Fix T47038: Particles in Particle Edit Mode get added in completely wrong location.

It also fixes another issue (crash) related to symmetric editing.

Quite involved, we (try to!) fix complete broken logic of parts of particle code, which would use poly index
as tessface one (or vice-versa). Issue most probably goes back to BMesh integration time...

This patch mostly fixes particle editing mode:
  - Adding/removing particles when using generative modifiers (like subsurf) should now work.
  - Adding/removing particles with a non-tessellated mesh (i.e. one having ngons) should also mostly work.
  - X-axis-mirror-editing particles over ngons does not really work, not sure why currently.
  - All this in both 'modes' (with or without using modifier stack for particles).

Tech side:
  - Store a deformed-only DM in particle modifier data.
  - Rename existing DM to make it clear it's a final one.
  - Use deformed-only DM's tessface2poly mapping to 'solve' poly/tessface mismatches.
  - Make (part of) mirror-editing code able to use a DM instead of raw mesh, so that we can mirror based on final DM
    when editing particles using modifier stack (mandatory, since there is no way currently to find orig tessface
    from an final DM tessface index).

Note that this patch is not really nice and clean (current particles are beyond hope on this side anyway),
it's more like some urgency bandage. Whole crap needs complete rewrite anyway,
BMesh's polygons make it really hard to work with current system (and looptri would not help much here).

Also, did not test everything possibly affected by those changes, so it needs some users' testing & validation too.

Reviewers: psy-fi

Subscribers: dfelinto, eyecandy

Maniphest Tasks: T47038

Differential Revision: https://developer.blender.org/D1685

1 files changed, 20 insertions, 21 deletions

diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 130b56987e2..bf506c8545b 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -311,7 +311,7 @@ int psys_get_tot_child(Scene *scene, ParticleSystem *psys)
 /*			Distribution						*/
 /************************************************/
 
-void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
+void psys_calc_dmcache(Object *ob, DerivedMesh *dm_final, DerivedMesh *dm_deformed, ParticleSystem *psys)
 {
 	/* use for building derived mesh mapping info:
 	 *
@@ -324,13 +324,13 @@ void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
 	PARTICLE_P;
 	
 	/* CACHE LOCATIONS */
-	if (!dm->deformedOnly) {
+	if (!dm_final->deformedOnly) {
 		/* Will use later to speed up subsurf/derivedmesh */
 		LinkNode *node, *nodedmelem, **nodearray;
 		int totdmelem, totelem, i, *origindex, *origindex_poly = NULL;
 
 		if (psys->part->from == PART_FROM_VERT) {
-			totdmelem= dm->getNumVerts(dm);
+			totdmelem= dm_final->getNumVerts(dm_final);
 
 			if (use_modifier_stack) {
 				totelem= totdmelem;
@@ -338,11 +338,11 @@ void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
 			}
 			else {
 				totelem= me->totvert;
-				origindex= dm->getVertDataArray(dm, CD_ORIGINDEX);
+				origindex= dm_final->getVertDataArray(dm_final, CD_ORIGINDEX);
 			}
 		}
 		else { /* FROM_FACE/FROM_VOLUME */
-			totdmelem= dm->getNumTessFaces(dm);
+			totdmelem= dm_final->getNumTessFaces(dm_final);
 
 			if (use_modifier_stack) {
 				totelem= totdmelem;
@@ -350,20 +350,20 @@ void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
 				origindex_poly= NULL;
 			}
 			else {
-				totelem= me->totpoly;
-				origindex= dm->getTessFaceDataArray(dm, CD_ORIGINDEX);
+				totelem = dm_deformed->getNumTessFaces(dm_deformed);
+				origindex = dm_final->getTessFaceDataArray(dm_final, CD_ORIGINDEX);
 
 				/* for face lookups we need the poly origindex too */
-				origindex_poly= dm->getPolyDataArray(dm, CD_ORIGINDEX);
+				origindex_poly= dm_final->getPolyDataArray(dm_final, CD_ORIGINDEX);
 				if (origindex_poly == NULL) {
 					origindex= NULL;
 				}
 			}
 		}
-	
+
 		nodedmelem= MEM_callocN(sizeof(LinkNode)*totdmelem, "psys node elems");
 		nodearray= MEM_callocN(sizeof(LinkNode *)*totelem, "psys node array");
-		
+
 		for (i=0, node=nodedmelem; i<totdmelem; i++, node++) {
 			int origindex_final;
 			node->link = SET_INT_IN_POINTER(i);
@@ -392,7 +392,7 @@ void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
 				}
 			}
 		}
-		
+
 		/* cache the verts/faces! */
 		LOOP_PARTICLES {
 			if (pa->num < 0) {
@@ -414,9 +414,7 @@ void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
 						pa->num_dmcache = DMCACHE_NOTFOUND;
 				}
 				else { /* FROM_FACE/FROM_VOLUME */
-					/* Note that sometimes the pa->num is over the nodearray size, this is bad, maybe there is a better place to fix this,
-					 * but for now passing NULL is OK. every face will be searched for the particle so its slower - Campbell */
-					pa->num_dmcache= psys_particle_dm_face_lookup(ob, dm, pa->num, pa->fuv, pa->num < totelem ? nodearray[pa->num] : NULL);
+					pa->num_dmcache = psys_particle_dm_face_lookup(dm_final, dm_deformed, pa->num, pa->fuv, nodearray);
 				}
 			}
 		}
@@ -429,8 +427,9 @@ void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
 		 * should know to use the num or num_dmcache, set the num_dmcache to
 		 * an invalid value, just in case */
 		
-		LOOP_PARTICLES
+		LOOP_PARTICLES {
 			pa->num_dmcache = DMCACHE_NOTFOUND;
+		}
 	}
 }
 
@@ -439,7 +438,7 @@ void psys_thread_context_init(ParticleThreadContext *ctx, ParticleSimulationData
 {
 	memset(ctx, 0, sizeof(ParticleThreadContext));
 	ctx->sim = *sim;
-	ctx->dm = ctx->sim.psmd->dm;
+	ctx->dm = ctx->sim.psmd->dm_final;
 	ctx->ma = give_current_material(sim->ob, sim->psys->part->omat);
 }
 
@@ -3054,7 +3053,7 @@ static void hair_create_input_dm(ParticleSimulationData *sim, int totpoint, int
 		pa->hair_index = hair_index;
 		use_hair = psys_hair_use_simulation(pa, max_length);
 		
-		psys_mat_hair_to_object(sim->ob, sim->psmd->dm, psys->part->from, pa, hairmat);
+		psys_mat_hair_to_object(sim->ob, sim->psmd->dm_final, psys->part->from, pa, hairmat);
 		mul_m4_m4m4(root_mat, sim->ob->obmat, hairmat);
 		normalize_m4(root_mat);
 		
@@ -3209,7 +3208,7 @@ static void hair_step(ParticleSimulationData *sim, float cfra)
 
 	if (psys->recalc & PSYS_RECALC_RESET) {
 		/* need this for changing subsurf levels */
-		psys_calc_dmcache(sim->ob, sim->psmd->dm, psys);
+		psys_calc_dmcache(sim->ob, sim->psmd->dm_final, sim->psmd->dm_deformed, psys);
 
 		if (psys->clmd)
 			cloth_free_modifier(psys->clmd);
@@ -3256,7 +3255,7 @@ static void save_hair(ParticleSimulationData *sim, float UNUSED(cfra))
 
 		if (pa->totkey) {
 			sub_v3_v3(key->co, root->co);
-			psys_vec_rot_to_face(sim->psmd->dm, pa, key->co);
+			psys_vec_rot_to_face(sim->psmd->dm_final, pa, key->co);
 		}
 
 		key->time = pa->state.time;
@@ -4064,11 +4063,11 @@ void particle_system_update(Scene *scene, Object *ob, ParticleSystem *psys)
 			return;
 	}
 
-	if (!sim.psmd->dm)
+	if (!sim.psmd->dm_final)
 		return;
 
 	if (part->from != PART_FROM_VERT) {
-		DM_ensure_tessface(sim.psmd->dm);
+		DM_ensure_tessface(sim.psmd->dm_final);
 	}
 
 	/* execute drivers only, as animation has already been done */