Make particle edit mode work again

This is just to have hair rendering and editing mostly working as in
master. A better fix is probably needed, there seems to be some
missing depsgraph relations for particle edit settings, and particle
edit code doesn't rebuild caches after applying edits. But at least
you can see and interact with hair now until those things can be
sorted out.

1 files changed, 20 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/particle_system.c b/source/blender/blenkernel/intern/particle_system.c
index b9361f3499b..edc3f2e42fd 100644
--- a/source/blender/blenkernel/intern/particle_system.c
+++ b/source/blender/blenkernel/intern/particle_system.c
@@ -96,6 +96,8 @@
 
 #include "RE_shader_ext.h"
 
+#include "ED_particle.h"
+
 /* fluid sim particle import */
 #ifdef WITH_MOD_FLUID
 #include "DNA_object_fluidsim_types.h"
@@ -2906,9 +2908,7 @@ static void psys_update_path_cache(ParticleSimulationData *sim, float cfra, cons
 {
 	ParticleSystem *psys = sim->psys;
 	ParticleSettings *part = psys->part;
-#if 0
 	ParticleEditSettings *pset = &sim->scene->toolsettings->particle;
-#endif
 	int distr=0, alloc=0, skip=0;
 
 	if ((psys->part->childtype && psys->totchild != psys_get_tot_child(sim->scene, psys, use_render_params)) || psys->recalc&PSYS_RECALC_RESET)
@@ -2944,14 +2944,14 @@ static void psys_update_path_cache(ParticleSimulationData *sim, float cfra, cons
 		else if (psys->pointcache->flag & PTCACHE_BAKING)
 			skip = 1; /* no need to cache paths while baking dynamics */
 
-#if 0 /* TODO(mai): something is very wrong with these conditionals, they dont make sense and the cache isnt updating */
 		else if (psys_in_edit_mode(sim->depsgraph, psys)) {
 			if ((pset->flag & PE_DRAW_PART)==0)
 				skip = 1;
+#if 0 /* TODO(mai): something is very wrong with these conditionals, they dont make sense and the cache isnt updating */
 			else if (part->childtype==0 && (psys->flag & PSYS_HAIR_DYNAMICS && psys->pointcache->flag & PTCACHE_BAKED)==0)
 				skip = 1; /* in edit mode paths are needed for child particles and dynamic hair */
-		}
 #endif
+		}
 	}
 
 
@@ -4384,6 +4384,22 @@ void particle_system_update(struct Depsgraph *depsgraph, Scene *scene, Object *o
 	/* save matrix for duplicators, at rendertime the actual dupliobject's matrix is used so don't update! */
 	invert_m4_m4(psys->imat, ob->obmat);
 
+	if (ob->mode & OB_MODE_PARTICLE_EDIT && ob == OBACT(DEG_get_evaluated_view_layer(depsgraph))) {
+		PTCacheEdit *edit = PE_create_current(depsgraph, scene, ob);
+
+		if (edit && edit->psys == psys) {
+			if (edit->psys && edit->psys->flag & PSYS_HAIR_UPDATED) {
+				PE_update_object(depsgraph, scene, ob, 0);
+			}
+
+			/* create path and child path cache if it doesn't exist already */
+			if (edit->pathcache == NULL) {
+				psys_cache_edit_paths(depsgraph, scene, ob, edit, DEG_get_ctime(depsgraph), DEG_get_mode(depsgraph) == DAG_EVAL_RENDER);
+
+			}
+		}
+	}
+
 	BKE_particle_batch_cache_dirty(psys, BKE_PARTICLE_BATCH_DIRTY_ALL);
 }