[blender-staging.git] / source / blender / blenkernel / intern / constraint.c

/**
 * $Id$
 *
 * ***** 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, 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): 2007, Joshua Leung, major recode
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <stdio.h> 
#include <stddef.h>
#include <string.h>
#include <math.h>
#include <float.h>

#include "MEM_guardedalloc.h"
//XXX #include "nla.h"

#include "BLI_blenlib.h"
#include "BLI_arithb.h"
#include "BLI_editVert.h"

#include "DNA_armature_types.h"
#include "DNA_constraint_types.h"
#include "DNA_object_types.h"
#include "DNA_action_types.h"
#include "DNA_curve_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_lattice_types.h"
#include "DNA_scene_types.h"
#include "DNA_text_types.h"

#include "BKE_utildefines.h"
#include "BKE_action.h"
#include "BKE_anim.h" /* for the curve calculation part */
#include "BKE_armature.h"
#include "BKE_blender.h"
#include "BKE_constraint.h"
#include "BKE_displist.h"
#include "BKE_deform.h"
#include "BKE_DerivedMesh.h"    /* for geometry targets */
#include "BKE_cdderivedmesh.h" /* for geometry targets */
#include "BKE_object.h"
#include "BKE_ipo.h"
#include "BKE_global.h"
#include "BKE_library.h"
#include "BKE_idprop.h"

#ifndef DISABLE_PYTHON
#include "BPY_extern.h"
#endif

#include "ED_mesh.h"

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifndef M_PI
#define M_PI            3.14159265358979323846
#endif



/* ************************ Constraints - General Utilities *************************** */
/* These functions here don't act on any specific constraints, and are therefore should/will
 * not require any of the special function-pointers afforded by the relevant constraint 
 * type-info structs.
 */

/* -------------- Naming -------------- */

/* Find the first available, non-duplicate name for a given constraint */
void unique_constraint_name (bConstraint *con, ListBase *list)
{
        BLI_uniquename(list, con, "Const", offsetof(bConstraint, name), 32);
}

/* ----------------- Evaluation Loop Preparation --------------- */

/* package an object/bone for use in constraint evaluation */
/* This function MEM_calloc's a bConstraintOb struct, that will need to be freed after evaluation */
bConstraintOb *constraints_make_evalob (Scene *scene, Object *ob, void *subdata, short datatype)
{
        bConstraintOb *cob;
        
        /* create regardless of whether we have any data! */
        cob= MEM_callocN(sizeof(bConstraintOb), "bConstraintOb");
        
        /* for system time, part of deglobalization, code nicer later with local time (ton) */
        cob->scene= scene;
        
        /* based on type of available data */
        switch (datatype) {
                case CONSTRAINT_OBTYPE_OBJECT:
                {
                        /* disregard subdata... calloc should set other values right */
                        if (ob) {
                                cob->ob = ob;
                                cob->type = datatype;
                                Mat4CpyMat4(cob->matrix, ob->obmat);
                        }
                        else
                                Mat4One(cob->matrix);
                        
                        Mat4CpyMat4(cob->startmat, cob->matrix);
                }
                        break;
                case CONSTRAINT_OBTYPE_BONE:
                {
                        /* only set if we have valid bone, otherwise default */
                        if (ob && subdata) {
                                cob->ob = ob;
                                cob->pchan = (bPoseChannel *)subdata;
                                cob->type = datatype;
                                
                                /* matrix in world-space */
                                Mat4MulMat4(cob->matrix, cob->pchan->pose_mat, ob->obmat);
                        }
                        else
                                Mat4One(cob->matrix);
                                
                        Mat4CpyMat4(cob->startmat, cob->matrix);
                }
                        break;
                        
                default: /* other types not yet handled */
                        Mat4One(cob->matrix);
                        Mat4One(cob->startmat);
                        break;
        }
        
        return cob;
}

/* cleanup after constraint evaluation */
void constraints_clear_evalob (bConstraintOb *cob)
{
        float delta[4][4], imat[4][4];
        
        /* prevent crashes */
        if (cob == NULL) 
                return;
        
        /* calculate delta of constraints evaluation */
        Mat4Invert(imat, cob->startmat);
        Mat4MulMat4(delta, imat, cob->matrix);
        
        /* copy matrices back to source */
        switch (cob->type) {
                case CONSTRAINT_OBTYPE_OBJECT:
                {
                        /* cob->ob might not exist! */
                        if (cob->ob) {
                                /* copy new ob-matrix back to owner */
                                Mat4CpyMat4(cob->ob->obmat, cob->matrix);
                                
                                /* copy inverse of delta back to owner */
                                Mat4Invert(cob->ob->constinv, delta);
                        }
                }
                        break;
                case CONSTRAINT_OBTYPE_BONE:
                {
                        /* cob->ob or cob->pchan might not exist */
                        if (cob->ob && cob->pchan) {
                                /* copy new pose-matrix back to owner */
                                Mat4MulMat4(cob->pchan->pose_mat, cob->matrix, cob->ob->imat);
                                
                                /* copy inverse of delta back to owner */
                                Mat4Invert(cob->pchan->constinv, delta);
                        }
                }
                        break;
        }
        
        /* free tempolary struct */
        MEM_freeN(cob);
}

/* -------------- Space-Conversion API -------------- */

/* This function is responsible for the correct transformations/conversions 
 * of a matrix from one space to another for constraint evaluation.
 * For now, this is only implemented for Objects and PoseChannels.
 */
void constraint_mat_convertspace (Object *ob, bPoseChannel *pchan, float mat[][4], short from, short to)
{
        float tempmat[4][4];
        float diff_mat[4][4];
        float imat[4][4];
        
        /* prevent crashes in these unlikely events  */
        if (ob==NULL || mat==NULL) return;
        /* optimise trick - check if need to do anything */
        if (from == to) return;
        
        /* are we dealing with pose-channels or objects */
        if (pchan) {
                /* pose channels */
                switch (from) {
                        case CONSTRAINT_SPACE_WORLD: /* ---------- FROM WORLDSPACE ---------- */
                        {
                                /* world to pose */
                                Mat4Invert(imat, ob->obmat);
                                Mat4CpyMat4(tempmat, mat);
                                Mat4MulMat4(mat, tempmat, imat);
                                
                                /* use pose-space as stepping stone for other spaces... */
                                if (ELEM(to, CONSTRAINT_SPACE_LOCAL, CONSTRAINT_SPACE_PARLOCAL)) {
                                        /* call self with slightly different values */
                                        constraint_mat_convertspace(ob, pchan, mat, CONSTRAINT_SPACE_POSE, to);
                                }
                        }
                                break;
                        case CONSTRAINT_SPACE_POSE:     /* ---------- FROM POSESPACE ---------- */
                        {
                                /* pose to world */
                                if (to == CONSTRAINT_SPACE_WORLD) {
                                        Mat4CpyMat4(tempmat, mat);
                                        Mat4MulMat4(mat, tempmat, ob->obmat);
                                }
                                /* pose to local */
                                else if (to == CONSTRAINT_SPACE_LOCAL) {
                                        if (pchan->bone) {
                                                if (pchan->parent) {
                                                        float offs_bone[4][4];
                                                                
                                                        /* construct offs_bone the same way it is done in armature.c */
                                                        Mat4CpyMat3(offs_bone, pchan->bone->bone_mat);
                                                        VECCOPY(offs_bone[3], pchan->bone->head);
                                                        offs_bone[3][1]+= pchan->bone->parent->length;
                                                        
                                                        if (pchan->bone->flag & BONE_HINGE) {
                                                                /* pose_mat = par_pose-space_location * chan_mat */
                                                                float tmat[4][4];
                                                                
                                                                /* the rotation of the parent restposition */
                                                                Mat4CpyMat4(tmat, pchan->bone->parent->arm_mat);
                                                                
                                                                /* the location of actual parent transform */
                                                                VECCOPY(tmat[3], offs_bone[3]);
                                                                offs_bone[3][0]= offs_bone[3][1]= offs_bone[3][2]= 0.0f;
                                                                Mat4MulVecfl(pchan->parent->pose_mat, tmat[3]);
                                                                
                                                                Mat4MulMat4(diff_mat, offs_bone, tmat);
                                                                Mat4Invert(imat, diff_mat);
                                                        }
                                                        else {
                                                                /* pose_mat = par_pose_mat * bone_mat * chan_mat */
                                                                Mat4MulMat4(diff_mat, offs_bone, pchan->parent->pose_mat);
                                                                Mat4Invert(imat, diff_mat);
                                                        }
                                                }
                                                else {
                                                        /* pose_mat = chan_mat * arm_mat */
                                                        Mat4Invert(imat, pchan->bone->arm_mat);
                                                }
                                                
                                                Mat4CpyMat4(tempmat, mat);
                                                Mat4MulMat4(mat, tempmat, imat);
                                        }
                                }
                                /* pose to local with parent */
                                else if (to == CONSTRAINT_SPACE_PARLOCAL) {
                                        if (pchan->bone) {
                                                Mat4Invert(imat, pchan->bone->arm_mat);
                                                Mat4CpyMat4(tempmat, mat);
                                                Mat4MulMat4(mat, tempmat, imat);
                                        }
                                }
                        }
                                break;
                        case CONSTRAINT_SPACE_LOCAL: /* ------------ FROM LOCALSPACE --------- */
                        {
                                /* local to pose - do inverse procedure that was done for pose to local */
                                if (pchan->bone) {
                                        /* we need the posespace_matrix = local_matrix + (parent_posespace_matrix + restpos) */                                         
                                        if (pchan->parent) {
                                                float offs_bone[4][4];
                                                
                                                /* construct offs_bone the same way it is done in armature.c */
                                                Mat4CpyMat3(offs_bone, pchan->bone->bone_mat);
                                                VECCOPY(offs_bone[3], pchan->bone->head);
                                                offs_bone[3][1]+= pchan->bone->parent->length;
                                                
                                                if (pchan->bone->flag & BONE_HINGE) {
                                                        /* pose_mat = par_pose-space_location * chan_mat */
                                                        float tmat[4][4];
                                                        
                                                        /* the rotation of the parent restposition */
                                                        Mat4CpyMat4(tmat, pchan->bone->parent->arm_mat);
                                                        
                                                        /* the location of actual parent transform */
                                                        VECCOPY(tmat[3], offs_bone[3]);
                                                        offs_bone[3][0]= offs_bone[3][1]= offs_bone[3][2]= 0.0f;
                                                        Mat4MulVecfl(pchan->parent->pose_mat, tmat[3]);
                                                        
                                                        Mat4MulMat4(diff_mat, offs_bone, tmat);
                                                        Mat4CpyMat4(tempmat, mat);
                                                        Mat4MulMat4(mat, tempmat, diff_mat);
                                                }
                                                else {
                                                        /* pose_mat = par_pose_mat * bone_mat * chan_mat */
                                                        Mat4MulMat4(diff_mat, offs_bone, pchan->parent->pose_mat);
                                                        Mat4CpyMat4(tempmat, mat);
                                                        Mat4MulMat4(mat, tempmat, diff_mat);
                                                }
                                        }
                                        else {
                                                Mat4CpyMat4(diff_mat, pchan->bone->arm_mat);
                                                
                                                Mat4CpyMat4(tempmat, mat);
                                                Mat4MulMat4(mat, tempmat, diff_mat);
                                        }
                                }
                                
                                /* use pose-space as stepping stone for other spaces */
                                if (ELEM(to, CONSTRAINT_SPACE_WORLD, CONSTRAINT_SPACE_PARLOCAL)) {
                                        /* call self with slightly different values */
                                        constraint_mat_convertspace(ob, pchan, mat, CONSTRAINT_SPACE_POSE, to);
                                }                               
                        }
                                break;
                        case CONSTRAINT_SPACE_PARLOCAL: /* -------------- FROM LOCAL WITH PARENT ---------- */
                        {
                                /* local + parent to pose */
                                if (pchan->bone) {                                      
                                        Mat4CpyMat4(diff_mat, pchan->bone->arm_mat);
                                        Mat4CpyMat4(tempmat, mat);
                                        Mat4MulMat4(mat, diff_mat, tempmat);
                                }
                                
                                /* use pose-space as stepping stone for other spaces */
                                if (ELEM(to, CONSTRAINT_SPACE_WORLD, CONSTRAINT_SPACE_LOCAL)) {
                                        /* call self with slightly different values */
                                        constraint_mat_convertspace(ob, pchan, mat, CONSTRAINT_SPACE_POSE, to);
                                }
                        }
                                break;
                }
        }
        else {
                /* objects */
                if (from==CONSTRAINT_SPACE_WORLD && to==CONSTRAINT_SPACE_LOCAL) {
                        /* check if object has a parent - otherwise this won't work */
                        if (ob->parent) {
                                /* 'subtract' parent's effects from owner */
                                Mat4MulMat4(diff_mat, ob->parentinv, ob->parent->obmat);
                                Mat4Invert(imat, diff_mat);
                                Mat4CpyMat4(tempmat, mat);
                                Mat4MulMat4(mat, tempmat, imat);
                        }
                }
                else if (from==CONSTRAINT_SPACE_LOCAL && to==CONSTRAINT_SPACE_WORLD) {
                        /* check that object has a parent - otherwise this won't work */
                        if (ob->parent) {
                                /* 'add' parent's effect back to owner */
                                Mat4CpyMat4(tempmat, mat);
                                Mat4MulMat4(diff_mat, ob->parentinv, ob->parent->obmat);
                                Mat4MulMat4(mat, tempmat, diff_mat);
                        }
                }
        }
}

/* ------------ General Target Matrix Tools ---------- */

/* function that sets the given matrix based on given vertex group in mesh */
static void contarget_get_mesh_mat (Object *ob, char *substring, float mat[][4])
{
        DerivedMesh *dm;
        Mesh *me= ob->data;
        EditMesh *em = EM_GetEditMesh(me);
        float vec[3] = {0.0f, 0.0f, 0.0f}, tvec[3];
        float normal[3] = {0.0f, 0.0f, 0.0f}, plane[3];
        float imat[3][3], tmat[3][3];
        int dgroup;
        
        /* initialize target matrix using target matrix */
        Mat4CpyMat4(mat, ob->obmat);
        
        /* get index of vertex group */
        dgroup = get_named_vertexgroup_num(ob, substring);
        if (dgroup < 0) return;
        
        /* get DerivedMesh */
        if (em) {
                /* target is in editmode, so get a special derived mesh */
                dm = CDDM_from_editmesh(em, ob->data);
        }
        else {
                /* when not in EditMode, this should exist */
                dm = (DerivedMesh *)ob->derivedFinal;
        }
        
        /* only continue if there's a valid DerivedMesh */
        if (dm) {
                MDeformVert *dvert = dm->getVertDataArray(dm, CD_MDEFORMVERT);
                int *index = (int *)dm->getVertDataArray(dm, CD_ORIGINDEX);
                int numVerts = dm->getNumVerts(dm);
                int i, j, count = 0;
                float co[3], nor[3];
                
                /* check that dvert and index are valid pointers (just in case) */
                if (dvert && index) {
                        /* get the average of all verts with that are in the vertex-group */
                        for (i = 0; i < numVerts; i++, index++) {       
                                for (j = 0; j < dvert[i].totweight; j++) {
                                        /* does this vertex belong to nominated vertex group? */
                                        if (dvert[i].dw[j].def_nr == dgroup) {
                                                dm->getVertCo(dm, i, co);
                                                dm->getVertNo(dm, i, nor);
                                                VecAddf(vec, vec, co);
                                                VecAddf(normal, normal, nor);
                                                count++;
                                                break;
                                        }
                                        
                                }
                        }
                        
                        
                        /* calculate averages of normal and coordinates */
                        if (count > 0) {
                                VecMulf(vec, 1.0f / count);
                                VecMulf(normal, 1.0f / count);
                        }
                        
                        
                        /* derive the rotation from the average normal: 
                         *              - code taken from transform_manipulator.c, 
                         *                      calc_manipulator_stats, V3D_MANIP_NORMAL case
                         */
                        /*      we need the transpose of the inverse for a normal... */
                        Mat3CpyMat4(imat, ob->obmat);
                        
                        Mat3Inv(tmat, imat);
                        Mat3Transp(tmat);
                        Mat3MulVecfl(tmat, normal);
                        
                        Normalize(normal);
                        VECCOPY(plane, tmat[1]);
                        
                        VECCOPY(tmat[2], normal);
                        Crossf(tmat[0], normal, plane);
                        Crossf(tmat[1], tmat[2], tmat[0]);
                        
                        Mat4CpyMat3(mat, tmat);
                        Mat4Ortho(mat);
                        
                        
                        /* apply the average coordinate as the new location */
                        VecMat4MulVecfl(tvec, ob->obmat, vec);
                        VECCOPY(mat[3], tvec);
                }
        }
        
        /* free temporary DerivedMesh created (in EditMode case) */
        if (em) {
                if (dm) dm->release(dm);
                EM_EndEditMesh(me, em);
        }
}

/* function that sets the given matrix based on given vertex group in lattice */
static void contarget_get_lattice_mat (Object *ob, char *substring, float mat[][4])
{
        Lattice *lt= (Lattice *)ob->data;
        
        DispList *dl = find_displist(&ob->disp, DL_VERTS);
        float *co = dl?dl->verts:NULL;
        BPoint *bp = lt->def;
        
        MDeformVert *dvert = lt->dvert;
        int tot_verts= lt->pntsu*lt->pntsv*lt->pntsw;
        float vec[3]= {0.0f, 0.0f, 0.0f}, tvec[3];
        int dgroup=0, grouped=0;
        int i, n;
        
        /* initialize target matrix using target matrix */
        Mat4CpyMat4(mat, ob->obmat);
        
        /* get index of vertex group */
        dgroup = get_named_vertexgroup_num(ob, substring);
        if (dgroup < 0) return;
        if (dvert == NULL) return;
        
        /* 1. Loop through control-points checking if in nominated vertex-group.
         * 2. If it is, add it to vec to find the average point.
         */
        for (i=0; i < tot_verts; i++, dvert++) {
                for (n= 0; n < dvert->totweight; n++) {
                        /* found match - vert is in vgroup */
                        if (dvert->dw[n].def_nr == dgroup) {
                                /* copy coordinates of point to temporary vector, then add to find average */
                                if (co)
                                        memcpy(tvec, co, 3*sizeof(float));
                                else
                                        memcpy(tvec, bp->vec, 3*sizeof(float));
                                        
                                VecAddf(vec, vec, tvec);
                                grouped++;
                                
                                break;
                        }
                }
                
                /* advance pointer to coordinate data */
                if (co) co+= 3;
                else bp++;
        }
        
        /* find average location, then multiply by ob->obmat to find world-space location */
        if (grouped)
                VecMulf(vec, 1.0f / grouped);
        VecMat4MulVecfl(tvec, ob->obmat, vec);
        
        /* copy new location to matrix */
        VECCOPY(mat[3], tvec);
}

/* generic function to get the appropriate matrix for most target cases */
/* The cases where the target can be object data have not been implemented */
static void constraint_target_to_mat4 (Object *ob, char *substring, float mat[][4], short from, short to, float headtail)
{
        /*      Case OBJECT */
        if (!strlen(substring)) {
                Mat4CpyMat4(mat, ob->obmat);
                constraint_mat_convertspace(ob, NULL, mat, from, to);
        }
        /*      Case VERTEXGROUP */
        /* Current method just takes the average location of all the points in the
         * VertexGroup, and uses that as the location value of the targets. Where 
         * possible, the orientation will also be calculated, by calculating an
         * 'average' vertex normal, and deriving the rotaation from that.
         *
         * NOTE: EditMode is not currently supported, and will most likely remain that
         *              way as constraints can only really affect things on object/bone level.
         */
        else if (ob->type == OB_MESH) {
                contarget_get_mesh_mat(ob, substring, mat);
                constraint_mat_convertspace(ob, NULL, mat, from, to);
        }
        else if (ob->type == OB_LATTICE) {
                contarget_get_lattice_mat(ob, substring, mat);
                constraint_mat_convertspace(ob, NULL, mat, from, to);
        }
        /*      Case BONE */
        else {
                bPoseChannel *pchan;
                
                pchan = get_pose_channel(ob->pose, substring);
                if (pchan) {
                        /* Multiply the PoseSpace accumulation/final matrix for this
                         * PoseChannel by the Armature Object's Matrix to get a worldspace
                         * matrix.
                         */
                        if (headtail < 0.000001) {
                                /* skip length interpolation if set to head */
                                Mat4MulMat4(mat, pchan->pose_mat, ob->obmat);
                        }
                        else {
                                float tempmat[4][4], loc[3];
                                
                                /* interpolate along length of bone */
                                VecLerpf(loc, pchan->pose_head, pchan->pose_tail, headtail);    
                                
                                /* use interpolated distance for subtarget */
                                Mat4CpyMat4(tempmat, pchan->pose_mat);  
                                VecCopyf(tempmat[3], loc);
                                
                                Mat4MulMat4(mat, tempmat, ob->obmat);
                        }
                } 
                else
                        Mat4CpyMat4(mat, ob->obmat);
                        
                /* convert matrix space as required */
                constraint_mat_convertspace(ob, pchan, mat, from, to);
        }
}

/* ************************* Specific Constraints ***************************** */
/* Each constraint defines a set of functions, which will be called at the appropriate
 * times. In addition to this, each constraint should have a type-info struct, where
 * its functions are attached for use. 
 */
 
/* Template for type-info data:
 *      - make a copy of this when creating new constraints, and just change the functions
 *        pointed to as necessary
 *      - although the naming of functions doesn't matter, it would help for code
 *        readability, to follow the same naming convention as is presented here
 *      - any functions that a constraint doesn't need to define, don't define
 *        for such cases, just use NULL 
 *      - these should be defined after all the functions have been defined, so that
 *        forward-definitions/prototypes don't need to be used!
 *      - keep this copy #if-def'd so that future constraints can get based off this
 */
#if 0
static bConstraintTypeInfo CTI_CONSTRNAME = {
        CONSTRAINT_TYPE_CONSTRNAME, /* type */
        sizeof(bConstrNameConstraint), /* size */
        "ConstrName", /* name */
        "bConstrNameConstraint", /* struct name */
        constrname_free, /* free data */
        constrname_relink, /* relink data */
        constrname_copy, /* copy data */
        constrname_new_data, /* new data */
        constrname_get_tars, /* get constraint targets */
        constrname_flush_tars, /* flush constraint targets */
        constrname_get_tarmat, /* get target matrix */
        constrname_evaluate /* evaluate */
};
#endif

/* This function should be used for the get_target_matrix member of all 
 * constraints that are not picky about what happens to their target matrix.
 */
static void default_get_tarmat (bConstraint *con, bConstraintOb *cob, bConstraintTarget *ct, float ctime)
{
        if (VALID_CONS_TARGET(ct))
                constraint_target_to_mat4(ct->tar, ct->subtarget, ct->matrix, CONSTRAINT_SPACE_WORLD, ct->space, con->headtail);
        else if (ct)
                Mat4One(ct->matrix);
}

/* This following macro should be used for all standard single-target *_get_tars functions 
 * to save typing and reduce maintainance woes.
 * (Hopefully all compilers will be happy with the lines with just a space on them. Those are
 *  really just to help this code easier to read)
 */
#define SINGLETARGET_GET_TARS(con, datatar, datasubtarget, ct, list) \
        { \
                ct= MEM_callocN(sizeof(bConstraintTarget), "tempConstraintTarget"); \
                 \
                ct->tar= datatar; \
                strcpy(ct->subtarget, datasubtarget); \
                ct->space= con->tarspace; \
                ct->flag= CONSTRAINT_TAR_TEMP; \
                 \
                if (ct->tar) { \
                        if ((ct->tar->type==OB_ARMATURE) && (ct->subtarget[0])) ct->type = CONSTRAINT_OBTYPE_BONE; \
                        else if (ELEM(ct->tar->type, OB_MESH, OB_LATTICE) && (ct->subtarget[0])) ct->type = CONSTRAINT_OBTYPE_VERT; \
                        else ct->type = CONSTRAINT_OBTYPE_OBJECT; \
                } \
                 \
                BLI_addtail(list, ct); \
        }
        
/* This following macro should be used for all standard single-target *_get_tars functions 
 * to save typing and reduce maintainance woes. It does not do the subtarget related operations
 * (Hopefully all compilers will be happy with the lines with just a space on them. Those are
 *  really just to help this code easier to read)
 */
#define SINGLETARGETNS_GET_TARS(con, datatar, ct, list) \
        { \
                ct= MEM_callocN(sizeof(bConstraintTarget), "tempConstraintTarget"); \
                 \
                ct->tar= datatar; \
                ct->space= con->tarspace; \
                ct->flag= CONSTRAINT_TAR_TEMP; \
                 \
                if (ct->tar) ct->type = CONSTRAINT_OBTYPE_OBJECT; \
                 \
                BLI_addtail(list, ct); \
        }

/* This following macro should be used for all standard single-target *_flush_tars functions
 * to save typing and reduce maintainance woes.
 * Note: the pointer to ct will be changed to point to the next in the list (as it gets removed)
 * (Hopefully all compilers will be happy with the lines with just a space on them. Those are
 *  really just to help this code easier to read)
 */
#define SINGLETARGET_FLUSH_TARS(con, datatar, datasubtarget, ct, list, nocopy) \
        { \
                if (ct) { \
                        bConstraintTarget *ctn = ct->next; \
                        if (nocopy == 0) { \
                                datatar= ct->tar; \
                                strcpy(datasubtarget, ct->subtarget); \
                                con->tarspace= (char)ct->space; \
                        } \
                         \
                        BLI_freelinkN(list, ct); \
                        ct= ctn; \
                } \
        }
        
/* This following macro should be used for all standard single-target *_flush_tars functions
 * to save typing and reduce maintainance woes. It does not do the subtarget related operations.
 * Note: the pointer to ct will be changed to point to the next in the list (as it gets removed)
 * (Hopefully all compilers will be happy with the lines with just a space on them. Those are
 *  really just to help this code easier to read)
 */
#define SINGLETARGETNS_FLUSH_TARS(con, datatar, ct, list, nocopy) \
        { \
                if (ct) { \
                        bConstraintTarget *ctn = ct->next; \
                        if (nocopy == 0) { \
                                datatar= ct->tar; \
                                con->tarspace= (char)ct->space; \
                        } \
                         \
                        BLI_freelinkN(list, ct); \
                        ct= ctn; \
                } \
        }
 
/* --------- ChildOf Constraint ------------ */

static void childof_new_data (void *cdata)
{
        bChildOfConstraint *data= (bChildOfConstraint *)cdata;
        
        data->flag = (CHILDOF_LOCX | CHILDOF_LOCY | CHILDOF_LOCZ |
                                        CHILDOF_ROTX |CHILDOF_ROTY | CHILDOF_ROTZ |
                                        CHILDOF_SIZEX | CHILDOF_SIZEY | CHILDOF_SIZEZ);
        Mat4One(data->invmat);
}

static int childof_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bChildOfConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void childof_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bChildOfConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void childof_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bChildOfConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        /* only evaluate if there is a target */
        if (VALID_CONS_TARGET(ct)) {
                float parmat[4][4], invmat[4][4], tempmat[4][4];
                float loc[3], eul[3], size[3];
                float loco[3], eulo[3], sizo[3];
                
                /* get offset (parent-inverse) matrix */
                Mat4CpyMat4(invmat, data->invmat);
                
                /* extract components of both matrices */
                VECCOPY(loc, ct->matrix[3]);
                Mat4ToEul(ct->matrix, eul);
                Mat4ToSize(ct->matrix, size);
                
                VECCOPY(loco, invmat[3]);
                Mat4ToEul(invmat, eulo);
                Mat4ToSize(invmat, sizo);
                
                /* disable channels not enabled */
                if (!(data->flag & CHILDOF_LOCX)) loc[0]= loco[0]= 0.0f;
                if (!(data->flag & CHILDOF_LOCY)) loc[1]= loco[1]= 0.0f;
                if (!(data->flag & CHILDOF_LOCZ)) loc[2]= loco[2]= 0.0f;
                if (!(data->flag & CHILDOF_ROTX)) eul[0]= eulo[0]= 0.0f;
                if (!(data->flag & CHILDOF_ROTY)) eul[1]= eulo[1]= 0.0f;
                if (!(data->flag & CHILDOF_ROTZ)) eul[2]= eulo[2]= 0.0f;
                if (!(data->flag & CHILDOF_SIZEX)) size[0]= sizo[0]= 1.0f;
                if (!(data->flag & CHILDOF_SIZEY)) size[1]= sizo[1]= 1.0f;
                if (!(data->flag & CHILDOF_SIZEZ)) size[2]= sizo[2]= 1.0f;
                
                /* make new target mat and offset mat */
                LocEulSizeToMat4(ct->matrix, loc, eul, size);
                LocEulSizeToMat4(invmat, loco, eulo, sizo);
                
                /* multiply target (parent matrix) by offset (parent inverse) to get 
                 * the effect of the parent that will be exherted on the owner
                 */
                Mat4MulMat4(parmat, invmat, ct->matrix);
                
                /* now multiply the parent matrix by the owner matrix to get the 
                 * the effect of this constraint (i.e.  owner is 'parented' to parent)
                 */
                Mat4CpyMat4(tempmat, cob->matrix);
                Mat4MulMat4(cob->matrix, tempmat, parmat); 
        }
}

static bConstraintTypeInfo CTI_CHILDOF = {
        CONSTRAINT_TYPE_CHILDOF, /* type */
        sizeof(bChildOfConstraint), /* size */
        "ChildOf", /* name */
        "bChildOfConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        childof_new_data, /* new data */
        childof_get_tars, /* get constraint targets */
        childof_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get a target matrix */
        childof_evaluate /* evaluate */
};

/* -------- TrackTo Constraint ------- */

static void trackto_new_data (void *cdata)
{
        bTrackToConstraint *data= (bTrackToConstraint *)cdata;
        
        data->reserved1 = TRACK_Y;
        data->reserved2 = UP_Z;
}       

static int trackto_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bTrackToConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void trackto_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bTrackToConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}


static int basis_cross (int n, int m)
{
        switch (n-m) {
                case 1: 
                case -2:
                        return 1;
                        
                case -1: 
                case 2:
                        return -1;
                        
                default:
                        return 0;
        }
}

static void vectomat (float *vec, float *target_up, short axis, short upflag, short flags, float m[][3])
{
        float n[3];
        float u[3]; /* vector specifying the up axis */
        float proj[3];
        float right[3];
        float neg = -1;
        int right_index;
        
        VecCopyf(n, vec);
        if (Normalize(n) == 0.0) { 
                n[0] = 0.0;
                n[1] = 0.0;
                n[2] = 1.0;
        }
        if (axis > 2) axis -= 3;
        else VecNegf(n);

        /* n specifies the transformation of the track axis */
        if (flags & TARGET_Z_UP) { 
                /* target Z axis is the global up axis */
                u[0] = target_up[0];
                u[1] = target_up[1];
                u[2] = target_up[2];
        }
        else { 
                /* world Z axis is the global up axis */
                u[0] = 0;
                u[1] = 0;
                u[2] = 1;
        }

        /* project the up vector onto the plane specified by n */
        Projf(proj, u, n); /* first u onto n... */
        VecSubf(proj, u, proj); /* then onto the plane */
        /* proj specifies the transformation of the up axis */

        if (Normalize(proj) == 0.0) { /* degenerate projection */
                proj[0] = 0.0;
                proj[1] = 1.0;
                proj[2] = 0.0;
        }

        /* Normalized cross product of n and proj specifies transformation of the right axis */
        Crossf(right, proj, n);
        Normalize(right);

        if (axis != upflag) {
                right_index = 3 - axis - upflag;
                neg = (float)basis_cross(axis, upflag);
                
                /* account for up direction, track direction */
                m[right_index][0] = neg * right[0];
                m[right_index][1] = neg * right[1];
                m[right_index][2] = neg * right[2];
                
                m[upflag][0] = proj[0];
                m[upflag][1] = proj[1];
                m[upflag][2] = proj[2];
                
                m[axis][0] = n[0];
                m[axis][1] = n[1];
                m[axis][2] = n[2];
        }
        /* identity matrix - don't do anything if the two axes are the same */
        else {
                m[0][0]= m[1][1]= m[2][2]= 1.0;
                m[0][1]= m[0][2]= 0.0;
                m[1][0]= m[1][2]= 0.0;
                m[2][0]= m[2][1]= 0.0;
        }
}


static void trackto_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bTrackToConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        if (VALID_CONS_TARGET(ct)) {
                float size[3], vec[3];
                float totmat[3][3];
                float tmat[4][4];
                
                /* Get size property, since ob->size is only the object's own relative size, not its global one */
                Mat4ToSize(cob->matrix, size);
                
                /* Clear the object's rotation */       
                cob->matrix[0][0]=size[0];
                cob->matrix[0][1]=0;
                cob->matrix[0][2]=0;
                cob->matrix[1][0]=0;
                cob->matrix[1][1]=size[1];
                cob->matrix[1][2]=0;
                cob->matrix[2][0]=0;
                cob->matrix[2][1]=0;
                cob->matrix[2][2]=size[2];
                
                /* targetmat[2] instead of ownermat[2] is passed to vectomat
                 * for backwards compatability it seems... (Aligorith)
                 */
                VecSubf(vec, cob->matrix[3], ct->matrix[3]);
                vectomat(vec, ct->matrix[2], 
                                (short)data->reserved1, (short)data->reserved2, 
                                data->flags, totmat);
                
                Mat4CpyMat4(tmat, cob->matrix);
                Mat4MulMat34(cob->matrix, totmat, tmat);
        }
}

static bConstraintTypeInfo CTI_TRACKTO = {
        CONSTRAINT_TYPE_TRACKTO, /* type */
        sizeof(bTrackToConstraint), /* size */
        "TrackTo", /* name */
        "bTrackToConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        trackto_new_data, /* new data */
        trackto_get_tars, /* get constraint targets */
        trackto_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        trackto_evaluate /* evaluate */
};

/* --------- Inverse-Kinemetics --------- */

static void kinematic_new_data (void *cdata)
{
        bKinematicConstraint *data= (bKinematicConstraint *)cdata;
        
        data->weight= (float)1.0;
        data->orientweight= (float)1.0;
        data->iterations = 500;
        data->flag= CONSTRAINT_IK_TIP|CONSTRAINT_IK_STRETCH|CONSTRAINT_IK_POS;
}

static int kinematic_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bKinematicConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints is used twice here */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                SINGLETARGET_GET_TARS(con, data->poletar, data->polesubtarget, ct, list)
                
                return 2;
        }
        
        return 0;
}

static void kinematic_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bKinematicConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
                SINGLETARGET_FLUSH_TARS(con, data->poletar, data->polesubtarget, ct, list, nocopy)
        }
}

static void kinematic_get_tarmat (bConstraint *con, bConstraintOb *cob, bConstraintTarget *ct, float ctime)
{
        bKinematicConstraint *data= con->data;
        
        if (VALID_CONS_TARGET(ct)) 
                constraint_target_to_mat4(ct->tar, ct->subtarget, ct->matrix, CONSTRAINT_SPACE_WORLD, ct->space, con->headtail);
        else if (ct) {
                if (data->flag & CONSTRAINT_IK_AUTO) {
                        Object *ob= cob->ob;
                        
                        if (ob == NULL) {
                                Mat4One(ct->matrix);
                        }
                        else {
                                float vec[3];
                                /* move grabtarget into world space */
                                VECCOPY(vec, data->grabtarget);
                                Mat4MulVecfl(ob->obmat, vec);
                                Mat4CpyMat4(ct->matrix, ob->obmat);
                                VECCOPY(ct->matrix[3], vec);
                        }
                }
                else
                        Mat4One(ct->matrix);
        }
}

static bConstraintTypeInfo CTI_KINEMATIC = {
        CONSTRAINT_TYPE_KINEMATIC, /* type */
        sizeof(bKinematicConstraint), /* size */
        "IK", /* name */
        "bKinematicConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        kinematic_new_data, /* new data */
        kinematic_get_tars, /* get constraint targets */
        kinematic_flush_tars, /* flush constraint targets */
        kinematic_get_tarmat, /* get target matrix */
        NULL /* evaluate - solved as separate loop */
};

/* -------- Follow-Path Constraint ---------- */

static void followpath_new_data (void *cdata)
{
        bFollowPathConstraint *data= (bFollowPathConstraint *)cdata;
        
        data->trackflag = TRACK_Y;
        data->upflag = UP_Z;
        data->offset = 0;
        data->followflag = 0;
}

static int followpath_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bFollowPathConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints without subtargets */
                SINGLETARGETNS_GET_TARS(con, data->tar, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void followpath_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bFollowPathConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGETNS_FLUSH_TARS(con, data->tar, ct, list, nocopy)
        }
}

static void followpath_get_tarmat (bConstraint *con, bConstraintOb *cob, bConstraintTarget *ct, float ctime)
{
        bFollowPathConstraint *data= con->data;
        
        if (VALID_CONS_TARGET(ct)) {
                Curve *cu= ct->tar->data;
                float q[4], vec[4], dir[3], quat[4], x1;
                float totmat[4][4];
                float curvetime;
                
                Mat4One(totmat);
                Mat4One(ct->matrix);
                
                /* note: when creating constraints that follow path, the curve gets the CU_PATH set now,
                 *              currently for paths to work it needs to go through the bevlist/displist system (ton) 
                 */
                
                /* only happens on reload file, but violates depsgraph still... fix! */
                if (cu->path==NULL || cu->path->data==NULL) 
                        makeDispListCurveTypes(cob->scene, ct->tar, 0);
                
                if (cu->path && cu->path->data) {
                        curvetime= bsystem_time(cob->scene, ct->tar, (float)ctime, 0.0) - data->offset;
                        
#if 0 // XXX old animation system
                        if (calc_ipo_spec(cu->ipo, CU_SPEED, &curvetime)==0) {
                                curvetime /= cu->pathlen;
                                CLAMP(curvetime, 0.0, 1.0);
                        }
#endif // XXX old animation system
                        
                        if ( where_on_path(ct->tar, curvetime, vec, dir) ) {
                                if (data->followflag) {
                                        vectoquat(dir, (short) data->trackflag, (short) data->upflag, quat);
                                        
                                        Normalize(dir);
                                        q[0]= (float)cos(0.5*vec[3]);
                                        x1= (float)sin(0.5*vec[3]);
                                        q[1]= -x1*dir[0];
                                        q[2]= -x1*dir[1];
                                        q[3]= -x1*dir[2];
                                        QuatMul(quat, q, quat);
                                        
                                        QuatToMat4(quat, totmat);
                                }
                                VECCOPY(totmat[3], vec);
                                
                                Mat4MulSerie(ct->matrix, ct->tar->obmat, totmat, NULL, NULL, NULL, NULL, NULL, NULL);
                        }
                }
        }
        else if (ct)
                Mat4One(ct->matrix);
}

static void followpath_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bConstraintTarget *ct= targets->first;
        
        /* only evaluate if there is a target */
        if (VALID_CONS_TARGET(ct)) {
                float obmat[4][4];
                float size[3], obsize[3];
                
                /* get Object local transform (loc/rot/size) to determine transformation from path */
                //object_to_mat4(ob, obmat);
                Mat4CpyMat4(obmat, cob->matrix); // FIXME!!!
                
                /* get scaling of object before applying constraint */
                Mat4ToSize(cob->matrix, size);
                
                /* apply targetmat - containing location on path, and rotation */
                Mat4MulSerie(cob->matrix, ct->matrix, obmat, NULL, NULL, NULL, NULL, NULL, NULL);
                
                /* un-apply scaling caused by path */
                Mat4ToSize(cob->matrix, obsize);
                if (obsize[0])
                        VecMulf(cob->matrix[0], size[0] / obsize[0]);
                if (obsize[1])
                        VecMulf(cob->matrix[1], size[1] / obsize[1]);
                if (obsize[2])
                        VecMulf(cob->matrix[2], size[2] / obsize[2]);
        }
}

static bConstraintTypeInfo CTI_FOLLOWPATH = {
        CONSTRAINT_TYPE_FOLLOWPATH, /* type */
        sizeof(bFollowPathConstraint), /* size */
        "Follow Path", /* name */
        "bFollowPathConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        followpath_new_data, /* new data */
        followpath_get_tars, /* get constraint targets */
        followpath_flush_tars, /* flush constraint targets */
        followpath_get_tarmat, /* get target matrix */
        followpath_evaluate /* evaluate */
};

/* --------- Limit Location --------- */


static void loclimit_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bLocLimitConstraint *data = con->data;
        
        if (data->flag & LIMIT_XMIN) {
                if (cob->matrix[3][0] < data->xmin)
                        cob->matrix[3][0] = data->xmin;
        }
        if (data->flag & LIMIT_XMAX) {
                if (cob->matrix[3][0] > data->xmax)
                        cob->matrix[3][0] = data->xmax;
        }
        if (data->flag & LIMIT_YMIN) {
                if (cob->matrix[3][1] < data->ymin)
                        cob->matrix[3][1] = data->ymin;
        }
        if (data->flag & LIMIT_YMAX) {
                if (cob->matrix[3][1] > data->ymax)
                        cob->matrix[3][1] = data->ymax;
        }
        if (data->flag & LIMIT_ZMIN) {
                if (cob->matrix[3][2] < data->zmin) 
                        cob->matrix[3][2] = data->zmin;
        }
        if (data->flag & LIMIT_ZMAX) {
                if (cob->matrix[3][2] > data->zmax)
                        cob->matrix[3][2] = data->zmax;
        }
}

static bConstraintTypeInfo CTI_LOCLIMIT = {
        CONSTRAINT_TYPE_LOCLIMIT, /* type */
        sizeof(bLocLimitConstraint), /* size */
        "Limit Location", /* name */
        "bLocLimitConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        NULL, /* new data */
        NULL, /* get constraint targets */
        NULL, /* flush constraint targets */
        NULL, /* get target matrix */
        loclimit_evaluate /* evaluate */
};

/* -------- Limit Rotation --------- */

static void rotlimit_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bRotLimitConstraint *data = con->data;
        float loc[3];
        float eul[3];
        float size[3];
        
        VECCOPY(loc, cob->matrix[3]);
        Mat4ToSize(cob->matrix, size);
        
        Mat4ToEul(cob->matrix, eul);
        
        /* eulers: radians to degrees! */
        eul[0] = (float)(eul[0] / M_PI * 180);
        eul[1] = (float)(eul[1] / M_PI * 180);
        eul[2] = (float)(eul[2] / M_PI * 180);
        
        /* limiting of euler values... */
        if (data->flag & LIMIT_XROT) {
                if (eul[0] < data->xmin) 
                        eul[0] = data->xmin;
                        
                if (eul[0] > data->xmax)
                        eul[0] = data->xmax;
        }
        if (data->flag & LIMIT_YROT) {
                if (eul[1] < data->ymin)
                        eul[1] = data->ymin;
                        
                if (eul[1] > data->ymax)
                        eul[1] = data->ymax;
        }
        if (data->flag & LIMIT_ZROT) {
                if (eul[2] < data->zmin)
                        eul[2] = data->zmin;
                        
                if (eul[2] > data->zmax)
                        eul[2] = data->zmax;
        }
                
        /* eulers: degrees to radians ! */
        eul[0] = (float)(eul[0] / 180 * M_PI); 
        eul[1] = (float)(eul[1] / 180 * M_PI);
        eul[2] = (float)(eul[2] / 180 * M_PI);
        
        LocEulSizeToMat4(cob->matrix, loc, eul, size);
}

static bConstraintTypeInfo CTI_ROTLIMIT = {
        CONSTRAINT_TYPE_ROTLIMIT, /* type */
        sizeof(bRotLimitConstraint), /* size */
        "Limit Rotation", /* name */
        "bRotLimitConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        NULL, /* new data */
        NULL, /* get constraint targets */
        NULL, /* flush constraint targets */
        NULL, /* get target matrix */
        rotlimit_evaluate /* evaluate */
};

/* --------- Limit Scaling --------- */


static void sizelimit_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bSizeLimitConstraint *data = con->data;
        float obsize[3], size[3];
        
        Mat4ToSize(cob->matrix, size);
        Mat4ToSize(cob->matrix, obsize);
        
        if (data->flag & LIMIT_XMIN) {
                if (size[0] < data->xmin) 
                        size[0] = data->xmin;   
        }
        if (data->flag & LIMIT_XMAX) {
                if (size[0] > data->xmax) 
                        size[0] = data->xmax;
        }
        if (data->flag & LIMIT_YMIN) {
                if (size[1] < data->ymin) 
                        size[1] = data->ymin;   
        }
        if (data->flag & LIMIT_YMAX) {
                if (size[1] > data->ymax) 
                        size[1] = data->ymax;
        }
        if (data->flag & LIMIT_ZMIN) {
                if (size[2] < data->zmin) 
                        size[2] = data->zmin;   
        }
        if (data->flag & LIMIT_ZMAX) {
                if (size[2] > data->zmax) 
                        size[2] = data->zmax;
        }
        
        if (obsize[0]) 
                VecMulf(cob->matrix[0], size[0]/obsize[0]);
        if (obsize[1]) 
                VecMulf(cob->matrix[1], size[1]/obsize[1]);
        if (obsize[2]) 
                VecMulf(cob->matrix[2], size[2]/obsize[2]);
}

static bConstraintTypeInfo CTI_SIZELIMIT = {
        CONSTRAINT_TYPE_SIZELIMIT, /* type */
        sizeof(bSizeLimitConstraint), /* size */
        "Limit Scaling", /* name */
        "bSizeLimitConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        NULL, /* new data */
        NULL, /* get constraint targets */
        NULL, /* flush constraint targets */
        NULL, /* get target matrix */
        sizelimit_evaluate /* evaluate */
};

/* ----------- Copy Location ------------- */

static void loclike_new_data (void *cdata)
{
        bLocateLikeConstraint *data= (bLocateLikeConstraint *)cdata;
        
        data->flag = LOCLIKE_X|LOCLIKE_Y|LOCLIKE_Z;
}

static int loclike_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bLocateLikeConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void loclike_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bLocateLikeConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void loclike_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bLocateLikeConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        if (VALID_CONS_TARGET(ct)) {
                float offset[3] = {0.0f, 0.0f, 0.0f};
                
                if (data->flag & LOCLIKE_OFFSET)
                        VECCOPY(offset, cob->matrix[3]);
                        
                if (data->flag & LOCLIKE_X) {
                        cob->matrix[3][0] = ct->matrix[3][0];
                        
                        if (data->flag & LOCLIKE_X_INVERT) cob->matrix[3][0] *= -1;
                        cob->matrix[3][0] += offset[0];
                }
                if (data->flag & LOCLIKE_Y) {
                        cob->matrix[3][1] = ct->matrix[3][1];
                        
                        if (data->flag & LOCLIKE_Y_INVERT) cob->matrix[3][1] *= -1;
                        cob->matrix[3][1] += offset[1];
                }
                if (data->flag & LOCLIKE_Z) {
                        cob->matrix[3][2] = ct->matrix[3][2];
                        
                        if (data->flag & LOCLIKE_Z_INVERT) cob->matrix[3][2] *= -1;
                        cob->matrix[3][2] += offset[2];
                }
        }
}

static bConstraintTypeInfo CTI_LOCLIKE = {
        CONSTRAINT_TYPE_LOCLIKE, /* type */
        sizeof(bLocateLikeConstraint), /* size */
        "Copy Location", /* name */
        "bLocateLikeConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        loclike_new_data, /* new data */
        loclike_get_tars, /* get constraint targets */
        loclike_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        loclike_evaluate /* evaluate */
};

/* ----------- Copy Rotation ------------- */

static void rotlike_new_data (void *cdata)
{
        bRotateLikeConstraint *data= (bRotateLikeConstraint *)cdata;
        
        data->flag = ROTLIKE_X|ROTLIKE_Y|ROTLIKE_Z;
}

static int rotlike_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bRotateLikeConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void rotlike_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bRotateLikeConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void rotlike_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bRotateLikeConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        if (VALID_CONS_TARGET(ct)) {
                float   loc[3];
                float   eul[3], obeul[3];
                float   size[3];
                
                VECCOPY(loc, cob->matrix[3]);
                Mat4ToSize(cob->matrix, size);
                
                Mat4ToEul(ct->matrix, eul);
                Mat4ToEul(cob->matrix, obeul);
                
                if ((data->flag & ROTLIKE_X)==0)
                        eul[0] = obeul[0];
                else {
                        if (data->flag & ROTLIKE_OFFSET)
                                euler_rot(eul, obeul[0], 'x');
                        
                        if (data->flag & ROTLIKE_X_INVERT)
                                eul[0] *= -1;
                }
                
                if ((data->flag & ROTLIKE_Y)==0)
                        eul[1] = obeul[1];
                else {
                        if (data->flag & ROTLIKE_OFFSET)
                                euler_rot(eul, obeul[1], 'y');
                        
                        if (data->flag & ROTLIKE_Y_INVERT)
                                eul[1] *= -1;
                }
                
                if ((data->flag & ROTLIKE_Z)==0)
                        eul[2] = obeul[2];
                else {
                        if (data->flag & ROTLIKE_OFFSET)
                                euler_rot(eul, obeul[2], 'z');
                        
                        if (data->flag & ROTLIKE_Z_INVERT)
                                eul[2] *= -1;
                }
                
                compatible_eul(eul, obeul);
                LocEulSizeToMat4(cob->matrix, loc, eul, size);
        }
}

static bConstraintTypeInfo CTI_ROTLIKE = {
        CONSTRAINT_TYPE_ROTLIKE, /* type */
        sizeof(bRotateLikeConstraint), /* size */
        "Copy Rotation", /* name */
        "bRotateLikeConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        rotlike_new_data, /* new data */
        rotlike_get_tars, /* get constraint targets */
        rotlike_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        rotlike_evaluate /* evaluate */
};

/* ---------- Copy Scaling ---------- */

static void sizelike_new_data (void *cdata)
{
        bSizeLikeConstraint *data= (bSizeLikeConstraint *)cdata;
        
        data->flag = SIZELIKE_X|SIZELIKE_Y|SIZELIKE_Z;
}

static int sizelike_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bSizeLikeConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void sizelike_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bSizeLikeConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void sizelike_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bSizeLikeConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        if (VALID_CONS_TARGET(ct)) {
                float obsize[3], size[3];
                
                Mat4ToSize(ct->matrix, size);
                Mat4ToSize(cob->matrix, obsize);
                
                if ((data->flag & SIZELIKE_X) && (obsize[0] != 0)) {
                        if (data->flag & SIZELIKE_OFFSET) {
                                size[0] += (obsize[0] - 1.0f);
                                VecMulf(cob->matrix[0], size[0] / obsize[0]);
                        }
                        else
                                VecMulf(cob->matrix[0], size[0] / obsize[0]);
                }
                if ((data->flag & SIZELIKE_Y) && (obsize[1] != 0)) {
                        if (data->flag & SIZELIKE_OFFSET) {
                                size[1] += (obsize[1] - 1.0f);
                                VecMulf(cob->matrix[1], size[1] / obsize[1]);
                        }
                        else
                                VecMulf(cob->matrix[1], size[1] / obsize[1]);
                }
                if ((data->flag & SIZELIKE_Z) && (obsize[2] != 0)) {
                        if (data->flag & SIZELIKE_OFFSET) {
                                size[2] += (obsize[2] - 1.0f);
                                VecMulf(cob->matrix[2], size[2] / obsize[2]);
                        }
                        else
                                VecMulf(cob->matrix[2], size[2] / obsize[2]);
                }
        }
}

static bConstraintTypeInfo CTI_SIZELIKE = {
        CONSTRAINT_TYPE_SIZELIKE, /* type */
        sizeof(bSizeLikeConstraint), /* size */
        "Copy Scale", /* name */
        "bSizeLikeConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        sizelike_new_data, /* new data */
        sizelike_get_tars, /* get constraint targets */
        sizelike_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        sizelike_evaluate /* evaluate */
};


/* ----------- Python Constraint -------------- */

static void pycon_free (bConstraint *con)
{
        bPythonConstraint *data= con->data;
        
        /* id-properties */
        IDP_FreeProperty(data->prop);
        MEM_freeN(data->prop);
        
        /* multiple targets */
        BLI_freelistN(&data->targets);
}       

static void pycon_relink (bConstraint *con)
{
        bPythonConstraint *data= con->data;
        
        ID_NEW(data->text);
}

static void pycon_copy (bConstraint *con, bConstraint *srccon)
{
        bPythonConstraint *pycon = (bPythonConstraint *)con->data;
        bPythonConstraint *opycon = (bPythonConstraint *)srccon->data;
        
        pycon->prop = IDP_CopyProperty(opycon->prop);
        BLI_duplicatelist(&pycon->targets, &opycon->targets);
}

static void pycon_new_data (void *cdata)
{
        bPythonConstraint *data= (bPythonConstraint *)cdata;
        
        /* everything should be set correctly by calloc, except for the prop->type constant.*/
        data->prop = MEM_callocN(sizeof(IDProperty), "PyConstraintProps");
        data->prop->type = IDP_GROUP;
}

static int pycon_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bPythonConstraint *data= con->data;
                
                list->first = data->targets.first;
                list->last = data->targets.last;
                
                return data->tarnum;
        }
        
        return 0;
}

/* Whether this approach is maintained remains to be seen (aligorith) */
static void pycon_get_tarmat (bConstraint *con, bConstraintOb *cob, bConstraintTarget *ct, float ctime)
{
        bPythonConstraint *data= con->data;
        
        if (VALID_CONS_TARGET(ct)) {
                /* special exception for curves - depsgraph issues */
                if (ct->tar->type == OB_CURVE) {
                        Curve *cu= ct->tar->data;
                        
                        /* this check is to make sure curve objects get updated on file load correctly.*/
                        if (cu->path==NULL || cu->path->data==NULL) /* only happens on reload file, but violates depsgraph still... fix! */
                                makeDispListCurveTypes(cob->scene, ct->tar, 0);                         
                }
                
                /* firstly calculate the matrix the normal way, then let the py-function override
                 * this matrix if it needs to do so
                 */
                constraint_target_to_mat4(ct->tar, ct->subtarget, ct->matrix, CONSTRAINT_SPACE_WORLD, ct->space, con->headtail);
                
                /* only execute target calculation if allowed */
#ifndef DISABLE_PYTHON
                if (G.f & G_DOSCRIPTLINKS)
                        BPY_pyconstraint_target(data, ct);
#endif
        }
        else if (ct)
                Mat4One(ct->matrix);
}

static void pycon_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
#ifdef DISABLE_PYTHON
        return;
#else
        bPythonConstraint *data= con->data;
        
        /* only evaluate in python if we're allowed to do so */
        if ((G.f & G_DOSCRIPTLINKS)==0)  return;
        
/* currently removed, until I this can be re-implemented for multiple targets */
#if 0
        /* Firstly, run the 'driver' function which has direct access to the objects involved 
         * Technically, this is potentially dangerous as users may abuse this and cause dependency-problems,
         * but it also allows certain 'clever' rigging hacks to work.
         */
        BPY_pyconstraint_driver(data, cob, targets);
#endif
        
        /* Now, run the actual 'constraint' function, which should only access the matrices */
        BPY_pyconstraint_eval(data, cob, targets);
#endif /* DISABLE_PYTHON */
}

static bConstraintTypeInfo CTI_PYTHON = {
        CONSTRAINT_TYPE_PYTHON, /* type */
        sizeof(bPythonConstraint), /* size */
        "Script", /* name */
        "bPythonConstraint", /* struct name */
        pycon_free, /* free data */
        pycon_relink, /* relink data */
        pycon_copy, /* copy data */
        pycon_new_data, /* new data */
        pycon_get_tars, /* get constraint targets */
        NULL, /* flush constraint targets */
        pycon_get_tarmat, /* get target matrix */
        pycon_evaluate /* evaluate */
};

/* -------- Action Constraint ----------- */

static void actcon_relink (bConstraint *con)
{
        bActionConstraint *data= con->data;
        ID_NEW(data->act);
}

static void actcon_new_data (void *cdata)
{
        bActionConstraint *data= (bActionConstraint *)cdata;
        
        /* set type to 20 (Loc X), as 0 is Rot X for backwards compatability */
        data->type = 20;
}

static int actcon_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bActionConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void actcon_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bActionConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void actcon_get_tarmat (bConstraint *con, bConstraintOb *cob, bConstraintTarget *ct, float ctime)
{
        extern void chan_calc_mat(bPoseChannel *chan);
        bActionConstraint *data = con->data;
        
        if (VALID_CONS_TARGET(ct)) {
                float tempmat[4][4], vec[3];
                float s, t;
                short axis;
                
                /* initialise return matrix */
                Mat4One(ct->matrix);
                
                /* get the transform matrix of the target */
                constraint_target_to_mat4(ct->tar, ct->subtarget, tempmat, CONSTRAINT_SPACE_WORLD, ct->space, con->headtail);
                
                /* determine where in transform range target is */
                /* data->type is mapped as follows for backwards compatability:
                 *      00,01,02        - rotation (it used to be like this)
                 *      10,11,12        - scaling
                 *      20,21,22        - location
                 */
                if (data->type < 10) {
                        /* extract rotation (is in whatever space target should be in) */
                        Mat4ToEul(tempmat, vec);
                        vec[0] *= (float)(180.0/M_PI);
                        vec[1] *= (float)(180.0/M_PI);
                        vec[2] *= (float)(180.0/M_PI);
                        axis= data->type;
                }
                else if (data->type < 20) {
                        /* extract scaling (is in whatever space target should be in) */
                        Mat4ToSize(tempmat, vec);
                        axis= data->type - 10;
                }
                else {
                        /* extract location */
                        VECCOPY(vec, tempmat[3]);
                        axis= data->type - 20;
                }
                
                /* Target defines the animation */
                s = (vec[axis]-data->min) / (data->max-data->min);
                CLAMP(s, 0, 1);
                t = ( s * (data->end-data->start)) + data->start;
                
                if (G.f & G_DEBUG)
                        printf("do Action Constraint %s - Ob %s Pchan %s \n", con->name, cob->ob->id.name+2, (cob->pchan)?cob->pchan->name:NULL);
                
                /* Get the appropriate information from the action */
                // XXX probably we might need some special filtering methods to make this more efficient
                if (cob->type == CONSTRAINT_OBTYPE_BONE) {
                        Object workob;
                        bPose *pose;
                        bPoseChannel *pchan, *tchan;
                        
                        /* make a temporary pose and evaluate using that */
                        pose = MEM_callocN(sizeof(bPose), "pose");
                        
                        /* make a copy of the bone of interest in the temp pose before evaluating action, so that it can get set */
                        pchan = cob->pchan;
                        tchan= verify_pose_channel(pose, pchan->name);
                        
                        /* evaluate action using workob (it will only set the PoseChannel in question) */
                        // XXX we need some flags to prevent evaluation from setting disabled flags on all other settings
                        what_does_obaction(cob->scene, cob->ob, &workob, pose, data->act, t);
                        
                        /* convert animation to matrices for use here */
                        chan_calc_mat(tchan);
                        Mat4CpyMat4(ct->matrix, tchan->chan_mat);
                        
                        /* Clean up */
                        free_pose(pose);
                }
                else if (cob->type == CONSTRAINT_OBTYPE_OBJECT) {
                        Object workob;
                        
                        /* evaluate using workob */
                        what_does_obaction(cob->scene, cob->ob, &workob, NULL, data->act, t);
                        object_to_mat4(&workob, ct->matrix);
                }
                else {
                        /* behaviour undefined... */
                        puts("Error: unknown owner type for Action Constraint");
                }
        }
}

static void actcon_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bConstraintTarget *ct= targets->first;
        
        if (VALID_CONS_TARGET(ct)) {
                float temp[4][4];
                
                /* Nice and simple... we just need to multiply the matrices, as the get_target_matrix
                 * function has already taken care of everything else.
                 */
                Mat4CpyMat4(temp, cob->matrix);
                Mat4MulMat4(cob->matrix, ct->matrix, temp);
        }
}

static bConstraintTypeInfo CTI_ACTION = {
        CONSTRAINT_TYPE_ACTION, /* type */
        sizeof(bActionConstraint), /* size */
        "Action", /* name */
        "bActionConstraint", /* struct name */
        NULL, /* free data */
        actcon_relink, /* relink data */
        NULL, /* copy data */
        actcon_new_data, /* new data */
        actcon_get_tars, /* get constraint targets */
        actcon_flush_tars, /* flush constraint targets */
        actcon_get_tarmat, /* get target matrix */
        actcon_evaluate /* evaluate */
};

/* --------- Locked Track ---------- */

static void locktrack_new_data (void *cdata)
{
        bLockTrackConstraint *data= (bLockTrackConstraint *)cdata;
        
        data->trackflag = TRACK_Y;
        data->lockflag = LOCK_Z;
}       

static int locktrack_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bLockTrackConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void locktrack_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bLockTrackConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void locktrack_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bLockTrackConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        if (VALID_CONS_TARGET(ct)) {
                float vec[3],vec2[3];
                float totmat[3][3];
                float tmpmat[3][3];
                float invmat[3][3];
                float tmat[4][4];
                float mdet;
                
                /* Vector object -> target */
                VecSubf(vec, ct->matrix[3], cob->matrix[3]);
                switch (data->lockflag){
                case LOCK_X: /* LOCK X */
                {
                        switch (data->trackflag) {
                                case TRACK_Y: /* LOCK X TRACK Y */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[0]);
                                        VecSubf(totmat[1], vec, vec2);
                                        Normalize(totmat[1]);
                                        
                                        /* the x axis is fixed */
                                        totmat[0][0] = cob->matrix[0][0];
                                        totmat[0][1] = cob->matrix[0][1];
                                        totmat[0][2] = cob->matrix[0][2];
                                        Normalize(totmat[0]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[2], totmat[0], totmat[1]);
                                }
                                        break;
                                case TRACK_Z: /* LOCK X TRACK Z */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[0]);
                                        VecSubf(totmat[2], vec, vec2);
                                        Normalize(totmat[2]);
                                        
                                        /* the x axis is fixed */
                                        totmat[0][0] = cob->matrix[0][0];
                                        totmat[0][1] = cob->matrix[0][1];
                                        totmat[0][2] = cob->matrix[0][2];
                                        Normalize(totmat[0]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[1], totmat[2], totmat[0]);
                                }
                                        break;
                                case TRACK_nY: /* LOCK X TRACK -Y */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[0]);
                                        VecSubf(totmat[1], vec, vec2);
                                        Normalize(totmat[1]);
                                        VecNegf(totmat[1]);
                                        
                                        /* the x axis is fixed */
                                        totmat[0][0] = cob->matrix[0][0];
                                        totmat[0][1] = cob->matrix[0][1];
                                        totmat[0][2] = cob->matrix[0][2];
                                        Normalize(totmat[0]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[2], totmat[0], totmat[1]);
                                }
                                        break;
                                case TRACK_nZ: /* LOCK X TRACK -Z */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[0]);
                                        VecSubf(totmat[2], vec, vec2);
                                        Normalize(totmat[2]);
                                        VecNegf(totmat[2]);
                                                
                                        /* the x axis is fixed */
                                        totmat[0][0] = cob->matrix[0][0];
                                        totmat[0][1] = cob->matrix[0][1];
                                        totmat[0][2] = cob->matrix[0][2];
                                        Normalize(totmat[0]);
                                                
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[1], totmat[2], totmat[0]);
                                }
                                        break;
                                default:
                                {
                                        totmat[0][0] = 1;totmat[0][1] = 0;totmat[0][2] = 0;
                                        totmat[1][0] = 0;totmat[1][1] = 1;totmat[1][2] = 0;
                                        totmat[2][0] = 0;totmat[2][1] = 0;totmat[2][2] = 1;
                                }
                                        break;
                        }
                }
                        break;
                case LOCK_Y: /* LOCK Y */
                {
                        switch (data->trackflag) {
                                case TRACK_X: /* LOCK Y TRACK X */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[1]);
                                        VecSubf(totmat[0], vec, vec2);
                                        Normalize(totmat[0]);
                                        
                                        /* the y axis is fixed */
                                        totmat[1][0] = cob->matrix[1][0];
                                        totmat[1][1] = cob->matrix[1][1];
                                        totmat[1][2] = cob->matrix[1][2];
                                        Normalize(totmat[1]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[2], totmat[0], totmat[1]);
                                }
                                        break;
                                case TRACK_Z: /* LOCK Y TRACK Z */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[1]);
                                        VecSubf(totmat[2], vec, vec2);
                                        Normalize(totmat[2]);

                                        /* the y axis is fixed */
                                        totmat[1][0] = cob->matrix[1][0];
                                        totmat[1][1] = cob->matrix[1][1];
                                        totmat[1][2] = cob->matrix[1][2];
                                        Normalize(totmat[1]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[0], totmat[1], totmat[2]);
                                }
                                        break;
                                case TRACK_nX: /* LOCK Y TRACK -X */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[1]);
                                        VecSubf(totmat[0], vec, vec2);
                                        Normalize(totmat[0]);
                                        VecNegf(totmat[0]);
                                        
                                        /* the y axis is fixed */
                                        totmat[1][0] = cob->matrix[1][0];
                                        totmat[1][1] = cob->matrix[1][1];
                                        totmat[1][2] = cob->matrix[1][2];
                                        Normalize(totmat[1]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[2], totmat[0], totmat[1]);
                                }
                                        break;
                                case TRACK_nZ: /* LOCK Y TRACK -Z */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[1]);
                                        VecSubf(totmat[2], vec, vec2);
                                        Normalize(totmat[2]);
                                        VecNegf(totmat[2]);
                                        
                                        /* the y axis is fixed */
                                        totmat[1][0] = cob->matrix[1][0];
                                        totmat[1][1] = cob->matrix[1][1];
                                        totmat[1][2] = cob->matrix[1][2];
                                        Normalize(totmat[1]);
                                        
                                        /* the z axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[0], totmat[1], totmat[2]);
                                }
                                        break;
                                default:
                                {
                                        totmat[0][0] = 1;totmat[0][1] = 0;totmat[0][2] = 0;
                                        totmat[1][0] = 0;totmat[1][1] = 1;totmat[1][2] = 0;
                                        totmat[2][0] = 0;totmat[2][1] = 0;totmat[2][2] = 1;
                                }
                                        break;
                        }
                }
                        break;
                case LOCK_Z: /* LOCK Z */
                {
                        switch (data->trackflag) {
                                case TRACK_X: /* LOCK Z TRACK X */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[2]);
                                        VecSubf(totmat[0], vec, vec2);
                                        Normalize(totmat[0]);
                                        
                                        /* the z axis is fixed */
                                        totmat[2][0] = cob->matrix[2][0];
                                        totmat[2][1] = cob->matrix[2][1];
                                        totmat[2][2] = cob->matrix[2][2];
                                        Normalize(totmat[2]);
                                        
                                        /* the x axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[1], totmat[2], totmat[0]);
                                }
                                        break;
                                case TRACK_Y: /* LOCK Z TRACK Y */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[2]);
                                        VecSubf(totmat[1], vec, vec2);
                                        Normalize(totmat[1]);
                                        
                                        /* the z axis is fixed */
                                        totmat[2][0] = cob->matrix[2][0];
                                        totmat[2][1] = cob->matrix[2][1];
                                        totmat[2][2] = cob->matrix[2][2];
                                        Normalize(totmat[2]);
                                                
                                        /* the x axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[0], totmat[1], totmat[2]);
                                }
                                        break;
                                case TRACK_nX: /* LOCK Z TRACK -X */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[2]);
                                        VecSubf(totmat[0], vec, vec2);
                                        Normalize(totmat[0]);
                                        VecNegf(totmat[0]);
                                        
                                        /* the z axis is fixed */
                                        totmat[2][0] = cob->matrix[2][0];
                                        totmat[2][1] = cob->matrix[2][1];
                                        totmat[2][2] = cob->matrix[2][2];
                                        Normalize(totmat[2]);
                                        
                                        /* the x axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[1], totmat[2], totmat[0]);
                                }
                                        break;
                                case TRACK_nY: /* LOCK Z TRACK -Y */
                                {
                                        /* Projection of Vector on the plane */
                                        Projf(vec2, vec, cob->matrix[2]);
                                        VecSubf(totmat[1], vec, vec2);
                                        Normalize(totmat[1]);
                                        VecNegf(totmat[1]);
                                        
                                        /* the z axis is fixed */
                                        totmat[2][0] = cob->matrix[2][0];
                                        totmat[2][1] = cob->matrix[2][1];
                                        totmat[2][2] = cob->matrix[2][2];
                                        Normalize(totmat[2]);
                                                
                                        /* the x axis gets mapped onto a third orthogonal vector */
                                        Crossf(totmat[0], totmat[1], totmat[2]);
                                }
                                        break;
                                default:
                                {
                                                totmat[0][0] = 1;totmat[0][1] = 0;totmat[0][2] = 0;
                                                totmat[1][0] = 0;totmat[1][1] = 1;totmat[1][2] = 0;
                                                totmat[2][0] = 0;totmat[2][1] = 0;totmat[2][2] = 1;
                                }
                                        break;
                        }
                }
                        break;
                default:
                        {
                                totmat[0][0] = 1;totmat[0][1] = 0;totmat[0][2] = 0;
                                totmat[1][0] = 0;totmat[1][1] = 1;totmat[1][2] = 0;
                                totmat[2][0] = 0;totmat[2][1] = 0;totmat[2][2] = 1;
                        }
                        break;
                }
                /* Block to keep matrix heading */
                tmpmat[0][0] = cob->matrix[0][0];tmpmat[0][1] = cob->matrix[0][1];tmpmat[0][2] = cob->matrix[0][2];
                tmpmat[1][0] = cob->matrix[1][0];tmpmat[1][1] = cob->matrix[1][1];tmpmat[1][2] = cob->matrix[1][2];
                tmpmat[2][0] = cob->matrix[2][0];tmpmat[2][1] = cob->matrix[2][1];tmpmat[2][2] = cob->matrix[2][2];
                Normalize(tmpmat[0]);
                Normalize(tmpmat[1]);
                Normalize(tmpmat[2]);
                Mat3Inv(invmat, tmpmat);
                Mat3MulMat3(tmpmat, totmat, invmat);
                totmat[0][0] = tmpmat[0][0];totmat[0][1] = tmpmat[0][1];totmat[0][2] = tmpmat[0][2];
                totmat[1][0] = tmpmat[1][0];totmat[1][1] = tmpmat[1][1];totmat[1][2] = tmpmat[1][2];
                totmat[2][0] = tmpmat[2][0];totmat[2][1] = tmpmat[2][1];totmat[2][2] = tmpmat[2][2];
                
                Mat4CpyMat4(tmat, cob->matrix);
                
                mdet = Det3x3(  totmat[0][0],totmat[0][1],totmat[0][2],
                                                totmat[1][0],totmat[1][1],totmat[1][2],
                                                totmat[2][0],totmat[2][1],totmat[2][2]);
                if (mdet==0) {
                        totmat[0][0] = 1;totmat[0][1] = 0;totmat[0][2] = 0;
                        totmat[1][0] = 0;totmat[1][1] = 1;totmat[1][2] = 0;
                        totmat[2][0] = 0;totmat[2][1] = 0;totmat[2][2] = 1;
                }
                
                /* apply out transformaton to the object */
                Mat4MulMat34(cob->matrix, totmat, tmat);
        }
}

static bConstraintTypeInfo CTI_LOCKTRACK = {
        CONSTRAINT_TYPE_LOCKTRACK, /* type */
        sizeof(bLockTrackConstraint), /* size */
        "Locked Track", /* name */
        "bLockTrackConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        locktrack_new_data, /* new data */
        locktrack_get_tars, /* get constraint targets */
        locktrack_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        locktrack_evaluate /* evaluate */
};

/* ---------- Limit Distance Constraint ----------- */

static void distlimit_new_data (void *cdata)
{
        bDistLimitConstraint *data= (bDistLimitConstraint *)cdata;
        
        data->dist= 0.0;
}

static int distlimit_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bDistLimitConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void distlimit_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bDistLimitConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void distlimit_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bDistLimitConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        /* only evaluate if there is a target */
        if (VALID_CONS_TARGET(ct)) {
                float dvec[3], dist=0.0f, sfac=1.0f;
                short clamp_surf= 0;
                
                /* calculate our current distance from the target */
                dist= VecLenf(cob->matrix[3], ct->matrix[3]);
                
                /* set distance (flag is only set when user demands it) */
                if (data->dist == 0)
                        data->dist= dist;
                
                /* check if we're which way to clamp from, and calculate interpolation factor (if needed) */
                if (data->mode == LIMITDIST_OUTSIDE) {
                        /* if inside, then move to surface */
                        if (dist <= data->dist) {
                                clamp_surf= 1;
                                sfac= data->dist / dist;
                        }
                        /* if soft-distance is enabled, start fading once owner is dist+softdist from the target */
                        else if (data->flag & LIMITDIST_USESOFT) {
                                if (dist <= (data->dist + data->soft)) {
                                        
                                }
                        }
                }
                else if (data->mode == LIMITDIST_INSIDE) {
                        /* if outside, then move to surface */
                        if (dist >= data->dist) {
                                clamp_surf= 1;
                                sfac= data->dist / dist;
                        }
                        /* if soft-distance is enabled, start fading once owner is dist-soft from the target */
                        else if (data->flag & LIMITDIST_USESOFT) {
                                // FIXME: there's a problem with "jumping" when this kicks in
                                if (dist >= (data->dist - data->soft)) {
                                        sfac = (float)( data->soft*(1.0 - exp(-(dist - data->dist)/data->soft)) + data->dist );
                                        sfac /= dist;
                                        
                                        clamp_surf= 1;
                                }
                        }
                }
                else {
                        if (IS_EQ(dist, data->dist)==0) {
                                clamp_surf= 1;
                                sfac= data->dist / dist;
                        }
                }
                
                /* clamp to 'surface' (i.e. move owner so that dist == data->dist) */
                if (clamp_surf) {
                        /* simply interpolate along line formed by target -> owner */
                        VecLerpf(dvec, ct->matrix[3], cob->matrix[3], sfac);
                        
                        /* copy new vector onto owner */
                        VECCOPY(cob->matrix[3], dvec);
                }
        }
}

static bConstraintTypeInfo CTI_DISTLIMIT = {
        CONSTRAINT_TYPE_DISTLIMIT, /* type */
        sizeof(bDistLimitConstraint), /* size */
        "Limit Distance", /* name */
        "bDistLimitConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        distlimit_new_data, /* new data */
        distlimit_get_tars, /* get constraint targets */
        distlimit_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get a target matrix */
        distlimit_evaluate /* evaluate */
};

/* ---------- Stretch To ------------ */

static void stretchto_new_data (void *cdata)
{
        bStretchToConstraint *data= (bStretchToConstraint *)cdata;
        
        data->volmode = 0;
        data->plane = 0;
        data->orglength = 0.0; 
        data->bulge = 1.0;
}

static int stretchto_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bStretchToConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void stretchto_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bStretchToConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void stretchto_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bStretchToConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        /* only evaluate if there is a target */
        if (VALID_CONS_TARGET(ct)) {
                float size[3], scale[3], vec[3], xx[3], zz[3], orth[3];
                float totmat[3][3];
                float tmat[4][4];
                float dist;
                
                /* store scaling before destroying obmat */
                Mat4ToSize(cob->matrix, size);
                
                /* store X orientation before destroying obmat */
                xx[0] = cob->matrix[0][0];
                xx[1] = cob->matrix[0][1];
                xx[2] = cob->matrix[0][2];
                Normalize(xx);
                
                /* store Z orientation before destroying obmat */
                zz[0] = cob->matrix[2][0];
                zz[1] = cob->matrix[2][1];
                zz[2] = cob->matrix[2][2];
                Normalize(zz);
                
                VecSubf(vec, cob->matrix[3], ct->matrix[3]);
                vec[0] /= size[0];
                vec[1] /= size[1];
                vec[2] /= size[2];
                
                dist = Normalize(vec);
                //dist = VecLenf( ob->obmat[3], targetmat[3]);
                
                /* data->orglength==0 occurs on first run, and after 'R' button is clicked */
                if (data->orglength == 0)  
                        data->orglength = dist;
                if (data->bulge == 0) 
                        data->bulge = 1.0;
                
                scale[1] = dist/data->orglength;
                switch (data->volmode) {
                /* volume preserving scaling */
                case VOLUME_XZ :
                        scale[0] = 1.0f - (float)sqrt(data->bulge) + (float)sqrt(data->bulge*(data->orglength/dist));
                        scale[2] = scale[0];
                        break;
                case VOLUME_X:
                        scale[0] = 1.0f + data->bulge * (data->orglength /dist - 1);
                        scale[2] = 1.0;
                        break;
                case VOLUME_Z:
                        scale[0] = 1.0;
                        scale[2] = 1.0f + data->bulge * (data->orglength /dist - 1);
                        break;
                        /* don't care for volume */
                case NO_VOLUME:
                        scale[0] = 1.0;
                        scale[2] = 1.0;
                        break;
                default: /* should not happen, but in case*/
                        return;    
                } /* switch (data->volmode) */

                /* Clear the object's rotation and scale */
                cob->matrix[0][0]=size[0]*scale[0];
                cob->matrix[0][1]=0;
                cob->matrix[0][2]=0;
                cob->matrix[1][0]=0;
                cob->matrix[1][1]=size[1]*scale[1];
                cob->matrix[1][2]=0;
                cob->matrix[2][0]=0;
                cob->matrix[2][1]=0;
                cob->matrix[2][2]=size[2]*scale[2];
                
                VecSubf(vec, cob->matrix[3], ct->matrix[3]);
                Normalize(vec);
                
                /* new Y aligns  object target connection*/
                totmat[1][0] = -vec[0];
                totmat[1][1] = -vec[1];
                totmat[1][2] = -vec[2];
                switch (data->plane) {
                case PLANE_X:
                        /* build new Z vector */
                        /* othogonal to "new Y" "old X! plane */
                        Crossf(orth, vec, xx);
                        Normalize(orth);
                        
                        /* new Z*/
                        totmat[2][0] = orth[0];
                        totmat[2][1] = orth[1];
                        totmat[2][2] = orth[2];
                        
                        /* we decided to keep X plane*/
                        Crossf(xx, orth, vec);
                        Normalize(xx);
                        totmat[0][0] = xx[0];
                        totmat[0][1] = xx[1];
                        totmat[0][2] = xx[2];
                        break;
                case PLANE_Z:
                        /* build new X vector */
                        /* othogonal to "new Y" "old Z! plane */
                        Crossf(orth, vec, zz);
                        Normalize(orth);
                        
                        /* new X */
                        totmat[0][0] = -orth[0];
                        totmat[0][1] = -orth[1];
                        totmat[0][2] = -orth[2];
                        
                        /* we decided to keep Z */
                        Crossf(zz, orth, vec);
                        Normalize(zz);
                        totmat[2][0] = zz[0];
                        totmat[2][1] = zz[1];
                        totmat[2][2] = zz[2];
                        break;
                } /* switch (data->plane) */
                
                Mat4CpyMat4(tmat, cob->matrix);
                Mat4MulMat34(cob->matrix, totmat, tmat);
        }
}

static bConstraintTypeInfo CTI_STRETCHTO = {
        CONSTRAINT_TYPE_STRETCHTO, /* type */
        sizeof(bStretchToConstraint), /* size */
        "Stretch To", /* name */
        "bStretchToConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        stretchto_new_data, /* new data */
        stretchto_get_tars, /* get constraint targets */
        stretchto_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        stretchto_evaluate /* evaluate */
};

/* ---------- Floor ------------ */

static void minmax_new_data (void *cdata)
{
        bMinMaxConstraint *data= (bMinMaxConstraint *)cdata;
        
        data->minmaxflag = TRACK_Z;
        data->offset = 0.0f;
        data->cache[0] = data->cache[1] = data->cache[2] = 0.0f;
        data->flag = 0;
}

static int minmax_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bMinMaxConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints */
                SINGLETARGET_GET_TARS(con, data->tar, data->subtarget, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void minmax_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bMinMaxConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGET_FLUSH_TARS(con, data->tar, data->subtarget, ct, list, nocopy)
        }
}

static void minmax_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bMinMaxConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        /* only evaluate if there is a target */
        if (VALID_CONS_TARGET(ct)) {
                float obmat[4][4], imat[4][4], tarmat[4][4], tmat[4][4];
                float val1, val2;
                int index;
                
                Mat4CpyMat4(obmat, cob->matrix);
                Mat4CpyMat4(tarmat, ct->matrix);
                
                if (data->flag & MINMAX_USEROT) {
                        /* take rotation of target into account by doing the transaction in target's localspace */
                        Mat4Invert(imat, tarmat);
                        Mat4MulMat4(tmat, obmat, imat);
                        Mat4CpyMat4(obmat, tmat);
                        Mat4One(tarmat);
                }
                
                switch (data->minmaxflag) {
                case TRACK_Z:
                        val1 = tarmat[3][2];
                        val2 = obmat[3][2]-data->offset;
                        index = 2;
                        break;
                case TRACK_Y:
                        val1 = tarmat[3][1];
                        val2 = obmat[3][1]-data->offset;
                        index = 1;
                        break;
                case TRACK_X:
                        val1 = tarmat[3][0];
                        val2 = obmat[3][0]-data->offset;
                        index = 0;
                        break;
                case TRACK_nZ:
                        val2 = tarmat[3][2];
                        val1 = obmat[3][2]-data->offset;
                        index = 2;
                        break;
                case TRACK_nY:
                        val2 = tarmat[3][1];
                        val1 = obmat[3][1]-data->offset;
                        index = 1;
                        break;
                case TRACK_nX:
                        val2 = tarmat[3][0];
                        val1 = obmat[3][0]-data->offset;
                        index = 0;
                        break;
                default:
                        return;
                }
                
                if (val1 > val2) {
                        obmat[3][index] = tarmat[3][index] + data->offset;
                        if (data->flag & MINMAX_STICKY) {
                                if (data->flag & MINMAX_STUCK) {
                                        VECCOPY(obmat[3], data->cache);
                                } 
                                else {
                                        VECCOPY(data->cache, obmat[3]);
                                        data->flag |= MINMAX_STUCK;
                                }
                        }
                        if (data->flag & MINMAX_USEROT) {
                                /* get out of localspace */
                                Mat4MulMat4(tmat, obmat, ct->matrix);
                                Mat4CpyMat4(cob->matrix, tmat);
                        } 
                        else {                  
                                VECCOPY(cob->matrix[3], obmat[3]);
                        }
                } 
                else {
                        data->flag &= ~MINMAX_STUCK;
                }
        }
}

static bConstraintTypeInfo CTI_MINMAX = {
        CONSTRAINT_TYPE_MINMAX, /* type */
        sizeof(bMinMaxConstraint), /* size */
        "Floor", /* name */
        "bMinMaxConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        minmax_new_data, /* new data */
        minmax_get_tars, /* get constraint targets */
        minmax_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        minmax_evaluate /* evaluate */
};

/* ------- RigidBody Joint ---------- */

static void rbj_new_data (void *cdata)
{
        bRigidBodyJointConstraint *data= (bRigidBodyJointConstraint *)cdata;
        
        // removed code which set target of this constraint  
    data->type=1;
}

static int rbj_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bRigidBodyJointConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints without subtargets */
                SINGLETARGETNS_GET_TARS(con, data->tar, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void rbj_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bRigidBodyJointConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGETNS_FLUSH_TARS(con, data->tar, ct, list, nocopy)
        }
}

static bConstraintTypeInfo CTI_RIGIDBODYJOINT = {
        CONSTRAINT_TYPE_RIGIDBODYJOINT, /* type */
        sizeof(bRigidBodyJointConstraint), /* size */
        "RigidBody Joint", /* name */
        "bRigidBodyJointConstraint", /* struct name */
        NULL, /* free data */
        NULL, /* relink data */
        NULL, /* copy data */
        rbj_new_data, /* new data */
        rbj_get_tars, /* get constraint targets */
        rbj_flush_tars, /* flush constraint targets */
        default_get_tarmat, /* get target matrix */
        NULL /* evaluate - this is not solved here... is just an interface for game-engine */
};

/* -------- Clamp To ---------- */

static int clampto_get_tars (bConstraint *con, ListBase *list)
{
        if (con && list) {
                bClampToConstraint *data= con->data;
                bConstraintTarget *ct;
                
                /* standard target-getting macro for single-target constraints without subtargets */
                SINGLETARGETNS_GET_TARS(con, data->tar, ct, list)
                
                return 1;
        }
        
        return 0;
}

static void clampto_flush_tars (bConstraint *con, ListBase *list, short nocopy)
{
        if (con && list) {
                bClampToConstraint *data= con->data;
                bConstraintTarget *ct= list->first;
                
                /* the following macro is used for all standard single-target constraints */
                SINGLETARGETNS_FLUSH_TARS(con, data->tar, ct, list, nocopy)
        }
}

static void clampto_get_tarmat (bConstraint *con, bConstraintOb *cob, bConstraintTarget *ct, float ctime)
{
        if (VALID_CONS_TARGET(ct)) {
                Curve *cu= ct->tar->data;
                
                /* note: when creating constraints that follow path, the curve gets the CU_PATH set now,
                 *              currently for paths to work it needs to go through the bevlist/displist system (ton) 
                 */
                
                /* only happens on reload file, but violates depsgraph still... fix! */
                if (cu->path==NULL || cu->path->data==NULL) 
                        makeDispListCurveTypes(cob->scene, ct->tar, 0);
        }
        
        /* technically, this isn't really needed for evaluation, but we don't know what else
         * might end up calling this...
         */
        if (ct)
                Mat4One(ct->matrix);
}

static void clampto_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *targets)
{
        bClampToConstraint *data= con->data;
        bConstraintTarget *ct= targets->first;
        
        /* only evaluate if there is a target and it is a curve */
        if (VALID_CONS_TA