Gizmo: optional custom orientations for transform

This aims to resolve a conflict where some users want to keep keyboard
axis setting global, even when the orientation is set to something else.

Move/rotate/scale can optionally each have a separate orientation.

Some UI changes will be made next.

17 files changed, 259 insertions, 94 deletions

diff --git a/source/blender/blenkernel/BKE_scene.h b/source/blender/blenkernel/BKE_scene.h
index 6344d29a2a0..fd1ba56fd8b 100644
--- a/source/blender/blenkernel/BKE_scene.h
+++ b/source/blender/blenkernel/BKE_scene.h
@@ -139,6 +139,10 @@ float BKE_scene_frame_get(const struct Scene *scene);
 float BKE_scene_frame_get_from_ctime(const struct Scene *scene, const float frame);
 void  BKE_scene_frame_set(struct Scene *scene, double cfra);
 
+struct TransformOrientationSlot *BKE_scene_orientation_slot_get(struct Scene *scene, int flag);
+void BKE_scene_orientation_slot_set_index(struct TransformOrientationSlot *orient_slot, int orientation);
+int BKE_scene_orientation_slot_get_index(const struct TransformOrientationSlot *orient_slot);
+
 /* **  Scene evaluation ** */
 
 void BKE_scene_graph_update_tagged(struct Depsgraph *depsgraph,
diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 3de1ddb1e1e..05603efb2c3 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -864,7 +864,9 @@ void BKE_scene_init(Scene *sce)
 	sce->toolsettings->annotate_v3d_align = GP_PROJECT_VIEWSPACE | GP_PROJECT_CURSOR;
 	sce->toolsettings->annotate_thickness = 3;
 
-	sce->orientation_index_custom = -1;
+	for (int i = 0; i < ARRAY_SIZE(sce->orientation_slots); i++) {
+		sce->orientation_slots[i].index_custom = -1;
+	}
 
 	/* Master Collection */
 	sce->master_collection = BKE_collection_master_add();
@@ -1321,7 +1323,6 @@ float BKE_scene_frame_get_from_ctime(const Scene *scene, const float frame)
 
 	return ctime;
 }
-
 /**
  * Sets the frame int/float components.
  */
@@ -1332,6 +1333,52 @@ void BKE_scene_frame_set(struct Scene *scene, double cfra)
 	scene->r.cfra = (int)intpart;
 }
 
+
+/* -------------------------------------------------------------------- */
+/** \name Scene Orientation Slots
+ * \{ */
+
+TransformOrientationSlot *BKE_scene_orientation_slot_get(Scene *scene, int flag)
+{
+	BLI_assert(flag && !(flag & ~(SCE_GIZMO_SHOW_TRANSLATE | SCE_GIZMO_SHOW_ROTATE | SCE_GIZMO_SHOW_SCALE)));
+	int index = SCE_ORIENT_DEFAULT;
+	if (flag & SCE_GIZMO_SHOW_TRANSLATE) {
+		index = SCE_ORIENT_TRANSLATE;
+	}
+	else if (flag & SCE_GIZMO_SHOW_ROTATE) {
+		index = SCE_ORIENT_ROTATE;
+	}
+	else if (flag & SCE_GIZMO_SHOW_SCALE) {
+		index = SCE_ORIENT_SCALE;
+	}
+
+	if ((scene->orientation_slots[index].flag & SELECT) == 0) {
+		index = SCE_ORIENT_DEFAULT;
+	}
+	return &scene->orientation_slots[index];
+}
+
+/**
+ * Activate a transform orientation in a 3D view based on an enum value.
+ *
+ * \param orientation: If this is #V3D_MANIP_CUSTOM or greater, the custom transform orientation
+ * with index \a orientation - #V3D_MANIP_CUSTOM gets activated.
+ */
+void BKE_scene_orientation_slot_set_index(TransformOrientationSlot *orient_slot, int orientation)
+{
+	const bool is_custom = orientation >= V3D_MANIP_CUSTOM;
+	orient_slot->type = is_custom ? V3D_MANIP_CUSTOM : orientation;
+	orient_slot->index_custom = is_custom ? (orientation - V3D_MANIP_CUSTOM) : -1;
+}
+
+int BKE_scene_orientation_slot_get_index(const TransformOrientationSlot *orient_slot)
+{
+	return (orient_slot->type == V3D_MANIP_CUSTOM) ? (orient_slot->type + orient_slot->index_custom) : orient_slot->type;
+}
+
+/** \} */
+
+
 /* That's like really a bummer, because currently animation data for armatures
  * might want to use pose, and pose might be missing on the object.
  * This happens when changing visible layers, which leads to situations when
@@ -2166,11 +2213,16 @@ void BKE_scene_transform_orientation_remove(
         Scene *scene, TransformOrientation *orientation)
 {
 	const int orientation_index = BKE_scene_transform_orientation_get_index(scene, orientation);
-	if (scene->orientation_index_custom == orientation_index) {
-		/* could also use orientation_index-- */
-		scene->orientation_type = V3D_MANIP_GLOBAL;
-		scene->orientation_index_custom = -1;
+
+	for (int i = 0; i < ARRAY_SIZE(scene->orientation_slots); i++) {
+		TransformOrientationSlot *orient_slot = &scene->orientation_slots[i];
+		if (orient_slot->index_custom == orientation_index) {
+			/* could also use orientation_index-- */
+			orient_slot->type = V3D_MANIP_GLOBAL;
+			orient_slot->index_custom = -1;
+		}
 	}
+
 	BLI_freelinkN(&scene->transform_spaces, orientation);
 }
 
diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 0c9b9806425..9b3add62722 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -1230,12 +1230,6 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 			}
 		}
 
-		if (!DNA_struct_elem_find(fd->filesdna, "Scene", "int", "orientation_index_custom")) {
-			for (Scene *scene = bmain->scene.first; scene; scene = scene->id.next) {
-				scene->orientation_index_custom = -1;
-			}
-		}
-
 		for (bScreen *sc = bmain->screen.first; sc; sc = sc->id.next) {
 			for (ScrArea *sa = sc->areabase.first; sa; sa = sa->next) {
 				for (SpaceLink *sl = sa->spacedata.first; sl; sl = sl->next) {
@@ -2762,5 +2756,13 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 				}
 			}
 		}
+
+		if (!DNA_struct_find(fd->filesdna, "TransformOrientationSlot")) {
+			for (Scene *scene = bmain->scene.first; scene; scene = scene->id.next) {
+				for (int i = 0; i < ARRAY_SIZE(scene->orientation_slots); i++) {
+					scene->orientation_slots[i].index_custom = -1;
+				}
+			}
+		}
 	}
 }
diff --git a/source/blender/editors/include/ED_transform.h b/source/blender/editors/include/ED_transform.h
index 718c8a48300..ad39c1ccc8a 100644
--- a/source/blender/editors/include/ED_transform.h
+++ b/source/blender/editors/include/ED_transform.h
@@ -132,7 +132,6 @@ void BIF_createTransformOrientation(struct bContext *C, struct ReportList *repor
                                     const char *name, const bool use_view,
                                     const bool activate, const bool overwrite);
 void BIF_selectTransformOrientation(struct bContext *C, struct TransformOrientation *ts);
-void BIF_selectTransformOrientationValue(struct Scene *scene, int orientation);
 
 void ED_getTransformOrientationMatrix(const struct bContext *C, float orientation_mat[3][3], const short around);
 
@@ -210,7 +209,8 @@ void ED_transform_calc_orientation_from_type(
          const struct bContext *C, float r_mat[3][3],
          /* extra args */
          struct Scene *scene, struct RegionView3D *rv3d, struct Object *ob, struct Object *obedit,
-         const short orientation_type, const int pivot_point);
+         const short orientation_type, int orientation_index_custom,
+         const int pivot_point);
 
 struct TransformBounds {
 	float center[3];		/* Center for transform widget. */
@@ -226,6 +226,7 @@ struct TransformCalcParams {
 	uint use_local_axis : 1;
 	/* Use 'Scene.orientation_type' when zero, otherwise subtract one and use. */
 	ushort orientation_type;
+	ushort orientation_index_custom;
 };
 int ED_transform_calc_gizmo_stats(
         const struct bContext *C,
diff --git a/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c b/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c
index 92b655b6d8d..dd5f97cd010 100644
--- a/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c
+++ b/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c
@@ -25,6 +25,7 @@
 #include "BLI_math.h"
 
 #include "BKE_context.h"
+#include "BKE_scene.h"
 
 #include "RNA_define.h"
 #include "RNA_access.h"
@@ -244,7 +245,8 @@ static void gizmo_mesh_spin_init_draw_prepare(
 
 	{
 		Scene *scene = CTX_data_scene(C);
-		switch (scene->orientation_type) {
+		const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, SCE_GIZMO_SHOW_ROTATE);
+		switch (orient_slot->type) {
 			case V3D_MANIP_VIEW:
 			{
 				if (!equals_m3m3(viewinv_m3, ggd->prev.viewinv_m3)) {
@@ -444,10 +446,8 @@ static void gizmo_mesh_spin_init_message_subscribe(
 	RNA_id_pointer_create(&scene->id, &scene_ptr);
 
 	{
-		extern PropertyRNA rna_Scene_transform_orientation;
 		extern PropertyRNA rna_Scene_cursor_location;
 		const PropertyRNA *props[] = {
-			&rna_Scene_transform_orientation,
 			&rna_Scene_cursor_location,
 		};
 		for (int i = 0; i < ARRAY_SIZE(props); i++) {
diff --git a/source/blender/editors/mesh/editmesh_select.c b/source/blender/editors/mesh/editmesh_select.c
index 4ab00dd5962..fdd8a124652 100644
--- a/source/blender/editors/mesh/editmesh_select.c
+++ b/source/blender/editors/mesh/editmesh_select.c
@@ -4372,7 +4372,7 @@ static int edbm_select_axis_exec(bContext *C, wmOperator *op)
 	ED_transform_calc_orientation_from_type_ex(
 	        C, axis_mat,
 	        scene, CTX_wm_region_view3d(C), obedit, obedit,
-	        orientation, V3D_AROUND_ACTIVE);
+	        orientation, 0, V3D_AROUND_ACTIVE);
 
 	const float *axis_vector = axis_mat[axis];
 
diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index 0f555bcc5b7..7509b88ccff 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -2147,10 +2147,11 @@ void saveTransform(bContext *C, TransInfo *t, wmOperator *op)
 			    !RNA_property_is_set(op->ptr, prop) &&
 			    (t->orientation.user != V3D_MANIP_CUSTOM_MATRIX))
 			{
-				t->scene->orientation_type = t->orientation.user;
-				BLI_assert(((t->scene->orientation_index_custom == -1) && (t->orientation.custom == NULL)) ||
+				TransformOrientationSlot *orient_slot = &t->scene->orientation_slots[SCE_ORIENT_DEFAULT];
+				orient_slot->type = t->orientation.user;
+				BLI_assert(((orient_slot->index_custom == -1) && (t->orientation.custom == NULL)) ||
 				           (BKE_scene_transform_orientation_get_index(
-				                    t->scene, t->orientation.custom) == t->scene->orientation_index_custom));
+				                    t->scene, t->orientation.custom) == orient_slot->index_custom));
 			}
 		}
 	}
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 75044e77110..3970261ac02 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -509,7 +509,7 @@ typedef struct TransInfo {
 		short		user_alt;
 		short		index;
 		short		*types[2];
-		/* this gets used when current_orientation is V3D_MANIP_CUSTOM */
+		/* this gets used when custom_orientation is V3D_MANIP_CUSTOM */
 		TransformOrientation *custom;
 	} orientation;
 	short		gizmo_flag;			/* backup from view3d, to restore on end */
diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index c1a2eb218cf..f1dc5525dbc 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -1401,9 +1401,9 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 			t->around = V3D_AROUND_CURSOR;
 		}
 
-		t->orientation.user = t->scene->orientation_type;
-		t->orientation.custom = BKE_scene_transform_orientation_find(
-		        t->scene, t->scene->orientation_index_custom);
+		TransformOrientationSlot *orient_slot = &t->scene->orientation_slots[SCE_ORIENT_DEFAULT];
+		t->orientation.user = orient_slot->type;
+		t->orientation.custom = BKE_scene_transform_orientation_find(t->scene, orient_slot->index_custom);
 
 		t->orientation.index = 0;
 		ARRAY_SET_ITEMS(
diff --git a/source/blender/editors/transform/transform_gizmo_3d.c b/source/blender/editors/transform/transform_gizmo_3d.c
index 5a26245c14d..b17a345ee09 100644
--- a/source/blender/editors/transform/transform_gizmo_3d.c
+++ b/source/blender/editors/transform/transform_gizmo_3d.c
@@ -638,19 +638,21 @@ void ED_transform_calc_orientation_from_type(
 	Object *obedit = CTX_data_edit_object(C);
 	RegionView3D *rv3d = ar->regiondata;
 	Object *ob = OBACT(view_layer);
-	const short orientation_type = scene->orientation_type;
+	const short orientation_type = scene->orientation_slots[SCE_ORIENT_DEFAULT].type;
+	const short orientation_index_custom = scene->orientation_slots[SCE_ORIENT_DEFAULT].index_custom;
 	const int pivot_point = scene->toolsettings->transform_pivot_point;
 
 	ED_transform_calc_orientation_from_type_ex(
 	        C, r_mat,
-	        scene, rv3d, ob, obedit, orientation_type, pivot_point);
+	        scene, rv3d, ob, obedit, orientation_type, orientation_index_custom, pivot_point);
 }
 
 void ED_transform_calc_orientation_from_type_ex(
         const bContext *C, float r_mat[3][3],
         /* extra args (can be accessed from context) */
         Scene *scene, RegionView3D *rv3d, Object *ob, Object *obedit,
-        const short orientation_type, const int pivot_point)
+        const short orientation_type, int orientation_index_custom,
+        const int pivot_point)
 {
 	bool ok = false;
 
@@ -712,7 +714,7 @@ void ED_transform_calc_orientation_from_type_ex(
 		case V3D_MANIP_CUSTOM:
 		{
 			TransformOrientation *custom_orientation = BKE_scene_transform_orientation_find(
-			        scene, scene->orientation_index_custom);
+			        scene, orientation_index_custom);
 			if (applyTransformOrientation(custom_orientation, r_mat, NULL)) {
 				ok = true;
 			}
@@ -759,11 +761,14 @@ int ED_transform_calc_gizmo_stats(
 	/* global, local or normal orientation?
 	 * if we could check 'totsel' now, this should be skipped with no selection. */
 	if (ob) {
-		const short orientation_type = params->orientation_type ? (params->orientation_type - 1) : scene->orientation_type;
+		const short orientation_type = params->orientation_type ?
+			(params->orientation_type - 1) : scene->orientation_slots[SCE_ORIENT_DEFAULT].type;
+		const short orientation_index_custom = params->orientation_type ?
+			params->orientation_index_custom : scene->orientation_slots[SCE_ORIENT_DEFAULT].index_custom;
 		float mat[3][3];
 		ED_transform_calc_orientation_from_type_ex(
 		        C, mat,
-		        scene, rv3d, ob, obedit, orientation_type, pivot_point);
+		        scene, rv3d, ob, obedit, orientation_type, orientation_index_custom, pivot_point);
 		copy_m4_m3(rv3d->twmat, mat);
 	}
 
@@ -1206,6 +1211,8 @@ static void gizmo_xform_message_subscribe(
         wmGizmoGroup *gzgroup, struct wmMsgBus *mbus,
         Scene *scene, bScreen *UNUSED(screen), ScrArea *UNUSED(sa), ARegion *ar, const void *type_fn)
 {
+	GizmoGroup *ggd = gzgroup->customdata;
+
 	/* Subscribe to view properties */
 	wmMsgSubscribeValue msg_sub_value_gz_tag_refresh = {
 		.owner = ar,
@@ -1217,10 +1224,10 @@ static void gizmo_xform_message_subscribe(
 	RNA_id_pointer_create(&scene->id, &scene_ptr);
 
 	{
-		extern PropertyRNA rna_Scene_transform_orientation;
+		extern PropertyRNA rna_Scene_transform_orientation_slots;
 		extern PropertyRNA rna_Scene_cursor_location;
 		const PropertyRNA *props[] = {
-			&rna_Scene_transform_orientation,
+			&rna_Scene_transform_orientation_slots,
 			(scene->toolsettings->transform_pivot_point == V3D_AROUND_CURSOR) ? &rna_Scene_cursor_location : NULL,
 		};
 		for (int i = 0; i < ARRAY_SIZE(props); i++) {
@@ -1230,15 +1237,30 @@ static void gizmo_xform_message_subscribe(
 		}
 	}
 
+	TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, ggd->twtype_init);
+	PointerRNA orient_ref_ptr;
+	RNA_pointer_create(&scene->id, &RNA_TransformOrientationSlot, orient_slot, &orient_ref_ptr);
+	{
+		extern PropertyRNA rna_TransformOrientationSlot_type;
+		extern PropertyRNA rna_TransformOrientationSlot_use;
+		const PropertyRNA *props[] = {
+			&rna_TransformOrientationSlot_type,
+			&rna_TransformOrientationSlot_use,
+		};
+		for (int i = 0; i < ARRAY_SIZE(props); i++) {
+			if (props[i]) {
+				WM_msg_subscribe_rna(mbus, &orient_ref_ptr, props[i], &msg_sub_value_gz_tag_refresh, __func__);
+			}
+		}
+	}
+
 	PointerRNA toolsettings_ptr;
 	RNA_pointer_create(&scene->id, &RNA_ToolSettings, scene->toolsettings, &toolsettings_ptr);
 
 	if (type_fn == TRANSFORM_GGT_gizmo) {
 		extern PropertyRNA rna_ToolSettings_transform_pivot_point;
-		extern PropertyRNA rna_ToolSettings_use_gizmo_mode;
 		const PropertyRNA *props[] = {
 			&rna_ToolSettings_transform_pivot_point,
-			&rna_ToolSettings_use_gizmo_mode,
 		};
 		for (int i = 0; i < ARRAY_SIZE(props); i++) {
 			WM_msg_subscribe_rna(mbus, &toolsettings_ptr, props[i], &msg_sub_value_gz_tag_refresh, __func__);
@@ -1610,12 +1632,12 @@ static void WIDGETGROUP_gizmo_setup(const bContext *C, wmGizmoGroup *gzgroup)
 static void WIDGETGROUP_gizmo_refresh(const bContext *C, wmGizmoGroup *gzgroup)
 {
 	GizmoGroup *ggd = gzgroup->customdata;
+	Scene *scene = CTX_data_scene(C);
 	ARegion *ar = CTX_wm_region(C);
 	RegionView3D *rv3d = ar->regiondata;
 	struct TransformBounds tbounds;
 
 	if (ggd->use_twtype_refresh) {
-		Scene *scene = CTX_data_scene(C);
 		ggd->twtype = scene->toolsettings->gizmo_flag & ggd->twtype_init;
 		if (ggd->twtype != ggd->twtype_prev) {
 			ggd->twtype_prev = ggd->twtype;
@@ -1623,11 +1645,15 @@ static void WIDGETGROUP_gizmo_refresh(const bContext *C, wmGizmoGroup *gzgroup)
 		}
 	}
 
+	const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, ggd->twtype_init);
+
 	/* skip, we don't draw anything anyway */
 	if ((ggd->all_hidden =
 	     (ED_transform_calc_gizmo_stats(
 	             C, &(struct TransformCalcParams){
 	                 .use_only_center = true,
+	                 .orientation_type = orient_slot->type + 1,
+	                 .orientation_index_custom = orient_slot->index_custom,
 	             }, &tbounds) == 0)))
 	{
 		return;
@@ -1757,7 +1783,8 @@ static void WIDGETGROUP_gizmo_draw_prepare(const bContext *C, wmGizmoGroup *gzgr
 	if (!equals_m3m3(viewinv_m3, ggd->prev.viewinv_m3)) {
 		{
 			Scene *scene = CTX_data_scene(C);
-			switch (scene->orientation_type) {
+			const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, ggd->twtype_init);
+			switch (orient_slot->type) {
 				case V3D_MANIP_VIEW:
 				{
 					WIDGETGROUP_gizmo_refresh(C, gzgroup);
@@ -1774,8 +1801,26 @@ static void WIDGETGROUP_gizmo_invoke_prepare(
         const bContext *C, wmGizmoGroup *gzgroup, wmGizmo *gz)
 {
 
-	/* Support shift click to constrain axis. */
 	GizmoGroup *ggd = gzgroup->customdata;
+
+	/* Support gizmo spesific orientation. */
+	{
+		Scene *scene = CTX_data_scene(C);
+		wmGizmoOpElem *gzop = WM_gizmo_operator_get(gz, 0);
+		PointerRNA *ptr = &gzop->ptr;
+		PropertyRNA *prop_constraint_orientation = RNA_struct_find_property(ptr, "constraint_orientation");
+		const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, ggd->twtype_init);
+		if (orient_slot == &scene->orientation_slots[SCE_ORIENT_DEFAULT]) {
+			RNA_property_unset(ptr, prop_constraint_orientation);
+		}
+		else {
+			/* TODO: APIfunction */
+			int index = BKE_scene_orientation_slot_get_index(orient_slot);
+			RNA_property_enum_set(ptr, prop_constraint_orientation, index);
+		}
+	}
+
+	/* Support shift click to constrain axis. */
 	const int axis_idx = BLI_array_findindex(ggd->gizmos, ARRAY_SIZE(ggd->gizmos), &gz);
 	int axis = -1;
 	switch (axis_idx) {
@@ -1932,15 +1977,20 @@ static void WIDGETGROUP_xform_cage_refresh(const bContext *C, wmGizmoGroup *gzgr
 {
 	ARegion *ar = CTX_wm_region(C);
 	RegionView3D *rv3d = ar->regiondata;
+	Scene *scene = CTX_data_scene(C);
 
 	struct XFormCageWidgetGroup *xgzgroup = gzgroup->customdata;
 	wmGizmo *gz = xgzgroup->gizmo;
 
 	struct TransformBounds tbounds;
 
+	const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, SCE_GIZMO_SHOW_SCALE);
+
 	if ((ED_transform_calc_gizmo_stats(
 	             C, &(struct TransformCalcParams) {
 	                 .use_local_axis = true,
+	                 .orientation_type = orient_slot->type + 1,
+	                 .orientation_index_custom = orient_slot->index_custom,
 	             }, &tbounds) == 0) ||
 	    equals_v3v3(rv3d->tw_axis_min, rv3d->tw_axis_max))
 	{
@@ -2016,7 +2066,8 @@ static void WIDGETGROUP_xform_cage_draw_prepare(const bContext *C, wmGizmoGroup
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
 	{
 		Scene *scene = CTX_data_scene(C);
-		switch (scene->orientation_type) {
+		const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, SCE_GIZMO_SHOW_SCALE);
+		switch (orient_slot->type) {
 			case V3D_MANIP_VIEW:
 			{
 				float viewinv_m3[3][3];
@@ -2173,7 +2224,9 @@ static void WIDGETGROUP_xform_shear_draw_prepare(const bContext *C, wmGizmoGroup
 	RegionView3D *rv3d = CTX_wm_region_view3d(C);
 	{
 		Scene *scene = CTX_data_scene(C);
-		switch (scene->orientation_type) {
+		/* Shear is like rotate, use the rotate setting. */
+		const TransformOrientationSlot *orient_slot = BKE_scene_orientation_slot_get(scene, SCE_GIZMO_SHOW_ROTATE);
+		switch (orient_slot->type) {
 			case V3D_MANIP_VIEW:
 			{
 				float viewinv_m3[3][3];
diff --git a/source/blender/editors/transform/transform_gizmo_extrude_3d.c b/source/blender/editors/transform/transform_gizmo_extrude_3d.c
index 1dc50f476fa..441141e9718 100644
--- a/source/blender/editors/transform/transform_gizmo_extrude_3d.c
+++ b/source/blender/editors/transform/transform_gizmo_extrude_3d.c
@@ -233,7 +233,7 @@ static void gizmo_mesh_extrude_refresh(const bContext *C, wmGizmoGroup *gzgroup)
 		axis_type = RNA_property_enum_get(&ptr, ggd->gzgt_axis_type_prop);
 	}
 
-	ggd->data.orientation_type = scene->orientation_type;
+	ggd->data.orientation_type = scene->orientation_slots[SCE_ORIENT_DEFAULT].type;
 	const bool use_normal = (
 	        (ggd->data.orientation_type != V3D_MANIP_NORMAL) ||
 	        (axis_type == EXTRUDE_AXIS_NORMAL));
@@ -431,7 +431,7 @@ static void gizmo_mesh_extrude_message_subscribe(
 	};
 
 	{
-		WM_msg_subscribe_rna_anon_prop(mbus, Scene, transform_orientation, &msg_sub_value_gz_tag_refresh);
+		WM_msg_subscribe_rna_anon_prop(mbus, TransformOrientationSlot, type, &msg_sub_value_gz_tag_refresh);
 	}
 
 
diff --git a/source/blender/editors/transform/transform_ops.c b/source/blender/editors/transform/transform_ops.c
index d11cfa8d3d3..5a3575c04d9 100644
--- a/source/blender/editors/transform/transform_ops.c
+++ b/source/blender/editors/transform/transform_ops.c
@@ -39,6 +39,7 @@
 #include "BKE_global.h"
 #include "BKE_report.h"
 #include "BKE_editmesh.h"
+#include "BKE_scene.h"
 
 #include "RNA_access.h"
 #include "RNA_define.h"
@@ -168,12 +169,12 @@ static int select_orientation_exec(bContext *C, wmOperator *op)
 	Scene *scene = CTX_data_scene(C);
 	int orientation = RNA_enum_get(op->ptr, "orientation");
 
-	BIF_selectTransformOrientationValue(scene, orientation);
+	BKE_scene_orientation_slot_set_index(&scene->orientation_slots[SCE_ORIENT_DEFAULT], orientation);
 
 	WM_event_add_notifier(C, NC_SCENE | ND_TOOLSETTINGS, NULL);
 
 	struct wmMsgBus *mbus = CTX_wm_message_bus(C);
-	WM_msg_publish_rna_prop(mbus, &scene->id, scene, Scene, transform_orientation);
+	WM_msg_publish_rna_prop(mbus, &scene->id, scene, TransformOrientationSlot, type);
 
 	return OPERATOR_FINISHED;
 }
@@ -215,7 +216,7 @@ static void TRANSFORM_OT_select_orientation(struct wmOperatorType *ot)
 static int delete_orientation_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Scene *scene = CTX_data_scene(C);
-	BIF_removeTransformOrientationIndex(C, scene->orientation_index_custom);
+	BIF_removeTransformOrientationIndex(C, scene->orientation_slots[SCE_ORIENT_DEFAULT].index_custom);
 
 	WM_event_add_notifier(C, NC_SCENE | NA_EDITED, scene);
 
@@ -234,7 +235,8 @@ static bool delete_orientation_poll(bContext *C)
 	if (ED_operator_areaactive(C) == 0)
 		return 0;
 
-	return (scene->orientation_type >= V3D_MANIP_CUSTOM) && (scene->orientation_index_custom != -1);
+	return ((scene->orientation_slots[SCE_ORIENT_DEFAULT].type >= V3D_MANIP_CUSTOM) &&
+	        (scene->orientation_slots[SCE_ORIENT_DEFAULT].index_custom != -1));
 }
 
 static void TRANSFORM_OT_delete_orientation(struct wmOperatorType *ot)
diff --git a/source/blender/editors/transform/transform_orientations.c b/source/blender/editors/transform/transform_orientations.c
index a21882fc206..04999213c63 100644
--- a/source/blender/editors/transform/transform_orientations.c
+++ b/source/blender/editors/transform/transform_orientations.c
@@ -71,9 +71,12 @@ void BIF_clearTransformOrientation(bContext *C)
 
 	BLI_freelistN(transform_orientations);
 
-	if (scene->orientation_type == V3D_MANIP_CUSTOM) {
-		scene->orientation_type = V3D_MANIP_GLOBAL; /* fallback to global */
-		scene->orientation_index_custom = -1;
+	for (int i = 0; i < ARRAY_SIZE(scene->orientation_slots); i++) {
+		TransformOrientationSlot *orient_slot = &scene->orientation_slots[i];
+		if (orient_slot->type == V3D_MANIP_CUSTOM) {
+			orient_slot->type = V3D_MANIP_GLOBAL; /* fallback to global */
+			orient_slot->index_custom = -1;
+		}
 	}
 }
 
@@ -366,21 +369,8 @@ void BIF_selectTransformOrientation(bContext *C, TransformOrientation *target)
 
 	BLI_assert(index != -1);
 
-	scene->orientation_type = V3D_MANIP_CUSTOM;
-	scene->orientation_index_custom = index;
-}
-
-/**
- * Activate a transform orientation in a 3D view based on an enum value.
- *
- * \param orientation: If this is #V3D_MANIP_CUSTOM or greater, the custom transform orientation
- *                     with index \a orientation - #V3D_MANIP_CUSTOM gets activated.
- */
-void BIF_selectTransformOrientationValue(Scene *scene, int orientation)
-{
-	const bool is_custom = orientation >= V3D_MANIP_CUSTOM;
-	scene->orientation_type = is_custom ? V3D_MANIP_CUSTOM : orientation;
-	scene->orientation_index_custom = is_custom ? (orientation - V3D_MANIP_CUSTOM) : -1;
+	scene->orientation_slots[SCE_ORIENT_DEFAULT].type = V3D_MANIP_CUSTOM;
+	scene->orientation_slots[SCE_ORIENT_DEFAULT].index_custom = index;
 }
 
 int BIF_countTransformOrientation(const bContext *C)
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index d312566a4fd..467d70ffd81 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1521,6 +1521,21 @@ typedef struct SceneEEVEE {
 /* *************************************************************** */
 /* Scene ID-Block */
 
+typedef struct TransformOrientationSlot {
+	int type;
+	int index_custom;
+	char flag;
+	char _pad0[7];
+} TransformOrientationSlot;
+
+/* Indices when used in Scene.orientation. */
+enum {
+	SCE_ORIENT_DEFAULT = 0,
+	SCE_ORIENT_TRANSLATE = 1,
+	SCE_ORIENT_ROTATE = 2,
+	SCE_ORIENT_SCALE = 3,
+};
+
 typedef struct Scene {
 	ID id;
 	struct AnimData *adt;	/* animation data (must be immediately after id for utilities to use it) */
@@ -1561,8 +1576,8 @@ typedef struct Scene {
 	ListBase markers;
 	ListBase transform_spaces;
 
-	int orientation_index_custom;
-	int orientation_type;
+	/* First is the [scene, translate, rotate, scale]. */
+	TransformOrientationSlot orientation_slots[4];
 
 	void *sound_scene;
 	void *playback_handle;
diff --git a/source/blender/makesdna/DNA_view3d_types.h b/source/blender/makesdna/DNA_view3d_types.h
index 1fc143ed71f..336dbec214b 100644
--- a/source/blender/makesdna/DNA_view3d_types.h
+++ b/source/blender/makesdna/DNA_view3d_types.h
@@ -514,7 +514,7 @@ enum {
 #define V3D_SHOW_Y              (1 << 2)
 #define V3D_SHOW_Z              (1 << 3)
 
-/* Scene.orientation_type */
+/** #TransformOrientationSlot.type */
 #define V3D_MANIP_GLOBAL		0
 #define V3D_MANIP_LOCAL			1
 #define V3D_MANIP_NORMAL		2
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 86f0f2d85bf..f6bfcb2bb32 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -697,6 +697,7 @@ extern StructRNA RNA_TintGpencilModifier;
 extern StructRNA RNA_ToolSettings;
 extern StructRNA RNA_TrackToConstraint;
 extern StructRNA RNA_TransformConstraint;
+extern StructRNA RNA_TransformOrientationSlot;
 extern StructRNA RNA_TransformSequence;
 extern StructRNA RNA_UILayout;
 extern StructRNA RNA_UIList;
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index 6719eaceaad..58bde163442 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -1567,6 +1567,20 @@ static void rna_Scene_use_persistent_data_update(Main *UNUSED(bmain), Scene *UNU
 		RE_FreePersistentData();
 }
 
+/* Scene.orientation_slots */
+static void rna_Scene_transform_orientation_slots_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
+{
+	Scene *scene = (Scene *)ptr->id.data;
+	TransformOrientationSlot *orient_slot = &scene->orientation_slots[0];
+	rna_iterator_array_begin(iter, orient_slot, sizeof(*orient_slot), ARRAY_SIZE(scene->orientation_slots), 0, NULL);
+}
+
+static int rna_Scene_transform_orientation_slots_length(PointerRNA *ptr)
+{
+	Scene *scene = (Scene *)ptr->id.data;
+	return ARRAY_SIZE(scene->orientation_slots);
+}
+
 static bool rna_Scene_use_audio_get(PointerRNA *ptr)
 {
 	Scene *scene = (Scene *)ptr->data;
@@ -1961,32 +1975,29 @@ static void rna_ViewLayer_remove(
 	}
 }
 
-static int rna_Scene_transform_orientation_get(PointerRNA *ptr)
+static int rna_TransformOrientationSlot_type_get(PointerRNA *ptr)
 {
-	Scene *scene = ptr->data;
-	/* convert to enum value */
-	return (scene->orientation_type == V3D_MANIP_CUSTOM) ?
-	            (scene->orientation_type + scene->orientation_index_custom) : scene->orientation_type;
+	TransformOrientationSlot *orient_slot = ptr->data;
+	return BKE_scene_orientation_slot_get_index(orient_slot);
 }
 
-void rna_Scene_transform_orientation_set(PointerRNA *ptr, int value)
+void rna_TransformOrientationSlot_type_set(PointerRNA *ptr, int value)
 {
-	Scene *scene = ptr->data;
-	BIF_selectTransformOrientationValue(scene, value);
+	TransformOrientationSlot *orient_slot = ptr->data;
+	BKE_scene_orientation_slot_set_index(orient_slot, value);
 }
 
-static PointerRNA rna_Scene_current_orientation_get(PointerRNA *ptr)
+static PointerRNA rna_TransformOrientationSlot_get(PointerRNA *ptr)
 {
-	Scene *scene = ptr->data;
+	Scene *scene = ptr->id.data;
+	TransformOrientationSlot *orient_slot = ptr->data;
 	TransformOrientation *orientation;
-
-	if (scene->orientation_type < V3D_MANIP_CUSTOM) {
+	if (orient_slot->type < V3D_MANIP_CUSTOM) {
 		orientation = NULL;
 	}
 	else {
-		orientation = BKE_scene_transform_orientation_find(scene, scene->orientation_index_custom);
+		orientation = BKE_scene_transform_orientation_find(scene, orient_slot->index_custom);
 	}
-
 	return rna_pointer_inherit_refine(ptr, &RNA_TransformOrientation, orientation);
 }
 
@@ -2180,6 +2191,39 @@ static void rna_def_transform_orientation(BlenderRNA *brna)
 	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
 }
 
+static void rna_def_transform_orientation_slot(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+
+	srna = RNA_def_struct(brna, "TransformOrientationSlot", NULL);
+	RNA_def_struct_sdna(srna, "TransformOrientationSlot");
+	RNA_def_struct_ui_text(srna, "Orientation Slot", "");
+
+	/* Orientations */
+	prop = RNA_def_property(srna, "type", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_items(prop, rna_enum_transform_orientation_items);
+	RNA_def_property_enum_funcs(
+	        prop,
+	        "rna_TransformOrientationSlot_type_get",
+	        "rna_TransformOrientationSlot_type_set",
+	        "rna_TransformOrientation_itemf");
+	RNA_def_property_ui_text(prop, "Transform Orientation", "Transformation orientation");
+	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+
+	prop = RNA_def_property(srna, "custom_orientation", PROP_POINTER, PROP_NONE);
+	RNA_def_property_struct_type(prop, "TransformOrientation");
+	RNA_def_property_pointer_funcs(prop, "rna_TransformOrientationSlot_get", NULL, NULL, NULL);
+	RNA_def_property_ui_text(prop, "Current Transform Orientation", "");
+
+	/* flag */
+	prop = RNA_def_property(srna, "use", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_negative_sdna(prop, NULL, "flag", SELECT);
+	RNA_def_property_ui_text(prop, "Use", "Disable to unlink the orientation from the scene-setting");
+	RNA_def_property_update(prop, NC_SCENE | ND_TOOLSETTINGS, NULL);
+}
+
+
 static void rna_def_tool_settings(BlenderRNA  *brna)
 {
 	StructRNA *srna;
@@ -6429,19 +6473,18 @@ void RNA_def_scene(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Timeline Markers", "Markers used in all timelines for the current scene");
 	rna_def_timeline_markers(brna, prop);
 
-	/* Orientations */
-	prop = RNA_def_property(srna, "transform_orientation", PROP_ENUM, PROP_NONE);
-	RNA_def_property_enum_sdna(prop, NULL, "orientation_type");
-	RNA_def_property_enum_items(prop, rna_enum_transform_orientation_items);
-	RNA_def_property_enum_funcs(prop, "rna_Scene_transform_orientation_get", "rna_Scene_transform_orientation_set",
-	                            "rna_TransformOrientation_itemf");
-	RNA_def_property_ui_text(prop, "Transform Orientation", "Transformation orientation");
-	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
-
-	prop = RNA_def_property(srna, "current_orientation", PROP_POINTER, PROP_NONE);
-	RNA_def_property_struct_type(prop, "TransformOrientation");
-	RNA_def_property_pointer_funcs(prop, "rna_Scene_current_orientation_get", NULL, NULL, NULL);
-	RNA_def_property_ui_text(prop, "Current Transform Orientation", "Current transformation orientation");
+	/* Transform Orientations */
+	prop = RNA_def_property(srna, "transform_orientation_slots", PROP_COLLECTION, PROP_NONE);
+	RNA_def_property_collection_funcs(
+	        prop,
+	        "rna_Scene_transform_orientation_slots_begin",
+	        "rna_iterator_array_next",
+	        "rna_iterator_array_end",
+	        "rna_iterator_array_get",
+	        "rna_Scene_transform_orientation_slots_length",
+	        NULL, NULL, NULL);
+	RNA_def_property_struct_type(prop, "TransformOrientationSlot");
+	RNA_def_property_ui_text(prop, "Transform Orientation Slots", "");
 
 	/* Audio Settings */
 	prop = RNA_def_property(srna, "use_audio", PROP_BOOLEAN, PROP_NONE);
@@ -6566,6 +6609,7 @@ void RNA_def_scene(BlenderRNA *brna)
 	rna_def_unit_settings(brna);
 	rna_def_scene_image_format_data(brna);
 	rna_def_transform_orientation(brna);
+	rna_def_transform_orientation_slot(brna);
 	rna_def_selected_uv_element(brna);
 	rna_def_display_safe_areas(brna);
 	rna_def_scene_display(brna);