */
                mode= cu_isectLL(prevbevp->vec, bevp->vec, hvec1, hvec2, 0, 1, &lab, &mu, vec);
                /* if lab==0.0 or lab==1.0 then the edge intersects exactly a transition
                       only allow for one situation: we choose lab= 1.0
                 */
                if(mode >= 0 && lab != 0.0f) {
                    if(vec[0]<hvec1[0]) links++;
                    else rechts++;
                }
            }
        }
        prevbevp= bevp;
        bevp++;
    }
    
    if( (links & 1) && (rechts & 1) ) return 1;
    return 0;
}


struct bevelsort {
    float left;
    BevList *bl;
    int dir;
};

static int vergxcobev(const void *a1, const void *a2)
{
    const struct bevelsort *x1=a1,*x2=a2;

    if( x1->left > x2->left ) return 1;
    else if( x1->left < x2->left) return -1;
    return 0;
}

/* this function cannot be replaced with atan2, but why? */

static void calc_bevel_sin_cos(float x1, float y1, float x2, float y2, float *sina, float *cosa)
{
    float t01, t02, x3, y3;

    t01= (float)sqrt(x1*x1+y1*y1);
    t02= (float)sqrt(x2*x2+y2*y2);
    if(t01==0.0f) t01= 1.0f;
    if(t02==0.0f) t02= 1.0f;

    x1/=t01; 
    y1/=t01;
    x2/=t02; 
    y2/=t02;

    t02= x1*x2+y1*y2;
    if(fabs(t02)>=1.0) t02= .5*M_PI;
    else t02= (saacos(t02))/2.0f;

    t02= (float)sin(t02);
    if(t02==0.0f) t02= 1.0f;

    x3= x1-x2;
    y3= y1-y2;
    if(x3==0 && y3==0) {
        x3= y1;
        y3= -x1;
    } else {
        t01= (float)sqrt(x3*x3+y3*y3);
        x3/=t01; 
        y3/=t01;
    }

    *sina= -y3/t02;
    *cosa= x3/t02;

}

static void alfa_bezpart(BezTriple *prevbezt, BezTriple *bezt, Nurb *nu, float *tilt_array, float *radius_array, float *weight_array, int resolu, int stride)
{
    BezTriple *pprev, *next, *last;
    float fac, dfac, t[4];
    int a;
    
    if(tilt_array==NULL && radius_array==NULL)
        return;
    
    last= nu->bezt+(nu->pntsu-1);
    
    /* returns a point */
    if(prevbezt==nu->bezt) {
        if(nu->flagu & CU_NURB_CYCLIC) pprev= last;
        else pprev= prevbezt;
    }
    else pprev= prevbezt-1;
    
    /* next point */
    if(bezt==last) {
        if(nu->flagu & CU_NURB_CYCLIC) next= nu->bezt;
        else next= bezt;
    }
    else next= bezt+1;
    
    fac= 0.0;
    dfac= 1.0f/(float)resolu;
    
    for(a=0; a<resolu; a++, fac+= dfac) {
        if (tilt_array) {
            if (nu->tilt_interp==KEY_CU_EASE) { /* May as well support for tilt also 2.47 ease interp */
                *tilt_array = prevbezt->alfa + (bezt->alfa - prevbezt->alfa)*(3.0f*fac*fac - 2.0f*fac*fac*fac);
            } else {
                key_curve_position_weights(fac, t, nu->tilt_interp);
                *tilt_array= t[0]*pprev->alfa + t[1]*prevbezt->alfa + t[2]*bezt->alfa + t[3]*next->alfa;
            }
            
            tilt_array = (float *)(((char *)tilt_array) + stride); 
        }
        
        if (radius_array) {
            if (nu->radius_interp==KEY_CU_EASE) {
                /* Support 2.47 ease interp
                 * Note! - this only takes the 2 points into account,
                 * giving much more localized results to changes in radius, sometimes you want that */
                *radius_array = prevbezt->radius + (bezt->radius - prevbezt->radius)*(3.0f*fac*fac - 2.0f*fac*fac*fac);
            } else {
                
                /* reuse interpolation from tilt if we can */
                if (tilt_array==NULL || nu->tilt_interp != nu->radius_interp) {
                    key_curve_position_weights(fac, t, nu->radius_interp);
                }
                *radius_array= t[0]*pprev->radius + t[1]*prevbezt->radius + t[2]*bezt->radius + t[3]*next->radius;
            }
            
            radius_array = (float *)(((char *)radius_array) + stride); 
        }

        if(weight_array) {
            /* basic interpolation for now, could copy tilt interp too  */
            *weight_array = prevbezt->weight + (bezt->weight - prevbezt->weight)*(3.0f*fac*fac - 2.0f*fac*fac*fac);

            weight_array = (float *)(((char *)weight_array) + stride);
        }
    }
}

/* make_bevel_list_3D_* funcs, at a minimum these must
 * fill in the bezp->quat and bezp->dir values */

/* correct non-cyclic cases by copying direction and rotation
 * values onto the first & last end-points */
static void bevel_list_cyclic_fix_3D(BevList *bl)
{
    BevPoint *bevp, *bevp1;

    bevp= (BevPoint *)(bl+1);
    bevp1= bevp+1;
    copy_qt_qt(bevp->quat, bevp1->quat);
    copy_v3_v3(bevp->dir, bevp1->dir);
    copy_v3_v3(bevp->tan, bevp1->tan);
    bevp= (BevPoint *)(bl+1);
    bevp+= (bl->nr-1);
    bevp1= bevp-1;
    copy_qt_qt(bevp->quat, bevp1->quat);
    copy_v3_v3(bevp->dir, bevp1->dir);
    copy_v3_v3(bevp->tan, bevp1->tan);
}
/* utility for make_bevel_list_3D_* funcs */
static void bevel_list_calc_bisect(BevList *bl)
{
    BevPoint *bevp2, *bevp1, *bevp0;
    int nr;

    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);
    bevp0= bevp1-1;

    nr= bl->nr;
    while(nr--) {
        /* totally simple */
        bisect_v3_v3v3v3(bevp1->dir, bevp0->vec, bevp1->vec, bevp2->vec);

        bevp0= bevp1;
        bevp1= bevp2;
        bevp2++;
    }
}
static void bevel_list_flip_tangents(BevList *bl)
{
    BevPoint *bevp2, *bevp1, *bevp0;
    int nr;

    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);
    bevp0= bevp1-1;

    nr= bl->nr;
    while(nr--) {
        if(RAD2DEGF(angle_v2v2(bevp0->tan, bevp1->tan)) > 90.0f)
            negate_v3(bevp1->tan);

        bevp0= bevp1;
        bevp1= bevp2;
        bevp2++;
    }
}
/* apply user tilt */
static void bevel_list_apply_tilt(BevList *bl)
{
    BevPoint *bevp2, *bevp1;
    int nr;
    float q[4];

    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);

    nr= bl->nr;
    while(nr--) {
        axis_angle_to_quat(q, bevp1->dir, bevp1->alfa);
        mul_qt_qtqt(bevp1->quat, q, bevp1->quat);
        normalize_qt(bevp1->quat);

        bevp1= bevp2;
        bevp2++;
    }
}
/* smooth quats, this function should be optimized, it can get slow with many iterations. */
static void bevel_list_smooth(BevList *bl, int smooth_iter)
{
    BevPoint *bevp2, *bevp1, *bevp0;
    int nr;

    float q[4];
    float bevp0_quat[4];
    int a;

    for(a=0; a < smooth_iter; a++) {

        bevp2= (BevPoint *)(bl+1);
        bevp1= bevp2+(bl->nr-1);
        bevp0= bevp1-1;

        nr= bl->nr;

        if(bl->poly== -1) { /* check its not cyclic */
            /* skip the first point */
            /* bevp0= bevp1; */
            bevp1= bevp2;
            bevp2++;
            nr--;

            bevp0= bevp1;
            bevp1= bevp2;
            bevp2++;
            nr--;

        }

        copy_qt_qt(bevp0_quat, bevp0->quat);

        while(nr--) {
            /* interpolate quats */
            float zaxis[3] = {0,0,1}, cross[3], q2[4];
            interp_qt_qtqt(q, bevp0_quat, bevp2->quat, 0.5);
            normalize_qt(q);

            mul_qt_v3(q, zaxis);
            cross_v3_v3v3(cross, zaxis, bevp1->dir);
            axis_angle_to_quat(q2, cross, angle_normalized_v3v3(zaxis, bevp1->dir));
            normalize_qt(q2);

            copy_qt_qt(bevp0_quat, bevp1->quat);
            mul_qt_qtqt(q, q2, q);
            interp_qt_qtqt(bevp1->quat, bevp1->quat, q, 0.5);
            normalize_qt(bevp1->quat);


            /* bevp0= bevp1; */ /* UNUSED */
            bevp1= bevp2;
            bevp2++;
        }
    }
}

static void make_bevel_list_3D_zup(BevList *bl)
{
    BevPoint *bevp2, *bevp1, *bevp0; /* standard for all make_bevel_list_3D_* funcs */
    int nr;

    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);
    bevp0= bevp1-1;

    nr= bl->nr;
    while(nr--) {
        /* totally simple */
        bisect_v3_v3v3v3(bevp1->dir, bevp0->vec, bevp1->vec, bevp2->vec);
        vec_to_quat( bevp1->quat,bevp1->dir, 5, 1);

        bevp0= bevp1;
        bevp1= bevp2;
        bevp2++;
    }
}

static void make_bevel_list_3D_minimum_twist(BevList *bl)
{
    BevPoint *bevp2, *bevp1, *bevp0; /* standard for all make_bevel_list_3D_* funcs */
    int nr;
    float q[4];

    bevel_list_calc_bisect(bl);

    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);
    bevp0= bevp1-1;

    nr= bl->nr;
    while(nr--) {

        if(nr+4 > bl->nr) { /* first time and second time, otherwise first point adjusts last */
            vec_to_quat( bevp1->quat,bevp1->dir, 5, 1);
        }
        else {
            float angle= angle_normalized_v3v3(bevp0->dir, bevp1->dir);

            if(angle > 0.0f) { /* otherwise we can keep as is */
                float cross_tmp[3];
                cross_v3_v3v3(cross_tmp, bevp0->dir, bevp1->dir);
                axis_angle_to_quat(q, cross_tmp, angle);
                mul_qt_qtqt(bevp1->quat, q, bevp0->quat);
            }
            else {
                copy_qt_qt(bevp1->quat, bevp0->quat);
            }
        }

        bevp0= bevp1;
        bevp1= bevp2;
        bevp2++;
    }

    if(bl->poly != -1) { /* check for cyclic */

        /* Need to correct for the start/end points not matching
         * do this by calculating the tilt angle difference, then apply
         * the rotation gradually over the entire curve
         *
         * note that the split is between last and second last, rather than first/last as youd expect.
         *
         * real order is like this
         * 0,1,2,3,4 --> 1,2,3,4,0
         *
         * this is why we compare last with second last
         * */
        float vec_1[3]= {0,1,0}, vec_2[3]= {0,1,0}, angle, ang_fac, cross_tmp[3];

        BevPoint *bevp_first;
        BevPoint *bevp_last;


        bevp_first= (BevPoint *)(bl+1);
        bevp_first+= bl->nr-1;
        bevp_last = bevp_first;
        bevp_last--;

        /* quats and vec's are normalized, should not need to re-normalize */
        mul_qt_v3(bevp_first->quat, vec_1);
        mul_qt_v3(bevp_last->quat, vec_2);
        normalize_v3(vec_1);
        normalize_v3(vec_2);

        /* align the vector, can avoid this and it looks 98% OK but
         * better to align the angle quat roll's before comparing */
        {
            cross_v3_v3v3(cross_tmp, bevp_last->dir, bevp_first->dir);
            angle = angle_normalized_v3v3(bevp_first->dir, bevp_last->dir);
            axis_angle_to_quat(q, cross_tmp, angle);
            mul_qt_v3(q, vec_2);
        }

        angle= angle_normalized_v3v3(vec_1, vec_2);

        /* flip rotation if needs be */
        cross_v3_v3v3(cross_tmp, vec_1, vec_2);
        normalize_v3(cross_tmp);
        if(angle_normalized_v3v3(bevp_first->dir, cross_tmp) < DEG2RADF(90.0f))
            angle = -angle;

        bevp2= (BevPoint *)(bl+1);
        bevp1= bevp2+(bl->nr-1);
        bevp0= bevp1-1;

        nr= bl->nr;
        while(nr--) {
            ang_fac= angle * (1.0f-((float)nr/bl->nr)); /* also works */

            axis_angle_to_quat(q, bevp1->dir, ang_fac);
            mul_qt_qtqt(bevp1->quat, q, bevp1->quat);

            bevp0= bevp1;
            bevp1= bevp2;
            bevp2++;
        }
    }
}

static void make_bevel_list_3D_tangent(BevList *bl)
{
    BevPoint *bevp2, *bevp1, *bevp0; /* standard for all make_bevel_list_3D_* funcs */
    int nr;

    float bevp0_tan[3], cross_tmp[3];

    bevel_list_calc_bisect(bl);
    if(bl->poly== -1) /* check its not cyclic */
        bevel_list_cyclic_fix_3D(bl); // XXX - run this now so tangents will be right before doing the flipping
    bevel_list_flip_tangents(bl);

    /* correct the tangents */
    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);
    bevp0= bevp1-1;

    nr= bl->nr;
    while(nr--) {

        cross_v3_v3v3(cross_tmp, bevp1->tan, bevp1->dir);
        cross_v3_v3v3(bevp1->tan, cross_tmp, bevp1->dir);
        normalize_v3(bevp1->tan);

        bevp0= bevp1;
        bevp1= bevp2;
        bevp2++;
    }


    /* now for the real twist calc */
    bevp2= (BevPoint *)(bl+1);
    bevp1= bevp2+(bl->nr-1);
    bevp0= bevp1-1;

    copy_v3_v3(bevp0_tan, bevp0->tan);

    nr= bl->nr;
    while(nr--) {

        /* make perpendicular, modify tan in place, is ok */
        float cross_tmp[3];
        float zero[3] = {0,0,0};

        cross_v3_v3v3(cross_tmp, bevp1->tan, bevp1->dir);
        normalize_v3(cross_tmp);
        tri_to_quat( bevp1->quat,zero, cross_tmp, bevp1->tan); /* XXX - could be faster */

        /* bevp0= bevp1; */ /* UNUSED */
        bevp1= bevp2;
        bevp2++;
    }
}

static void make_bevel_list_3D(BevList *bl, int smooth_iter, int twist_mode)
{
    switch(twist_mode) {
    case CU_TWIST_TANGENT:
        make_bevel_list_3D_tangent(bl);
        break;
    case CU_TWIST_MINIMUM:
        make_bevel_list_3D_minimum_twist(bl);
        break;
    default: /* CU_TWIST_Z_UP default, pre 2.49c */
        make_bevel_list_3D_zup(bl);
    }

    if(bl->poly== -1) /* check its not cyclic */
        bevel_list_cyclic_fix_3D(bl);

    if(smooth_iter)
        bevel_list_smooth(bl, smooth_iter);

    bevel_list_apply_tilt(bl);
}



/* only for 2 points */
static void make_bevel_list_segment_3D(BevList *bl)
{
    float q[4];

    BevPoint *bevp2= (BevPoint *)(bl+1);
    BevPoint *bevp1= bevp2+1;

    /* simple quat/dir */
    sub_v3_v3v3(bevp1->dir, bevp1->vec, bevp2->vec);
    normalize_v3(bevp1->dir);

    vec_to_quat( bevp1->quat,bevp1->dir, 5, 1);

    axis_angle_to_quat(q, bevp1->dir, bevp1->alfa);
    mul_qt_qtqt(bevp1->quat, q, bevp1->quat);
    normalize_qt(bevp1->quat);
    copy_v3_v3(bevp2->dir, bevp1->dir);
    copy_qt_qt(bevp2->quat, bevp1->quat);
}



void makeBevelList(Object *ob)
{
    /*
     - convert all curves to polys, with indication of resol and flags for double-vertices
     - possibly; do a smart vertice removal (in case Nurb)
     - separate in individual blicks with BoundBox
     - AutoHole detection
    */
    Curve *cu;
    Nurb *nu;
    BezTriple *bezt, *prevbezt;
    BPoint *bp;
    BevList *bl, *blnew, *blnext;
    BevPoint *bevp, *bevp2, *bevp1 = NULL, *bevp0;
    float min, inp, x1, x2, y1, y2;
    struct bevelsort *sortdata, *sd, *sd1;
    int a, b, nr, poly, resolu = 0, len = 0;
    int do_tilt, do_radius, do_weight;
    
    /* this function needs an object, because of tflag and upflag */
    cu= ob->data;

    /* do we need to calculate the radius for each point? */
    /* do_radius = (cu->bevobj || cu->taperobj || (cu->flag & CU_FRONT) || (cu->flag & CU_BACK)) ? 0 : 1; */
    
    /* STEP 1: MAKE POLYS  */

    BLI_freelistN(&(cu->bev));
    if(cu->editnurb && ob->type!=OB_FONT) {
        ListBase *nurbs= curve_editnurbs(cu);
        nu= nurbs->first;
    } else nu= cu->nurb.first;
    
    while(nu) {
        
        /* check if we will calculate tilt data */
        do_tilt = CU_DO_TILT(cu, nu);
        do_radius = CU_DO_RADIUS(cu, nu); /* normal display uses the radius, better just to calculate them */
        do_weight = 1;
        
        /* check we are a single point? also check we are not a surface and that the orderu is sane,
         * enforced in the UI but can go wrong possibly */
        if(!check_valid_nurb_u(nu)) {
            bl= MEM_callocN(sizeof(BevList)+1*sizeof(BevPoint), "makeBevelList1");
            BLI_addtail(&(cu->bev), bl);
            bl->nr= 0;
        } else {
            if(G.rendering && cu->resolu_ren!=0) 
                resolu= cu->resolu_ren;
            else
                resolu= nu->resolu;
            
            if(nu->type == CU_POLY) {
                len= nu->pntsu;
                bl= MEM_callocN(sizeof(BevList)+len*sizeof(BevPoint), "makeBevelList2");
                BLI_addtail(&(cu->bev), bl);
    
                if(nu->flagu & CU_NURB_CYCLIC) bl->poly= 0;
                else bl->poly= -1;
                bl->nr= len;
                bl->dupe_nr= 0;
                bevp= (BevPoint *)(bl+1);
                bp= nu->bp;
    
                while(len--) {
                    copy_v3_v3(bevp->vec, bp->vec);
                    bevp->alfa= bp->alfa;
                    bevp->radius= bp->radius;
                    bevp->weight= bp->weight;
                    bevp->split_tag= TRUE;
                    bevp++;
                    bp++;
                }
            }
            else if(nu->type == CU_BEZIER) {
    
                len= resolu*(nu->pntsu+ (nu->flagu & CU_NURB_CYCLIC) -1)+1; /* in case last point is not cyclic */
                bl= MEM_callocN(sizeof(BevList)+len*sizeof(BevPoint), "makeBevelBPoints");
                BLI_addtail(&(cu->bev), bl);
    
                if(nu->flagu & CU_NURB_CYCLIC) bl->poly= 0;
                else bl->poly= -1;
                bevp= (BevPoint *)(bl+1);
    
                a= nu->pntsu-1;
                bezt= nu->bezt;
                if(nu->flagu & CU_NURB_CYCLIC) {
                    a++;
                    prevbezt= nu->bezt+(nu->pntsu-1);
                }
                else {
                    prevbezt= bezt;
                    bezt++;
                }
                
                while(a--) {
                    if(prevbezt->h2==HD_VECT && bezt->h1==HD_VECT) {

                        copy_v3_v3(bevp->vec, prevbezt->vec[1]);
                        bevp->alfa= prevbezt->alfa;
                        bevp->radius= prevbezt->radius;
                        bevp->weight= prevbezt->weight;
                        bevp->split_tag= TRUE;
                        bevp->dupe_tag= FALSE;
                        bevp++;
                        bl->nr++;
                        bl->dupe_nr= 1;
                    }
                    else {
                        /* always do all three, to prevent data hanging around */
                        int j;
                        
                        /* BevPoint must stay aligned to 4 so sizeof(BevPoint)/sizeof(float) works */
                        for(j=0; j<3; j++) {
                            forward_diff_bezier(    prevbezt->vec[1][j],    prevbezt->vec[2][j],
                                                    bezt->vec[0][j],        bezt->vec[1][j],
                                                    &(bevp->vec[j]), resolu, sizeof(BevPoint));
                        }
                        
                        /* if both arrays are NULL do nothiong */
                        alfa_bezpart(   prevbezt, bezt, nu,
                                         do_tilt    ? &bevp->alfa : NULL,
                                         do_radius  ? &bevp->radius : NULL,
                                         do_weight  ? &bevp->weight : NULL,
                                         resolu, sizeof(BevPoint));

                        
                        if(cu->twist_mode==CU_TWIST_TANGENT) {
                            forward_diff_bezier_cotangent(
                                                    prevbezt->vec[1],   prevbezt->vec[2],
                                                    bezt->vec[0],       bezt->vec[1],
                                                    bevp->tan, resolu, sizeof(BevPoint));
                        }

                        /* indicate with handlecodes double points */
                        if(prevbezt->h1==prevbezt->h2) {
                            if(prevbezt->h1==0 || prevbezt->h1==HD_VECT) bevp->split_tag= TRUE;
                        }
                        else {
                            if(prevbezt->h1==0 || prevbezt->h1==HD_VECT) bevp->split_tag= TRUE;
                            else if(prevbezt->h2==0 || prevbezt->h2==HD_VECT) bevp->split_tag= TRUE;
                        }
                        bl->nr+= resolu;
                        bevp+= resolu;
                    }
                    prevbezt= bezt;
                    bezt++;
                }
                
                if((nu->flagu & CU_NURB_CYCLIC)==0) {       /* not cyclic: endpoint */
                    copy_v3_v3(bevp->vec, prevbezt->vec[1]);
                    bevp->alfa= prevbezt->alfa;
                    bevp->radius= prevbezt->radius;
                    bevp->weight= prevbezt->weight;
                    bl->nr++;
                }
            }
            else if(nu->type == CU_NURBS) {
                if(nu->pntsv==1) {
                    len= (resolu*SEGMENTSU(nu));
                    
                    bl= MEM_callocN(sizeof(BevList)+len*sizeof(BevPoint), "makeBevelList3");
                    BLI_addtail(&(cu->bev), bl);
                    bl->nr= len;
                    bl->dupe_nr= 0;
                    if(nu->flagu & CU_NURB_CYCLIC) bl->poly= 0;
                    else bl->poly= -1;
                    bevp= (BevPoint *)(bl+1);
                    
                    makeNurbcurve(  nu, &bevp->vec[0],
                                    do_tilt     ? &bevp->alfa : NULL,
                                    do_radius   ? &bevp->radius : NULL,
                                    do_weight   ? &bevp->weight : NULL,
                                    resolu, sizeof(BevPoint));
                }
            }
        }
        nu= nu->next;
    }

    /* STEP 2: DOUBLE POINTS AND AUTOMATIC RESOLUTION, REDUCE DATABLOCKS */
    bl= cu->bev.first;
    while(bl) {
        if (bl->nr) { /* null bevel items come from single points */
            nr= bl->nr;
            bevp1= (BevPoint *)(bl+1);
            bevp0= bevp1+(nr-1);
            nr--;
            while(nr--) {
                if( fabs(bevp0->vec[0]-bevp1->vec[0])<0.00001 ) {
                    if( fabs(bevp0->vec[1]-bevp1->vec[1])<0.00001 ) {
                        if( fabs(bevp0->vec[2]-bevp1->vec[2])<0.00001 ) {
                            bevp0->dupe_tag= TRUE;
                            bl->dupe_nr++;
                        }
                    }
                }
                bevp0= bevp1;
                bevp1++;
            }
        }
        bl= bl->next;
    }
    bl= cu->bev.first;
    while(bl) {
        blnext= bl->next;
        if(bl->nr && bl->dupe_nr) {
            nr= bl->nr- bl->dupe_nr+1;  /* +1 because vectorbezier sets flag too */
            blnew= MEM_mallocN(sizeof(BevList)+nr*sizeof(BevPoint), "makeBevelList4");
            memcpy(blnew, bl, sizeof(BevList));
            blnew->nr= 0;
            BLI_remlink(&(cu->bev), bl);
            BLI_insertlinkbefore(&(cu->bev),blnext,blnew);  /* to make sure bevlijst is tuned with nurblist */
            bevp0= (BevPoint *)(bl+1);
            bevp1= (BevPoint *)(blnew+1);
            nr= bl->nr;
            while(nr--) {
                if(bevp0->dupe_tag==0) {
                    memcpy(bevp1, bevp0, sizeof(BevPoint));
                    bevp1++;
                    blnew->nr++;
                }
                bevp0++;
            }
            MEM_freeN(bl);
            blnew->dupe_nr= 0;
        }
        bl= blnext;
    }

    /* STEP 3: POLYS COUNT AND AUTOHOLE */
    bl= cu->bev.first;
    poly= 0;
    while(bl) {
        if(bl->nr && bl->poly>=0) {
            poly++;
            bl->poly= poly;
            bl->hole= 0;
        }
        bl= bl->next;
    }
    

    /* find extreme left points, also test (turning) direction */
    if(poly>0) {
        sd= sortdata= MEM_mallocN(sizeof(struct bevelsort)*poly, "makeBevelList5");
        bl= cu->bev.first;
        while(bl) {
            if(bl->poly>0) {

                min= 300000.0;
                bevp= (BevPoint *)(bl+1);
                nr= bl->nr;
                while(nr--) {
                    if(min>bevp->vec[0]) {
                        min= bevp->vec[0];
                        bevp1= bevp;
                    }
                    bevp++;
                }
                sd->bl= bl;
                sd->left= min;

                bevp= (BevPoint *)(bl+1);
                if(bevp1== bevp) bevp0= bevp+ (bl->nr-1);
                else bevp0= bevp1-1;
                bevp= bevp+ (bl->nr-1);
                if(bevp1== bevp) bevp2= (BevPoint *)(bl+1);
                else bevp2= bevp1+1;

                inp= (bevp1->vec[0]- bevp0->vec[0]) * (bevp0->vec[1]- bevp2->vec[1]) + (bevp0->vec[1]- bevp1->vec[1]) * (bevp0->vec[0]- bevp2->vec[0]);

                if(inp > 0.0f) sd->dir= 1;
                else sd->dir= 0;

                sd++;
            }

            bl= bl->next;
        }
        qsort(sortdata,poly,sizeof(struct bevelsort), vergxcobev);

        sd= sortdata+1;
        for(a=1; a<poly; a++, sd++) {
            bl= sd->bl;     /* is bl a hole? */
            sd1= sortdata+ (a-1);
            for(b=a-1; b>=0; b--, sd1--) {  /* all polys to the left */
                if(bevelinside(sd1->bl, bl)) {
                    bl->hole= 1- sd1->bl->hole;
                    break;
                }
            }
        }

        /* turning direction */
        if((cu->flag & CU_3D)==0) {
            sd= sortdata;
            for(a=0; a<poly; a++, sd++) {
                if(sd->bl->hole==sd->dir) {
                    bl= sd->bl;
                    bevp1= (BevPoint *)(bl+1);
                    bevp2= bevp1+ (bl->nr-1);
                    nr= bl->nr/2;
                    while(nr--) {
                        SWAP(BevPoint, *bevp1, *bevp2);
                        bevp1++;
                        bevp2--;
                    }
                }
            }
        }
        MEM_freeN(sortdata);
    }

    /* STEP 4: 2D-COSINES or 3D ORIENTATION */
    if((cu->flag & CU_3D)==0) {
        /* note: bevp->dir and bevp->quat are not needed for beveling but are
         * used when making a path from a 2D curve, therefor they need to be set - Campbell */
        bl= cu->bev.first;
        while(bl) {

            if(bl->nr < 2) {
                /* do nothing */
            }
            else if(bl->nr==2) {    /* 2 pnt, treat separate */
                bevp2= (BevPoint *)(bl+1);
                bevp1= bevp2+1;

                x1= bevp1->vec[0]- bevp2->vec[0];
                y1= bevp1->vec[1]- bevp2->vec[1];

                calc_bevel_sin_cos(x1, y1, -x1, -y1, &(bevp1->sina), &(bevp1->cosa));
                bevp2->sina= bevp1->sina;
                bevp2->cosa= bevp1->cosa;

                /* fill in dir & quat */
                make_bevel_list_segment_3D(bl);
            }
            else {
                bevp2= (BevPoint *)(bl+1);
                bevp1= bevp2+(bl->nr-1);
                bevp0= bevp1-1;

                nr= bl->nr;
                while(nr--) {
                    x1= bevp1->vec[0]- bevp0->vec[0];
                    x2= bevp1->vec[0]- bevp2->vec[0];
                    y1= bevp1->vec[1]- bevp0->vec[1];
                    y2= bevp1->vec[1]- bevp2->vec[1];

                    calc_bevel_sin_cos(x1, y1, x2, y2, &(bevp1->sina), &(bevp1->cosa));

                    /* from: make_bevel_list_3D_zup, could call but avoid a second loop.
                     * no need for tricky tilt calculation as with 3D curves */
                    bisect_v3_v3v3v3(bevp1->dir, bevp0->vec, bevp1->vec, bevp2->vec);
                    vec_to_quat( bevp1->quat,bevp1->dir, 5, 1);
                    /* done with inline make_bevel_list_3D_zup */

                    bevp0= bevp1;
                    bevp1= bevp2;
                    bevp2++;
                }

                /* correct non-cyclic cases */
                if(bl->poly== -1) {
                    bevp= (BevPoint *)(bl+1);
                    bevp1= bevp+1;
                    bevp->sina= bevp1->sina;
                    bevp->cosa= bevp1->cosa;
                    bevp= (BevPoint *)(bl+1);
                    bevp+= (bl->nr-1);
                    bevp1= bevp-1;
                    bevp->sina= bevp1->sina;
                    bevp->cosa= bevp1->cosa;

                    /* correct for the dir/quat, see above why its needed */
                    bevel_list_cyclic_fix_3D(bl);
                }
            }
            bl= bl->next;
        }
    }
    else { /* 3D Curves */
        bl= cu->bev.first;
        while(bl) {

            if(bl->nr < 2) {
                /* do nothing */
            }
            else if(bl->nr==2) {    /* 2 pnt, treat separate */
                make_bevel_list_segment_3D(bl);
            }
            else {
                make_bevel_list_3D(bl, (int)(resolu*cu->twist_smooth), cu->twist_mode);
            }
            bl= bl->next;
        }
    }
}

/* ****************** HANDLES ************** */

/*
 *   handlecodes:
 *      0: nothing,  1:auto,  2:vector,  3:aligned
 */

/* mode: is not zero when FCurve, is 2 when forced horizontal for autohandles */
void calchandleNurb(BezTriple *bezt, BezTriple *prev, BezTriple *next, int mode)
{
    float *p1,*p2,*p3, pt[3];
    float dvec_a[3], dvec_b[3];
    float len, len_a, len_b;
    const float eps= 1e-5;

    if(bezt->h1==0 && bezt->h2==0) {
        return;
    }

    p2= bezt->vec[1];

    if(prev==NULL) {
        p3= next->vec[1];
        pt[0]= 2.0f*p2[0] - p3[0];
        pt[1]= 2.0f*p2[1] - p3[1];
        pt[2]= 2.0f*p2[2] - p3[2];
        p1= pt;
    }
    else {
        p1= prev->vec[1];
    }

    if(next==NULL) {
        pt[0]= 2.0f*p2[0] - p1[0];
        pt[1]= 2.0f*p2[1] - p1[1];
        pt[2]= 2.0f*p2[2] - p1[2];
        p3= pt;
    }
    else {
        p3= next->vec[1];
    }

    sub_v3_v3v3(dvec_a, p2, p1);
    sub_v3_v3v3(dvec_b, p3, p2);

    if (mode != 0) {
        len_a= dvec_a[0];
        len_b= dvec_b[0];
    }
    else {
        len_a= len_v3(dvec_a);
        len_b= len_v3(dvec_b);
    }

    if(len_a==0.0f) len_a=1.0f;
    if(len_b==0.0f) len_b=1.0f;


    if(ELEM(bezt->h1,HD_AUTO,HD_AUTO_ANIM) || ELEM(bezt->h2,HD_AUTO,HD_AUTO_ANIM)) {    /* auto */
        float tvec[3];
        tvec[0]= dvec_b[0]/len_b + dvec_a[0]/len_a;
        tvec[1]= dvec_b[1]/len_b + dvec_a[1]/len_a;
        tvec[2]= dvec_b[2]/len_b + dvec_a[2]/len_a;
        len= len_v3(tvec) * 2.5614f;

        if(len!=0.0f) {
            int leftviolate=0, rightviolate=0;  /* for mode==2 */
            
            if(len_a>5.0f*len_b) len_a= 5.0f*len_b;
            if(len_b>5.0f*len_a) len_b= 5.0f*len_a;
            
            if(ELEM(bezt->h1,HD_AUTO,HD_AUTO_ANIM)) {
                len_a/=len;
                madd_v3_v3v3fl(p2-3, p2, tvec, -len_a);
                
                if((bezt->h1==HD_AUTO_ANIM) && next && prev) { /* keep horizontal if extrema */
                    float ydiff1= prev->vec[1][1] - bezt->vec[1][1];
                    float ydiff2= next->vec[1][1] - bezt->vec[1][1];
                    if( (ydiff1 <= 0.0f && ydiff2 <= 0.0f) || (ydiff1 >= 0.0f && ydiff2 >= 0.0f) ) {
                        bezt->vec[0][1]= bezt->vec[1][1];
                    }
                    else { /* handles should not be beyond y coord of two others */
                        if(ydiff1 <= 0.0f) {
                            if(prev->vec[1][1] > bezt->vec[0][1]) {
                                bezt->vec[0][1]= prev->vec[1][1]; 
                                leftviolate= 1;
                            }
                        }
                        else {
                            if(prev->vec[1][1] < bezt->vec[0][1]) {
                                bezt->vec[0][1]= prev->vec[1][1]; 
                                leftviolate= 1;
                            }
                        }
                    }
                }
            }
            if(ELEM(bezt->h2,HD_AUTO,HD_AUTO_ANIM)) {
                len_b/=len;
                madd_v3_v3v3fl(p2+3, p2, tvec,  len_b);
                
                if((bezt->h2==HD_AUTO_ANIM) && next && prev) { /* keep horizontal if extrema */
                    float ydiff1= prev->vec[1][1] - bezt->vec[1][1];
                    float ydiff2= next->vec[1][1] - bezt->vec[1][1];
                    if( (ydiff1 <= 0.0f && ydiff2 <= 0.0f) || (ydiff1 >= 0.0f && ydiff2 >= 0.0f) ) {
                        bezt->vec[2][1]= bezt->vec[1][1];
                    }
                    else { /* andles should not be beyond y coord of two others */
                        if(ydiff1 <= 0.0f) {
                            if(next->vec[1][1] < bezt->vec[2][1]) {
                                bezt->vec[2][1]= next->vec[1][1]; 
                                rightviolate= 1;
                            }
                        }
                        else {
                            if(next->vec[1][1] > bezt->vec[2][1]) {
                                bezt->vec[2][1]= next->vec[1][1]; 
                                rightviolate= 1;
                            }
                        }
                    }
                }
            }
            if(leftviolate || rightviolate) { /* align left handle */
                float h1[3], h2[3];
                float dot;
                
                sub_v3_v3v3(h1, p2-3, p2);
                sub_v3_v3v3(h2, p2, p2+3);

                len_a= normalize_v3(h1);
                len_b= normalize_v3(h2);

                dot= dot_v3v3(h1, h2);

                if(leftviolate) {
                    mul_v3_fl(h1, dot * len_b);
                    sub_v3_v3v3(p2+3, p2, h1);
                }
                else {
                    mul_v3_fl(h2, dot * len_a);
                    add_v3_v3v3(p2-3, p2, h2);
                }
            }
            
        }
    }

    if(bezt->h1==HD_VECT) { /* vector */
        madd_v3_v3v3fl(p2-3, p2, dvec_a, -1.0f/3.0f);
    }
    if(bezt->h2==HD_VECT) {
        madd_v3_v3v3fl(p2+3, p2, dvec_b,  1.0f/3.0f);
    }

    len_b= len_v3v3(p2, p2+3);
    len_a= len_v3v3(p2, p2-3);
    if(len_a==0.0f) len_a= 1.0f;
    if(len_b==0.0f) len_b= 1.0f;

    if(bezt->f1 & SELECT) { /* order of calculation */
        if(bezt->h2==HD_ALIGN) { /* aligned */
            if(len_a>eps) {
                len= len_b/len_a;
                p2[3]= p2[0]+len*(p2[0] - p2[-3]);
                p2[4]= p2[1]+len*(p2[1] - p2[-2]);
                p2[5]= p2[2]+len*(p2[2] - p2[-1]);
            }
        }
        if(bezt->h1==HD_ALIGN) {
            if(len_b>eps) {
                len= len_a/len_b;
                p2[-3]= p2[0]+len*(p2[0] - p2[3]);
                p2[-2]= p2[1]+len*(p2[1] - p2[4]);
                p2[-1]= p2[2]+len*(p2[2] - p2[5]);
            }
        }
    }
    else {
        if(bezt->h1==HD_ALIGN) {
            if(len_b>eps) {
                len= len_a/len_b;
                p2[-3]= p2[0]+len*(p2[0] - p2[3]);
                p2[-2]= p2[1]+len*(p2[1] - p2[4]);
                p2[-1]= p2[2]+len*(p2[2] - p2[5]);
            }
        }
        if(bezt->h2==HD_ALIGN) {    /* aligned */
            if(len_a>eps) {
                len= len_b/len_a;
                p2[3]= p2[0]+len*(p2[0] - p2[-3]);
                p2[4]= p2[1]+len*(p2[1] - p2[-2]);
                p2[5]= p2[2]+len*(p2[2] - p2[-1]);
            }
        }
    }
}

void calchandlesNurb(Nurb *nu) /* first, if needed, set handle flags */
{
    BezTriple *bezt, *prev, *next;
    short a;

    if(nu->type != CU_BEZIER) return;
    if(nu->pntsu<2) return;
    
    a= nu->pntsu;
    bezt= nu->bezt;
    if(nu->flagu & CU_NURB_CYCLIC) prev= bezt+(a-1);
    else prev= NULL;
    next= bezt+1;

    while(a--) {
        calchandleNurb(bezt, prev, next, 0);
        prev= bezt;
        if(a==1) {
            if(nu->flagu & CU_NURB_CYCLIC) next= nu->bezt;
            else next= NULL;
        }
        else next++;

        bezt++;
    }
}


void testhandlesNurb(Nurb *nu)
{
    /* use when something has changed with handles.
    it treats all BezTriples with the following rules:
    PHASE 1: do types have to be altered?
       Auto handles: become aligned when selection status is NOT(000 || 111)
       Vector handles: become 'nothing' when (one half selected AND other not)
    PHASE 2: recalculate handles
    */
    BezTriple *bezt;
    short flag, a;

    if(nu->type != CU_BEZIER) return;

    bezt= nu->bezt;
    a= nu->pntsu;
    while(a--) {
        flag= 0;
        if(bezt->f1 & SELECT) flag++;
        if(bezt->f2 & SELECT) flag += 2;
        if(bezt->f3 & SELECT) flag += 4;
        
        if( !(flag==0 || flag==7) ) {
            if(ELEM(bezt->h1, HD_AUTO, HD_AUTO_ANIM)) {   /* auto */
                bezt->h1= HD_ALIGN;
            }
            if(ELEM(bezt->h2, HD_AUTO, HD_AUTO_ANIM)) {   /* auto */
                bezt->h2= HD_ALIGN;
            }
            
            if(bezt->h1==HD_VECT) {   /* vector */
                if(flag < 4) bezt->h1= 0;
            }
            if(bezt->h2==HD_VECT) {   /* vector */
                if( flag > 3) bezt->h2= 0;
            }
        }
        bezt++;
    }
    
    calchandlesNurb(nu);
}

void autocalchandlesNurb(Nurb *nu, int flag)
{
    /* checks handle coordinates and calculates type */
    
    BezTriple *bezt2, *bezt1, *bezt0;
    int i, align, leftsmall, rightsmall;

    if(nu==NULL || nu->bezt==NULL) return;
    
    bezt2 = nu->bezt;
    bezt1 = bezt2 + (nu->pntsu-1);
    bezt0 = bezt1 - 1;
    i = nu->pntsu;

    while(i--) {
        
        align= leftsmall= rightsmall= 0;
        
        /* left handle: */
        if(flag==0 || (bezt1->f1 & flag) ) {
            bezt1->h1= 0;
            /* distance too short: vectorhandle */
            if( len_v3v3( bezt1->vec[1], bezt0->vec[1] ) < 0.0001f) {
                bezt1->h1= HD_VECT;
                leftsmall= 1;
            }
            else {
                /* aligned handle? */
                if(dist_to_line_v2(bezt1->vec[1], bezt1->vec[0], bezt1->vec[2]) < 0.0001f) {
                    align= 1;
                    bezt1->h1= HD_ALIGN;
                }
                /* or vector handle? */
                if(dist_to_line_v2(bezt1->vec[0], bezt1->vec[1], bezt0->vec[1]) < 0.0001f)
                    bezt1->h1= HD_VECT;
                
            }
        }
        /* right handle: */
        if(flag==0 || (bezt1->f3 & flag) ) {
            bezt1->h2= 0;
            /* distance too short: vectorhandle */
            if( len_v3v3( bezt1->vec[1], bezt2->vec[1] ) < 0.0001f) {
                bezt1->h2= HD_VECT;
                rightsmall= 1;
            }
            else {
                /* aligned handle? */
                if(align) bezt1->h2= HD_ALIGN;

                /* or vector handle? */
                if(dist_to_line_v2(bezt1->vec[2], bezt1->vec[1], bezt2->vec[1]) < 0.0001f)
                    bezt1->h2= HD_VECT;
                
            }
        }
        if(leftsmall && bezt1->h2==HD_ALIGN) bezt1->h2= 0;
        if(rightsmall && bezt1->h1==HD_ALIGN) bezt1->h1= 0;
        
        /* undesired combination: */
        if(bezt1->h1==HD_ALIGN && bezt1->h2==HD_VECT) bezt1->h1= 0;
        if(bezt1->h2==HD_ALIGN && bezt1->h1==HD_VECT) bezt1->h2= 0;
        
        bezt0= bezt1;
        bezt1= bezt2;
        bezt2++;
    }

    calchandlesNurb(nu);
}

void autocalchandlesNurb_all(ListBase *editnurb, int flag)
{
    Nurb *nu;
    
    nu= editnurb->first;
    while(nu) {
        autocalchandlesNurb(nu, flag);
        nu= nu->next;
    }
}

void sethandlesNurb(ListBase *editnurb, short code)
{
    /* code==1: set autohandle */
    /* code==2: set vectorhandle */
    /* code==3 (HD_ALIGN) it toggle, vectorhandles become HD_FREE */
    /* code==4: sets icu flag to become IPO_AUTO_HORIZ, horizontal extremes on auto-handles */
    /* code==5: Set align, like 3 but no toggle */
    /* code==6: Clear align, like 3 but no toggle */
    Nurb *nu;
    BezTriple *bezt;
    short a, ok=0;

    if(code==1 || code==2) {
        nu= editnurb->first;
        while(nu) {
            if(nu->type == CU_BEZIER) {
                bezt= nu->bezt;
                a= nu->pntsu;
                while(a--) {
                    if((bezt->f1 & SELECT) || (bezt->f3 & SELECT)) {
                        if(bezt->f1 & SELECT) bezt->h1= code;
                        if(bezt->f3 & SELECT) bezt->h2= code;
                        if(bezt->h1!=bezt->h2) {
                            if ELEM(bezt->h1, HD_ALIGN, HD_AUTO) bezt->h1= HD_FREE;
                            if ELEM(bezt->h2, HD_ALIGN, HD_AUTO) bezt->h2= HD_FREE;
                        }
                    }
                    bezt++;
                }
                calchandlesNurb(nu);
            }
            nu= nu->next;
        }
    }
    else {
        /* there is 1 handle not FREE: FREE it all, else make ALIGNED  */
        
        nu= editnurb->first;
        if (code == 5) {
            ok = HD_ALIGN;
        } else if (code == 6) {
            ok = HD_FREE;
        } else {
            /* Toggle */
            while(nu) {
                if(nu->type == CU_BEZIER) {
                    bezt= nu->bezt;
                    a= nu->pntsu;
                    while(a--) {
                        if((bezt->f1 & SELECT) && bezt->h1) ok= 1;
                        if((bezt->f3 & SELECT) && bezt->h2) ok= 1;
                        if(ok) break;
                        bezt++;
                    }
                }
                nu= nu->next;
            }
            if(ok) ok= HD_FREE;
            else ok= HD_ALIGN;
        }
        nu= editnurb->first;
        while(nu) {
            if(nu->type == CU_BEZIER) {
                bezt= nu->bezt;
                a= nu->pntsu;
                while(a--) {
                    if(bezt->f1 & SELECT) bezt->h1= ok;
                    if(bezt->f3 & SELECT) bezt->h2= ok;
    
                    bezt++;
                }
                calchandlesNurb(nu);
            }
            nu= nu->next;
        }
    }
}

static void swapdata(void *adr1, void *adr2, int len)
{

    if(len<=0) return;

    if(len<65) {
        char adr[64];

        memcpy(adr, adr1, len);
        memcpy(adr1, adr2, len);
        memcpy(adr2, adr, len);
    }
    else {
        char *adr;

        adr= (char *)MEM_mallocN(len, "curve swap");
        memcpy(adr, adr1, len);
        memcpy(adr1, adr2, len);
        memcpy(adr2, adr, len);
        MEM_freeN(adr);
    }
}

void switchdirectionNurb(Nurb *nu)
{
    BezTriple *bezt1, *bezt2;
    BPoint *bp1, *bp2;
    float *fp1, *fp2, *tempf;
    int a, b;

    if(nu->pntsu==1 && nu->pntsv==1) return;

    if(nu->type == CU_BEZIER) {
        a= nu->pntsu;
        bezt1= nu->bezt;
        bezt2= bezt1+(a-1);
        if(a & 1) a+= 1;    /* if odd, also swap middle content */
        a/= 2;
        while(a>0) {
            if(bezt1!=bezt2) SWAP(BezTriple, *bezt1, *bezt2);

            swapdata(bezt1->vec[0], bezt1->vec[2], 12);
            if(bezt1!=bezt2) swapdata(bezt2->vec[0], bezt2->vec[2], 12);

            SWAP(char, bezt1->h1, bezt1->h2);
            SWAP(short, bezt1->f1, bezt1->f3);
            
            if(bezt1!=bezt2) {
                SWAP(char, bezt2->h1, bezt2->h2);
                SWAP(short, bezt2->f1, bezt2->f3);
                bezt1->alfa= -bezt1->alfa;
                bezt2->alfa= -bezt2->alfa;
            }
            a--;
            bezt1++; 
            bezt2--;
        }
    }
    else if(nu->pntsv==1) {
        a= nu->pntsu;
        bp1= nu->bp;
        bp2= bp1+(a-1);
        a/= 2;
        while(bp1!=bp2 && a>0) {
            SWAP(BPoint, *bp1, *bp2);
            a--;
            bp1->alfa= -bp1->alfa;
            bp2->alfa= -bp2->alfa;
            bp1++; 
            bp2--;
        }
        if(nu->type == CU_NURBS) {
            /* no knots for too short paths */
            if(nu->knotsu) {
                /* inverse knots */
                a= KNOTSU(nu);
                fp1= nu->knotsu;
                fp2= fp1+(a-1);
                a/= 2;
                while(fp1!=fp2 && a>0) {
                    SWAP(float, *fp1, *fp2);
                    a--;
                    fp1++; 
                    fp2--;
                }
                /* and make in increasing order again */
                a= KNOTSU(nu);
                fp1= nu->knotsu;
                fp2=tempf= MEM_mallocN(sizeof(float)*a, "switchdirect");
                while(a--) {
                    fp2[0]= fabs(fp1[1]-fp1[0]);
                    fp1++;
                    fp2++;
                }
        
                a= KNOTSU(nu)-1;
                fp1= nu->knotsu;
                fp2= tempf;
                fp1[0]= 0.0;
                fp1++;
                while(a--) {
                    fp1[0]= fp1[-1]+fp2[0];
                    fp1++;
                    fp2++;
                }
                MEM_freeN(tempf);
            }
        }
    }
    else {
        
        for(b=0; b<nu->pntsv; b++) {
        
            bp1= nu->bp+b*nu->pntsu;
            a= nu->pntsu;
            bp2= bp1+(a-1);
            a/= 2;
            
            while(bp1!=bp2 && a>0) {
                SWAP(BPoint, *bp1, *bp2);
                a--;
                bp1++; 
                bp2--;
            }
        }
    }
}


float (*curve_getVertexCos(Curve *UNUSED(cu), ListBase *lb, int *numVerts_r))[3]
{
    int i, numVerts = *numVerts_r = count_curveverts(lb);
    float *co, (*cos)[3] = MEM_mallocN(sizeof(*cos)*numVerts, "cu_vcos");
    Nurb *nu;

    co = cos[0];
    for (nu=lb->first; nu; nu=nu->next) {
        if (nu->type == CU_BEZIER) {
            BezTriple *bezt = nu->bezt;

            for (i=0; i<nu->pntsu; i++,bezt++) {
                copy_v3_v3(co, bezt->vec[0]); co+=3;
                copy_v3_v3(co, bezt->vec[1]); co+=3;
                copy_v3_v3(co, bezt->vec[2]); co+=3;
            }
        } else {
            BPoint *bp = nu->bp;

            for (i=0; i<nu->pntsu*nu->pntsv; i++,bp++) {
                copy_v3_v3(co, bp->vec); co+=3;
            }
        }
    }

    return cos;
}

void curve_applyVertexCos(Curve *UNUSED(cu), ListBase *lb, float (*vertexCos)[3])
{
    float *co = vertexCos[0];
    Nurb *nu;
    int i;

    for (nu=lb->first; nu; nu=nu->next) {
        if (nu->type == CU_BEZIER) {
            BezTriple *bezt = nu->bezt;

            for (i=0; i<nu->pntsu; i++,bezt++) {
                copy_v3_v3(bezt->vec[0], co); co+=3;
                copy_v3_v3(bezt->vec[1], co); co+=3;
                copy_v3_v3(bezt->vec[2], co); co+=3;
            }
        } else {
            BPoint *bp = nu->bp;

            for (i=0; i<nu->pntsu*nu->pntsv; i++,bp++) {
                copy_v3_v3(bp->vec, co); co+=3;
            }
        }
    }
}

float (*curve_getKeyVertexCos(Curve *UNUSED(cu), ListBase *lb, float *key))[3]
{
    int i, numVerts = count_curveverts(lb);
    float *co, (*cos)[3] = MEM_mallocN(sizeof(*cos)*numVerts, "cu_vcos");
    Nurb *nu;

    co = cos[0];
    for (nu=lb->first; nu; nu=nu->next) {
        if (nu->type == CU_BEZIER) {
            BezTriple *bezt = nu->bezt;

            for (i=0; i<nu->pntsu; i++,bezt++) {
                copy_v3_v3(co, key); co+=3; key+=3;
                copy_v3_v3(co, key); co+=3; key+=3;
                copy_v3_v3(co, key); co+=3; key+=3;
                key+=3; /* skip tilt */
            }
        }
        else {
            BPoint *bp = nu->bp;

            for(i=0; i<nu->pntsu*nu->pntsv; i++,bp++) {
                copy_v3_v3(co, key); co+=3; key+=3;
                key++; /* skip tilt */
            }
        }
    }

    return cos;
}

void curve_applyKeyVertexTilts(Curve *UNUSED(cu), ListBase *lb, float *key)
{
    Nurb *nu;
    int i;

    for(nu=lb->first; nu; nu=nu->next) {
        if(nu->type == CU_BEZIER) {
            BezTriple *bezt = nu->bezt;

            for(i=0; i<nu->pntsu; i++,bezt++) {
                key+=3*3;
                bezt->alfa= *key;
                key+=3;
            }
        }
        else {
            BPoint *bp = nu->bp;

            for(i=0; i<nu->pntsu*nu->pntsv; i++,bp++) {
                key+=3;
                bp->alfa= *key;
                key++;
            }
        }
    }
}

int check_valid_nurb_u( struct Nurb *nu )
{
    if (nu==NULL)                       return 0;
    if (nu->pntsu <= 1)                 return 0;
    if (nu->type != CU_NURBS)           return 1; /* not a nurb, lets assume its valid */
    
    if (nu->pntsu < nu->orderu)         return 0;
    if (((nu->flag & CU_NURB_CYCLIC)==0) && (nu->flagu & CU_NURB_BEZIER)) { /* Bezier U Endpoints */
        if (nu->orderu==4) {
            if (nu->pntsu < 5)          return 0; /* bezier with 4 orderu needs 5 points */
        } else if (nu->orderu != 3)     return 0; /* order must be 3 or 4 */
    }
    return 1;
}
int check_valid_nurb_v( struct Nurb *nu)
{
    if (nu==NULL)                       return 0;
    if (nu->pntsv <= 1)                 return 0;
    if (nu->type != CU_NURBS)           return 1; /* not a nurb, lets assume its valid */
    
    if (nu->pntsv < nu->orderv)         return 0;
    if (((nu->flag & CU_NURB_CYCLIC)==0) && (nu->flagv & CU_NURB_BEZIER)) { /* Bezier V Endpoints */
        if (nu->orderv==4) {
            if (nu->pntsv < 5)          return 0; /* bezier with 4 orderu needs 5 points */
        } else if (nu->orderv != 3)     return 0; /* order must be 3 or 4 */
    }
    return 1;
}

int clamp_nurb_order_u( struct Nurb *nu )
{
    int change = 0;
    if(nu->pntsu<nu->orderu) {
        nu->orderu= nu->pntsu;
        change= 1;
    }
    if(((nu->flagu & CU_NURB_CYCLIC)==0) && (nu->flagu & CU_NURB_BEZIER)) {
        CLAMP(nu->orderu, 3,4);
        change= 1;
    }
    return change;
}

int clamp_nurb_order_v( struct Nurb *nu)
{
    int change = 0;
    if(nu->pntsv<nu->orderv) {
        nu->orderv= nu->pntsv;
        change= 1;
    }
    if(((nu->flagv & CU_NURB_CYCLIC)==0) && (nu->flagv & CU_NURB_BEZIER)) {
        CLAMP(nu->orderv, 3,4);
        change= 1;
    }
    return change;
}

/* Get edit nurbs or normal nurbs list */
ListBase *BKE_curve_nurbs(Curve *cu)
{
    if (cu->editnurb) {
        return curve_editnurbs(cu);
    }

    return &cu->nurb;
}


/* basic vertex data functions */
int minmax_curve(Curve *cu, float min[3], float max[3])
{
    ListBase *nurb_lb= BKE_curve_nurbs(cu);
    Nurb *nu;

    for(nu= nurb_lb->first; nu; nu= nu->next)
        minmaxNurb(nu, min, max);

    return (nurb_lb->first != NULL);
}

int curve_center_median(Curve *cu, float cent[3])
{
    ListBase *nurb_lb= BKE_curve_nurbs(cu);
    Nurb *nu;
    int total= 0;

    zero_v3(cent);

    for(nu= nurb_lb->first; nu; nu= nu->next) {
        int i;

        if(nu->type == CU_BEZIER) {
            BezTriple *bezt;
            i= nu->pntsu;
            total += i * 3;
            for(bezt= nu->bezt; i--; bezt++) {
                add_v3_v3(cent, bezt->vec[0]);
                add_v3_v3(cent, bezt->vec[1]);
                add_v3_v3(cent, bezt->vec[2]);
            }
        }
        else {
            BPoint *bp;
            i= nu->pntsu*nu->pntsv;
            total += i;
            for(bp= nu->bp; i--; bp++) {
                add_v3_v3(cent, bp->vec);
            }
        }
    }

    mul_v3_fl(cent, 1.0f/(float)total);

    return (total != 0);
}

int curve_center_bounds(Curve *cu, float cent[3])
{
    float min[3], max[3];
    INIT_MINMAX(min, max);
    if(minmax_curve(cu, min, max)) {
        mid_v3_v3v3(cent, min, max);
        return 1;
    }

    return 0;
}

void curve_translate(Curve *cu, float offset[3], int do_keys)
{
    ListBase *nurb_lb= BKE_curve_nurbs(cu);
    Nurb *nu;
    int i;

    for(nu= nurb_lb->first; nu; nu= nu->next) {
        BezTriple *bezt;
        BPoint *bp;

        if(nu->type == CU_BEZIER) {
            i= nu->pntsu;
            for(bezt= nu->bezt; i--; bezt++) {
                add_v3_v3(bezt->vec[0], offset);
                add_v3_v3(bezt->vec[1], offset);
                add_v3_v3(bezt->vec[2], offset);
            }
        }
        else {
            i= nu->pntsu*nu->pntsv;
            for(bp= nu->bp; i--; bp++) {
                add_v3_v3(bp->vec, offset);
            }
        }
    }

    if (do_keys && cu->key) {
        KeyBlock *kb;
        for (kb=cu->key->block.first; kb; kb=kb->next) {
            float *fp= kb->data;
            for (i= kb->totelem; i--; fp+=3) {
                add_v3_v3(fp, offset);
            }
        }
    }
}

void curve_delete_material_index(Curve *cu, int index)
{
    const int curvetype= curve_type(cu);

    if(curvetype == OB_FONT) {
        struct CharInfo *info= cu->strinfo;
        int i;
        for(i= cu->len-1; i >= 0; i--, info++) {
            if (info->mat_nr && info->mat_nr>=index) {
                info->mat_nr--;
            }
        }
    }
    else {
        Nurb *nu;

        for (nu= cu->nurb.first; nu; nu= nu->next) {
            if(nu->mat_nr && nu->mat_nr>=index) {
                nu->mat_nr--;
                if (curvetype == OB_CURVE) nu->charidx--;
            }
        }
    }
}