Merge branch 'master' into blender2.8

- Undo that changes modes currently asserts,
  since undo is now screen data.

  Most likely we will change how object mode and workspaces work
  since it's not practical/maintainable at the moment.

- Removed view_layer from particle settings
  (wasn't needed and complicated undo).

7 files changed, 151 insertions, 213 deletions

diff --git a/source/blender/editors/physics/particle_edit.c b/source/blender/editors/physics/particle_edit.c
index 224790269e2..9deae22e4e1 100644
--- a/source/blender/editors/physics/particle_edit.c
+++ b/source/blender/editors/physics/particle_edit.c
@@ -101,21 +101,20 @@ int PE_poll(bContext *C)
 	if (!scene || !view_layer || !ob || !(workspace->object_mode & OB_MODE_PARTICLE_EDIT)) {
 		return 0;
 	}
-	return (PE_get_current(scene, view_layer, ob) != NULL);
+	return (PE_get_current(scene, ob) != NULL);
 }
 
 int PE_hair_poll(bContext *C)
 {
 	const WorkSpace *workspace = CTX_wm_workspace(C);
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
 	PTCacheEdit *edit;
 
 	if (!scene || !ob || !(workspace->object_mode & OB_MODE_PARTICLE_EDIT)) {
 		return 0;
 	}
-	edit= PE_get_current(scene, view_layer, ob);
+	edit= PE_get_current(scene, ob);
 
 	return (edit && edit->psys);
 }
@@ -136,8 +135,6 @@ void PE_free_ptcache_edit(PTCacheEdit *edit)
 
 	if (edit==0) return;
 
-	PTCacheUndo_clear(edit);
-
 	if (edit->points) {
 		LOOP_POINTS {
 			if (point->keys)
@@ -201,7 +198,7 @@ static float pe_brush_size_get(const Scene *UNUSED(scene), ParticleBrushData *br
  * note: this function runs on poll, therefor it can runs many times a second
  * keep it fast! */
 static PTCacheEdit *pe_get_current(
-        const EvaluationContext *eval_ctx, Scene *scene, ViewLayer *view_layer, Object *ob, int create)
+        const EvaluationContext *eval_ctx, Scene *scene, Object *ob, int create)
 {
 	ParticleEditSettings *pset= PE_settings(scene);
 	PTCacheEdit *edit = NULL;
@@ -212,7 +209,6 @@ static PTCacheEdit *pe_get_current(
 		return NULL;
 
 	pset->scene = scene;
-	pset->view_layer = view_layer;
 	pset->object = ob;
 
 	BKE_ptcache_ids_from_object(&pidlist, ob, NULL, 0);
@@ -241,18 +237,18 @@ static PTCacheEdit *pe_get_current(
 				if (psys->part && psys->part->type == PART_HAIR) {
 					if (psys->flag & PSYS_HAIR_DYNAMICS && psys->pointcache->flag & PTCACHE_BAKED) {
 						if (create && !psys->pointcache->edit)
-							PE_create_particle_edit(eval_ctx, scene, view_layer, ob, pid->cache, NULL);
+							PE_create_particle_edit(eval_ctx, scene, ob, pid->cache, NULL);
 						edit = pid->cache->edit;
 					}
 					else {
 						if (create && !psys->edit && psys->flag & PSYS_HAIR_DONE)
-							PE_create_particle_edit(eval_ctx, scene, view_layer, ob, NULL, psys);
+							PE_create_particle_edit(eval_ctx, scene, ob, NULL, psys);
 						edit = psys->edit;
 					}
 				}
 				else {
 					if (create && pid->cache->flag & PTCACHE_BAKED && !pid->cache->edit)
-						PE_create_particle_edit(eval_ctx, scene, view_layer, ob, pid->cache, psys);
+						PE_create_particle_edit(eval_ctx, scene, ob, pid->cache, psys);
 					edit = pid->cache->edit;
 				}
 
@@ -263,7 +259,7 @@ static PTCacheEdit *pe_get_current(
 			if (create && pid->cache->flag & PTCACHE_BAKED && !pid->cache->edit) {
 				pset->flag |= PE_FADE_TIME;
 				// NICE TO HAVE but doesn't work: pset->brushtype = PE_BRUSH_COMB;
-				PE_create_particle_edit(eval_ctx, scene, view_layer, ob, pid->cache, NULL);
+				PE_create_particle_edit(eval_ctx, scene, ob, pid->cache, NULL);
 			}
 			edit = pid->cache->edit;
 			break;
@@ -272,7 +268,7 @@ static PTCacheEdit *pe_get_current(
 			if (create && pid->cache->flag & PTCACHE_BAKED && !pid->cache->edit) {
 				pset->flag |= PE_FADE_TIME;
 				// NICE TO HAVE but doesn't work: pset->brushtype = PE_BRUSH_COMB;
-				PE_create_particle_edit(eval_ctx, scene, view_layer, ob, pid->cache, NULL);
+				PE_create_particle_edit(eval_ctx, scene, ob, pid->cache, NULL);
 			}
 			edit = pid->cache->edit;
 			break;
@@ -287,14 +283,14 @@ static PTCacheEdit *pe_get_current(
 	return edit;
 }
 
-PTCacheEdit *PE_get_current(Scene *scene, ViewLayer *view_layer, Object *ob)
+PTCacheEdit *PE_get_current(Scene *scene, Object *ob)
 {
-	return pe_get_current(NULL, scene, view_layer, ob, 0);
+	return pe_get_current(NULL, scene, ob, 0);
 }
 
 PTCacheEdit *PE_create_current(const EvaluationContext *eval_ctx, Scene *scene, Object *ob)
 {
-	return pe_get_current(eval_ctx, scene, eval_ctx->view_layer, ob, 1);
+	return pe_get_current(eval_ctx, scene, ob, 1);
 }
 
 void PE_current_changed(const EvaluationContext *eval_ctx, Scene *scene, Object *ob)
@@ -385,7 +381,7 @@ static void PE_set_data(bContext *C, PEData *data)
 	data->view_layer = CTX_data_view_layer(C);
 	data->ob = CTX_data_active_object(C);
 	CTX_data_eval_ctx(C, &data->eval_ctx);
-	data->edit = PE_get_current(data->scene, data->view_layer, data->ob);
+	data->edit = PE_get_current(data->scene, data->ob);
 }
 
 static void PE_set_view3d_data(bContext *C, PEData *data)
@@ -1146,7 +1142,7 @@ void recalc_emitter_field(Object *ob, ParticleSystem *psys)
 
 static void PE_update_selection(const EvaluationContext *eval_ctx, Scene *scene, Object *ob, int useflag)
 {
-	PTCacheEdit *edit = PE_get_current(scene, eval_ctx->view_layer, ob);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
 	HairKey *hkey;
 	POINT_P; KEY_K;
 
@@ -1256,7 +1252,7 @@ void PE_update_object(const EvaluationContext *eval_ctx, Scene *scene, Object *o
 	/* use this to do partial particle updates, not usable when adding or
 	 * removing, then a full redo is necessary and calling this may crash */
 	ParticleEditSettings *pset= PE_settings(scene);
-	PTCacheEdit *edit = PE_get_current(scene, eval_ctx->view_layer, ob);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
 	POINT_P;
 
 	if (!edit)
@@ -1396,7 +1392,7 @@ static int pe_select_all_exec(bContext *C, wmOperator *op)
 	EvaluationContext eval_ctx;
 	CTX_data_eval_ctx(C, &eval_ctx);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, eval_ctx.view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	POINT_P; KEY_K;
 	int action = RNA_enum_get(op->ptr, "action");
 
@@ -1448,9 +1444,8 @@ int PE_mouse_particles(bContext *C, const int mval[2], bool extend, bool deselec
 {
 	PEData data;
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	POINT_P; KEY_K;
 
 	if (!PE_start_edit(edit))
@@ -1642,7 +1637,7 @@ static int select_random_exec(bContext *C, wmOperator *op)
 	data.select_action = SEL_SELECT;
 	scene = CTX_data_scene(C);
 	ob = CTX_data_active_object(C);
-	edit = PE_get_current(scene, data.eval_ctx.view_layer, ob);
+	edit = PE_get_current(scene, ob);
 
 	rng = BLI_rng_new_srandom(seed);
 
@@ -1759,9 +1754,8 @@ void PE_deselect_all_visible(PTCacheEdit *edit)
 int PE_border_select(bContext *C, rcti *rect, bool select, bool extend)
 {
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	PEData data;
 
 	if (!PE_start_edit(edit))
@@ -1787,9 +1781,8 @@ int PE_border_select(bContext *C, rcti *rect, bool select, bool extend)
 int PE_circle_select(bContext *C, int selecting, const int mval[2], float rad)
 {
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	PEData data;
 
 	if (!PE_start_edit(edit))
@@ -1813,11 +1806,10 @@ int PE_circle_select(bContext *C, int selecting, const int mval[2], float rad)
 int PE_lasso_select(bContext *C, const int mcords[][2], const short moves, bool extend, bool select)
 {
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
 	ARegion *ar= CTX_wm_region(C);
 	ParticleEditSettings *pset= PE_settings(scene);
-	PTCacheEdit *edit = PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
 	ParticleSystem *psys = edit->psys;
 	ParticleSystemModifierData *psmd = psys_get_modifier(ob, psys);
 	POINT_P; KEY_K;
@@ -1906,7 +1898,7 @@ static int hide_exec(bContext *C, wmOperator *op)
 	EvaluationContext eval_ctx;
 	CTX_data_eval_ctx(C, &eval_ctx);
 
-	PTCacheEdit *edit= PE_get_current(scene, eval_ctx.view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	POINT_P; KEY_K;
 
 
@@ -1961,7 +1953,7 @@ static int reveal_exec(bContext *C, wmOperator *op)
 	Scene *scene= CTX_data_scene(C);
 	EvaluationContext eval_ctx;
 	CTX_data_eval_ctx(C, &eval_ctx);
-	PTCacheEdit *edit= PE_get_current(scene, eval_ctx.view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	const bool select = RNA_boolean_get(op->ptr, "select");
 	POINT_P; KEY_K;
 
@@ -2228,9 +2220,9 @@ void PARTICLE_OT_rekey(wmOperatorType *ot)
 	RNA_def_int(ot->srna, "keys_number", 2, 2, INT_MAX, "Number of Keys", "", 2, 100);
 }
 
-static void rekey_particle_to_time(const bContext *C, Scene *scene, ViewLayer *view_layer, Object *ob, int pa_index, float path_time)
+static void rekey_particle_to_time(const bContext *C, Scene *scene, Object *ob, int pa_index, float path_time)
 {
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	ParticleSystem *psys;
 	ParticleSimulationData sim = {0};
 	ParticleData *pa;
@@ -2570,9 +2562,8 @@ void PARTICLE_OT_subdivide(wmOperatorType *ot)
 static int remove_doubles_exec(bContext *C, wmOperator *op)
 {
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	ParticleSystem *psys = edit->psys;
 	ParticleSystemModifierData *psmd;
 	KDTree *tree;
@@ -2663,10 +2654,9 @@ void PARTICLE_OT_remove_doubles(wmOperatorType *ot)
 static int weight_set_exec(bContext *C, wmOperator *op)
 {
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	ParticleEditSettings *pset= PE_settings(scene);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	ParticleSystem *psys = edit->psys;
 	POINT_P;
 	KEY_K;
@@ -2824,11 +2814,11 @@ void PARTICLE_OT_delete(wmOperatorType *ot)
 /*************************** mirror operator **************************/
 
 static void PE_mirror_x(
-        Scene *scene, ViewLayer *view_layer, Object *ob, int tagged)
+        Scene *scene, Object *ob, int tagged)
 {
 	Mesh *me= (Mesh *)(ob->data);
 	ParticleSystemModifierData *psmd;
-	PTCacheEdit *edit = PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
 	ParticleSystem *psys = edit->psys;
 	ParticleData *pa, *newpa, *new_pars;
 	PTCacheEditPoint *newpoint, *new_points;
@@ -2975,11 +2965,10 @@ static void PE_mirror_x(
 static int mirror_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Scene *scene= CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	
-	PE_mirror_x(scene, view_layer, ob, 0);
+	PE_mirror_x(scene, ob, 0);
 
 	update_world_cos(ob, edit);
 	WM_event_add_notifier(C, NC_OBJECT|ND_PARTICLE|NA_EDITED, ob);
@@ -3116,7 +3105,7 @@ static void brush_cut(PEData *data, int pa_index)
 			edit->points[pa_index].flag |= PEP_TAG;
 		}
 		else {
-			rekey_particle_to_time(data->context, data->scene, data->view_layer, ob, pa_index, cut_time);
+			rekey_particle_to_time(data->context, data->scene, ob, pa_index, cut_time);
 			edit->points[pa_index].flag |= PEP_EDIT_RECALC;
 		}
 	}
@@ -3771,7 +3760,7 @@ static int brush_edit_init(bContext *C, wmOperator *op)
 	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob= CTX_data_active_object(C);
 	ParticleEditSettings *pset= PE_settings(scene);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	ARegion *ar= CTX_wm_region(C);
 	BrushEdit *bedit;
 	float min[3], max[3];
@@ -3805,7 +3794,6 @@ static void brush_edit_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
 {
 	BrushEdit *bedit= op->customdata;
 	Scene *scene= bedit->scene;
-	ViewLayer *view_layer = bedit->view_layer;
 	Object *ob= bedit->ob;
 	PTCacheEdit *edit= bedit->edit;
 	ParticleEditSettings *pset= PE_settings(scene);
@@ -4000,7 +3988,7 @@ static void brush_edit_apply(bContext *C, wmOperator *op, PointerRNA *itemptr)
 
 			if (ELEM(pset->brushtype, PE_BRUSH_ADD, PE_BRUSH_CUT) && (added || removed)) {
 				if (pset->brushtype == PE_BRUSH_ADD && pe_x_mirror(ob))
-					PE_mirror_x(scene, view_layer, ob, 1);
+					PE_mirror_x(scene, ob, 1);
 
 				update_world_cos(ob, edit);
 				psys_free_path_cache(NULL, edit);
@@ -4223,7 +4211,7 @@ static void shape_cut(PEData *data, int pa_index)
 			edit->points[pa_index].flag |= PEP_TAG;
 		}
 		else {
-			rekey_particle_to_time(data->context, data->scene, data->view_layer, ob, pa_index, cut_time);
+			rekey_particle_to_time(data->context, data->scene, ob, pa_index, cut_time);
 			edit->points[pa_index].flag |= PEP_EDIT_RECALC;
 		}
 	}
@@ -4232,10 +4220,9 @@ static void shape_cut(PEData *data, int pa_index)
 static int shape_cut_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Scene *scene = CTX_data_scene(C);
-	ViewLayer *view_layer = CTX_data_view_layer(C);
 	Object *ob = CTX_data_active_object(C);
 	ParticleEditSettings *pset = PE_settings(scene);
-	PTCacheEdit *edit = PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
 	Object *shapeob = pset->shape_object;
 	int selected = count_selected_keys(scene, edit);
 	int lock_root = pset->flag & PE_LOCK_FIRST;
@@ -4310,7 +4297,7 @@ void PARTICLE_OT_shape_cut(wmOperatorType *ot)
 int PE_minmax(Scene *scene, ViewLayer *view_layer, float min[3], float max[3])
 {
 	Object *ob= OBACT(view_layer);
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, ob);
+	PTCacheEdit *edit= PE_get_current(scene, ob);
 	ParticleSystem *psys;
 	ParticleSystemModifierData *psmd = NULL;
 	POINT_P; KEY_K;
@@ -4348,7 +4335,7 @@ int PE_minmax(Scene *scene, ViewLayer *view_layer, float min[3], float max[3])
 
 /* initialize needed data for bake edit */
 void PE_create_particle_edit(
-        const EvaluationContext *eval_ctx, Scene *scene, ViewLayer *view_layer, Object *ob, PointCache *cache, ParticleSystem *psys)
+        const EvaluationContext *eval_ctx, Scene *scene, Object *ob, PointCache *cache, ParticleSystem *psys)
 {
 	PTCacheEdit *edit;
 	ParticleSystemModifierData *psmd = (psys) ? psys_get_modifier(ob, psys) : NULL;
@@ -4450,9 +4437,6 @@ void PE_create_particle_edit(
 		if (psys && !cache)
 			recalc_emitter_field(ob, psys);
 		PE_update_object(eval_ctx, scene, ob, 1);
-
-		PTCacheUndo_clear(edit);
-		PE_undo_push(scene, view_layer, "Original");
 	}
 }
 
@@ -4666,7 +4650,7 @@ static int unify_length_exec(bContext *C, wmOperator *UNUSED(op))
 	EvaluationContext eval_ctx;
 	CTX_data_eval_ctx(C, &eval_ctx);
 
-	PTCacheEdit *edit = PE_get_current(scene, eval_ctx.view_layer, ob);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
 	float average_length = calculate_average_length(edit);
 
 	if (average_length == 0.0f) {
diff --git a/source/blender/editors/physics/particle_edit_undo.c b/source/blender/editors/physics/particle_edit_undo.c
index 45eb5923e57..1264800afc8 100644
--- a/source/blender/editors/physics/particle_edit_undo.c
+++ b/source/blender/editors/physics/particle_edit_undo.c
@@ -38,6 +38,7 @@
 
 #include "DNA_scene_types.h"
 #include "DNA_meshdata_types.h"
+#include "DNA_windowmanager_types.h"
 
 #include "BLI_listbase.h"
 #include "BLI_string.h"
@@ -46,40 +47,31 @@
 #include "BKE_global.h"
 #include "BKE_particle.h"
 #include "BKE_pointcache.h"
+#include "BKE_context.h"
+#include "BKE_main.h"
+#include "BKE_undo_system.h"
 
 #include "DEG_depsgraph.h"
 
+#include "ED_object.h"
 #include "ED_particle.h"
+#include "ED_physics.h"
 
 #include "particle_edit_utildefines.h"
 
 #include "physics_intern.h"
 
-static void free_PTCacheUndo(PTCacheUndo *undo)
-{
-	PTCacheEditPoint *point;
-	int i;
+/* -------------------------------------------------------------------- */
+/** \name Undo Conversion
+ * \{ */
 
-	for (i=0, point=undo->points; i<undo->totpoint; i++, point++) {
-		if (undo->particles && (undo->particles + i)->hair)
-			MEM_freeN((undo->particles + i)->hair);
-		if (point->keys)
-			MEM_freeN(point->keys);
-	}
-	if (undo->points)
-		MEM_freeN(undo->points);
-
-	if (undo->particles)
-		MEM_freeN(undo->particles);
-
-	BKE_ptcache_free_mem(&undo->mem_cache);
-}
-
-static void make_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
+static void undoptcache_from_editcache(PTCacheUndo *undo, PTCacheEdit *edit)
 {
 	PTCacheEditPoint *point;
 	int i;
 
+	size_t mem_used_prev = MEM_get_memory_in_use();
+
 	undo->totpoint= edit->totpoint;
 
 	if (edit->psys) {
@@ -87,8 +79,9 @@ static void make_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
 
 		pa= undo->particles= MEM_dupallocN(edit->psys->particles);
 
-		for (i=0; i<edit->totpoint; i++, pa++)
+		for (i=0; i<edit->totpoint; i++, pa++) {
 			pa->hair= MEM_dupallocN(pa->hair);
+		}
 
 		undo->psys_flag = edit->psys->flag;
 	}
@@ -99,8 +92,9 @@ static void make_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
 		pm = undo->mem_cache.first;
 
 		for (; pm; pm=pm->next) {
-			for (i=0; i<BPHYS_TOT_DATA; i++)
+			for (i=0; i<BPHYS_TOT_DATA; i++) {
 				pm->data[i] = MEM_dupallocN(pm->data[i]);
+			}
 		}
 	}
 
@@ -111,9 +105,13 @@ static void make_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
 		point->keys= MEM_dupallocN(point->keys);
 		/* no need to update edit key->co & key->time pointers here */
 	}
+
+	size_t mem_used_curr = MEM_get_memory_in_use();
+
+	undo->undo_size = mem_used_prev < mem_used_curr ? mem_used_curr - mem_used_prev : sizeof(PTCacheUndo);
 }
 
-static void get_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
+static void undoptcache_to_editcache(PTCacheUndo *undo, PTCacheEdit *edit)
 {
 	ParticleSystem *psys = edit->psys;
 	ParticleData *pa;
@@ -121,16 +119,20 @@ static void get_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
 	POINT_P; KEY_K;
 
 	LOOP_POINTS {
-		if (psys && psys->particles[p].hair)
+		if (psys && psys->particles[p].hair) {
 			MEM_freeN(psys->particles[p].hair);
+		}
 
-		if (point->keys)
+		if (point->keys) {
 			MEM_freeN(point->keys);
+		}
 	}
-	if (psys && psys->particles)
+	if (psys && psys->particles) {
 		MEM_freeN(psys->particles);
-	if (edit->points)
+	}
+	if (edit->points) {
 		MEM_freeN(edit->points);
+	}
 	if (edit->mirror_cache) {
 		MEM_freeN(edit->mirror_cache);
 		edit->mirror_cache= NULL;
@@ -172,9 +174,9 @@ static void get_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
 		pm = edit->pid.cache->mem_cache.first;
 
 		for (; pm; pm=pm->next) {
-			for (i=0; i<BPHYS_TOT_DATA; i++)
+			for (i = 0; i < BPHYS_TOT_DATA; i++) {
 				pm->data[i] = MEM_dupallocN(pm->data[i]);
-
+			}
 			BKE_ptcache_mem_pointers_init(pm);
 
 			LOOP_POINTS {
@@ -192,150 +194,110 @@ static void get_PTCacheUndo(PTCacheEdit *edit, PTCacheUndo *undo)
 	}
 }
 
-void PE_undo_push(Scene *scene, ViewLayer *view_layer, const char *str)
+static void undoptcache_free_data(PTCacheUndo *undo)
 {
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, OBACT(view_layer));
-	PTCacheUndo *undo;
-	int nr;
-
-	if (!edit) return;
-
-	/* remove all undos after (also when curundo==NULL) */
-	while (edit->undo.last != edit->curundo) {
-		undo= edit->undo.last;
-		BLI_remlink(&edit->undo, undo);
-		free_PTCacheUndo(undo);
-		MEM_freeN(undo);
-	}
+	PTCacheEditPoint *point;
+	int i;
 
-	/* make new */
-	edit->curundo= undo= MEM_callocN(sizeof(PTCacheUndo), "particle undo file");
-	BLI_strncpy(undo->name, str, sizeof(undo->name));
-	BLI_addtail(&edit->undo, undo);
-
-	/* and limit amount to the maximum */
-	nr= 0;
-	undo= edit->undo.last;
-	while (undo) {
-		nr++;
-		if (nr==U.undosteps) break;
-		undo= undo->prev;
-	}
-	if (undo) {
-		while (edit->undo.first != undo) {
-			PTCacheUndo *first= edit->undo.first;
-			BLI_remlink(&edit->undo, first);
-			free_PTCacheUndo(first);
-			MEM_freeN(first);
+	for (i = 0, point=undo->points; i < undo->totpoint; i++, point++) {
+		if (undo->particles && (undo->particles + i)->hair) {
+			MEM_freeN((undo->particles + i)->hair);
+		}
+		if (point->keys) {
+			MEM_freeN(point->keys);
 		}
 	}
-
-	/* copy  */
-	make_PTCacheUndo(edit, edit->curundo);
+	if (undo->points) {
+		MEM_freeN(undo->points);
+	}
+	if (undo->particles) {
+		MEM_freeN(undo->particles);
+	}
+	BKE_ptcache_free_mem(&undo->mem_cache);
 }
 
-void PE_undo_step(Scene *scene, ViewLayer *view_layer, int step)
-{
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, OBACT(view_layer));
+/** \} */
 
-	if (!edit) return;
+/* -------------------------------------------------------------------- */
+/** \name Implements ED Undo System
+ * \{ */
 
-	if (step==0) {
-		get_PTCacheUndo(edit, edit->curundo);
-	}
-	else if (step==1) {
+typedef struct ParticleUndoStep {
+	UndoStep step;
+	UndoRefID_Scene scene_ref;
+	UndoRefID_Object object_ref;
+	PTCacheUndo data;
+} ParticleUndoStep;
 
-		if (edit->curundo==NULL || edit->curundo->prev==NULL) {
-			/* pass */
-		}
-		else {
-			if (G.debug & G_DEBUG) printf("undo %s\n", edit->curundo->name);
-			edit->curundo= edit->curundo->prev;
-			get_PTCacheUndo(edit, edit->curundo);
-		}
-	}
-	else {
-		/* curundo has to remain current situation! */
-
-		if (edit->curundo==NULL || edit->curundo->next==NULL) {
-			/* pass */
-		}
-		else {
-			get_PTCacheUndo(edit, edit->curundo->next);
-			edit->curundo= edit->curundo->next;
-			if (G.debug & G_DEBUG) printf("redo %s\n", edit->curundo->name);
-		}
-	}
-
-	DEG_id_tag_update(&OBACT(view_layer)->id, OB_RECALC_DATA);
+static bool particle_undosys_poll(struct bContext *C)
+{
+	Scene *scene = CTX_data_scene(C);
+	ViewLayer *view_layer = CTX_data_view_layer(C);
+	Object *ob = OBACT(view_layer);
+	PTCacheEdit *edit = PE_get_current(scene, ob);
+	
+	return (edit != NULL);
 }
 
-bool PE_undo_is_valid(Scene *scene, ViewLayer *view_layer)
+static bool particle_undosys_step_encode(struct bContext *C, UndoStep *us_p)
 {
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, OBACT(view_layer));
-
-	if (edit) {
-		return (edit->undo.last != edit->undo.first);
-	}
-	return 0;
+	ParticleUndoStep *us = (ParticleUndoStep *)us_p;
+	ViewLayer *view_layer = CTX_data_view_layer(C);
+	us->scene_ref.ptr = CTX_data_scene(C);
+	us->object_ref.ptr = OBACT(view_layer);
+	PTCacheEdit *edit = PE_get_current(us->scene_ref.ptr, us->object_ref.ptr);
+	undoptcache_from_editcache(&us->data, edit);
+	return true;
 }
 
-void PTCacheUndo_clear(PTCacheEdit *edit)
+static void particle_undosys_step_decode(struct bContext *C, UndoStep *us_p, int UNUSED(dir))
 {
-	PTCacheUndo *undo;
-
-	if (edit==NULL) return;
-
-	undo= edit->undo.first;
-	while (undo) {
-		free_PTCacheUndo(undo);
-		undo= undo->next;
+	/* TODO(campbell): undo_system: use low-level API to set mode. */
+	ED_object_mode_set(C, OB_MODE_PARTICLE_EDIT);
+	BLI_assert(particle_undosys_poll(C));
+
+	ParticleUndoStep *us = (ParticleUndoStep *)us_p;
+	Scene *scene = us->scene_ref.ptr;
+	Object *ob = us->object_ref.ptr;
+	PTCacheEdit *edit = PE_get_current(scene, ob);
+	if (edit) {
+		undoptcache_to_editcache(&us->data, edit);
+		DEG_id_tag_update(&ob->id, OB_RECALC_DATA);
+	}
+	else {
+		BLI_assert(0);
 	}
-	BLI_freelistN(&edit->undo);
-	edit->curundo= NULL;
 }
 
-void PE_undo(Scene *scene, ViewLayer *view_layer)
+static void particle_undosys_step_free(UndoStep *us_p)
 {
-	PE_undo_step(scene, view_layer, 1);
+	ParticleUndoStep *us = (ParticleUndoStep *)us_p;
+	undoptcache_free_data(&us->data);
 }
 
-void PE_redo(Scene *scene, ViewLayer *view_layer)
+static void particle_undosys_foreach_ID_ref(
+        UndoStep *us_p, UndoTypeForEachIDRefFn foreach_ID_ref_fn, void *user_data)
 {
-	PE_undo_step(scene, view_layer, -1);
+	ParticleUndoStep *us = (ParticleUndoStep *)us_p;
+	foreach_ID_ref_fn(user_data, ((UndoRefID *)&us->scene_ref));
+	foreach_ID_ref_fn(user_data, ((UndoRefID *)&us->object_ref));
 }
 
-void PE_undo_number(Scene *scene, ViewLayer *view_layer, int nr)
+/* Export for ED_undo_sys. */
+void ED_particle_undosys_type(UndoType *ut)
 {
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, OBACT(view_layer));
-	PTCacheUndo *undo;
-	int a=0;
-
-	for (undo= edit->undo.first; undo; undo= undo->next, a++) {
-		if (a==nr) break;
-	}
-	edit->curundo= undo;
-	PE_undo_step(scene, view_layer, 0);
-}
-
+	ut->name = "Edit Particle";
+	ut->poll = particle_undosys_poll;
+	ut->step_encode = particle_undosys_step_encode;
+	ut->step_decode = particle_undosys_step_decode;
+	ut->step_free = particle_undosys_step_free;
 
-/* get name of undo item, return null if no item with this index */
-/* if active pointer, set it to 1 if true */
-const char *PE_undo_get_name(Scene *scene, ViewLayer *view_layer, int nr, bool *r_active)
-{
-	PTCacheEdit *edit= PE_get_current(scene, view_layer, OBACT(view_layer));
-	PTCacheUndo *undo;
+	ut->step_foreach_ID_ref = particle_undosys_foreach_ID_ref;
 
-	if (r_active) *r_active = false;
+	ut->mode = BKE_UNDOTYPE_MODE_STORE;
+	ut->use_context = true;
 
-	if (edit) {
-		undo= BLI_findlink(&edit->undo, nr);
-		if (undo) {
-			if (r_active && (undo == edit->curundo)) {
-				*r_active = true;
-			}
-			return undo->name;
-		}
-	}
-	return NULL;
+	ut->step_size = sizeof(ParticleUndoStep);
 }
+
+/** \} */
diff --git a/source/blender/editors/physics/particle_object.c b/source/blender/editors/physics/particle_object.c
index 71810d09135..f6ece9d4bdc 100644
--- a/source/blender/editors/physics/particle_object.c
+++ b/source/blender/editors/physics/particle_object.c
@@ -931,10 +931,7 @@ static void copy_particle_edit(
 	
 	edit->emitter_field = NULL;
 	edit->emitter_cosnos = NULL;
-	
-	BLI_listbase_clear(&edit->undo);
-	edit->curundo = NULL;
-	
+
 	edit->points = MEM_dupallocN(edit_from->points);
 	pa = psys->particles;
 	LOOP_POINTS {
@@ -963,9 +960,6 @@ static void copy_particle_edit(
 	recalc_lengths(edit);
 	recalc_emitter_field(ob, psys);
 	PE_update_object(eval_ctx, scene, ob, true);
-	
-	PTCacheUndo_clear(edit);
-	PE_undo_push(scene, view_layer, "Original");
 }
 
 static void remove_particle_systems_from_object(Object *ob_to)
diff --git a/source/blender/editors/physics/physics_fluid.c b/source/blender/editors/physics/physics_fluid.c
index d9a7d288f9c..bb29a619139 100644
--- a/source/blender/editors/physics/physics_fluid.c
+++ b/source/blender/editors/physics/physics_fluid.c
@@ -48,7 +48,6 @@
 #include "BKE_context.h"
 #include "BKE_customdata.h"
 #include "BKE_fluidsim.h"
-#include "BKE_global.h"
 #include "BKE_main.h"
 #include "BKE_modifier.h"
 #include "BKE_object.h"
@@ -69,6 +68,8 @@
 /* enable/disable overall compilation */
 #ifdef WITH_MOD_FLUID
 
+#include "BKE_global.h"
+
 #include "WM_api.h"
 
 #include "DNA_scene_types.h"
diff --git a/source/blender/editors/physics/physics_intern.h b/source/blender/editors/physics/physics_intern.h
index 8888589b5d7..246bf79360f 100644
--- a/source/blender/editors/physics/physics_intern.h
+++ b/source/blender/editors/physics/physics_intern.h
@@ -70,9 +70,8 @@ void PARTICLE_OT_edited_clear(struct wmOperatorType *ot);
 
 void PARTICLE_OT_unify_length(struct wmOperatorType *ot);
 
-void PTCacheUndo_clear(struct PTCacheEdit *edit);
 void PE_create_particle_edit(
-        const struct EvaluationContext *eval_ctx, struct Scene *scene, struct ViewLayer *view_layer,
+        const struct EvaluationContext *eval_ctx, struct Scene *scene,
         struct Object *ob, struct PointCache *cache, struct ParticleSystem *psys);
 void recalc_lengths(struct PTCacheEdit *edit);
 void recalc_emitter_field(struct Object *ob, struct ParticleSystem *psys);
diff --git a/source/blender/editors/physics/rigidbody_constraint.c b/source/blender/editors/physics/rigidbody_constraint.c
index f77e164ba16..3bcc047bf5b 100644
--- a/source/blender/editors/physics/rigidbody_constraint.c
+++ b/source/blender/editors/physics/rigidbody_constraint.c
@@ -38,7 +38,6 @@
 #include "DNA_scene_types.h"
 
 #include "BKE_context.h"
-#include "BKE_global.h"
 #include "BKE_group.h"
 #include "BKE_main.h"
 #include "BKE_report.h"
diff --git a/source/blender/editors/physics/rigidbody_object.c b/source/blender/editors/physics/rigidbody_object.c
index 3b667520550..3553ffa5033 100644
--- a/source/blender/editors/physics/rigidbody_object.c
+++ b/source/blender/editors/physics/rigidbody_object.c
@@ -43,7 +43,6 @@
 #include "BLT_translation.h"
 
 #include "BKE_context.h"
-#include "BKE_global.h"
 #include "BKE_group.h"
 #include "BKE_main.h"
 #include "BKE_report.h"