== Constraints System - Recode 2 ==

Once again, I've recoded the constraints system. This time, the goals were:
* To make it more future-proof by 'modernising' the coding style. The long functions filled with switch statements, have given way to function-pointers with smaller functions for specific purposes.
* To make it support constraints which use multiple targets more readily that it did. In the past, it was assumed that constraints could only have at most one target.

As a result, a lot of code has been shuffled around, and modified. Also, the subversion number has been bumped up.

Known issues:
* PyConstraints, which were the main motivation for supporting multiple-targets, are currently broken. There are some bimport() error that keeps causing problems. I've also temporarily removed the doDriver support, although it may return in another form soon. 
* Constraints BPy-API is currently has a few features which currently don't work yet
* Outliner currently only displays the names of the constraints instead of the fancy subtarget/target/constraint-name display it used to do. What gets displayed here needs further investigation, as the old way was certainly not that great (and is not compatible with the new system too) 

1 files changed, 104 insertions, 61 deletions

diff --git a/source/blender/blenkernel/intern/depsgraph.c b/source/blender/blenkernel/intern/depsgraph.c
index eb651a925e0..fc7e6d61f8a 100644
--- a/source/blender/blenkernel/intern/depsgraph.c
+++ b/source/blender/blenkernel/intern/depsgraph.c
@@ -368,27 +368,34 @@ static void build_dag_object(DagForest *dag, DagNode *scenenode, Object *ob, int
 		if (ob->pose){
 			bPoseChannel *pchan;
 			bConstraint *con;
-			Object * target;
-			char *subtarget;
 			
-			for (pchan = ob->pose->chanbase.first; pchan; pchan=pchan->next){
-				for (con = pchan->constraints.first; con; con=con->next){
-					if (constraint_has_target(con)) {
+			for (pchan = ob->pose->chanbase.first; pchan; pchan=pchan->next) {
+				for (con = pchan->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);
 						
-						target = get_constraint_target(con, &subtarget);
-						if (target!=ob) {
-							// fprintf(stderr,"armature %s target :%s \n", ob->id.name, target->id.name);
-							node3 = dag_get_node(dag, target);
-							
-							if(subtarget && subtarget[0])
-								dag_add_relation(dag,node3,node, DAG_RL_OB_DATA|DAG_RL_DATA_DATA);
-							else if(ELEM(con->type, CONSTRAINT_TYPE_FOLLOWPATH, CONSTRAINT_TYPE_CLAMPTO)) 	
-								dag_add_relation(dag,node3,node, DAG_RL_DATA_DATA|DAG_RL_OB_DATA);
-							else
-								dag_add_relation(dag,node3,node, DAG_RL_OB_DATA);
-							
+						for (ct= targets.first; ct; ct= ct->next) {
+							if (ct->tar != ob) {
+								// fprintf(stderr,"armature %s target :%s \n", ob->id.name, target->id.name);
+								node3 = dag_get_node(dag, ct->tar);
+								
+								if (ct->subtarget[0])
+									dag_add_relation(dag,node3,node, DAG_RL_OB_DATA|DAG_RL_DATA_DATA);
+								else if(ELEM(con->type, CONSTRAINT_TYPE_FOLLOWPATH, CONSTRAINT_TYPE_CLAMPTO)) 	
+									dag_add_relation(dag,node3,node, DAG_RL_DATA_DATA|DAG_RL_OB_DATA);
+								else
+									dag_add_relation(dag,node3,node, DAG_RL_OB_DATA);
+							}
 						}
+						
+						if (cti->flush_constraint_targets)
+							cti->flush_constraint_targets(con, &targets, 1);
 					}
+					
 				}
 			}
 		}
@@ -581,20 +588,35 @@ static void build_dag_object(DagForest *dag, DagNode *scenenode, Object *ob, int
 	}
 	
 	for (con = ob->constraints.first; con; con=con->next) {
-		if (constraint_has_target(con)) {
-			char *str;
-			Object *obt= get_constraint_target(con, &str);
+		bConstraintTypeInfo *cti= constraint_get_typeinfo(con);
+		ListBase targets = {NULL, NULL};
+		bConstraintTarget *ct;
+		
+		if (cti && cti->get_constraint_targets) {
+			cti->get_constraint_targets(con, &targets);
 			
-			node2 = dag_get_node(dag, obt);
-			if(ELEM(con->type, CONSTRAINT_TYPE_FOLLOWPATH, CONSTRAINT_TYPE_CLAMPTO))
-				dag_add_relation(dag, node2, node, DAG_RL_DATA_OB|DAG_RL_OB_OB);
-			else {
-				if(ELEM3(obt->type, OB_ARMATURE, OB_MESH, OB_LATTICE) && str && str[0])
-					dag_add_relation(dag, node2, node, DAG_RL_DATA_OB|DAG_RL_OB_OB);
+			for (ct= targets.first; ct; ct= ct->next) {
+				Object *obt;
+				
+				if (ct->tar)
+					obt= ct->tar;
 				else
-					dag_add_relation(dag, node2, node, DAG_RL_OB_OB);
+					continue;
+				
+				node2 = dag_get_node(dag, obt);
+				if (ELEM(con->type, CONSTRAINT_TYPE_FOLLOWPATH, CONSTRAINT_TYPE_CLAMPTO))
+					dag_add_relation(dag, node2, node, DAG_RL_DATA_OB|DAG_RL_OB_OB);
+				else {
+					if (ELEM3(obt->type, OB_ARMATURE, OB_MESH, OB_LATTICE) && (ct->subtarget[0]))
+						dag_add_relation(dag, node2, node, DAG_RL_DATA_OB|DAG_RL_OB_OB);
+					else
+						dag_add_relation(dag, node2, node, DAG_RL_OB_OB);
+				}
+				addtoroot = 0;
 			}
-			addtoroot = 0;
+			
+			if (cti->flush_constraint_targets)
+				cti->flush_constraint_targets(con, &targets, 1);
 		}
 	}
 
@@ -1718,10 +1740,23 @@ static void dag_object_time_update_flags(Object *ob)
 	if(ob->ipo) ob->recalc |= OB_RECALC_OB;
 	else if(ob->constraints.first) {
 		bConstraint *con;
-		for (con = ob->constraints.first; con; con=con->next){
-			if (constraint_has_target(con)) {
-				ob->recalc |= OB_RECALC_OB;
-				break;
+		for (con = ob->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) {
+						ob->recalc |= OB_RECALC_OB;
+						break;
+					}
+				}
+				
+				if (cti->flush_constraint_targets)
+					cti->flush_constraint_targets(con, &targets, 1);
 			}
 		}
 	}
@@ -2076,42 +2111,50 @@ void DAG_pose_sort(Object *ob)
 			dag_add_parent_relation(dag, node2, node, 0);
 			addtoroot = 0;
 		}
-		for (con = pchan->constraints.first; con; con=con->next){
-			if (constraint_has_target(con)) {
-				char *subtarget;
-				Object *target = get_constraint_target(con, &subtarget);
+		for (con = pchan->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);
 				
-				if (target==ob && subtarget) {
-					bPoseChannel *target= get_pose_channel(ob->pose, subtarget);
-					if(target) {
-						node2= dag_get_node(dag, target);
-						dag_add_relation(dag, node2, node, 0);
-						dag_add_parent_relation(dag, node2, node, 0);
-						
-						if(con->type==CONSTRAINT_TYPE_KINEMATIC) {
-							bKinematicConstraint *data = (bKinematicConstraint*)con->data;
-							bPoseChannel *parchan;
-							int segcount= 0;
+				for (ct= targets.first; ct; ct= ct->next) {
+					if (ct->tar==ob && ct->subtarget[0]) {
+						bPoseChannel *target= get_pose_channel(ob->pose, ct->subtarget);
+						if (target) {
+							node2= dag_get_node(dag, target);
+							dag_add_relation(dag, node2, node, 0);
+							dag_add_parent_relation(dag, node2, node, 0);
 							
-							/* exclude tip from chain? */
-							if(!(data->flag & CONSTRAINT_IK_TIP))
-								parchan= pchan->parent;
-							else
-								parchan= pchan;
-							
-							/* Walk to the chain's root */
-							while (parchan){
-								node3= dag_get_node(dag, parchan);
-								dag_add_relation(dag, node2, node3, 0);
-								dag_add_parent_relation(dag, node2, node3, 0);
+							if (con->type==CONSTRAINT_TYPE_KINEMATIC) {
+								bKinematicConstraint *data = (bKinematicConstraint *)con->data;
+								bPoseChannel *parchan;
+								int segcount= 0;
 								
-								segcount++;
-								if(segcount==data->rootbone || segcount>255) break; // 255 is weak
-								parchan= parchan->parent;
+								/* exclude tip from chain? */
+								if(!(data->flag & CONSTRAINT_IK_TIP))
+									parchan= pchan->parent;
+								else
+									parchan= pchan;
+								
+								/* Walk to the chain's root */
+								while (parchan) {
+									node3= dag_get_node(dag, parchan);
+									dag_add_relation(dag, node2, node3, 0);
+									dag_add_parent_relation(dag, node2, node3, 0);
+									
+									segcount++;
+									if (segcount==data->rootbone || segcount>255) break; // 255 is weak
+									parchan= parchan->parent;
+								}
 							}
 						}
 					}
 				}
+				
+				if (cti->flush_constraint_targets)
+					cti->flush_constraint_targets(con, &targets, 1);
 			}
 		}
 		if (addtoroot == 1 ) {