blender-archive/source/blender/blenkernel/intern/depsgraph.c

/**
 * $Id$
 *
 * ***** BEGIN GPL/BL DUAL 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. The Blender
 * Foundation also sells licenses for use in proprietary software under
 * the Blender License.  See http://www.blender.org/BL/ for information
 * about this.
 *
 * 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) 2004 Blender Foundation.
 * All rights reserved.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL/BL DUAL LICENSE BLOCK *****
 */
 
#include <stdio.h>
#include <string.h>
#include <math.h>

#ifdef _WIN32
#include "BLI_winstuff.h"
#endif

//#include "BMF_Api.h"

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

#include "DNA_ID.h"
#include "DNA_object_types.h"
#include "DNA_oops_types.h"
#include "DNA_scene_types.h"
#include "DNA_action_types.h"
#include "DNA_screen_types.h"
#include "DNA_space_types.h"
#include "DNA_view2d_types.h"

#include "BKE_utildefines.h"
#include "BKE_global.h"

#include "MEM_guardedalloc.h"
#include "blendef.h"

 
 #include "depsgraph_private.h"
 
/* Queue and stack operations for dag traversal 
 *
 * the queue store a list of freenodes to avoid successives alloc/dealloc
 */

DagNodeQueue * queue_create (int slots) 
{
	DagNodeQueue * queue;
	DagNodeQueueElem * elem;
	int i;
	
	queue = MEM_mallocN(sizeof(DagNodeQueue),"DAG queue");
	queue->freenodes = MEM_mallocN(sizeof(DagNodeQueue),"DAG queue");
	queue->count = 0;
	queue->maxlevel = 0;
	queue->first = queue->last = NULL;
	elem = MEM_mallocN(sizeof(DagNodeQueueElem),"DAG queue elem3");
	elem->node = NULL;
	elem->next = NULL;
	queue->freenodes->first = queue->freenodes->last = elem;
	
	for (i = 1; i <slots;i++) {
		elem = MEM_mallocN(sizeof(DagNodeQueueElem),"DAG queue elem4");
		elem->node = NULL;
		elem->next = NULL;
		queue->freenodes->last->next = elem;
		queue->freenodes->last = elem;
	}
	queue->freenodes->count = slots;
	return queue;
}

void queue_raz(DagNodeQueue *queue)
{
	DagNodeQueueElem * elem;
	
	elem = queue->first;
	if (queue->freenodes->last)
		queue->freenodes->last->next = elem;
	else
		queue->freenodes->first = queue->freenodes->last = elem;
	
	elem->node = NULL;
	queue->freenodes->count++;
	while (elem->next) {
		elem = elem->next;
		elem->node = NULL;
		queue->freenodes->count++;
	}
	queue->freenodes->last = elem;
	queue->count = 0;
}

void queue_delete(DagNodeQueue *queue)
{
	DagNodeQueueElem * elem;
	DagNodeQueueElem * temp;
	
	elem = queue->first;
	while (elem) {
		temp = elem;
		elem = elem->next;
		MEM_freeN(temp);
	}
	
	elem = queue->freenodes->first;
	while (elem) {
		temp = elem;
		elem = elem->next;
		MEM_freeN(temp);
	}
	
	MEM_freeN(queue->freenodes);			
	MEM_freeN(queue);			
}

/* insert in queue, remove in front */
void push_queue(DagNodeQueue *queue, DagNode *node)
{
	DagNodeQueueElem * elem;
	int i;

	if (node == NULL) {
		fprintf(stderr,"pushing null node \n");
		return;
	}
	/*fprintf(stderr,"BFS push : %s %d\n",((ID *) node->ob)->name, queue->count);*/

	elem = queue->freenodes->first;
	if (elem != NULL) {
		queue->freenodes->first = elem->next;
		if ( queue->freenodes->last == elem) {
			queue->freenodes->last = NULL;
			queue->freenodes->first = NULL;
		}
		queue->freenodes->count--;
	} else { /* alllocating more */		
		elem = MEM_mallocN(sizeof(DagNodeQueueElem),"DAG queue elem1");
		elem->node = NULL;
		elem->next = NULL;
		queue->freenodes->first = queue->freenodes->last = elem;

		for (i = 1; i <DAGQUEUEALLOC;i++) {
			elem = MEM_mallocN(sizeof(DagNodeQueueElem),"DAG queue elem2");
			elem->node = NULL;
			elem->next = NULL;
			queue->freenodes->last->next = elem;
			queue->freenodes->last = elem;
		}
		queue->freenodes->count = DAGQUEUEALLOC;
			
		elem = queue->freenodes->first;	
		queue->freenodes->first = elem->next;	
	}
	elem->next = NULL;
	elem->node = node;
	if (queue->last != NULL)
		queue->last->next = elem;
	queue->last = elem;
	if (queue->first == NULL) {
		queue->first = elem;
	}
	queue->count++;
}


/* insert in front, remove in front */
void push_stack(DagNodeQueue *queue, DagNode *node)
{
	DagNodeQueueElem * elem;
	int i;

	elem = queue->freenodes->first;	
	if (elem != NULL) {
		queue->freenodes->first = elem->next;
		if ( queue->freenodes->last == elem) {
			queue->freenodes->last = NULL;
			queue->freenodes->first = NULL;
		}
		queue->freenodes->count--;
	} else { /* alllocating more */
		elem = MEM_mallocN(sizeof(DagNodeQueueElem),"DAG queue elem1");
		elem->node = NULL;
		elem->next = NULL;
		queue->freenodes->first = queue->freenodes->last = elem;

		for (i = 1; i <DAGQUEUEALLOC;i++) {
			elem = MEM_mallocN(sizeof(DagNodeQueueElem),"DAG queue elem2");
			elem->node = NULL;
			elem->next = NULL;
			queue->freenodes->last->next = elem;
			queue->freenodes->last = elem;
		}
		queue->freenodes->count = DAGQUEUEALLOC;
			
		elem = queue->freenodes->first;	
		queue->freenodes->first = elem->next;	
	}
	elem->next = queue->first;
	elem->node = node;
	queue->first = elem;
	if (queue->last == NULL)
		queue->last = elem;
	queue->count++;
}


DagNode * pop_queue(DagNodeQueue *queue)
{
	DagNodeQueueElem * elem;
	DagNode *node;

	elem = queue->first;
	if (elem) {
		queue->first = elem->next;
		if (queue->last == elem) {
			queue->last=NULL;
			queue->first=NULL;
		}
		queue->count--;
		if (queue->freenodes->last)
			queue->freenodes->last->next=elem;
		queue->freenodes->last=elem;
		if (queue->freenodes->first == NULL)
			queue->freenodes->first=elem;
		node = elem->node;
		elem->node = NULL;
		elem->next = NULL;
		queue->freenodes->count++;
		return node;
	} else {
		fprintf(stderr,"return null \n");
		return NULL;
	}
}

void	*pop_ob_queue(struct DagNodeQueue *queue) {
	return(pop_queue(queue)->ob);
}

DagNode * get_top_node_queue(DagNodeQueue *queue) 
{
	return queue->first->node;
}

int		queue_count(struct DagNodeQueue *queue){
	return queue->count;
}


DagForest * dag_init()
{
	DagForest *forest;
	
	forest = MEM_mallocN(sizeof(DagForest),"DAG root");
	forest->DagNode.first = NULL;
	forest->DagNode.last = NULL;
	forest->numNodes = 0;
	return forest;
}

struct DagForest	*build_dag(struct Scene *sce, short mask) 
{
	Base *base;
	Object *ob;
	DagNode * node;
	DagNode * node2;
	DagNode * node3;
	DagNode * scenenode;
	DagForest *dag;

	dag = sce->theDag;
	sce->dagisvalid=1;
	if ( dag)
		free_forest( dag ); 
	else {
		dag = dag_init();
		sce->theDag = dag;
	}
	
	// add base node for scene. scene is always the first node in DAG
	scenenode = dag_add_node(dag, sce);	
	
	/* targets in object struct yet to be added. should even they ?
		struct Ipo *ipo;
	ListBase nlastrips;
	ListBase hooks;
	*/
	
	
	base = sce->base.first;
	while(base) { // add all objects in any case
		int addtoroot = 1;
		ob= (Object *) base->object;
		
		node = dag_get_node(dag,ob);
		
		if ((ob->data) && (mask&DAG_RL_DATA_MASK)) {
			node2 = dag_get_node(dag,ob->data);
			dag_add_relation(dag,node,node2,DAG_RL_DATA);
			node2->first_ancestor = ob;
			node2->ancestor_count += 1;
			
			if ((ob->type == OB_ARMATURE) && (mask&DAG_RL_DATA_CONSTRAINT_MASK)) { // add armature constraints to datas
				if (ob->pose){
					bPoseChannel *pchan;
					bConstraint *con;
					Object * target;
					
					for (pchan = ob->pose->chanbase.first; pchan; pchan=pchan->next){
						for (con = pchan->constraints.first; con; con=con->next){
							if (constraint_has_target(con)) {
								target = get_constraint_target(con);
								if (strcmp(target->id.name, ob->id.name) != 0) {
									//fprintf(stderr,"armature target :%s \n", target->id.name);
									node3 = dag_get_node(dag,target);
									dag_add_relation(dag,node3,node2,DAG_RL_CONSTRAINT);
								}
							}
						}
					}
				}
			}
			
			if ((ob->hooks.first) && (mask&DAG_RL_HOOK)) {
				ObHook *hook;
				
				for(hook= ob->hooks.first; hook; hook= hook->next) {
					if(hook->parent) {
						node3 = dag_get_node(dag,hook->parent);
						dag_add_relation(dag,node3,node2,DAG_RL_HOOK);
					}
				}
			}
		} else { // add armature constraints to object itself
			if ((ob->type == OB_ARMATURE) && (mask&DAG_RL_DATA_CONSTRAINT_MASK)) {
				if (ob->pose){
					bPoseChannel *pchan;
					bConstraint *con;
					Object * target;
					
					for (pchan = ob->pose->chanbase.first; pchan; pchan=pchan->next){
						for (con = pchan->constraints.first; con; con=con->next){
							if (constraint_has_target(con)) {
								target = get_constraint_target(con);
								if (strcmp(target->id.name, ob->id.name) != 0) {
									//fprintf(stderr,"armature target :%s \n", target->id.name);
									node3 = dag_get_node(dag,target);
									dag_add_relation(dag,node3,node,DAG_RL_CONSTRAINT);
								}
							}
						}
					}
				}
			}
			if ((ob->hooks.first)  && (mask&DAG_RL_HOOK)) {
				ObHook *hook;
				
				for(hook= ob->hooks.first; hook; hook= hook->next) {
					if(hook->parent) {
						node3 = dag_get_node(dag,hook->parent);
						dag_add_relation(dag,node3,node,DAG_RL_HOOK);
					}
				}
			}			
		}
		
		if ((ob->parent) && (mask&DAG_RL_PARENT_MASK)){
			node2 = dag_get_node(dag,ob->parent);
			dag_add_relation(dag,node2,node,DAG_RL_PARENT);
			addtoroot = 0;
		}
		if ((ob->track) && (mask&DAG_RL_TRACK_MASK)){
			node2 = dag_get_node(dag,ob->track);
			dag_add_relation(dag,node2,node,DAG_RL_TRACK);
			addtoroot = 0;
			
		}
		if ((ob->path) && (mask&DAG_RL_PATH_MASK)){
			node2 = dag_get_node(dag,ob->track);
			dag_add_relation(dag,node2,node,DAG_RL_PATH);
			addtoroot = 0;
			
		}
		
		/* Count constraints */
		if (mask & DAG_RL_CONSTRAINT_MASK) {
			bConstraint *con;
			for (con = ob->constraints.first; con; con=con->next){
				if (constraint_has_target(con)) {
					node2 = dag_get_node(dag,get_constraint_target(con));
					dag_add_relation(dag,node2,node,DAG_RL_CONSTRAINT);
					addtoroot = 0;
					
				}
			}
		}	
		
		
		if (addtoroot == 1 )
			dag_add_relation(dag,scenenode,node,DAG_RL_SCENE);
		
		addtoroot = 1;
		base= base->next;
	}
	
	// cycle detection and solving
	// solve_cycles(dag);	
	
	return dag;
}


void free_forest(DagForest *Dag) 
{  /* remove all nodes and deps */
	DagNode *tempN;
	DagAdjList *tempA;	
	DagAdjList *itA;
	DagNode *itN = Dag->DagNode.first;
	
	while (itN) {
		itA = itN->child;	
		while (itA) {
			tempA = itA;
			itA = itA->next;
			MEM_freeN(tempA);			
		}
		tempN = itN;
		itN = itN->next;
		MEM_freeN(tempN);
	}
	Dag->DagNode.first = NULL;
	Dag->DagNode.last = NULL;
	Dag->numNodes = 0;

}

DagNode * dag_find_node (DagForest *forest,void * fob)
{
		DagNode *node = forest->DagNode.first;
		
		while (node) {
			if (node->ob == fob)
				return node;
			node = node->next;
		}
		return NULL;
}

/* no checking of existance, use dag_find_node first or dag_get_node */
DagNode * dag_add_node (DagForest *forest,void * fob)
{
	DagNode *node;
		
	node = MEM_mallocN(sizeof(DagNode),"DAG node");
	if (node) {
		node->ob = fob;
		node->color = DAG_WHITE;
		node->BFS_dist = 0;		
		node->DFS_dist = 0;		
		node->DFS_dvtm = 0;		
		node->DFS_fntm = 0;
		node->child = NULL;
		node->next = NULL;
		node->first_ancestor = NULL;
		node->ancestor_count = 0;

		node->type = GS(((ID *) fob)->name);
		if (forest->numNodes) {
			((DagNode *) forest->DagNode.last)->next = node;
			forest->DagNode.last = node;
			forest->numNodes++;
		} else {
			forest->DagNode.last = node;
			forest->DagNode.first = node;
			forest->numNodes = 1;
		}
	}
	return node;
}

DagNode * dag_get_node (DagForest *forest,void * fob)
{
	DagNode *node;
	
	node = dag_find_node (forest, fob);	
	if (!node) 
		node = dag_add_node(forest, fob);
	return node;
}



DagNode * dag_get_sub_node (DagForest *forest,void * fob)
{
	DagNode *node;
	DagAdjList *mainchild, *prev=NULL;
	
	mainchild = ((DagNode *) forest->DagNode.first)->child;
	/* remove from first node (scene) adj list if present */
	while (mainchild) {
		if (mainchild->node == fob) {
			if (prev) {
				prev->next = mainchild->next;
				MEM_freeN(mainchild);
				break;
			} else {
				((DagNode *) forest->DagNode.first)->child = mainchild->next;
				MEM_freeN(mainchild);
				break;
			}
		}
		prev = mainchild;
		mainchild = mainchild->next;
	}
	node = dag_find_node (forest, fob);	
	if (!node) 
		node = dag_add_node(forest, fob);
	return node;
}

void dag_add_relation(DagForest *forest, DagNode *fob1, DagNode *fob2, dag_rel_type rel) 
{
	DagAdjList *itA = fob1->child;
	
	while (itA) { /* search if relation exist already */
		if (itA->node == fob2) {
			if (itA->type == rel) { 
				itA->count += 1;
				return;
			}
		}
		itA = itA->next;
	}
	/* create new relation and insert at head */
	itA = MEM_mallocN(sizeof(DagAdjList),"DAG adj list");
	itA->node = fob2;
	itA->type = rel;
	itA->count = 1;
	itA->next = fob1->child;
	fob1->child = itA;
}


/*
 * MainDAG is the DAG of all objects in current scene
 * used only for drawing there is one also in each scene
 */
static DagForest * MainDag = NULL;

DagForest *getMainDag(void)
{
	return MainDag;
}


void setMainDag(DagForest *dag)
{
	MainDag = dag;
}


/*
 * note for BFS/DFS
 * in theory we should sweep the whole array
 * but in our case the first node is the scene
 * and is linked to every other object
 *
 * for general case we will need to add outer loop
 */

/*
 * ToDo : change pos kludge
 */

/* adjust levels for drawing in oops space */
void graph_bfs(void)
{
	DagNode *node;
	DagNodeQueue *nqueue;
	int pos[50];
	int i;
	DagAdjList *itA;
	int minheight;
	
	/* fprintf(stderr,"starting BFS \n ------------\n"); */	
	nqueue = queue_create(DAGQUEUEALLOC);
	for ( i=0; i<50; i++)
		pos[i] = 0;
	
	/* Init
	 * dagnode.first is alway the root (scene) 
	 */
	node = MainDag->DagNode.first;
	while(node) {
		node->color = DAG_WHITE;
		node->BFS_dist = 9999;
		node->k = 0;
		node = node->next;
	}
	
	node = MainDag->DagNode.first;
	if (node->color == DAG_WHITE) {
		node->color = DAG_GRAY;
		node->BFS_dist = 1;
		push_queue(nqueue,node);  
		while(nqueue->count) {
			node = pop_queue(nqueue);
			
			minheight = pos[node->BFS_dist];
			itA = node->child;
			while(itA != NULL) {
				if((itA->node->color == DAG_WHITE) ) {
					itA->node->color = DAG_GRAY;
					itA->node->BFS_dist = node->BFS_dist + 1;
					itA->node->k = minheight;
					push_queue(nqueue,itA->node);
				}
				
				 else {
					fprintf(stderr,"bfs not dag tree edge color :%i \n",itA->node->color);
				}
				 
				
				itA = itA->next;
			}
			if (pos[node->BFS_dist] > node->k ) {
				pos[node->BFS_dist] += 1;				
				node->k = pos[node->BFS_dist];
			} else {
				pos[node->BFS_dist] = node->k +1;
			}
			set_node_xy(node, DEPSX*2*node->BFS_dist, pos[node->BFS_dist]*DEPSY*2);
			node->color = DAG_BLACK;
			/*
			 fprintf(stderr,"BFS node : %20s %i %5.0f %5.0f\n",((ID *) node->ob)->name,node->BFS_dist, node->x, node->y);	
			 */
		}
	}
	queue_delete(nqueue);
}

int pre_and_post_BFS(DagForest *dag, short mask, graph_action_func pre_func, graph_action_func post_func, void **data) {
	DagNode *node;
	
	node = dag->DagNode.first;
	return pre_and_post_source_BFS(dag, mask,  node,  pre_func,  post_func, data);
}


int pre_and_post_source_BFS(DagForest *dag, short mask, DagNode *source, graph_action_func pre_func, graph_action_func post_func, void **data)
{
	DagNode *node;
	DagNodeQueue *nqueue;
	DagAdjList *itA;
	int	retval = 0;
	/* fprintf(stderr,"starting BFS \n ------------\n"); */	
	
	/* Init
		* dagnode.first is alway the root (scene) 
		*/
	node = dag->DagNode.first;
	nqueue = queue_create(DAGQUEUEALLOC);
	while(node) {
		node->color = DAG_WHITE;
		node->BFS_dist = 9999;
		node = node->next;
	}
	
	node = source;
	if (node->color == DAG_WHITE) {
		node->color = DAG_GRAY;
		node->BFS_dist = 1;
		pre_func(node->ob,data);
		
		while(nqueue->count) {
			node = pop_queue(nqueue);
			
			itA = node->child;
			while(itA != NULL) {
				if((itA->node->color == DAG_WHITE) && (itA->type & mask)) {
					itA->node->color = DAG_GRAY;
					itA->node->BFS_dist = node->BFS_dist + 1;
					push_queue(nqueue,itA->node);
					pre_func(node->ob,data);
				}
				
				else { // back or cross edge
					retval = 1;
				}
				itA = itA->next;
			}
			post_func(node->ob,data);
			node->color = DAG_BLACK;
			/*
			 fprintf(stderr,"BFS node : %20s %i %5.0f %5.0f\n",((ID *) node->ob)->name,node->BFS_dist, node->x, node->y);	
			 */
		}
	}
	queue_delete(nqueue);
	return retval;
}

/* non recursive version of DFS, return queue -- outer loop present to catch odd cases (first level cycles)*/
DagNodeQueue * graph_dfs(void)
{
	DagNode *node;
	DagNodeQueue *nqueue;
	DagNodeQueue *retqueue;
	int pos[50];
	int i;
	DagAdjList *itA;
	int time;
	int skip = 0;
	int minheight;
	int maxpos=0;
	int	is_cycle = 0;
	/*
	 *fprintf(stderr,"starting DFS \n ------------\n");
	 */	
	nqueue = queue_create(DAGQUEUEALLOC);
	retqueue = queue_create(MainDag->numNodes);
	for ( i=0; i<50; i++)
		pos[i] = 0;
	
	/* Init
	 * dagnode.first is alway the root (scene) 
	 */
	node = MainDag->DagNode.first;
	while(node) {
		node->color = DAG_WHITE;
		node->DFS_dist = 9999;
		node->DFS_dvtm = node->DFS_fntm = 9999;
		node->k = 0;
		node =  node->next;
	}
	
	time = 1;
	
	node = MainDag->DagNode.first;

	do {
	if (node->color == DAG_WHITE) {
		node->color = DAG_GRAY;
		node->DFS_dist = 1;
		node->DFS_dvtm = time;
		time++;
		push_stack(nqueue,node);  
			
		while(nqueue->count) {
			//graph_print_queue(nqueue);

			 skip = 0;
			node = get_top_node_queue(nqueue);
			
			minheight = pos[node->DFS_dist];

			itA = node->child;
			while(itA != NULL) {
				if((itA->node->color == DAG_WHITE) ) {
					itA->node->DFS_dvtm = time;
					itA->node->color = DAG_GRAY;

					time++;
					itA->node->DFS_dist = node->DFS_dist + 1;
					itA->node->k = minheight;
					push_stack(nqueue,itA->node);
					skip = 1;
					break;
				} else { 
					if (itA->node->color == DAG_GRAY) { // back edge
						fprintf(stderr,"dfs back edge :%15s %15s \n",((ID *) node->ob)->name, ((ID *) itA->node->ob)->name);
						is_cycle = 1;
					} else if (itA->node->color == DAG_BLACK) {
						;
						/* already processed node but we may want later to change distance either to shorter to longer.
						 * DFS_dist is the first encounter  
						*/
						/*if (node->DFS_dist >= itA->node->DFS_dist)
							itA->node->DFS_dist = node->DFS_dist + 1;
						 	
							fprintf(stderr,"dfs forward or cross edge :%15s %i-%i %15s %i-%i \n",
								((ID *) node->ob)->name,
								node->DFS_dvtm, 
								node->DFS_fntm, 
								((ID *) itA->node->ob)->name, 
								itA->node->DFS_dvtm,
								itA->node->DFS_fntm);
					*/
					} else 
						fprintf(stderr,"dfs unknown edge \n");
				}
				itA = itA->next;
			}			

			if (!skip) {
				node = pop_queue(nqueue);
				node->color = DAG_BLACK;

				node->DFS_fntm = time;
				time++;
				if (node->DFS_dist > maxpos)
					maxpos = node->DFS_dist;
				if (pos[node->DFS_dist] > node->k ) {
					pos[node->DFS_dist] += 1;				
					node->k = pos[node->DFS_dist];
				} else {
					pos[node->DFS_dist] = node->k +1;
				}
				set_node_xy(node, DEPSX*2*node->DFS_dist, pos[node->DFS_dist]*DEPSY*2);
				
				/*
				 fprintf(stderr,"DFS node : %20s %i %i %i %i\n",((ID *) node->ob)->name,node->BFS_dist, node->DFS_dist, node->DFS_dvtm, node->DFS_fntm ); 	
				*/
				 push_stack(retqueue,node);
				
			}
		}
	}
		node = node->next;
	} while (node);
//	  fprintf(stderr,"i size : %i \n", maxpos);
	  
	queue_delete(nqueue);
	  return(retqueue);
}

int pre_and_post_DFS(DagForest *dag, short mask, graph_action_func pre_func, graph_action_func post_func, void **data) {
	DagNode *node;

	node = dag->DagNode.first;
	return pre_and_post_source_DFS(dag, mask,  node,  pre_func,  post_func, data);
}

int pre_and_post_source_DFS(DagForest *dag, short mask, DagNode *source, graph_action_func pre_func, graph_action_func post_func, void **data)
{
	DagNode *node;
	DagNodeQueue *nqueue;
	DagAdjList *itA;
	int time;
	int skip = 0;
	int retval = 0;
	/*
	 *fprintf(stderr,"starting DFS \n ------------\n");
	 */	
	nqueue = queue_create(DAGQUEUEALLOC);
	
	/* Init
		* dagnode.first is alway the root (scene) 
		*/
	node = dag->DagNode.first;
	while(node) {
		node->color = DAG_WHITE;
		node->DFS_dist = 9999;
		node->DFS_dvtm = node->DFS_fntm = 9999;
		node->k = 0;
		node =  node->next;
	}
	
	time = 1;
	
	node = source;
	do {
		if (node->color == DAG_WHITE) {
			node->color = DAG_GRAY;
			node->DFS_dist = 1;
			node->DFS_dvtm = time;
			time++;
			push_stack(nqueue,node);  
			pre_func(node->ob,data);

			while(nqueue->count) {
				skip = 0;
				node = get_top_node_queue(nqueue);
								
				itA = node->child;
				while(itA != NULL) {
					if((itA->node->color == DAG_WHITE) && (itA->type & mask) ) {
						itA->node->DFS_dvtm = time;
						itA->node->color = DAG_GRAY;
						
						time++;
						itA->node->DFS_dist = node->DFS_dist + 1;
						push_stack(nqueue,itA->node);
						pre_func(node->ob,data);

						skip = 1;
						break;
					} else {
						if (itA->node->color == DAG_GRAY) {// back edge
							retval = 1;
						}
//						else if (itA->node->color == DAG_BLACK) { // cross or forward
//							;
					}
					itA = itA->next;
				}			
				
				if (!skip) {
					node = pop_queue(nqueue);
					node->color = DAG_BLACK;
					
					node->DFS_fntm = time;
					time++;
					post_func(node->ob,data);
				}
			}
		}
		node = node->next;
	} while (node);
	queue_delete(nqueue);
	return(retval);
}

// sort the base list on place
void topo_sort_baselist(struct Scene *sce){
	DagNode *node;
	DagNodeQueue *nqueue;
	DagAdjList *itA;
	int time;
	int skip = 0;
	ListBase tempbase;
	Base *base;
	
	tempbase.first= tempbase.last= 0;
	
	build_dag(sce,DAG_RL_ALL_BUT_DATA_MASK);
	
	nqueue = queue_create(DAGQUEUEALLOC);
	
	node = sce->theDag->DagNode.first;
	while(node) {
		node->color = DAG_WHITE;
		node =  node->next;
	}
	
	time = 1;
	
	node = sce->theDag->DagNode.first;
	
	node->color = DAG_GRAY;
	time++;
	push_stack(nqueue,node);  
	
	while(nqueue->count) {
		
		skip = 0;
		node = get_top_node_queue(nqueue);
		
		itA = node->child;
		while(itA != NULL) {
			if((itA->node->color == DAG_WHITE) ) {
				itA->node->DFS_dvtm = time;
				itA->node->color = DAG_GRAY;
				
				time++;
				push_stack(nqueue,itA->node);
				skip = 1;
				break;
			} 
			itA = itA->next;
		}			
		
		if (!skip) {
			if (node) {
				node = pop_queue(nqueue);
				if (node->ob == sce)	// we are done
					break ;
				node->color = DAG_BLACK;
				
				time++;
				base = sce->base.first;
				while (base->object != node->ob)
					base = base->next;
				BLI_remlink(&sce->base,base);
				BLI_addhead(&tempbase,base);
			}	
		}
	}
	
	// temporal correction for circular dependancies
	base = sce->base.first;
	while (base) {
		BLI_remlink(&sce->base,base);
		BLI_addhead(&tempbase,base);
		base = sce->base.first;
	}
	
	sce->base = tempbase;
	queue_delete(nqueue);
}


// used to get the obs owning a datablock
struct DagNodeQueue *get_obparents(struct DagForest	*dag, void *ob) 
{
	DagNode * node, *node1;
	DagNodeQueue *nqueue;
	DagAdjList *itA;

	node = dag_find_node(dag,ob);
	if (node->ancestor_count == 1) { // simple case
		nqueue = queue_create(1);
		push_queue(nqueue,node);
	} else {	// need to go over the whole dag for adj list
		nqueue = queue_create(node->ancestor_count);
		
		node1 = dag->DagNode.first;
		do {
			if (node1->DFS_fntm > node->DFS_fntm) { // a parent is finished after child. must check adj list
				itA = node->child;
				while(itA != NULL) {
					if ((itA->node == node) && (itA->type == DAG_RL_DATA)) {
						push_queue(nqueue,node);
					}
					itA = itA->next;
				}
			}
			node1 = node1->next;
		} while (node1);
	}
	return nqueue;
}

struct DagNodeQueue *get_first_ancestors(struct DagForest	*dag, void *ob)
{
	DagNode * node, *node1;
	DagNodeQueue *nqueue;
	DagAdjList *itA;
	
	node = dag_find_node(dag,ob);
	
	// need to go over the whole dag for adj list
	nqueue = queue_create(node->ancestor_count);
	
	node1 = dag->DagNode.first;
	do {
		if (node1->DFS_fntm > node->DFS_fntm) { 
			itA = node->child;
			while(itA != NULL) {
				if (itA->node == node) {
					push_queue(nqueue,node);
				}
				itA = itA->next;
			}
		}
		node1 = node1->next;
	} while (node1);
	
	return nqueue;	
}

// standard DFS list
struct DagNodeQueue *get_all_childs(struct DagForest	*dag, void *ob)
{
	DagNode *node;
	DagNodeQueue *nqueue;
	DagNodeQueue *retqueue;
	DagAdjList *itA;
	int time;
	int skip = 0;

	nqueue = queue_create(DAGQUEUEALLOC);
	retqueue = queue_create(MainDag->numNodes);
	
	node = dag->DagNode.first;
	while(node) {
		node->color = DAG_WHITE;
		node =  node->next;
	}
	
	time = 1;
	
	node = dag_find_node(dag,ob);
	
	node->color = DAG_GRAY;
	time++;
	push_stack(nqueue,node);  
	
	while(nqueue->count) {
		
		skip = 0;
		node = get_top_node_queue(nqueue);
				
		itA = node->child;
		while(itA != NULL) {
			if((itA->node->color == DAG_WHITE) ) {
				itA->node->DFS_dvtm = time;
				itA->node->color = DAG_GRAY;
				
				time++;
				push_stack(nqueue,itA->node);
				skip = 1;
				break;
			} 
			itA = itA->next;
		}			
		
		if (!skip) {
			node = pop_queue(nqueue);
			node->color = DAG_BLACK;
			
			time++;
			push_stack(retqueue,node);			
		}
	}
		
	queue_delete(nqueue);
	return(retqueue);
}

dag_rel_type	are_obs_related(struct DagForest	*dag, void *ob1, void *ob2) {
	DagNode * node;
	DagAdjList *itA;
	
	node = dag_find_node(dag,ob1);
	
	itA = node->child;
	while(itA != NULL) {
		if((itA->node->ob == ob2) ) {
			return itA->node->type;
		} 
		itA = itA->next;
	}
	return DAG_NO_RELATION;
}

int	is_acyclic( DagForest	*dag) {
	return dag->is_acyclic;
}

void set_node_xy(DagNode *node, float x, float y)
{
 	node->x = x;
	node->y = y;
}


/* debug test functions */

void graph_print_queue(DagNodeQueue *nqueue)
{	
	DagNodeQueueElem *queueElem;
	
	queueElem = nqueue->first;
	while(queueElem) {
		fprintf(stderr,"** %s %i %i-%i ",((ID *) queueElem->node->ob)->name,queueElem->node->color,queueElem->node->DFS_dvtm,queueElem->node->DFS_fntm);
		queueElem = queueElem->next;		
	}
	fprintf(stderr,"\n");
}

void graph_print_queue_dist(DagNodeQueue *nqueue)
{	
	DagNodeQueueElem *queueElem;
	int max, count;
	
	queueElem = nqueue->first;
	max = queueElem->node->DFS_fntm;
	count = 0;
	while(queueElem) {
		fprintf(stderr,"** %25s %2.2i-%2.2i ",((ID *) queueElem->node->ob)->name,queueElem->node->DFS_dvtm,queueElem->node->DFS_fntm);
		while (count < queueElem->node->DFS_dvtm-1) { fputc(' ',stderr); count++;}
		fputc('|',stderr); 
		while (count < queueElem->node->DFS_fntm-2) { fputc('-',stderr); count++;}
		fputc('|',stderr);
		fputc('\n',stderr);
		count = 0;
		queueElem = queueElem->next;		
	}
	fprintf(stderr,"\n");
}

void graph_print_adj_list(void)
{
	DagNode *node;
	DagAdjList *itA;
	
	node = (getMainDag())->DagNode.first;
	while(node) {
		fprintf(stderr,"node : %s col: %i",((ID *) node->ob)->name, node->color);		
		itA = node->child;
		while (itA) {
			fprintf(stderr,"-- %s ",((ID *) itA->node->ob)->name);
			
			itA = itA->next;
		}
		fprintf(stderr,"\n");
		node = node->next;
	}
}