Merge with trunk/2.5 at r25563

Most likely will not compile for others, I'd appreciate any build errors
and missing files reports (I can never seem to get everything committed
and all the build systems working without help).

Porting over the sculpt/multires tools was a breeze,
thanks goes to brecht for a design that didn't exclude
ngons and was easy to port.

Note that I've not tested externally-backed multires
file support yet.  Also, I still need to write version
patch code for some cases.

Some notes:

* Like trunk, topological changes don't update multires right,
  so e.g. subdivide will duplicate multires data on the new faces,
  instead of subdividing it.
* If you set the debug value (ctrl-alt-d) to 1 it'll turn on
  my experiments in speeding up sculpting on higher-res multires
  meshes (but note it makes partial redraw not completely accurate).
* There's a bug where you have to go through editmode to get out
  of sculpt mode, not sure if I inherited or created this myself.

source/blender/blenkernel/intern/particle.c

@@ -791,7 +791,7 @@ int psys_render_simplify_distribution(ParticleThreadContext *ctx, int tot)
 	totface= dm->getNumTessFaces(dm);
 	totorigface= me->totface;
 
-	if(totface == 0 || totorigface == 0 || origindex == NULL)
+	if(totface == 0 || totorigface == 0)
 		return tot;
 
 	facearea= MEM_callocN(sizeof(float)*totorigface, "SimplifyFaceArea");
@@ -808,14 +808,14 @@ int psys_render_simplify_distribution(ParticleThreadContext *ctx, int tot)
 
 	/* compute number of children per original face */
 	for(a=0; a<tot; a++) {
-		b= origindex[ctx->index[a]];
+		b= (origindex)? origindex[ctx->index[a]]: ctx->index[a];
 		if(b != -1)
 			elems[b].totchild++;
 	}
 
 	/* compute areas and centers of original faces */
 	for(mf=mface, a=0; a<totface; a++, mf++) {
-		b= origindex[a];
+		b= (origindex)? origindex[a]: a;
 
 		if(b != -1) {
 			VECCOPY(co1, mvert[mf->v1].co);
@@ -911,7 +911,7 @@ int psys_render_simplify_distribution(ParticleThreadContext *ctx, int tot)
 
 	skipped= 0;
 	for(a=0, newtot=0; a<tot; a++) {
-		b= origindex[ctx->index[a]];
+		b= (origindex)? origindex[ctx->index[a]]: ctx->index[a];
 		if(b != -1) {
 			if(elems[b].curchild++ < ceil(elems[b].lambda*elems[b].totchild)) {
 				ctx->index[newtot]= ctx->index[a];
@@ -944,7 +944,7 @@ int psys_render_simplify_params(ParticleSystem *psys, ChildParticle *cpa, float
 	if(!data->dosimplify)
 		return 0;
 	
-	b= data->origindex[cpa->num];
+	b= (data->origindex)? data->origindex[cpa->num]: cpa->num;
 	if(b == -1)
 		return 0;
 
@@ -2333,6 +2333,7 @@ static int psys_threads_init_path(ParticleThread *threads, Scene *scene, float c
 	ctx->totparent= totparent;
 	ctx->parent_pass= 0;
 	ctx->cfra= cfra;
+	ctx->editupdate= editupdate;
 
 	psys->lattice = psys_get_lattice(&ctx->sim);
 
@@ -2444,7 +2445,7 @@ static void psys_thread_create_path(ParticleThread *thread, struct ChildParticle
 			mul_m4_v3(ob->obmat,cpa_1st);
 		}
 
-		pa = psys->particles + cpa->parent;
+		pa = psys->particles + cpa->pa[0];
 
 		psys_mat_hair_to_global(ob, ctx->sim.psmd->dm, psys->part->from, pa, hairmat);
 
@@ -2616,6 +2617,9 @@ static void psys_thread_create_path(ParticleThread *thread, struct ChildParticle
 				get_strand_normal(ctx->ma, ornor, cur_length, (state-1)->vel);
 		}
 
+		if(k == ctx->steps)
+			VECSUB(state->vel,state->co,(state-1)->co);
+
 		/* check if path needs to be cut before actual end of data points */
 		if(k){
 			VECSUB(dvec,state->co,(state-1)->co);
@@ -3269,14 +3273,14 @@ void psys_mat_hair_to_global(Object *ob, DerivedMesh *dm, short from, ParticleDa
 /************************************************/
 /*			ParticleSettings handling			*/
 /************************************************/
-void object_add_particle_system(Scene *scene, Object *ob)
+ModifierData *object_add_particle_system(Scene *scene, Object *ob, char *name)
 {
 	ParticleSystem *psys;
 	ModifierData *md;
 	ParticleSystemModifierData *psmd;
 
 	if(!ob || ob->type != OB_MESH)
-		return;
+		return NULL;
 
 	psys = ob->particlesystem.first;
 	for(; psys; psys=psys->next)
@@ -3294,7 +3298,11 @@ void object_add_particle_system(Scene *scene, Object *ob)
 		strcpy(psys->name, "ParticleSystem");
 
 	md= modifier_new(eModifierType_ParticleSystem);
-	sprintf(md->name, "ParticleSystem %i", BLI_countlist(&ob->particlesystem));
+
+	if(name)	BLI_strncpy(md->name, name, sizeof(md->name));
+	else		sprintf(md->name, "ParticleSystem %i", BLI_countlist(&ob->particlesystem));
+	modifier_unique_name(&ob->modifiers, md);
+
 	psmd= (ParticleSystemModifierData*) md;
 	psmd->psys=psys;
 	BLI_addtail(&ob->modifiers, md);
@@ -3305,6 +3313,8 @@ void object_add_particle_system(Scene *scene, Object *ob)
 
 	DAG_scene_sort(scene);
 	DAG_id_flush_update(&ob->id, OB_RECALC_DATA);
+
+	return md;
 }
 void object_remove_particle_system(Scene *scene, Object *ob)
 {
@@ -4060,7 +4070,7 @@ int psys_get_particle_state(ParticleSimulationData *sim, int p, ParticleKey *sta
 	else{
 		if(cpa){
 			ParticleKey *key1;
-			float t = (cfra - pa->time + pa->loop * pa->lifetime) / pa->lifetime;
+			float t = (cfra - pa->time) / pa->lifetime;
 
 			key1=&pa->state;
 			offset_child(cpa, key1, state, part->childflat, part->childrad);