Added new data in the cloth modifier for hair root information.

This will allow us to implement moving reference frames for hair and
make "fictitious" forces optional, aiding in creating stable and
controllable hair systems.

Adding data in this place is a nasty hack, but it's too difficult to
encode as a DM data layer and the whole cloth modifier/DM intermediate
data copying for hair should be removed anyway.

5 files changed, 25 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_cloth.h b/source/blender/blenkernel/BKE_cloth.h
index df118276809..10a336a075a 100644
--- a/source/blender/blenkernel/BKE_cloth.h
+++ b/source/blender/blenkernel/BKE_cloth.h
@@ -59,6 +59,11 @@ struct PartDeflect;
 #define CLOTH_VERT_FLAG_PINNED 1
 #define CLOTH_VERT_FLAG_NOSELFCOLL 2 /* vertex NOT used for self collisions */
 
+typedef struct ClothHairRoot {
+	float loc[3];
+	float rot[3][3];
+} ClothHairRoot;
+
 /**
  * This structure describes a cloth object against which the
  * simulation can run.
diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index 71656240369..14082af4cbd 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -4010,12 +4010,19 @@ static void do_hair_dynamics(ParticleSimulationData *sim)
 	if (dm && (totpoint != dm->getNumVerts(dm) || totedge != dm->getNumEdges(dm))) {
 		dm->release(dm);
 		dm = psys->hair_in_dm = NULL;
+		
+		MEM_freeN(psys->clmd->roots);
+		psys->clmd->roots = NULL;
 	}
 
 	if (!dm) {
 		dm = psys->hair_in_dm = CDDM_new(totpoint, totedge, 0, 0, 0);
 		DM_add_vert_layer(dm, CD_MDEFORMVERT, CD_CALLOC, NULL);
 	}
+	
+	if (!psys->clmd->roots) {
+		psys->clmd->roots = MEM_mallocN(sizeof(ClothHairRoot) * totpoint, "hair roots");
+	}
 
 	mvert = CDDM_get_verts(dm);
 	medge = CDDM_get_edges(dm);
@@ -4032,6 +4039,7 @@ static void do_hair_dynamics(ParticleSimulationData *sim)
 		psys_mat_hair_to_object(sim->ob, sim->psmd->dm, psys->part->from, pa, hairmat);
 
 		for (k=0, key=pa->hair; k<pa->totkey; k++,key++) {
+			ClothHairRoot *root = &psys->clmd->roots[pa->hair_index + k - 1];
 			
 			/* create fake root before actual root to resist bending */
 			if (k==0) {
@@ -4057,6 +4065,10 @@ static void do_hair_dynamics(ParticleSimulationData *sim)
 				}
 			}
 
+			/* store root transform in cloth data */
+			copy_v3_v3(root->loc, hairmat[3]);
+			copy_m3_m4(root->rot, hairmat);
+
 			copy_v3_v3(mvert->co, key->co);
 			mul_m4_v3(hairmat, mvert->co);
 			mvert++;
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 902f2a41800..53ceaa00703 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -3934,6 +3934,7 @@ static void direct_link_particlesystems(FileData *fd, ListBase *particles)
 		if (psys->clmd) {
 			psys->clmd = newdataadr(fd, psys->clmd);
 			psys->clmd->clothObject = NULL;
+			psys->clmd->roots = NULL;
 			
 			psys->clmd->sim_parms= newdataadr(fd, psys->clmd->sim_parms);
 			psys->clmd->coll_parms= newdataadr(fd, psys->clmd->coll_parms);
@@ -4662,6 +4663,7 @@ static void direct_link_modifiers(FileData *fd, ListBase *lb)
 			ClothModifierData *clmd = (ClothModifierData *)md;
 			
 			clmd->clothObject = NULL;
+			clmd->roots = NULL;
 			
 			clmd->sim_parms= newdataadr(fd, clmd->sim_parms);
 			clmd->coll_parms= newdataadr(fd, clmd->coll_parms);
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 812e7d20e2a..3dd9ebb5f37 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -564,6 +564,8 @@ typedef struct ClothModifierData {
 	struct ClothCollSettings *coll_parms; /* definition is in DNA_cloth_types.h */
 	struct PointCache *point_cache;       /* definition is in DNA_object_force.h */
 	struct ListBase ptcaches;
+	/* XXX nasty hack, remove once hair can be separated from cloth modifier data */
+	struct ClothHairRoot *roots;
 	
 	struct SimDebugData *debug_data;      /* debug info */
 } ClothModifierData;
diff --git a/source/blender/modifiers/intern/MOD_cloth.c b/source/blender/modifiers/intern/MOD_cloth.c
index 15a73c0a34d..5c5e38f3444 100644
--- a/source/blender/modifiers/intern/MOD_cloth.c
+++ b/source/blender/modifiers/intern/MOD_cloth.c
@@ -178,6 +178,7 @@ static void copyData(ModifierData *md, ModifierData *target)
 	tclmd->point_cache = BKE_ptcache_add(&tclmd->ptcaches);
 	tclmd->point_cache->step = 1;
 	tclmd->clothObject = NULL;
+	tclmd->roots = NULL;
 	tclmd->debug_data = NULL;
 }
 
@@ -207,6 +208,9 @@ static void freeData(ModifierData *md)
 		BKE_ptcache_free_list(&clmd->ptcaches);
 		clmd->point_cache = NULL;
 		
+		if (clmd->roots)
+			MEM_freeN(clmd->roots);
+		
 		BKE_sim_debug_data_free(clmd->debug_data);
 	}
 }