/*
 * $Id$
 *
 * ***** 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * Contributor(s): Full recode, Ton Roosendaal, Crete 2005
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/blenkernel/intern/armature.c
 *  \ingroup bke
 */


#include <ctype.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <stdio.h>
#include <float.h>

#include "MEM_guardedalloc.h"

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

#include "DNA_anim_types.h"
#include "DNA_armature_types.h"
#include "DNA_constraint_types.h"
#include "DNA_mesh_types.h"
#include "DNA_lattice_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_nla_types.h"
#include "DNA_scene_types.h"
#include "DNA_object_types.h"

#include "BKE_animsys.h"
#include "BKE_armature.h"
#include "BKE_action.h"
#include "BKE_anim.h"
#include "BKE_constraint.h"
#include "BKE_curve.h"
#include "BKE_depsgraph.h"
#include "BKE_DerivedMesh.h"
#include "BKE_deform.h"
#include "BKE_displist.h"
#include "BKE_global.h"
#include "BKE_idprop.h"
#include "BKE_library.h"
#include "BKE_lattice.h"
#include "BKE_main.h"
#include "BKE_object.h"

#include "BIK_api.h"
#include "BKE_sketch.h"

/*	**************** Generic Functions, data level *************** */

bArmature *add_armature(const char *name)
{
	bArmature *arm;
	
	arm= alloc_libblock (&G.main->armature, ID_AR, name);
	arm->deformflag = ARM_DEF_VGROUP|ARM_DEF_ENVELOPE;
	arm->flag = ARM_COL_CUSTOM; /* custom bone-group colors */
	arm->layer= 1;
	return arm;
}

bArmature *get_armature(Object *ob)
{
	if(ob->type==OB_ARMATURE)
		return (bArmature *)ob->data;
	return NULL;
}

void free_bonelist (ListBase *lb)
{
	Bone *bone;

	for(bone=lb->first; bone; bone=bone->next) {
		if(bone->prop) {
			IDP_FreeProperty(bone->prop);
			MEM_freeN(bone->prop);
		}
		free_bonelist(&bone->childbase);
	}
	
	BLI_freelistN(lb);
}

void free_armature(bArmature *arm)
{
	if (arm) {
		free_bonelist(&arm->bonebase);
		
		/* free editmode data */
		if (arm->edbo) {
			BLI_freelistN(arm->edbo);
			
			MEM_freeN(arm->edbo);
			arm->edbo= NULL;
		}

		/* free sketch */
		if (arm->sketch) {
			freeSketch(arm->sketch);
			arm->sketch = NULL;
		}
		
		/* free animation data */
		if (arm->adt) {
			BKE_free_animdata(&arm->id);
			arm->adt= NULL;
		}
	}
}

void make_local_armature(bArmature *arm)
{
	Main *bmain= G.main;
	int local=0, lib=0;
	Object *ob;

	if (arm->id.lib==NULL) return;
	if (arm->id.us==1) {
		arm->id.lib= NULL;
		arm->id.flag= LIB_LOCAL;
		new_id(&bmain->armature, (ID*)arm, NULL);
		return;
	}

	for(ob= bmain->object.first; ob && ELEM(0, lib, local); ob= ob->id.next) {
		if(ob->data == arm) {
			if(ob->id.lib) lib= 1;
			else local= 1;
		}
	}

	if(local && lib==0) {
		arm->id.lib= NULL;
		arm->id.flag= LIB_LOCAL;
		new_id(&bmain->armature, (ID *)arm, NULL);
	}
	else if(local && lib) {
		bArmature *armn= copy_armature(arm);
		armn->id.us= 0;
		
		for(ob= bmain->object.first; ob; ob= ob->id.next) {
			if(ob->data == arm) {
				if(ob->id.lib==NULL) {
					ob->data= armn;
					armn->id.us++;
					arm->id.us--;
				}
			}
		}
	}
}

static void	copy_bonechildren (Bone* newBone, Bone* oldBone, Bone* actBone, Bone **newActBone)
{
	Bone	*curBone, *newChildBone;
	
	if(oldBone == actBone)
		*newActBone= newBone;

	if(oldBone->prop)
		newBone->prop= IDP_CopyProperty(oldBone->prop);

	/*	Copy this bone's list*/
	BLI_duplicatelist(&newBone->childbase, &oldBone->childbase);
	
	/*	For each child in the list, update it's children*/
	newChildBone=newBone->childbase.first;
	for (curBone=oldBone->childbase.first;curBone;curBone=curBone->next){
		newChildBone->parent=newBone;
		copy_bonechildren(newChildBone, curBone, actBone, newActBone);
		newChildBone=newChildBone->next;
	}
}

bArmature *copy_armature(bArmature *arm)
{
	bArmature *newArm;
	Bone		*oldBone, *newBone;
	Bone		*newActBone= NULL;
	
	newArm= copy_libblock (arm);
	BLI_duplicatelist(&newArm->bonebase, &arm->bonebase);
	
	/*	Duplicate the childrens' lists*/
	newBone=newArm->bonebase.first;
	for (oldBone=arm->bonebase.first;oldBone;oldBone=oldBone->next){
		newBone->parent=NULL;
		copy_bonechildren (newBone, oldBone, arm->act_bone, &newActBone);
		newBone=newBone->next;
	};
	
	newArm->act_bone= newActBone;

	newArm->edbo= NULL;
	newArm->act_edbone= NULL;
	newArm->sketch= NULL;

	return newArm;
}

static Bone *get_named_bone_bonechildren (Bone *bone, const char *name)
{
	Bone *curBone, *rbone;
	
	if (!strcmp (bone->name, name))
		return bone;
	
	for (curBone=bone->childbase.first; curBone; curBone=curBone->next){
		rbone=get_named_bone_bonechildren (curBone, name);
		if (rbone)
			return rbone;
	}
	
	return NULL;
}


Bone *get_named_bone (bArmature *arm, const char *name)
/*
	Walk the list until the bone is found
 */
{
	Bone *bone=NULL, *curBone;
	
	if (!arm) return NULL;
	
	for (curBone=arm->bonebase.first; curBone; curBone=curBone->next){
		bone = get_named_bone_bonechildren (curBone, name);
		if (bone)
			return bone;
	}
	
	return bone;
}

/* Finds the best possible extension to the name on a particular axis. (For renaming, check for unique names afterwards)
 * 	strip_number: removes number extensions  (TODO: not used)
 *	axis: the axis to name on
 *	head/tail: the head/tail co-ordinate of the bone on the specified axis
 */
int bone_autoside_name (char name[MAXBONENAME], int UNUSED(strip_number), short axis, float head, float tail)
{
	unsigned int len;
	char	basename[MAXBONENAME]= "";
	char 	extension[5]= "";

	len= strlen(name);
	if (len == 0) return 0;
	BLI_strncpy(basename, name, sizeof(basename));
	
	/* Figure out extension to append: 
	 *	- The extension to append is based upon the axis that we are working on.
	 *	- If head happens to be on 0, then we must consider the tail position as well to decide
	 *	  which side the bone is on
	 *		-> If tail is 0, then it's bone is considered to be on axis, so no extension should be added
	 *		-> Otherwise, extension is added from perspective of object based on which side tail goes to
	 *	- If head is non-zero, extension is added from perspective of object based on side head is on
	 */
	if (axis == 2) {
		/* z-axis - vertical (top/bottom) */
		if (IS_EQ(head, 0)) {
			if (tail < 0)
				strcpy(extension, "Bot");
			else if (tail > 0)
				strcpy(extension, "Top");
		}
		else {
			if (head < 0)
				strcpy(extension, "Bot");
			else
				strcpy(extension, "Top");
		}
	}
	else if (axis == 1) {
		/* y-axis - depth (front/back) */
		if (IS_EQ(head, 0)) {
			if (tail < 0)
				strcpy(extension, "Fr");
			else if (tail > 0)
				strcpy(extension, "Bk");
		}
		else {
			if (head < 0)
				strcpy(extension, "Fr");
			else
				strcpy(extension, "Bk");
		}
	}
	else {
		/* x-axis - horizontal (left/right) */
		if (IS_EQ(head, 0)) {
			if (tail < 0)
				strcpy(extension, "R");
			else if (tail > 0)
				strcpy(extension, "L");
		}
		else {
			if (head < 0)
				strcpy(extension, "R");
			else if (head > 0)
				strcpy(extension, "L");
		}
	}

	/* Simple name truncation 
	 *	- truncate if there is an extension and it wouldn't be able to fit
	 *	- otherwise, just append to end
	 */
	if (extension[0]) {
		int change = 1;
		
		while (change) { /* remove extensions */
			change = 0;
			if (len > 2 && basename[len-2]=='.') {
				if (basename[len-1]=='L' || basename[len-1] == 'R' ) { /* L R */
					basename[len-2] = '\0';
					len-=2;
					change= 1;
				}
			} else if (len > 3 && basename[len-3]=='.') {
				if (	(basename[len-2]=='F' && basename[len-1] == 'r') ||	/* Fr */
						(basename[len-2]=='B' && basename[len-1] == 'k')	/* Bk */
				) {
					basename[len-3] = '\0';
					len-=3;
					change= 1;
				}
			} else if (len > 4 && basename[len-4]=='.') {
				if (	(basename[len-3]=='T' && basename[len-2]=='o' && basename[len-1] == 'p') ||	/* Top */
						(basename[len-3]=='B' && basename[len-2]=='o' && basename[len-1] == 't')	/* Bot */
				) {
					basename[len-4] = '\0';
					len-=4;
					change= 1;
				}
			}
		}

		if ((MAXBONENAME - len) < strlen(extension) + 1) { /* add 1 for the '.' */
			strncpy(name, basename, len-strlen(extension));
		}

		BLI_snprintf(name, MAXBONENAME, "%s.%s", basename, extension);

		return 1;
	}

	else {
		return 0;
	}
}

/* ************* B-Bone support ******************* */

#define MAX_BBONE_SUBDIV	32

/* data has MAX_BBONE_SUBDIV+1 interpolated points, will become desired amount with equal distances */
static void equalize_bezier(float *data, int desired)
{
	float *fp, totdist, ddist, dist, fac1, fac2;
	float pdist[MAX_BBONE_SUBDIV+1];
	float temp[MAX_BBONE_SUBDIV+1][4];
	int a, nr;
	
	pdist[0]= 0.0f;
	for(a=0, fp= data; a<MAX_BBONE_SUBDIV; a++, fp+=4) {
		QUATCOPY(temp[a], fp);
		pdist[a+1]= pdist[a]+len_v3v3(fp, fp+4);
	}
	/* do last point */
	QUATCOPY(temp[a], fp);
	totdist= pdist[a];
	
	/* go over distances and calculate new points */
	ddist= totdist/((float)desired);
	nr= 1;
	for(a=1, fp= data+4; a<desired; a++, fp+=4) {
		
		dist= ((float)a)*ddist;
		
		/* we're looking for location (distance) 'dist' in the array */
		while((dist>= pdist[nr]) && nr<MAX_BBONE_SUBDIV) {
			nr++;
		}
		
		fac1= pdist[nr]- pdist[nr-1];
		fac2= pdist[nr]-dist;
		fac1= fac2/fac1;
		fac2= 1.0f-fac1;
		
		fp[0]= fac1*temp[nr-1][0]+ fac2*temp[nr][0];
		fp[1]= fac1*temp[nr-1][1]+ fac2*temp[nr][1];
		fp[2]= fac1*temp[nr-1][2]+ fac2*temp[nr][2];
		fp[3]= fac1*temp[nr-1][3]+ fac2*temp[nr][3];
	}
	/* set last point, needed for orientation calculus */
	QUATCOPY(fp, temp[MAX_BBONE_SUBDIV]);
}

/* returns pointer to static array, filled with desired amount of bone->segments elements */
/* this calculation is done  within unit bone space */
Mat4 *b_bone_spline_setup(bPoseChannel *pchan, int rest)
{
	static Mat4 bbone_array[MAX_BBONE_SUBDIV];
	static Mat4 bbone_rest_array[MAX_BBONE_SUBDIV];
	Mat4 *result_array= (rest)? bbone_rest_array: bbone_array;
	bPoseChannel *next, *prev;
	Bone *bone= pchan->bone;
	float h1[3], h2[3], scale[3], length, hlength1, hlength2, roll1=0.0f, roll2;
	float mat3[3][3], imat[4][4], posemat[4][4], scalemat[4][4], iscalemat[4][4];
	float data[MAX_BBONE_SUBDIV+1][4], *fp;
	int a, doscale= 0;

	length= bone->length;

	if(!rest) {
		/* check if we need to take non-uniform bone scaling into account */
		scale[0]= len_v3(pchan->pose_mat[0]);
		scale[1]= len_v3(pchan->pose_mat[1]);
		scale[2]= len_v3(pchan->pose_mat[2]);

		if(fabsf(scale[0] - scale[1]) > 1e-6f || fabsf(scale[1] - scale[2]) > 1e-6f) {
			unit_m4(scalemat);
			scalemat[0][0]= scale[0];
			scalemat[1][1]= scale[1];
			scalemat[2][2]= scale[2];
			invert_m4_m4(iscalemat, scalemat);

			length *= scale[1];
			doscale = 1;
		}
	}
	
	hlength1= bone->ease1*length*0.390464f;		// 0.5*sqrt(2)*kappa, the handle length for near-perfect circles
	hlength2= bone->ease2*length*0.390464f;
	
	/* evaluate next and prev bones */
	if(bone->flag & BONE_CONNECTED)
		prev= pchan->parent;
	else
		prev= NULL;
	
	next= pchan->child;
	
	/* find the handle points, since this is inside bone space, the 
		first point = (0,0,0)
		last point =  (0, length, 0) */
	
	if(rest) {
		invert_m4_m4(imat, pchan->bone->arm_mat);
	}
	else if(doscale) {
		copy_m4_m4(posemat, pchan->pose_mat);
		normalize_m4(posemat);
		invert_m4_m4(imat, posemat);
	}
	else
		invert_m4_m4(imat, pchan->pose_mat);
	
	if(prev) {
		float difmat[4][4], result[3][3], imat3[3][3];

		/* transform previous point inside this bone space */
		if(rest)
			VECCOPY(h1, prev->bone->arm_head)
		else
			VECCOPY(h1, prev->pose_head)
		mul_m4_v3(imat, h1);

		if(prev->bone->segments>1) {
			/* if previous bone is B-bone too, use average handle direction */
			h1[1]-= length;
			roll1= 0.0f;
		}

		normalize_v3(h1);
		mul_v3_fl(h1, -hlength1);

		if(prev->bone->segments==1) {
			/* find the previous roll to interpolate */
			if(rest)
				mul_m4_m4m4(difmat, prev->bone->arm_mat, imat);
			else
				mul_m4_m4m4(difmat, prev->pose_mat, imat);
			copy_m3_m4(result, difmat);				// the desired rotation at beginning of next bone
			
			vec_roll_to_mat3(h1, 0.0f, mat3);			// the result of vec_roll without roll
			
			invert_m3_m3(imat3, mat3);
			mul_m3_m3m3(mat3, result, imat3);			// the matrix transforming vec_roll to desired roll
			
			roll1= (float)atan2(mat3[2][0], mat3[2][2]);
		}
	}
	else {
		h1[0]= 0.0f; h1[1]= hlength1; h1[2]= 0.0f;
		roll1= 0.0f;
	}
	if(next) {
		float difmat[4][4], result[3][3], imat3[3][3];
		
		/* transform next point inside this bone space */
		if(rest)
			VECCOPY(h2, next->bone->arm_tail)
		else
			VECCOPY(h2, next->pose_tail)
		mul_m4_v3(imat, h2);
		/* if next bone is B-bone too, use average handle direction */
		if(next->bone->segments>1);
		else h2[1]-= length;
		normalize_v3(h2);
		
		/* find the next roll to interpolate as well */
		if(rest)
			mul_m4_m4m4(difmat, next->bone->arm_mat, imat);
		else
			mul_m4_m4m4(difmat, next->pose_mat, imat);
		copy_m3_m4(result, difmat);				// the desired rotation at beginning of next bone
		
		vec_roll_to_mat3(h2, 0.0f, mat3);			// the result of vec_roll without roll
		
		invert_m3_m3(imat3, mat3);
		mul_m3_m3m3(mat3, imat3, result);			// the matrix transforming vec_roll to desired roll
		
		roll2= (float)atan2(mat3[2][0], mat3[2][2]);
		
		/* and only now negate handle */
		mul_v3_fl(h2, -hlength2);
	}
	else {
		h2[0]= 0.0f; h2[1]= -hlength2; h2[2]= 0.0f;
		roll2= 0.0;
	}

	/* make curve */
	if(bone->segments > MAX_BBONE_SUBDIV)
		bone->segments= MAX_BBONE_SUBDIV;
	
	forward_diff_bezier(0.0, h1[0],		h2[0],			0.0,		data[0],	MAX_BBONE_SUBDIV, 4*sizeof(float));
	forward_diff_bezier(0.0, h1[1],		length + h2[1],	length,		data[0]+1,	MAX_BBONE_SUBDIV, 4*sizeof(float));
	forward_diff_bezier(0.0, h1[2],		h2[2],			0.0,		data[0]+2,	MAX_BBONE_SUBDIV, 4*sizeof(float));
	forward_diff_bezier(roll1, roll1 + 0.390464f*(roll2-roll1), roll2 - 0.390464f*(roll2-roll1),	roll2,	data[0]+3,	MAX_BBONE_SUBDIV, 4*sizeof(float));
	
	equalize_bezier(data[0], bone->segments);	// note: does stride 4!
	
	/* make transformation matrices for the segments for drawing */
	for(a=0, fp= data[0]; a<bone->segments; a++, fp+=4) {
		sub_v3_v3v3(h1, fp+4, fp);
		vec_roll_to_mat3(h1, fp[3], mat3);		// fp[3] is roll

		copy_m4_m3(result_array[a].mat, mat3);
		VECCOPY(result_array[a].mat[3], fp);

		if(doscale) {
			/* correct for scaling when this matrix is used in scaled space */
			mul_serie_m4(result_array[a].mat, iscalemat, result_array[a].mat,
				scalemat, NULL, NULL, NULL, NULL, NULL);
		}
	}
	
	return result_array;
}

/* ************ Armature Deform ******************* */

typedef struct bPoseChanDeform {
	Mat4		*b_bone_mats;	
	DualQuat	*dual_quat;
	DualQuat	*b_bone_dual_quats;
} bPoseChanDeform;

static void pchan_b_bone_defmats(bPoseChannel *pchan, bPoseChanDeform *pdef_info, int use_quaternion)
{
	Bone *bone= pchan->bone;
	Mat4 *b_bone= b_bone_spline_setup(pchan, 0);
	Mat4 *b_bone_rest= b_bone_spline_setup(pchan, 1);
	Mat4 *b_bone_mats;
	DualQuat *b_bone_dual_quats= NULL;
	float tmat[4][4]= MAT4_UNITY;
	int a;
	
	/* allocate b_bone matrices and dual quats */
	b_bone_mats= MEM_mallocN((1+bone->segments)*sizeof(Mat4), "BBone defmats");
	pdef_info->b_bone_mats= b_bone_mats;

	if(use_quaternion) {
		b_bone_dual_quats= MEM_mallocN((bone->segments)*sizeof(DualQuat), "BBone dqs");
		pdef_info->b_bone_dual_quats= b_bone_dual_quats;
	}
	
	/* first matrix is the inverse arm_mat, to bring points in local bone space
	   for finding out which segment it belongs to */
	invert_m4_m4(b_bone_mats[0].mat, bone->arm_mat);

	/* then we make the b_bone_mats:
		- first transform to local bone space
		- translate over the curve to the bbone mat space
		- transform with b_bone matrix
		- transform back into global space */

	for(a=0; a<bone->segments; a++) {
		invert_m4_m4(tmat, b_bone_rest[a].mat);

		mul_serie_m4(b_bone_mats[a+1].mat, pchan->chan_mat, bone->arm_mat,
			b_bone[a].mat, tmat, b_bone_mats[0].mat, NULL, NULL, NULL);

		if(use_quaternion)
			mat4_to_dquat( &b_bone_dual_quats[a],bone->arm_mat, b_bone_mats[a+1].mat);
	}
}

static void b_bone_deform(bPoseChanDeform *pdef_info, Bone *bone, float *co, DualQuat *dq, float defmat[][3])
{
	Mat4 *b_bone= pdef_info->b_bone_mats;
	float (*mat)[4]= b_bone[0].mat;
	float segment, y;
	int a;
	
	/* need to transform co back to bonespace, only need y */
	y= mat[0][1]*co[0] + mat[1][1]*co[1] + mat[2][1]*co[2] + mat[3][1];
	
	/* now calculate which of the b_bones are deforming this */
	segment= bone->length/((float)bone->segments);
	a= (int)(y/segment);
	
	/* note; by clamping it extends deform at endpoints, goes best with
	   straight joints in restpos. */
	CLAMP(a, 0, bone->segments-1);

	if(dq) {
		copy_dq_dq(dq, &(pdef_info->b_bone_dual_quats)[a]);
	}
	else {
		mul_m4_v3(b_bone[a+1].mat, co);

		if(defmat)
			copy_m3_m4(defmat, b_bone[a+1].mat);
	}
}

/* using vec with dist to bone b1 - b2 */
float distfactor_to_bone (float vec[3], float b1[3], float b2[3], float rad1, float rad2, float rdist)
{
	float dist=0.0f; 
	float bdelta[3];
	float pdelta[3];
	float hsqr, a, l, rad;
	
	sub_v3_v3v3(bdelta, b2, b1);
	l = normalize_v3(bdelta);
	
	sub_v3_v3v3(pdelta, vec, b1);
	
	a = bdelta[0]*pdelta[0] + bdelta[1]*pdelta[1] + bdelta[2]*pdelta[2];
	hsqr = ((pdelta[0]*pdelta[0]) + (pdelta[1]*pdelta[1]) + (pdelta[2]*pdelta[2]));
	
	if (a < 0.0F){
		/* If we're past the end of the bone, do a spherical field attenuation thing */
		dist= ((b1[0]-vec[0])*(b1[0]-vec[0]) +(b1[1]-vec[1])*(b1[1]-vec[1]) +(b1[2]-vec[2])*(b1[2]-vec[2])) ;
		rad= rad1;
	}
	else if (a > l){
		/* If we're past the end of the bone, do a spherical field attenuation thing */
		dist= ((b2[0]-vec[0])*(b2[0]-vec[0]) +(b2[1]-vec[1])*(b2[1]-vec[1]) +(b2[2]-vec[2])*(b2[2]-vec[2])) ;
		rad= rad2;
	}
	else {
		dist= (hsqr - (a*a));
		
		if(l!=0.0f) {
			rad= a/l;
			rad= rad*rad2 + (1.0f-rad)*rad1;
		}
		else rad= rad1;
	}
	
	a= rad*rad;
	if(dist < a) 
		return 1.0f;
	else {
		l= rad+rdist;
		l*= l;
		if(rdist==0.0f || dist >= l) 
			return 0.0f;
		else {
			a= (float)sqrt(dist)-rad;
			return 1.0f-( a*a )/( rdist*rdist );
		}
	}
}

static void pchan_deform_mat_add(bPoseChannel *pchan, float weight, float bbonemat[][3], float mat[][3])
{
	float wmat[3][3];

	if(pchan->bone->segments>1)
		copy_m3_m3(wmat, bbonemat);
	else
		copy_m3_m4(wmat, pchan->chan_mat);

	mul_m3_fl(wmat, weight);
	add_m3_m3m3(mat, mat, wmat);
}

static float dist_bone_deform(bPoseChannel *pchan, bPoseChanDeform *pdef_info, float *vec, DualQuat *dq, float mat[][3], float *co)
{
	Bone *bone= pchan->bone;
	float fac, contrib=0.0;
	float cop[3], bbonemat[3][3];
	DualQuat bbonedq;

	if(bone==NULL) return 0.0f;
	
	VECCOPY (cop, co);

	fac= distfactor_to_bone(cop, bone->arm_head, bone->arm_tail, bone->rad_head, bone->rad_tail, bone->dist);
	
	if (fac > 0.0f) {
		
		fac*=bone->weight;
		contrib= fac;
		if(contrib > 0.0f) {
			if(vec) {
				if(bone->segments>1)
					// applies on cop and bbonemat
					b_bone_deform(pdef_info, bone, cop, NULL, (mat)?bbonemat:NULL);
				else
					mul_m4_v3(pchan->chan_mat, cop);

				//	Make this a delta from the base position
				sub_v3_v3(cop, co);
				madd_v3_v3fl(vec, cop, fac);

				if(mat)
					pchan_deform_mat_add(pchan, fac, bbonemat, mat);
			}
			else {
				if(bone->segments>1) {
					b_bone_deform(pdef_info, bone, cop, &bbonedq, NULL);
					add_weighted_dq_dq(dq, &bbonedq, fac);
				}
				else
					add_weighted_dq_dq(dq, pdef_info->dual_quat, fac);
			}
		}
	}
	
	return contrib;
}

static void pchan_bone_deform(bPoseChannel *pchan, bPoseChanDeform *pdef_info, float weight, float *vec, DualQuat *dq, float mat[][3], float *co, float *contrib)
{
	float cop[3], bbonemat[3][3];
	DualQuat bbonedq;

	if (!weight)
		return;

	VECCOPY(cop, co);

	if(vec) {
		if(pchan->bone->segments>1)
			// applies on cop and bbonemat
			b_bone_deform(pdef_info, pchan->bone, cop, NULL, (mat)?bbonemat:NULL);
		else
			mul_m4_v3(pchan->chan_mat, cop);
		
		vec[0]+=(cop[0]-co[0])*weight;
		vec[1]+=(cop[1]-co[1])*weight;
		vec[2]+=(cop[2]-co[2])*weight;

		if(mat)
			pchan_deform_mat_add(pchan, weight, bbonemat, mat);
	}
	else {
		if(pchan->bone->segments>1) {
			b_bone_deform(pdef_info, pchan->bone, cop, &bbonedq, NULL);
			add_weighted_dq_dq(dq, &bbonedq, weight);
		}
		else
			add_weighted_dq_dq(dq, pdef_info->dual_quat, weight);
	}

	(*contrib)+=weight;
}

void armature_deform_verts(Object *armOb, Object *target, DerivedMesh *dm,
						   float (*vertexCos)[3], float (*defMats)[3][3],
						   int numVerts, int deformflag, 
						   float (*prevCos)[3], const char *defgrp_name)
{
	bPoseChanDeform *pdef_info_array;
	bPoseChanDeform *pdef_info= NULL;
	bArmature *arm= armOb->data;
	bPoseChannel *pchan, **defnrToPC = NULL;
	int *defnrToPCIndex= NULL;
	MDeformVert *dverts = NULL;
	bDeformGroup *dg;
	DualQuat *dualquats= NULL;
	float obinv[4][4], premat[4][4], postmat[4][4];
	const short use_envelope = deformflag & ARM_DEF_ENVELOPE;
	const short use_quaternion = deformflag & ARM_DEF_QUATERNION;
	const short invert_vgroup= deformflag & ARM_DEF_INVERT_VGROUP;
	int numGroups = 0;		/* safety for vertexgroup index overflow */
	int i, target_totvert = 0;	/* safety for vertexgroup overflow */
	int use_dverts = 0;
	int armature_def_nr;
	int totchan;

	if(arm->edbo) return;
	
	invert_m4_m4(obinv, target->obmat);
	copy_m4_m4(premat, target->obmat);
	mul_m4_m4m4(postmat, armOb->obmat, obinv);
	invert_m4_m4(premat, postmat);

	/* bone defmats are already in the channels, chan_mat */
	
	/* initialize B_bone matrices and dual quaternions */
	totchan= BLI_countlist(&armOb->pose->chanbase);

	if(use_quaternion) {
		dualquats= MEM_callocN(sizeof(DualQuat)*totchan, "dualquats");
	}
	
	pdef_info_array= MEM_callocN(sizeof(bPoseChanDeform)*totchan, "bPoseChanDeform");

	totchan= 0;
	pdef_info= pdef_info_array;
	for(pchan= armOb->pose->chanbase.first; pchan; pchan= pchan->next, pdef_info++) {
		if(!(pchan->bone->flag & BONE_NO_DEFORM)) {
			if(pchan->bone->segments > 1)
				pchan_b_bone_defmats(pchan, pdef_info, use_quaternion);

			if(use_quaternion) {
				pdef_info->dual_quat= &dualquats[totchan++];
				mat4_to_dquat( pdef_info->dual_quat,pchan->bone->arm_mat, pchan->chan_mat);
			}
		}
	}

	/* get the def_nr for the overall armature vertex group if present */
	armature_def_nr= defgroup_name_index(target, defgrp_name);
	
	if(ELEM(target->type, OB_MESH, OB_LATTICE)) {
		numGroups = BLI_countlist(&target->defbase);
		
		if(target->type==OB_MESH) {
			Mesh *me= target->data;
			dverts = me->dvert;
			if(dverts)
				target_totvert = me->totvert;
		}
		else {
			Lattice *lt= target->data;
			dverts = lt->dvert;
			if(dverts)
				target_totvert = lt->pntsu*lt->pntsv*lt->pntsw;
		}
	}
	
	/* get a vertex-deform-index to posechannel array */
	if(deformflag & ARM_DEF_VGROUP) {
		if(ELEM(target->type, OB_MESH, OB_LATTICE)) {
			/* if we have a DerivedMesh, only use dverts if it has them */
			if(dm)
				if(dm->getVertData(dm, 0, CD_MDEFORMVERT))
					use_dverts = 1;
				else use_dverts = 0;
			else if(dverts) use_dverts = 1;

			if(use_dverts) {
				defnrToPC = MEM_callocN(sizeof(*defnrToPC) * numGroups, "defnrToBone");
				defnrToPCIndex = MEM_callocN(sizeof(*defnrToPCIndex) * numGroups, "defnrToIndex");
				for(i = 0, dg = target->defbase.first; dg;
					i++, dg = dg->next) {
					defnrToPC[i] = get_pose_channel(armOb->pose, dg->name);
					/* exclude non-deforming bones */
					if(defnrToPC[i]) {
						if(defnrToPC[i]->bone->flag & BONE_NO_DEFORM) {
							defnrToPC[i]= NULL;
						}
						else {
							defnrToPCIndex[i]= BLI_findindex(&armOb->pose->chanbase, defnrToPC[i]);
						}
					}
				}
			}
		}
	}

	for(i = 0; i < numVerts; i++) {
		MDeformVert *dvert;
		DualQuat sumdq, *dq = NULL;
		float *co, dco[3];
		float sumvec[3], summat[3][3];
		float *vec = NULL, (*smat)[3] = NULL;
		float contrib = 0.0f;
		float armature_weight = 1.0f;	/* default to 1 if no overall def group */
		float prevco_weight = 1.0f;		/* weight for optional cached vertexcos */
		int	  j;

		if(use_quaternion) {
			memset(&sumdq, 0, sizeof(DualQuat));
			dq= &sumdq;
		}
		else {
			sumvec[0] = sumvec[1] = sumvec[2] = 0.0f;
			vec= sumvec;

			if(defMats) {
				zero_m3(summat);
				smat = summat;
			}
		}

		if(use_dverts || armature_def_nr >= 0) {
			if(dm) dvert = dm->getVertData(dm, i, CD_MDEFORMVERT);
			else if(dverts && i < target_totvert) dvert = dverts + i;
			else dvert = NULL;
		} else
			dvert = NULL;

		if(armature_def_nr >= 0 && dvert) {
			armature_weight= defvert_find_weight(dvert, armature_def_nr);

			if(invert_vgroup) {
				armature_weight= 1.0f-armature_weight;
			}

			/* hackish: the blending factor can be used for blending with prevCos too */
			if(prevCos) {
				prevco_weight= armature_weight;
				armature_weight= 1.0f;
			}
		}

		/* check if there's any  point in calculating for this vert */
		if(armature_weight == 0.0f) continue;
		
		/* get the coord we work on */
		co= prevCos?prevCos[i]:vertexCos[i];
		
		/* Apply the object's matrix */
		mul_m4_v3(premat, co);
		
		if(use_dverts && dvert && dvert->totweight) { // use weight groups ?
			int deformed = 0;
			
			for(j = 0; j < dvert->totweight; j++){
				int index = dvert->dw[j].def_nr;
				if(index < numGroups && (pchan= defnrToPC[index])) {
					float weight = dvert->dw[j].weight;
					Bone *bone= pchan->bone;
					pdef_info= pdef_info_array + defnrToPCIndex[index];

					deformed = 1;
					
					if(bone && bone->flag & BONE_MULT_VG_ENV) {
						weight *= distfactor_to_bone(co, bone->arm_head,
													 bone->arm_tail,
													 bone->rad_head,
													 bone->rad_tail,
													 bone->dist);
					}
					pchan_bone_deform(pchan, pdef_info, weight, vec, dq, smat, co, &contrib);
				}
			}
			/* if there are vertexgroups but not groups with bones
			 * (like for softbody groups)
			 */
			if(deformed == 0 && use_envelope) {
				pdef_info= pdef_info_array;
				for(pchan= armOb->pose->chanbase.first; pchan;
					pchan= pchan->next, pdef_info++) {
					if(!(pchan->bone->flag & BONE_NO_DEFORM))
						contrib += dist_bone_deform(pchan, pdef_info, vec, dq, smat, co);
				}
			}
		}
		else if(use_envelope) {
			pdef_info= pdef_info_array;
			for(pchan = armOb->pose->chanbase.first; pchan;
				pchan = pchan->next, pdef_info++) {
				if(!(pchan->bone->flag & BONE_NO_DEFORM))
					contrib += dist_bone_deform(pchan, pdef_info, vec, dq, smat, co);
			}
		}

		/* actually should be EPSILON? weight values and contrib can be like 10e-39 small */
		if(contrib > 0.0001f) {
			if(use_quaternion) {
				normalize_dq(dq, contrib);

				if(armature_weight != 1.0f) {
					VECCOPY(dco, co);
					mul_v3m3_dq( dco, (defMats)? summat: NULL,dq);
					sub_v3_v3(dco, co);
					mul_v3_fl(dco, armature_weight);
					add_v3_v3(co, dco);
				}
				else
					mul_v3m3_dq( co, (defMats)? summat: NULL,dq);

				smat = summat;
			}
			else {
				mul_v3_fl(vec, armature_weight/contrib);
				add_v3_v3v3(co, vec, co);
			}

			if(defMats) {
				float pre[3][3], post[3][3], tmpmat[3][3];

				copy_m3_m4(pre, premat);
				copy_m3_m4(post, postmat);
				copy_m3_m3(tmpmat, defMats[i]);

				if(!use_quaternion) /* quaternion already is scale corrected */
					mul_m3_fl(smat, armature_weight/contrib);

				mul_serie_m3(defMats[i], tmpmat, pre, smat, post,
					NULL, NULL, NULL, NULL);
			}
		}
		
		/* always, check above code */
		mul_m4_v3(postmat, co);
		
		
		/* interpolate with previous modifier position using weight group */
		if(prevCos) {
			float mw= 1.0f - prevco_weight;
			vertexCos[i][0]= prevco_weight*vertexCos[i][0] + mw*co[0];
			vertexCos[i][1]= prevco_weight*vertexCos[i][1] + mw*co[1];
			vertexCos[i][2]= prevco_weight*vertexCos[i][2] + mw*co[2];
		}
	}

	if(dualquats) MEM_freeN(dualquats);
	if(defnrToPC) MEM_freeN(defnrToPC);
	if(defnrToPCIndex) MEM_freeN(defnrToPCIndex);

	/* free B_bone matrices */
	pdef_info= pdef_info_array;
	for(pchan = armOb->pose->chanbase.first; pchan; pchan = pchan->next, pdef_info++) {
		if(pdef_info->b_bone_mats) {
			MEM_freeN(pdef_info->b_bone_mats);
		}
		if(pdef_info->b_bone_dual_quats) {
			MEM_freeN(pdef_info->b_bone_dual_quats);
		}
	}

	MEM_freeN(pdef_info_array);
}

/* ************ END Armature Deform ******************* */

void get_objectspace_bone_matrix (struct Bone* bone, float M_accumulatedMatrix[][4], int UNUSED(root), int UNUSED(posed))
{
	copy_m4_m4(M_accumulatedMatrix, bone->arm_mat);
}

/* **************** Space to Space API ****************** */

/* Convert World-Space Matrix to Pose-Space Matrix */
void armature_mat_world_to_pose(Object *ob, float inmat[][4], float outmat[][4]) 
{
	float obmat[4][4];
	
	/* prevent crashes */
	if (ob==NULL) return;
	
	/* get inverse of (armature) object's matrix  */
	invert_m4_m4(obmat, ob->obmat);
	
	/* multiply given matrix by object's-inverse to find pose-space matrix */
	mul_m4_m4m4(outmat, obmat, inmat);
}

/* Convert Wolrd-Space Location to Pose-Space Location
 * NOTE: this cannot be used to convert to pose-space location of the supplied
 * 		pose-channel into its local space (i.e. 'visual'-keyframing) 
 */
void armature_loc_world_to_pose(Object *ob, float *inloc, float *outloc) 
{
	float xLocMat[4][4]= MAT4_UNITY;
	float nLocMat[4][4];
	
	/* build matrix for location */
	VECCOPY(xLocMat[3], inloc);

	/* get bone-space cursor matrix and extract location */
	armature_mat_world_to_pose(ob, xLocMat, nLocMat);
	VECCOPY(outloc, nLocMat[3]);
}

/* Convert Pose-Space Matrix to Bone-Space Matrix 
 * NOTE: this cannot be used to convert to pose-space transforms of the supplied
 * 		pose-channel into its local space (i.e. 'visual'-keyframing)
 */
void armature_mat_pose_to_bone(bPoseChannel *pchan, float inmat[][4], float outmat[][4])
{
	float pc_trans[4][4], inv_trans[4][4];
	float pc_posemat[4][4], inv_posemat[4][4];
	float pose_mat[4][4];

	/* paranoia: prevent crashes with no pose-channel supplied */
	if (pchan==NULL) return;

	/* default flag */
	if((pchan->bone->flag & BONE_NO_LOCAL_LOCATION)==0) {
		/* get the inverse matrix of the pchan's transforms */
		switch(pchan->rotmode) {
		case ROT_MODE_QUAT:
			loc_quat_size_to_mat4(pc_trans, pchan->loc, pchan->quat, pchan->size);
			break;
		case ROT_MODE_AXISANGLE:
			loc_axisangle_size_to_mat4(pc_trans, pchan->loc, pchan->rotAxis, pchan->rotAngle, pchan->size);
			break;
		default: /* euler */
			loc_eul_size_to_mat4(pc_trans, pchan->loc, pchan->eul, pchan->size);
		}

		copy_m4_m4(pose_mat, pchan->pose_mat);
	}
	else {
		/* local location, this is not default, different calculation
		 * note: only tested for location with pose bone snapping.
		 * If this is not useful in other cases the BONE_NO_LOCAL_LOCATION
		 * case may have to be split into its own function. */
		unit_m4(pc_trans);
		copy_v3_v3(pc_trans[3], pchan->loc);

		/* use parents rotation/scale space + own absolute position */
		if(pchan->parent)	copy_m4_m4(pose_mat, pchan->parent->pose_mat);
		else				unit_m4(pose_mat);

		copy_v3_v3(pose_mat[3], pchan->pose_mat[3]);
	}


	invert_m4_m4(inv_trans, pc_trans);
	
	/* Remove the pchan's transforms from it's pose_mat.
	 * This should leave behind the effects of restpose + 
	 * parenting + constraints
	 */
	mul_m4_m4m4(pc_posemat, inv_trans, pose_mat);
	
	/* get the inverse of the leftovers so that we can remove 
	 * that component from the supplied matrix
	 */
	invert_m4_m4(inv_posemat, pc_posemat);
	
	/* get the new matrix */
	mul_m4_m4m4(outmat, inmat, inv_posemat);
}

/* Convert Pose-Space Location to Bone-Space Location
 * NOTE: this cannot be used to convert to pose-space location of the supplied
 * 		pose-channel into its local space (i.e. 'visual'-keyframing) 
 */
void armature_loc_pose_to_bone(bPoseChannel *pchan, float *inloc, float *outloc) 
{
	float xLocMat[4][4]= MAT4_UNITY;
	float nLocMat[4][4];
	
	/* build matrix for location */
	VECCOPY(xLocMat[3], inloc);

	/* get bone-space cursor matrix and extract location */
	armature_mat_pose_to_bone(pchan, xLocMat, nLocMat);
	VECCOPY(outloc, nLocMat[3]);
}

/* same as object_mat3_to_rot() */
void pchan_mat3_to_rot(bPoseChannel *pchan, float mat[][3], short use_compat)
{
	switch(pchan->rotmode) {
	case ROT_MODE_QUAT:
		mat3_to_quat(pchan->quat, mat);
		break;
	case ROT_MODE_AXISANGLE:
		mat3_to_axis_angle(pchan->rotAxis, &pchan->rotAngle, mat);
		break;
	default: /* euler */
		if(use_compat)	mat3_to_compatible_eulO(pchan->eul, pchan->eul, pchan->rotmode, mat);
		else			mat3_to_eulO(pchan->eul, pchan->rotmode, mat);
	}
}

/* Apply a 4x4 matrix to the pose bone,
 * similar to object_apply_mat4()
 */
void pchan_apply_mat4(bPoseChannel *pchan, float mat[][4], short use_compat)
{
	float rot[3][3];
	mat4_to_loc_rot_size(pchan->loc, rot, pchan->size, mat);
	pchan_mat3_to_rot(pchan, rot, use_compat);
}

/* Remove rest-position effects from pose-transform for obtaining
 * 'visual' transformation of pose-channel.
 * (used by the Visual-Keyframing stuff)
 */
void armature_mat_pose_to_delta(float delta_mat[][4], float pose_mat[][4], float arm_mat[][4])
{
	float imat[4][4];
	
	invert_m4_m4(imat, arm_mat);
	mul_m4_m4m4(delta_mat, pose_mat, imat);
}

/* **************** Rotation Mode Conversions ****************************** */
/* Used for Objects and Pose Channels, since both can have multiple rotation representations */

/* Called from RNA when rotation mode changes 
 *	- the result should be that the rotations given in the provided pointers have had conversions 
 *	  applied (as appropriate), such that the rotation of the element hasn't 'visually' changed 
 */
void BKE_rotMode_change_values (float quat[4], float eul[3], float axis[3], float *angle, short oldMode, short newMode)
{
	/* check if any change - if so, need to convert data */
	if (newMode > 0) { /* to euler */
		if (oldMode == ROT_MODE_AXISANGLE) {
			/* axis-angle to euler */
			axis_angle_to_eulO( eul, newMode,axis, *angle);
		}
		else if (oldMode == ROT_MODE_QUAT) {
			/* quat to euler */
			normalize_qt(quat);
			quat_to_eulO( eul, newMode,quat);
		}
		/* else { no conversion needed } */
	}
	else if (newMode == ROT_MODE_QUAT) { /* to quat */
		if (oldMode == ROT_MODE_AXISANGLE) {
			/* axis angle to quat */
			axis_angle_to_quat(quat, axis, *angle);
		}
		else if (oldMode > 0) {
			/* euler to quat */
			eulO_to_quat( quat,eul, oldMode);
		}
		/* else { no conversion needed } */
	}
	else if (newMode == ROT_MODE_AXISANGLE) { /* to axis-angle */
		if (oldMode > 0) {
			/* euler to axis angle */
			eulO_to_axis_angle( axis, angle,eul, oldMode);
		}
		else if (oldMode == ROT_MODE_QUAT) {
			/* quat to axis angle */
			normalize_qt(quat);
			quat_to_axis_angle( axis, angle,quat);
		}
		
		/* when converting to axis-angle, we need a special exception for the case when there is no axis */
		if (IS_EQF(axis[0], axis[1]) && IS_EQF(axis[1], axis[2])) {
			/* for now, rotate around y-axis then (so that it simply becomes the roll) */
			axis[1]= 1.0f;
		}
	}
}

/* **************** The new & simple (but OK!) armature evaluation ********* */ 

/*  ****************** And how it works! ****************************************

  This is the bone transformation trick; they're hierarchical so each bone(b)
  is in the coord system of bone(b-1):

  arm_mat(b)= arm_mat(b-1) * yoffs(b-1) * d_root(b) * bone_mat(b) 
  
  -> yoffs is just the y axis translation in parent's coord system
  -> d_root is the translation of the bone root, also in parent's coord system

  pose_mat(b)= pose_mat(b-1) * yoffs(b-1) * d_root(b) * bone_mat(b) * chan_mat(b)

  we then - in init deform - store the deform in chan_mat, such that:

  pose_mat(b)= arm_mat(b) * chan_mat(b)
  
  *************************************************************************** */
/*  Computes vector and roll based on a rotation. "mat" must
	 contain only a rotation, and no scaling. */ 
void mat3_to_vec_roll(float mat[][3], float *vec, float *roll) 
{
	if (vec)
		copy_v3_v3(vec, mat[1]);

	if (roll) {
		float vecmat[3][3], vecmatinv[3][3], rollmat[3][3];

		vec_roll_to_mat3(mat[1], 0.0f, vecmat);
		invert_m3_m3(vecmatinv, vecmat);
		mul_m3_m3m3(rollmat, vecmatinv, mat);

		*roll= (float)atan2(rollmat[2][0], rollmat[2][2]);
	}
}

/*	Calculates the rest matrix of a bone based
	On its vector and a roll around that vector */
void vec_roll_to_mat3(float *vec, float roll, float mat[][3])
{
	float	nor[3], axis[3], target[3]={0,1,0};
	float	theta;
	float	rMatrix[3][3], bMatrix[3][3];

	normalize_v3_v3(nor, vec);
	
	/*	Find Axis & Amount for bone matrix*/
	cross_v3_v3v3(axis,target,nor);

	/* was 0.0000000000001, caused bug [#23954], smaller values give unstable
	 * roll when toggling editmode */
	if (dot_v3v3(axis,axis) > 0.00001f) {
		/* if nor is *not* a multiple of target ... */
		normalize_v3(axis);
		
		theta= angle_normalized_v3v3(target, nor);
		
		/*	Make Bone matrix*/
		vec_rot_to_mat3( bMatrix,axis, theta);
	}
	else {
		/* if nor is a multiple of target ... */
		float updown;
		
		/* point same direction, or opposite? */
		updown = ( dot_v3v3(target,nor) > 0 ) ? 1.0f : -1.0f;
		
		/* I think this should work ... */
		bMatrix[0][0]=updown; bMatrix[0][1]=0.0;    bMatrix[0][2]=0.0;
		bMatrix[1][0]=0.0;    bMatrix[1][1]=updown; bMatrix[1][2]=0.0;
		bMatrix[2][0]=0.0;    bMatrix[2][1]=0.0;    bMatrix[2][2]=1.0;
	}
	
	/*	Make Roll matrix*/
	vec_rot_to_mat3( rMatrix,nor, roll);
	
	/*	Combine and output result*/
	mul_m3_m3m3(mat, rMatrix, bMatrix);
}


/* recursive part, calculates restposition of entire tree of children */
/* used by exiting editmode too */
void where_is_armature_bone(Bone *bone, Bone *prevbone)
{
	float vec[3];
	
	/* Bone Space */
	sub_v3_v3v3(vec, bone->tail, bone->head);
	vec_roll_to_mat3(vec, bone->roll, bone->bone_mat);

	bone->length= len_v3v3(bone->head, bone->tail);
	
	/* this is called on old file reading too... */
	if(bone->xwidth==0.0f) {
		bone->xwidth= 0.1f;
		bone->zwidth= 0.1f;
		bone->segments= 1;
	}
	
	if(prevbone) {
		float offs_bone[4][4];  // yoffs(b-1) + root(b) + bonemat(b)
		
		/* bone transform itself */
		copy_m4_m3(offs_bone, bone->bone_mat);
				
		/* The bone's root offset (is in the parent's coordinate system) */
		VECCOPY(offs_bone[3], bone->head);

		/* Get the length translation of parent (length along y axis) */
		offs_bone[3][1]+= prevbone->length;
		
		/* Compose the matrix for this bone  */
		mul_m4_m4m4(bone->arm_mat, offs_bone, prevbone->arm_mat);
	}
	else {
		copy_m4_m3(bone->arm_mat, bone->bone_mat);
		VECCOPY(bone->arm_mat[3], bone->head);
	}
	
	/* and the kiddies */
	prevbone= bone;
	for(bone= bone->childbase.first; bone; bone= bone->next) {
		where_is_armature_bone(bone, prevbone);
	}
}

/* updates vectors and matrices on rest-position level, only needed 
   after editing armature itself, now only on reading file */
void where_is_armature (bArmature *arm)
{
	Bone *bone;
	
	/* hierarchical from root to children */
	for(bone= arm->bonebase.first; bone; bone= bone->next) {
		where_is_armature_bone(bone, NULL);
	}
}

/* if bone layer is protected, copy the data from from->pose
 * when used with linked libraries this copies from the linked pose into the local pose */
static void pose_proxy_synchronize(Object *ob, Object *from, int layer_protected)
{
	bPose *pose= ob->pose, *frompose= from->pose;
	bPoseChannel *pchan, *pchanp, pchanw;
	bConstraint *con;
	int error = 0;
	
	if (frompose==NULL) return;

	/* in some cases when rigs change, we cant synchronize
	 * to avoid crashing check for possible errors here */
	for (pchan= pose->chanbase.first; pchan; pchan= pchan->next) {
		if (pchan->bone->layer & layer_protected) {
			if(get_pose_channel(frompose, pchan->name) == NULL) {
				printf("failed to sync proxy armature because '%s' is missing pose channel '%s'\n", from->id.name, pchan->name);
				error = 1;
			}
		}
	}

	if(error)
		return;
	
	/* clear all transformation values from library */
	rest_pose(frompose);
	
	/* copy over all of the proxy's bone groups */
		/* TODO for later - implement 'local' bone groups as for constraints
		 *	Note: this isn't trivial, as bones reference groups by index not by pointer, 
		 *		 so syncing things correctly needs careful attention
		 */
	BLI_freelistN(&pose->agroups);
	BLI_duplicatelist(&pose->agroups, &frompose->agroups);
	pose->active_group= frompose->active_group;
	
	for (pchan= pose->chanbase.first; pchan; pchan= pchan->next) {
		pchanp= get_pose_channel(frompose, pchan->name);

		if (pchan->bone->layer & layer_protected) {
			ListBase proxylocal_constraints = {NULL, NULL};
			
			/* copy posechannel to temp, but restore important pointers */
			pchanw= *pchanp;
			pchanw.prev= pchan->prev;
			pchanw.next= pchan->next;
			pchanw.parent= pchan->parent;
			pchanw.child= pchan->child;
			pchanw.path= NULL;
			
			/* this is freed so copy a copy, else undo crashes */
			if(pchanw.prop) {
				pchanw.prop= IDP_CopyProperty(pchanw.prop);

				/* use the values from the the existing props */
				if(pchan->prop) {
					IDP_SyncGroupValues(pchanw.prop, pchan->prop);
				}
			}

			/* constraints - proxy constraints are flushed... local ones are added after 
			 *	1. extract constraints not from proxy (CONSTRAINT_PROXY_LOCAL) from pchan's constraints
			 *	2. copy proxy-pchan's constraints on-to new
			 *	3. add extracted local constraints back on top 
			 *
			 *  note for copy_constraints: when copying constraints, disable 'do_extern' otherwise we get the libs direct linked in this blend.
			 */
			extract_proxylocal_constraints(&proxylocal_constraints, &pchan->constraints);
			copy_constraints(&pchanw.constraints, &pchanp->constraints, FALSE);
			BLI_movelisttolist(&pchanw.constraints, &proxylocal_constraints);
			
			/* constraints - set target ob pointer to own object */
			for (con= pchanw.constraints.first; con; con= con->next) {
				bConstraintTypeInfo *cti= constraint_get_typeinfo(con);
				ListBase targets = {NULL, NULL};
				bConstraintTarget *ct;
				
				if (cti && cti->get_constraint_targets) {
					cti->get_constraint_targets(con, &targets);
					
					for (ct= targets.first; ct; ct= ct->next) {
						if (ct->tar == from)
							ct->tar = ob;
					}
					
					if (cti->flush_constraint_targets)
						cti->flush_constraint_targets(con, &targets, 0);
				}
			}
			
			/* free stuff from current channel */
			free_pose_channel(pchan);
			
			/* the final copy */
			*pchan= pchanw;
		}
		else {
			/* always copy custom shape */
			pchan->custom= pchanp->custom;
			pchan->custom_tx= pchanp->custom_tx;

			/* ID-Property Syncing */
			{
				IDProperty *prop_orig= pchan->prop;
				if(pchanp->prop) {
					pchan->prop= IDP_CopyProperty(pchanp->prop);
					if(prop_orig) {
						/* copy existing values across when types match */
						IDP_SyncGroupValues(pchan->prop, prop_orig);
					}
				}
				else {
					pchan->prop= NULL;
				}
				if (prop_orig) {
					IDP_FreeProperty(prop_orig);
					MEM_freeN(prop_orig);
				}
			}
		}
	}
}

static int rebuild_pose_bone(bPose *pose, Bone *bone, bPoseChannel *parchan, int counter)
{
	bPoseChannel *pchan = verify_pose_channel (pose, bone->name);   // verify checks and/or adds

	pchan->bone= bone;
	pchan->parent= parchan;
	
	counter++;
	
	for(bone= bone->childbase.first; bone; bone= bone->next) {
		counter= rebuild_pose_bone(pose, bone, pchan, counter);
		/* for quick detecting of next bone in chain, only b-bone uses it now */
		if(bone->flag & BONE_CONNECTED)
			pchan->child= get_pose_channel(pose, bone->name);
	}
	
	return counter;
}

/* only after leave editmode, duplicating, validating older files, library syncing */
/* NOTE: pose->flag is set for it */
void armature_rebuild_pose(Object *ob, bArmature *arm)
{
	Bone *bone;
	bPose *pose;
	bPoseChannel *pchan, *next;
	int counter=0;
		
	/* only done here */
	if(ob->pose==NULL) {
		/* create new pose */
		ob->pose= MEM_callocN(sizeof(bPose), "new pose");
		
		/* set default settings for animviz */
		animviz_settings_init(&ob->pose->avs);
	}
	pose= ob->pose;
	
	/* clear */
	for(pchan= pose->chanbase.first; pchan; pchan= pchan->next) {
		pchan->bone= NULL;
		pchan->child= NULL;
	}
	
	/* first step, check if all channels are there */
	for(bone= arm->bonebase.first; bone; bone= bone->next) {
		counter= rebuild_pose_bone(pose, bone, NULL, counter);
	}

	/* and a check for garbage */
	for(pchan= pose->chanbase.first; pchan; pchan= next) {
		next= pchan->next;
		if(pchan->bone==NULL) {
			free_pose_channel(pchan);
			free_pose_channels_hash(pose);
			BLI_freelinkN(&pose->chanbase, pchan);
		}
	}
	// printf("rebuild pose %s, %d bones\n", ob->id.name, counter);
	
	/* synchronize protected layers with proxy */
	if(ob->proxy) {
		object_copy_proxy_drivers(ob, ob->proxy);
		pose_proxy_synchronize(ob, ob->proxy, arm->layer_protected);
	}
	
	update_pose_constraint_flags(ob->pose); // for IK detection for example
	
	/* the sorting */
	if(counter>1)
		DAG_pose_sort(ob);
	
	ob->pose->flag &= ~POSE_RECALC;
	ob->pose->flag |= POSE_WAS_REBUILT;

	make_pose_channels_hash(ob->pose);
}


/* ********************** SPLINE IK SOLVER ******************* */

/* Temporary evaluation tree data used for Spline IK */
typedef struct tSplineIK_Tree {
	struct tSplineIK_Tree *next, *prev;
	
	int 	type;					/* type of IK that this serves (CONSTRAINT_TYPE_KINEMATIC or ..._SPLINEIK) */
	
	short free_points;				/* free the point positions array */
	short chainlen;					/* number of bones in the chain */
	
	float *points;					/* parametric positions for the joints along the curve */
	bPoseChannel **chain;			/* chain of bones to affect using Spline IK (ordered from the tip) */
	
	bPoseChannel *root;				/* bone that is the root node of the chain */
	
	bConstraint *con;				/* constraint for this chain */
	bSplineIKConstraint *ikData;	/* constraint settings for this chain */
} tSplineIK_Tree;

/* ----------- */

/* Tag the bones in the chain formed by the given bone for IK */
static void splineik_init_tree_from_pchan(Scene *scene, Object *UNUSED(ob), bPoseChannel *pchan_tip)
{
	bPoseChannel *pchan, *pchanRoot=NULL;
	bPoseChannel *pchanChain[255];
	bConstraint *con = NULL;
	bSplineIKConstraint *ikData = NULL;
	float boneLengths[255], *jointPoints;
	float totLength = 0.0f;
	short free_joints = 0;
	int segcount = 0;
	
	/* find the SplineIK constraint */
	for (con= pchan_tip->constraints.first; con; con= con->next) {
		if (con->type == CONSTRAINT_TYPE_SPLINEIK) {
			ikData= con->data;
			
			/* target can only be curve */
			if ((ikData->tar == NULL) || (ikData->tar->type != OB_CURVE))  
				continue;
			/* skip if disabled */
			if ( (con->enforce == 0.0f) || (con->flag & (CONSTRAINT_DISABLE|CONSTRAINT_OFF)) )
				continue;
			
			/* otherwise, constraint is ok... */
			break;
		}
	}
	if (con == NULL)
		return;
		
	/* make sure that the constraint targets are ok 
	 *	- this is a workaround for a depsgraph bug...
	 */
	if (ikData->tar) {
		Curve *cu= ikData->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(scene, ikData->tar, 0);
	}
	
	/* find the root bone and the chain of bones from the root to the tip 
	 * NOTE: this assumes that the bones are connected, but that may not be true...
	 */
	for (pchan= pchan_tip; pchan && (segcount < ikData->chainlen); pchan= pchan->parent, segcount++) {
		/* store this segment in the chain */
		pchanChain[segcount]= pchan;
		
		/* if performing rebinding, calculate the length of the bone */
		boneLengths[segcount]= pchan->bone->length;
		totLength += boneLengths[segcount];
	}
	
	if (segcount == 0)
		return;
	else
		pchanRoot= pchanChain[segcount-1];
	
	/* perform binding step if required */
	if ((ikData->flag & CONSTRAINT_SPLINEIK_BOUND) == 0) {
		float segmentLen= (1.0f / (float)segcount);
		int i;
		
		/* setup new empty array for the points list */
		if (ikData->points) 
			MEM_freeN(ikData->points);
		ikData->numpoints= ikData->chainlen+1; 
		ikData->points= MEM_callocN(sizeof(float)*ikData->numpoints, "Spline IK Binding");
		
		/* bind 'tip' of chain (i.e. first joint = tip of bone with the Spline IK Constraint) */
		ikData->points[0] = 1.0f;
		
		/* perform binding of the joints to parametric positions along the curve based 
		 * proportion of the total length that each bone occupies
		 */
		for (i = 0; i < segcount; i++) {
			/* 'head' joints, travelling towards the root of the chain
			 * 	- 2 methods; the one chosen depends on whether we've got usable lengths
			 */
			if ((ikData->flag & CONSTRAINT_SPLINEIK_EVENSPLITS) || (totLength == 0.0f)) {
				/* 1) equi-spaced joints */
				ikData->points[i+1]= ikData->points[i] - segmentLen;
			}
			else {
				/*	2) to find this point on the curve, we take a step from the previous joint
				 *	  a distance given by the proportion that this bone takes
				 */
				ikData->points[i+1]= ikData->points[i] - (boneLengths[i] / totLength);
			}
		}
		
		/* spline has now been bound */
		ikData->flag |= CONSTRAINT_SPLINEIK_BOUND;
	}
	
	/* apply corrections for sensitivity to scaling on a copy of the bind points,
	 * since it's easier to determine the positions of all the joints beforehand this way
	 */
	if ((ikData->flag & CONSTRAINT_SPLINEIK_SCALE_LIMITED) && (totLength != 0.0f)) {
		Curve *cu= (Curve *)ikData->tar->data;
		float splineLen, maxScale;
		int i;
		
		/* make a copy of the points array, that we'll store in the tree 
		 *	- although we could just multiply the points on the fly, this approach means that
		 * 	  we can introduce per-segment stretchiness later if it is necessary
		 */
		jointPoints= MEM_dupallocN(ikData->points);
		free_joints= 1;
		
		/* get the current length of the curve */
		// NOTE: this is assumed to be correct even after the curve was resized
		splineLen= cu->path->totdist;
		
		/* calculate the scale factor to multiply all the path values by so that the 
		 * bone chain retains its current length, such that
		 *	maxScale * splineLen = totLength
		 */
		maxScale = totLength / splineLen;
		
		/* apply scaling correction to all of the temporary points */
		// TODO: this is really not adequate enough on really short chains
		for (i = 0; i < segcount; i++)
			jointPoints[i] *= maxScale;
	}
	else {
		/* just use the existing points array */
		jointPoints= ikData->points;
		free_joints= 0;
	}
	
	/* make a new Spline-IK chain, and store it in the IK chains */
	// TODO: we should check if there is already an IK chain on this, since that would take presidence...
	{
		/* make new tree */
		tSplineIK_Tree *tree= MEM_callocN(sizeof(tSplineIK_Tree), "SplineIK Tree");
		tree->type= CONSTRAINT_TYPE_SPLINEIK;
		
		tree->chainlen= segcount;
		
		/* copy over the array of links to bones in the chain (from tip to root) */
		tree->chain= MEM_callocN(sizeof(bPoseChannel*)*segcount, "SplineIK Chain");
		memcpy(tree->chain, pchanChain, sizeof(bPoseChannel*)*segcount);
		
		/* store reference to joint position array */
		tree->points= jointPoints;
		tree->free_points= free_joints;
		
		/* store references to different parts of the chain */
		tree->root= pchanRoot;
		tree->con= con;
		tree->ikData= ikData;
		
		/* AND! link the tree to the root */
		BLI_addtail(&pchanRoot->iktree, tree);
	}
	
	/* mark root channel having an IK tree */
	pchanRoot->flag |= POSE_IKSPLINE;
}

/* Tag which bones are members of Spline IK chains */
static void splineik_init_tree(Scene *scene, Object *ob, float UNUSED(ctime))
{
	bPoseChannel *pchan;
	
	/* find the tips of Spline IK chains, which are simply the bones which have been tagged as such */
	for (pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
		if (pchan->constflag & PCHAN_HAS_SPLINEIK)
			splineik_init_tree_from_pchan(scene, ob, pchan);
	}
}

/* ----------- */

/* Evaluate spline IK for a given bone */
static void splineik_evaluate_bone(tSplineIK_Tree *tree, Scene *scene, Object *ob, bPoseChannel *pchan, int index, float ctime)
{
	bSplineIKConstraint *ikData= tree->ikData;
	float poseHead[3], poseTail[3], poseMat[4][4]; 
	float splineVec[3], scaleFac, radius=1.0f;
	
	/* firstly, calculate the bone matrix the standard way, since this is needed for roll control */
	where_is_pose_bone(scene, ob, pchan, ctime, 1);
	
	VECCOPY(poseHead, pchan->pose_head);
	VECCOPY(poseTail, pchan->pose_tail);
	
	/* step 1: determine the positions for the endpoints of the bone */
	{
		float vec[4], dir[3], rad;
		float tailBlendFac= 1.0f;
		
		/* determine if the bone should still be affected by SplineIK */
		if (tree->points[index+1] >= 1.0f) {
			/* spline doesn't affect the bone anymore, so done... */
			pchan->flag |= POSE_DONE;
			return;
		}
		else if ((tree->points[index] >= 1.0f) && (tree->points[index+1] < 1.0f)) {
			/* blending factor depends on the amount of the bone still left on the chain */
			tailBlendFac= (1.0f - tree->points[index+1]) / (tree->points[index] - tree->points[index+1]);
		}
		
		/* tail endpoint */
		if ( where_on_path(ikData->tar, tree->points[index], vec, dir, NULL, &rad, NULL) ) {
			/* apply curve's object-mode transforms to the position 
			 * unless the option to allow curve to be positioned elsewhere is activated (i.e. no root)
			 */
			if ((ikData->flag & CONSTRAINT_SPLINEIK_NO_ROOT) == 0)
				mul_m4_v3(ikData->tar->obmat, vec);
			
			/* convert the position to pose-space, then store it */
			mul_m4_v3(ob->imat, vec);
			interp_v3_v3v3(poseTail, pchan->pose_tail, vec, tailBlendFac);
			
			/* set the new radius */
			radius= rad;
		}
		
		/* head endpoint */
		if ( where_on_path(ikData->tar, tree->points[index+1], vec, dir, NULL, &rad, NULL) ) {
			/* apply curve's object-mode transforms to the position 
			 * unless the option to allow curve to be positioned elsewhere is activated (i.e. no root)
			 */
			if ((ikData->flag & CONSTRAINT_SPLINEIK_NO_ROOT) == 0)
				mul_m4_v3(ikData->tar->obmat, vec);
			
			/* store the position, and convert it to pose space */
			mul_m4_v3(ob->imat, vec);
			VECCOPY(poseHead, vec);
			
			/* set the new radius (it should be the average value) */
			radius = (radius+rad) / 2;
		}
	}
	
	/* step 2: determine the implied transform from these endpoints 
	 *	- splineVec: the vector direction that the spline applies on the bone
	 *	- scaleFac: the factor that the bone length is scaled by to get the desired amount
	 */
	sub_v3_v3v3(splineVec, poseTail, poseHead);
	scaleFac= len_v3(splineVec) / pchan->bone->length;
	
	/* step 3: compute the shortest rotation needed to map from the bone rotation to the current axis 
	 * 	- this uses the same method as is used for the Damped Track Constraint (see the code there for details)
	 */
	{
		float dmat[3][3], rmat[3][3], tmat[3][3];
		float raxis[3], rangle;
		
		/* compute the raw rotation matrix from the bone's current matrix by extracting only the
		 * orientation-relevant axes, and normalising them
		 */
		VECCOPY(rmat[0], pchan->pose_mat[0]);
		VECCOPY(rmat[1], pchan->pose_mat[1]);
		VECCOPY(rmat[2], pchan->pose_mat[2]);
		normalize_m3(rmat);
		
		/* also, normalise the orientation imposed by the bone, now that we've extracted the scale factor */
		normalize_v3(splineVec);
		
		/* calculate smallest axis-angle rotation necessary for getting from the
		 * current orientation of the bone, to the spline-imposed direction
		 */
		cross_v3_v3v3(raxis, rmat[1], splineVec);
		
		rangle= dot_v3v3(rmat[1], splineVec);
		rangle= acos( MAX2(-1.0f, MIN2(1.0f, rangle)) );
		
		/* multiply the magnitude of the angle by the influence of the constraint to 
		 * control the influence of the SplineIK effect 
		 */
		rangle *= tree->con->enforce;
		
		/* construct rotation matrix from the axis-angle rotation found above 
		 *	- this call takes care to make sure that the axis provided is a unit vector first
		 */
		axis_angle_to_mat3(dmat, raxis, rangle);
		
		/* combine these rotations so that the y-axis of the bone is now aligned as the spline dictates,
		 * while still maintaining roll control from the existing bone animation
		 */
		mul_m3_m3m3(tmat, dmat, rmat); // m1, m3, m2
		normalize_m3(tmat); /* attempt to reduce shearing, though I doubt this'll really help too much now... */
		copy_m4_m3(poseMat, tmat);
	}
	
	/* step 4: set the scaling factors for the axes */
	{
		/* only multiply the y-axis by the scaling factor to get nice volume-preservation */
		mul_v3_fl(poseMat[1], scaleFac);
		
		/* set the scaling factors of the x and z axes from... */
		switch (ikData->xzScaleMode) {
			case CONSTRAINT_SPLINEIK_XZS_ORIGINAL:
			{
				/* original scales get used */
				float scale;
				
				/* x-axis scale */
				scale= len_v3(pchan->pose_mat[0]);
				mul_v3_fl(poseMat[0], scale);
				/* z-axis scale */
				scale= len_v3(pchan->pose_mat[2]);
				mul_v3_fl(poseMat[2], scale);
			}
				break;
			case CONSTRAINT_SPLINEIK_XZS_VOLUMETRIC:
			{
				/* 'volume preservation' */
				float scale;
				
				/* calculate volume preservation factor which is 
				 * basically the inverse of the y-scaling factor 
				 */
				if (fabsf(scaleFac) != 0.0f) {
					scale= 1.0f / fabsf(scaleFac);
					
					/* we need to clamp this within sensible values */
					// NOTE: these should be fine for now, but should get sanitised in future
					CLAMP(scale, 0.0001f, 100000.0f);
				}
				else
					scale= 1.0f;
				
				/* apply the scaling */
				mul_v3_fl(poseMat[0], scale);
				mul_v3_fl(poseMat[2], scale);
			}
				break;
		}
		
		/* finally, multiply the x and z scaling by the radius of the curve too, 
		 * to allow automatic scales to get tweaked still
		 */
		if ((ikData->flag & CONSTRAINT_SPLINEIK_NO_CURVERAD) == 0) {
			mul_v3_fl(poseMat[0], radius);
			mul_v3_fl(poseMat[2], radius);
		}
	}
	
	/* step 5: set the location of the bone in the matrix */
	if (ikData->flag & CONSTRAINT_SPLINEIK_NO_ROOT) {
		/* when the 'no-root' option is affected, the chain can retain
		 * the shape but be moved elsewhere
		 */
		VECCOPY(poseHead, pchan->pose_head);
	}
	else if (tree->con->enforce < 1.0f) {
		/* when the influence is too low
		 *	- blend the positions for the 'root' bone
		 *	- stick to the parent for any other
		 */
		if (pchan->parent) {
			VECCOPY(poseHead, pchan->pose_head);
		}
		else {
			// FIXME: this introduces popping artifacts when we reach 0.0
			interp_v3_v3v3(poseHead, pchan->pose_head, poseHead, tree->con->enforce);
		}
	}
	VECCOPY(poseMat[3], poseHead);
	
	/* finally, store the new transform */
	copy_m4_m4(pchan->pose_mat, poseMat);
	VECCOPY(pchan->pose_head, poseHead);
	
	/* recalculate tail, as it's now outdated after the head gets adjusted above! */
	where_is_pose_bone_tail(pchan);
	
	/* done! */
	pchan->flag |= POSE_DONE;
}

/* Evaluate the chain starting from the nominated bone */
static void splineik_execute_tree(Scene *scene, Object *ob, bPoseChannel *pchan_root, float ctime)
{
	tSplineIK_Tree *tree;
	
	/* for each pose-tree, execute it if it is spline, otherwise just free it */
	for (tree= pchan_root->iktree.first; tree; tree= pchan_root->iktree.first) {
		/* only evaluate if tagged for Spline IK */
		if (tree->type == CONSTRAINT_TYPE_SPLINEIK) {
			int i;
			
			/* walk over each bone in the chain, calculating the effects of spline IK
			 * 	- the chain is traversed in the opposite order to storage order (i.e. parent to children)
			 *	  so that dependencies are correct
			 */
			for (i= tree->chainlen-1; i >= 0; i--) {
				bPoseChannel *pchan= tree->chain[i];
				splineik_evaluate_bone(tree, scene, ob, pchan, i, ctime);
			}
			
			/* free the tree info specific to SplineIK trees now */
			if (tree->chain) MEM_freeN(tree->chain);
			if (tree->free_points) MEM_freeN(tree->points);
		}
		
		/* free this tree */
		BLI_freelinkN(&pchan_root->iktree, tree);
	}
}

/* ********************** THE POSE SOLVER ******************* */

/* loc/rot/size to given mat4 */
void pchan_to_mat4(bPoseChannel *pchan, float chan_mat[4][4])
{
	float smat[3][3];
	float rmat[3][3];
	float tmat[3][3];
	
	/* get scaling matrix */
	size_to_mat3(smat, pchan->size);
	
	/* rotations may either be quats, eulers (with various rotation orders), or axis-angle */
	if (pchan->rotmode > 0) {
		/* euler rotations (will cause gimble lock, but this can be alleviated a bit with rotation orders) */
		eulO_to_mat3(rmat, pchan->eul, pchan->rotmode);
	}
	else if (pchan->rotmode == ROT_MODE_AXISANGLE) {
		/* axis-angle - not really that great for 3D-changing orientations */
		axis_angle_to_mat3(rmat, pchan->rotAxis, pchan->rotAngle);
	}
	else {
		/* quats are normalised before use to eliminate scaling issues */
		float quat[4];
		
		/* NOTE: we now don't normalise the stored values anymore, since this was kindof evil in some cases
		 * but if this proves to be too problematic, switch back to the old system of operating directly on 
		 * the stored copy
		 */
		normalize_qt_qt(quat, pchan->quat);
		quat_to_mat3(rmat, quat);
	}
	
	/* calculate matrix of bone (as 3x3 matrix, but then copy the 4x4) */
	mul_m3_m3m3(tmat, rmat, smat);
	copy_m4_m3(chan_mat, tmat);
	
	/* prevent action channels breaking chains */
	/* need to check for bone here, CONSTRAINT_TYPE_ACTION uses this call */
	if ((pchan->bone==NULL) || !(pchan->bone->flag & BONE_CONNECTED)) {
		VECCOPY(chan_mat[3], pchan->loc);
	}
}

/* loc/rot/size to mat4 */
/* used in constraint.c too */
void pchan_calc_mat(bPoseChannel *pchan)
{
	/* this is just a wrapper around the copy of this function which calculates the matrix 
	 * and stores the result in any given channel
	 */
	pchan_to_mat4(pchan, pchan->chan_mat);
}

/* NLA strip modifiers */
static void do_strip_modifiers(Scene *scene, Object *armob, Bone *bone, bPoseChannel *pchan)
{
	bActionModifier *amod;
	bActionStrip *strip, *strip2;
	float scene_cfra= (float)scene->r.cfra;
	int do_modif;

	for (strip=armob->nlastrips.first; strip; strip=strip->next) {
		do_modif=0;
		
		if (scene_cfra>=strip->start && scene_cfra<=strip->end)
			do_modif=1;
		
		if ((scene_cfra > strip->end) && (strip->flag & ACTSTRIP_HOLDLASTFRAME)) {
			do_modif=1;
			
			/* if there are any other strips active, ignore modifiers for this strip - 
			 * 'hold' option should only hold action modifiers if there are 
			 * no other active strips */
			for (strip2=strip->next; strip2; strip2=strip2->next) {
				if (strip2 == strip) continue;
				
				if (scene_cfra>=strip2->start && scene_cfra<=strip2->end) {
					if (!(strip2->flag & ACTSTRIP_MUTE))
						do_modif=0;
				}
			}
			
			/* if there are any later, activated, strips with 'hold' set, they take precedence, 
			 * so ignore modifiers for this strip */
			for (strip2=strip->next; strip2; strip2=strip2->next) {
				if (scene_cfra < strip2->start) continue;
				if ((strip2->flag & ACTSTRIP_HOLDLASTFRAME) && !(strip2->flag & ACTSTRIP_MUTE)) {
					do_modif=0;
				}
			}
		}
		
		if (do_modif) {
			/* temporal solution to prevent 2 strips accumulating */
			if(scene_cfra==strip->end && strip->next && strip->next->start==scene_cfra)
				continue;
			
			for(amod= strip->modifiers.first; amod; amod= amod->next) {
				switch (amod->type) {
				case ACTSTRIP_MOD_DEFORM:
				{
					/* validate first */
					if(amod->ob && amod->ob->type==OB_CURVE && amod->channel[0]) {
						
						if( strcmp(pchan->name, amod->channel)==0 ) {
							float mat4[4][4], mat3[3][3];
							
							curve_deform_vector(scene, amod->ob, armob, bone->arm_mat[3], pchan->pose_mat[3], mat3, amod->no_rot_axis);
							copy_m4_m4(mat4, pchan->pose_mat);
							mul_m4_m3m4(pchan->pose_mat, mat3, mat4);
							
						}
					}
				}
					break;
				case ACTSTRIP_MOD_NOISE:	
				{
					if( strcmp(pchan->name, amod->channel)==0 ) {
						float nor[3], loc[3], ofs;
						float eul[3], size[3], eulo[3], sizeo[3];
						
						/* calculate turbulance */
						ofs = amod->turbul / 200.0f;
						
						/* make a copy of starting conditions */
						VECCOPY(loc, pchan->pose_mat[3]);
						mat4_to_eul( eul,pchan->pose_mat);
						mat4_to_size( size,pchan->pose_mat);
						VECCOPY(eulo, eul);
						VECCOPY(sizeo, size);
						
						/* apply noise to each set of channels */
						if (amod->channels & 4) {
							/* for scaling */
							nor[0] = BLI_gNoise(amod->noisesize, size[0]+ofs, size[1], size[2], 0, 0) - ofs;
							nor[1] = BLI_gNoise(amod->noisesize, size[0], size[1]+ofs, size[2], 0, 0) - ofs;	
							nor[2] = BLI_gNoise(amod->noisesize, size[0], size[1], size[2]+ofs, 0, 0) - ofs;
							add_v3_v3(size, nor);
							
							if (sizeo[0] != 0)
								mul_v3_fl(pchan->pose_mat[0], size[0] / sizeo[0]);
							if (sizeo[1] != 0)
								mul_v3_fl(pchan->pose_mat[1], size[1] / sizeo[1]);
							if (sizeo[2] != 0)
								mul_v3_fl(pchan->pose_mat[2], size[2] / sizeo[2]);
						}
						if (amod->channels & 2) {
							/* for rotation */
							nor[0] = BLI_gNoise(amod->noisesize, eul[0]+ofs, eul[1], eul[2], 0, 0) - ofs;
							nor[1] = BLI_gNoise(amod->noisesize, eul[0], eul[1]+ofs, eul[2], 0, 0) - ofs;	
							nor[2] = BLI_gNoise(amod->noisesize, eul[0], eul[1], eul[2]+ofs, 0, 0) - ofs;
							
							compatible_eul(nor, eulo);
							add_v3_v3(eul, nor);
							compatible_eul(eul, eulo);
							
							loc_eul_size_to_mat4(pchan->pose_mat, loc, eul, size);
						}
						if (amod->channels & 1) {
							/* for location */
							nor[0] = BLI_gNoise(amod->noisesize, loc[0]+ofs, loc[1], loc[2], 0, 0) - ofs;
							nor[1] = BLI_gNoise(amod->noisesize, loc[0], loc[1]+ofs, loc[2], 0, 0) - ofs;	
							nor[2] = BLI_gNoise(amod->noisesize, loc[0], loc[1], loc[2]+ofs, 0, 0) - ofs;
							
							add_v3_v3v3(pchan->pose_mat[3], loc, nor);
						}
					}
				}
					break;
				}
			}
		}
	}
}

/* calculate tail of posechannel */
void where_is_pose_bone_tail(bPoseChannel *pchan)
{
	float vec[3];
	
	VECCOPY(vec, pchan->pose_mat[1]);
	mul_v3_fl(vec, pchan->bone->length);
	add_v3_v3v3(pchan->pose_tail, pchan->pose_head, vec);
}

/* The main armature solver, does all constraints excluding IK */
/* pchan is validated, as having bone and parent pointer
 * 'do_extra': when zero skips loc/size/rot, constraints and strip modifiers.
 */
void where_is_pose_bone(Scene *scene, Object *ob, bPoseChannel *pchan, float ctime, int do_extra)
{
	Bone *bone, *parbone;
	bPoseChannel *parchan;
	float vec[3];
	
	/* set up variables for quicker access below */
	bone= pchan->bone;
	parbone= bone->parent;
	parchan= pchan->parent;
	
	/* this gives a chan_mat with actions (ipos) results */
	if(do_extra)	pchan_calc_mat(pchan);
	else			unit_m4(pchan->chan_mat);

	/* construct the posemat based on PoseChannels, that we do before applying constraints */
	/* pose_mat(b)= pose_mat(b-1) * yoffs(b-1) * d_root(b) * bone_mat(b) * chan_mat(b) */
	
	if(parchan) {
		float offs_bone[4][4];  // yoffs(b-1) + root(b) + bonemat(b)
		
		/* bone transform itself */
		copy_m4_m3(offs_bone, bone->bone_mat);
		
		/* The bone's root offset (is in the parent's coordinate system) */
		VECCOPY(offs_bone[3], bone->head);
		
		/* Get the length translation of parent (length along y axis) */
		offs_bone[3][1]+= parbone->length;
		
		/* Compose the matrix for this bone  */
		if((bone->flag & BONE_HINGE) && (bone->flag & BONE_NO_SCALE)) {	// uses restposition rotation, but actual position
			float tmat[4][4];
			/* the rotation of the parent restposition */
			copy_m4_m4(tmat, parbone->arm_mat);
			mul_serie_m4(pchan->pose_mat, tmat, offs_bone, pchan->chan_mat, NULL, NULL, NULL, NULL, NULL);
		}
		else if(bone->flag & BONE_HINGE) {	// same as above but apply parent scale
			float tmat[4][4];

			/* apply the parent matrix scale */
			float tsmat[4][4], tscale[3];

			/* the rotation of the parent restposition */
			copy_m4_m4(tmat, parbone->arm_mat);

			/* extract the scale of the parent matrix */
			mat4_to_size(tscale, parchan->pose_mat);
			size_to_mat4(tsmat, tscale);
			mul_m4_m4m4(tmat, tmat, tsmat);

			mul_serie_m4(pchan->pose_mat, tmat, offs_bone, pchan->chan_mat, NULL, NULL, NULL, NULL, NULL);
		}
		else if(bone->flag & BONE_NO_SCALE) {
			float orthmat[4][4];
			
			/* do transform, with an ortho-parent matrix */
			copy_m4_m4(orthmat, parchan->pose_mat);
			normalize_m4(orthmat);
			mul_serie_m4(pchan->pose_mat, orthmat, offs_bone, pchan->chan_mat, NULL, NULL, NULL, NULL, NULL);
		}
		else
			mul_serie_m4(pchan->pose_mat, parchan->pose_mat, offs_bone, pchan->chan_mat, NULL, NULL, NULL, NULL, NULL);
		
		/* in these cases we need to compute location separately */
		if(bone->flag & (BONE_HINGE|BONE_NO_SCALE|BONE_NO_LOCAL_LOCATION)) {
			float bone_loc[3], chan_loc[3];

			mul_v3_m4v3(bone_loc, parchan->pose_mat, offs_bone[3]);
			copy_v3_v3(chan_loc, pchan->chan_mat[3]);

			/* no local location is not transformed by bone matrix */
			if(!(bone->flag & BONE_NO_LOCAL_LOCATION))
				mul_mat3_m4_v3(offs_bone, chan_loc);

			/* for hinge we use armature instead of pose mat */
			if(bone->flag & BONE_HINGE) mul_mat3_m4_v3(parbone->arm_mat, chan_loc);
			else mul_mat3_m4_v3(parchan->pose_mat, chan_loc);

			add_v3_v3v3(pchan->pose_mat[3], bone_loc, chan_loc);
		}
	}
	else {
		mul_m4_m4m4(pchan->pose_mat, pchan->chan_mat, bone->arm_mat);

		/* optional location without arm_mat rotation */
		if(bone->flag & BONE_NO_LOCAL_LOCATION)
			add_v3_v3v3(pchan->pose_mat[3], bone->arm_mat[3], pchan->chan_mat[3]);
		
		/* only rootbones get the cyclic offset (unless user doesn't want that) */
		if ((bone->flag & BONE_NO_CYCLICOFFSET) == 0)
			add_v3_v3(pchan->pose_mat[3], ob->pose->cyclic_offset);
	}
	
	if(do_extra) {
		/* do NLA strip modifiers - i.e. curve follow */
		do_strip_modifiers(scene, ob, bone, pchan);
		
		/* Do constraints */
		if (pchan->constraints.first) {
			bConstraintOb *cob;

			/* make a copy of location of PoseChannel for later */
			VECCOPY(vec, pchan->pose_mat[3]);

			/* prepare PoseChannel for Constraint solving
			 * - makes a copy of matrix, and creates temporary struct to use
			 */
			cob= constraints_make_evalob(scene, ob, pchan, CONSTRAINT_OBTYPE_BONE);

			/* Solve PoseChannel's Constraints */
			solve_constraints(&pchan->constraints, cob, ctime);	// ctime doesnt alter objects

			/* cleanup after Constraint Solving
			 * - applies matrix back to pchan, and frees temporary struct used
			 */
			constraints_clear_evalob(cob);

			/* prevent constraints breaking a chain */
			if(pchan->bone->flag & BONE_CONNECTED) {
				VECCOPY(pchan->pose_mat[3], vec);
			}
		}
	}
	
	/* calculate head */
	VECCOPY(pchan->pose_head, pchan->pose_mat[3]);
	/* calculate tail */
	where_is_pose_bone_tail(pchan);
}

/* This only reads anim data from channels, and writes to channels */
/* This is the only function adding poses */
void where_is_pose (Scene *scene, Object *ob)
{
	bArmature *arm;
	Bone *bone;
	bPoseChannel *pchan;
	float imat[4][4];
	float ctime;
	
	if(ob->type!=OB_ARMATURE) return;
	arm = ob->data;
	
	if(ELEM(NULL, arm, scene)) return;
	if((ob->pose==NULL) || (ob->pose->flag & POSE_RECALC)) 
		armature_rebuild_pose(ob, arm);
	   
	ctime= bsystem_time(scene, ob, (float)scene->r.cfra, 0.0);	/* not accurate... */
	
	/* In editmode or restposition we read the data from the bones */
	if(arm->edbo || (arm->flag & ARM_RESTPOS)) {
		
		for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
			bone= pchan->bone;
			if(bone) {
				copy_m4_m4(pchan->pose_mat, bone->arm_mat);
				VECCOPY(pchan->pose_head, bone->arm_head);
				VECCOPY(pchan->pose_tail, bone->arm_tail);
			}
		}
	}
	else {
		invert_m4_m4(ob->imat, ob->obmat);	// imat is needed 
		
		/* 1. clear flags */
		for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
			pchan->flag &= ~(POSE_DONE|POSE_CHAIN|POSE_IKTREE|POSE_IKSPLINE);
		}
		
		/* 2a. construct the IK tree (standard IK) */
		BIK_initialize_tree(scene, ob, ctime);
		
		/* 2b. construct the Spline IK trees 
		 *  - this is not integrated as an IK plugin, since it should be able
		 *	  to function in conjunction with standard IK
		 */
		splineik_init_tree(scene, ob, ctime);
		
		/* 3. the main loop, channels are already hierarchical sorted from root to children */
		for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
			/* 4a. if we find an IK root, we handle it separated */
			if(pchan->flag & POSE_IKTREE) {
				BIK_execute_tree(scene, ob, pchan, ctime);
			}
			/* 4b. if we find a Spline IK root, we handle it separated too */
			else if(pchan->flag & POSE_IKSPLINE) {
				splineik_execute_tree(scene, ob, pchan, ctime);
			}
			/* 5. otherwise just call the normal solver */
			else if(!(pchan->flag & POSE_DONE)) {
				where_is_pose_bone(scene, ob, pchan, ctime, 1);
			}
		}
		/* 6. release the IK tree */
		BIK_release_tree(scene, ob, ctime);
	}
		
	/* calculating deform matrices */
	for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
		if(pchan->bone) {
			invert_m4_m4(imat, pchan->bone->arm_mat);
			mul_m4_m4m4(pchan->chan_mat, imat, pchan->pose_mat);
		}
	}
}