Move custom transform orientations to workspace

This commit moves the list of transform orientations from scenes to workspaces.
Main reasons for this are:
* Transform orientations are UI data and should not be stored in the scene.
* Introducion of workspaces caused some (expected) glitches with transform orientations. Mainly when removing one.
* Improves code.

More technically speaking, this commit does:
* Move list of custom transform orientations from Scene to WorkSpace struct.
* Store active transform orientation index separate from View3D.twmode (twmode can only be set to preprocessor defined values now).
* Display custom transform orientation name in header when transforming in it (used to show "global" which isn't really correct).

25 files changed, 300 insertions, 189 deletions

diff --git a/source/blender/blenkernel/BKE_screen.h b/source/blender/blenkernel/BKE_screen.h
index 645a99d592f..6ff344fea38 100644
--- a/source/blender/blenkernel/BKE_screen.h
+++ b/source/blender/blenkernel/BKE_screen.h
@@ -42,6 +42,7 @@ struct Panel;
 struct Scene;
 struct ScrArea;
 struct SpaceType;
+struct TransformOrientation;
 struct View3D;
 struct bContext;
 struct bContextDataResult;
@@ -53,6 +54,7 @@ struct wmManipulatorMap;
 struct wmNotifier;
 struct wmWindow;
 struct wmWindowManager;
+struct WorkSpace;
 struct GPUFXSettings;
 
 #include "BLI_compiler_attrs.h"
@@ -309,8 +311,9 @@ unsigned int BKE_screen_view3d_layer_all(const struct bScreen *sc) ATTR_WARN_UNU
 
 void BKE_screen_view3d_sync(struct View3D *v3d, struct Scene *scene);
 void BKE_screen_view3d_scene_sync(struct bScreen *sc, struct Scene *scene);
-void BKE_screen_view3d_twmode_remove(struct View3D *v3d, const int i);
-void BKE_screen_view3d_main_twmode_remove(ListBase *screen_lb, struct Scene *scene, const int i);
+void BKE_screen_transform_orientation_remove(
+        const struct bScreen *screen, const struct WorkSpace *workspace,
+        const struct TransformOrientation *orientation) ATTR_NONNULL();
 void BKE_screen_gpu_fx_validate(struct GPUFXSettings *fx_settings);
 bool BKE_screen_is_fullscreen_area(const struct bScreen *screen) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 bool BKE_screen_is_used(const struct bScreen *screen) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
diff --git a/source/blender/blenkernel/BKE_workspace.h b/source/blender/blenkernel/BKE_workspace.h
index e7eaf72dd15..5595c874e27 100644
--- a/source/blender/blenkernel/BKE_workspace.h
+++ b/source/blender/blenkernel/BKE_workspace.h
@@ -28,6 +28,7 @@
 #include "BLI_compiler_attrs.h"
 
 struct bScreen;
+struct TransformOrientation;
 
 typedef struct WorkSpace WorkSpace;
 typedef struct WorkSpaceInstanceHook WorkSpaceInstanceHook;
@@ -66,11 +67,18 @@ void BKE_workspace_layout_remove(
 /* -------------------------------------------------------------------- */
 /* General Utils */
 
+void BKE_workspace_transform_orientation_remove(
+        WorkSpace *workspace, struct TransformOrientation *orientation) ATTR_NONNULL();
+struct TransformOrientation *BKE_workspace_transform_orientation_find(
+        const WorkSpace *workspace, const int index) ATTR_NONNULL();
+int BKE_workspace_transform_orientation_get_index(
+        const WorkSpace *workspace, const struct TransformOrientation *orientation) ATTR_NONNULL();
+
 WorkSpaceLayout *BKE_workspace_layout_find(
         const WorkSpace *workspace, const struct bScreen *screen) ATTR_NONNULL() ATTR_WARN_UNUSED_RESULT;
 WorkSpaceLayout *BKE_workspace_layout_find_global(
         const struct Main *bmain, const struct bScreen *screen,
-        WorkSpace **r_workspace) ATTR_NONNULL(1, 2) ATTR_WARN_UNUSED_RESULT;
+        WorkSpace **r_workspace) ATTR_NONNULL(1, 2);
 
 WorkSpaceLayout *BKE_workspace_layout_iter_circular(
         const WorkSpace *workspace, WorkSpaceLayout *start,
@@ -95,6 +103,7 @@ enum ObjectMode BKE_workspace_object_mode_get(const WorkSpace *workspace) GETTER
 #ifdef USE_WORKSPACE_MODE
 void            BKE_workspace_object_mode_set(WorkSpace *workspace, const enum ObjectMode mode) SETTER_ATTRS;
 #endif
+struct ListBase *BKE_workspace_transform_orientations_get(WorkSpace *workspace) GETTER_ATTRS;
 struct SceneLayer *BKE_workspace_render_layer_get(const WorkSpace *workspace) GETTER_ATTRS;
 void               BKE_workspace_render_layer_set(WorkSpace *workspace, struct SceneLayer *layer) SETTER_ATTRS;
 struct ListBase *BKE_workspace_layouts_get(WorkSpace *workspace) GETTER_ATTRS;
diff --git a/source/blender/blenkernel/intern/scene.c b/source/blender/blenkernel/intern/scene.c
index 92f5dade0a5..235d606ff3e 100644
--- a/source/blender/blenkernel/intern/scene.c
+++ b/source/blender/blenkernel/intern/scene.c
@@ -261,7 +261,6 @@ Scene *BKE_scene_copy(Main *bmain, Scene *sce, int type)
 			scen->rigidbody_world = BKE_rigidbody_world_copy(sce->rigidbody_world);
 
 		BLI_duplicatelist(&(scen->markers), &(sce->markers));
-		BLI_duplicatelist(&(scen->transform_spaces), &(sce->transform_spaces));
 		BLI_duplicatelist(&(scen->r.layers), &(sce->r.layers));
 		BLI_duplicatelist(&(scen->r.views), &(sce->r.views));
 		BKE_keyingsets_copy(&(scen->keyingsets), &(sce->keyingsets));
@@ -534,10 +533,9 @@ void BKE_scene_free(Scene *sce)
 	}
 
 	BLI_freelistN(&sce->markers);
-	BLI_freelistN(&sce->transform_spaces);
 	BLI_freelistN(&sce->r.layers);
 	BLI_freelistN(&sce->r.views);
-	
+
 	if (sce->toolsettings) {
 		if (sce->toolsettings->vpaint) {
 			BKE_paint_free(&sce->toolsettings->vpaint->paint);
diff --git a/source/blender/blenkernel/intern/screen.c b/source/blender/blenkernel/intern/screen.c
index b1f8f574b7e..91d675535f3 100644
--- a/source/blender/blenkernel/intern/screen.c
+++ b/source/blender/blenkernel/intern/screen.c
@@ -53,6 +53,7 @@
 #include "BKE_icons.h"
 #include "BKE_idprop.h"
 #include "BKE_screen.h"
+#include "BKE_workspace.h"
 
 /* ************ Spacetype/regiontype handling ************** */
 
@@ -611,33 +612,20 @@ void BKE_screen_view3d_scene_sync(bScreen *sc, Scene *scene)
 	}
 }
 
-/* XXX apply D2687 */
-void BKE_screen_view3d_twmode_remove(View3D *v3d, const int i)
+void BKE_screen_transform_orientation_remove(
+        const bScreen *screen, const WorkSpace *workspace, const TransformOrientation *orientation)
 {
-	const int selected_index = (v3d->twmode - V3D_MANIP_CUSTOM);
-	if (selected_index == i) {
-		v3d->twmode = V3D_MANIP_GLOBAL;
-	}
-	else if (selected_index > i) {
-		v3d->twmode--;
-	}
-}
+	const int orientation_index = BKE_workspace_transform_orientation_get_index(workspace, orientation);
 
-/* XXX apply D2687 */
-void BKE_screen_view3d_main_twmode_remove(ListBase *screen_lb, Scene *scene, const int i)
-{
-	bScreen *sc;
+	for (ScrArea *area = screen->areabase.first; area; area = area->next) {
+		for (SpaceLink *sl = area->spacedata.first; sl; sl = sl->next) {
+			if (sl->spacetype == SPACE_VIEW3D) {
+				View3D *v3d = (View3D *)sl;
 
-	for (sc = screen_lb->first; sc; sc = sc->id.next) {
-		if (sc->scene == scene) {
-			ScrArea *sa;
-			for (sa = sc->areabase.first; sa; sa = sa->next) {
-				SpaceLink *sl;
-				for (sl = sa->spacedata.first; sl; sl = sl->next) {
-					if (sl->spacetype == SPACE_VIEW3D) {
-						View3D *v3d = (View3D *)sl;
-						BKE_screen_view3d_twmode_remove(v3d, i);
-					}
+				if (v3d->custom_orientation_index == orientation_index) {
+					/* could also use orientation_index-- */
+					v3d->twmode = V3D_MANIP_GLOBAL;
+					v3d->custom_orientation_index = -1;
 				}
 			}
 		}
diff --git a/source/blender/blenkernel/intern/workspace.c b/source/blender/blenkernel/intern/workspace.c
index 8afad317dce..82fface7d06 100644
--- a/source/blender/blenkernel/intern/workspace.c
+++ b/source/blender/blenkernel/intern/workspace.c
@@ -35,6 +35,7 @@
 #include "BKE_global.h"
 #include "BKE_library.h"
 #include "BKE_main.h"
+#include "BKE_screen.h"
 #include "BKE_workspace.h"
 
 #include "DNA_object_types.h"
@@ -150,6 +151,7 @@ void BKE_workspace_free(WorkSpace *workspace)
 		workspace_relation_remove(&workspace->hook_layout_relations, relation);
 	}
 	BLI_freelistN(&workspace->layouts);
+	BLI_freelistN(&workspace->transform_orientations);
 }
 
 void BKE_workspace_remove(Main *bmain, WorkSpace *workspace)
@@ -223,6 +225,31 @@ void BKE_workspace_layout_remove(
 /* -------------------------------------------------------------------- */
 /* General Utils */
 
+void BKE_workspace_transform_orientation_remove(
+        WorkSpace *workspace, TransformOrientation *orientation)
+{
+	for (WorkSpaceLayout *layout = workspace->layouts.first; layout; layout = layout->next) {
+		BKE_screen_transform_orientation_remove(BKE_workspace_layout_screen_get(layout), workspace, orientation);
+	}
+
+	BLI_freelinkN(&workspace->transform_orientations, orientation);
+}
+
+TransformOrientation *BKE_workspace_transform_orientation_find(
+        const WorkSpace *workspace, const int index)
+{
+	return BLI_findlink(&workspace->transform_orientations, index);
+}
+
+/**
+ * \return the index that \a orientation has within \a workspace's transform-orientation list or -1 if not found.
+ */
+int BKE_workspace_transform_orientation_get_index(
+        const WorkSpace *workspace, const TransformOrientation *orientation)
+{
+	return BLI_findindex(&workspace->transform_orientations, orientation);
+}
+
 WorkSpaceLayout *BKE_workspace_layout_find(
         const WorkSpace *workspace, const bScreen *screen)
 {
@@ -240,6 +267,7 @@ WorkSpaceLayout *BKE_workspace_layout_find(
 
 /**
  * Find the layout for \a screen without knowing which workspace to look in.
+ * Can also be used to find the workspace that contains \a screen.
  *
  * \param r_workspace: Optionally return the workspace that contains the looked up layout (if found).
  */
@@ -353,6 +381,11 @@ void BKE_workspace_object_mode_set(WorkSpace *workspace, const ObjectMode mode)
 }
 #endif
 
+ListBase *BKE_workspace_transform_orientations_get(WorkSpace *workspace)
+{
+	return &workspace->transform_orientations;
+}
+
 SceneLayer *BKE_workspace_render_layer_get(const WorkSpace *workspace)
 {
 	return workspace->render_layer;
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 966cbce62db..8e89c61d9f7 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -2820,6 +2820,7 @@ static void direct_link_workspace(FileData *fd, WorkSpace *workspace, const Main
 {
 	link_list(fd, BKE_workspace_layouts_get(workspace));
 	link_list(fd, &workspace->hook_layout_relations);
+	link_list(fd, BKE_workspace_transform_orientations_get(workspace));
 
 	for (WorkSpaceDataRelation *relation = workspace->hook_layout_relations.first;
 	     relation;
@@ -2835,7 +2836,7 @@ static void direct_link_workspace(FileData *fd, WorkSpace *workspace, const Main
 		BKE_workspace_render_layer_set(workspace, NULL);
 	}
 
-	/* Same issue/fix as in direct_link_scene_update_screen_data: Can't read workspace data
+	/* Same issue/fix as in direct_link_workspace_link_scene_data: Can't read workspace data
 	 * when reading windows, so have to update windows after/when reading workspaces. */
 	for (wmWindowManager *wm = main->wm.first; wm; wm = wm->id.next) {
 		for (wmWindow *win = wm->windows.first; win; win = win->next) {
@@ -6057,7 +6058,10 @@ static void direct_link_layer_collections(FileData *fd, ListBase *lb)
 	}
 }
 
-static void direct_link_scene_update_screen_data(
+/**
+ * Workspaces store a render layer pointer which can only be read after scene is read.
+ */
+static void direct_link_workspace_link_scene_data(
         FileData *fd, const Scene *scene, const ListBase *workspaces)
 {
 	for (WorkSpace *workspace = workspaces->first; workspace; workspace = workspace->id.next) {
@@ -6285,7 +6289,7 @@ static void direct_link_scene(FileData *fd, Scene *sce, Main *bmain)
 	}
 	
 	link_list(fd, &(sce->markers));
-	link_list(fd, &(sce->transform_spaces));
+	link_list(fd, &(sce->transform_spaces)); /* only for old files */
 	link_list(fd, &(sce->r.layers));
 	link_list(fd, &(sce->r.views));
 
@@ -6371,7 +6375,7 @@ static void direct_link_scene(FileData *fd, Scene *sce, Main *bmain)
 	BKE_layer_collection_engine_settings_validate_scene(sce);
 	BKE_scene_layer_engine_settings_validate_scene(sce);
 
-	direct_link_scene_update_screen_data(fd, sce, &bmain->workspaces);
+	direct_link_workspace_link_scene_data(fd, sce, &bmain->workspaces);
 }
 
 /* ************ READ WM ***************** */
diff --git a/source/blender/blenloader/intern/versioning_280.c b/source/blender/blenloader/intern/versioning_280.c
index 2d14238eb6f..13da6e5d407 100644
--- a/source/blender/blenloader/intern/versioning_280.c
+++ b/source/blender/blenloader/intern/versioning_280.c
@@ -36,6 +36,7 @@
 #include "DNA_mesh_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_screen_types.h"
+#include "DNA_view3d_types.h"
 #include "DNA_genfile.h"
 
 #include "BKE_collection.h"
@@ -77,6 +78,7 @@ static void do_version_workspaces_create_from_screens(Main *bmain)
 	for (bScreen *screen = bmain->screen.first; screen; screen = screen->id.next) {
 		const bScreen *screen_parent = screen_parent_find(screen);
 		WorkSpace *workspace;
+		ListBase *transform_orientations;
 
 		if (screen_parent) {
 			/* fullscreen with "Back to Previous" option, don't create
@@ -89,6 +91,9 @@ static void do_version_workspaces_create_from_screens(Main *bmain)
 		}
 		BKE_workspace_layout_add(workspace, screen, screen->id.name + 2);
 		BKE_workspace_render_layer_set(workspace, screen->scene->render_layers.first);
+
+		transform_orientations = BKE_workspace_transform_orientations_get(workspace);
+		BLI_duplicatelist(transform_orientations, &screen->scene->transform_spaces);
 	}
 }
 
@@ -129,6 +134,7 @@ static void do_version_workspaces_after_lib_link(Main *bmain)
 
 	for (bScreen *screen = bmain->screen.first; screen; screen = screen->id.next) {
 		/* Deprecated from now on! */
+		BLI_freelistN(&screen->scene->transform_spaces);
 		screen->scene = NULL;
 	}
 }
@@ -373,5 +379,21 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *main)
 				}
 			}
 		}
+
+		if (!DNA_struct_elem_find(fd->filesdna, "View3D", "short", "custom_orientation_index")) {
+			for (bScreen *screen = main->screen.first; screen; screen = screen->id.next) {
+				for (ScrArea *area = screen->areabase.first; area; area = area->next) {
+					for (SpaceLink *sl = area->spacedata.first; sl; sl = sl->next) {
+						if (sl->spacetype == SPACE_VIEW3D) {
+							View3D *v3d = (View3D *)sl;
+							if (v3d->twmode >= V3D_MANIP_CUSTOM) {
+								v3d->custom_orientation_index = v3d->twmode - V3D_MANIP_CUSTOM;
+								v3d->twmode = V3D_MANIP_CUSTOM;
+							}
+						}
+					}
+				}
+			}
+		}
 	}
 }
diff --git a/source/blender/blenloader/intern/writefile.c b/source/blender/blenloader/intern/writefile.c
index 82d2e37dce0..c1628575398 100644
--- a/source/blender/blenloader/intern/writefile.c
+++ b/source/blender/blenloader/intern/writefile.c
@@ -2754,11 +2754,6 @@ static void write_scene(WriteData *wd, Scene *sce)
 		writestruct(wd, DATA, TimeMarker, 1, marker);
 	}
 
-	/* writing dynamic list of TransformOrientations to the blend file */
-	for (TransformOrientation *ts = sce->transform_spaces.first; ts; ts = ts->next) {
-		writestruct(wd, DATA, TransformOrientation, 1, ts);
-	}
-
 	for (SceneRenderLayer *srl = sce->r.layers.first; srl; srl = srl->next) {
 		writestruct(wd, DATA, SceneRenderLayer, 1, srl);
 		if (srl->prop) {
@@ -3754,10 +3749,12 @@ static void write_cachefile(WriteData *wd, CacheFile *cache_file)
 static void write_workspace(WriteData *wd, WorkSpace *workspace)
 {
 	ListBase *layouts = BKE_workspace_layouts_get(workspace);
+	ListBase *transform_orientations = BKE_workspace_transform_orientations_get(workspace);
 
 	writestruct(wd, ID_WS, WorkSpace, 1, workspace);
 	writelist(wd, DATA, WorkSpaceLayout, layouts);
 	writelist(wd, DATA, WorkSpaceDataRelation, &workspace->hook_layout_relations);
+	writelist(wd, DATA, TransformOrientation, transform_orientations);
 }
 
 /* Keep it last of write_foodata functions. */
diff --git a/source/blender/editors/include/ED_transform.h b/source/blender/editors/include/ED_transform.h
index 376ae8ca567..a20d2925564 100644
--- a/source/blender/editors/include/ED_transform.h
+++ b/source/blender/editors/include/ED_transform.h
@@ -43,6 +43,7 @@ struct wmEvent;
 struct wmKeyConfig;
 struct wmKeyMap;
 struct wmOperatorType;
+struct WorkSpace;
 struct Main;
 struct SnapObjectContext;
 struct SnapObjectParams;
@@ -130,7 +131,7 @@ 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 bContext *C, int orientation);
+void BIF_selectTransformOrientationValue(struct View3D *v3d, int orientation);
 
 void ED_getTransformOrientationMatrix(const struct bContext *C, float orientation_mat[3][3], const short around);
 
diff --git a/source/blender/editors/screen/workspace_edit.c b/source/blender/editors/screen/workspace_edit.c
index 3782d583003..d82b84ebede 100644
--- a/source/blender/editors/screen/workspace_edit.c
+++ b/source/blender/editors/screen/workspace_edit.c
@@ -216,10 +216,13 @@ WorkSpace *ED_workspace_duplicate(
 	WorkSpace *workspace_new = ED_workspace_add(
 	        bmain, workspace_old->id.name + 2,
 	        BKE_workspace_render_layer_get(workspace_old));
+	ListBase *transform_orientations_old = BKE_workspace_transform_orientations_get(workspace_old);
+	ListBase *transform_orientations_new = BKE_workspace_transform_orientations_get(workspace_new);
 
 #ifdef USE_WORKSPACE_MODE
 	BKE_workspace_object_mode_set(workspace_new, BKE_workspace_object_mode_get(workspace_old));
 #endif
+	BLI_duplicatelist(transform_orientations_new, transform_orientations_old);
 
 	for (WorkSpaceLayout *layout_old = layouts_old->first; layout_old; layout_old = layout_old->next) {
 		WorkSpaceLayout *layout_new = ED_workspace_layout_duplicate(workspace_new, layout_old, win);
diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index b29c75d566b..83f281e1e88 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -63,6 +63,7 @@
 #include "BKE_unit.h"
 #include "BKE_mask.h"
 #include "BKE_report.h"
+#include "BKE_workspace.h"
 
 #include "BIF_glutil.h"
 
@@ -2013,6 +2014,8 @@ void saveTransform(bContext *C, TransInfo *t, wmOperator *op)
 				View3D *v3d = t->view;
 
 				v3d->twmode = t->current_orientation;
+				BLI_assert(BKE_workspace_transform_orientation_get_index(CTX_wm_workspace(C), t->custom_orientation)
+				           == v3d->custom_orientation_index);
 			}
 		}
 	}
@@ -2032,15 +2035,20 @@ void saveTransform(bContext *C, TransInfo *t, wmOperator *op)
 	}
 
 	if ((prop = RNA_struct_find_property(op->ptr, "constraint_axis"))) {
-		/* constraint orientation can be global, event if user selects something else
-		 * so use the orientation in the constraint if set
-		 * */
-		if (t->con.mode & CON_APPLY) {
-			RNA_enum_set(op->ptr, "constraint_orientation", t->con.orientation);
-		}
-		else {
-			RNA_enum_set(op->ptr, "constraint_orientation", t->current_orientation);
+		/* constraint orientation can be global, even if user selects something else
+		 * so use the orientation in the constraint if set */
+		short orientation = (t->con.mode & CON_APPLY) ? t->con.orientation : t->current_orientation;
+
+		if (orientation == V3D_MANIP_CUSTOM) {
+			WorkSpace *workspace = CTX_wm_workspace(C);
+			const int custom_orientation_index = BKE_workspace_transform_orientation_get_index(
+			                                       workspace, t->custom_orientation);
+
+			/* Maybe we need a t->con.custom_orientation? Seems like it would always match t->custom_orientation. */
+			orientation = V3D_MANIP_CUSTOM + custom_orientation_index;
+			BLI_assert(orientation >= V3D_MANIP_CUSTOM);
 		}
+		RNA_enum_set(op->ptr, "constraint_orientation", orientation);
 
 		if (t->con.mode & CON_APPLY) {
 			if (t->con.mode & CON_AXIS0) {
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 5544b08bbe9..d415b3eabeb 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -447,6 +447,7 @@ typedef struct TransInfo {
 	short		launch_event; 	/* event type used to launch transform */
 
 	short		current_orientation;
+	TransformOrientation *custom_orientation; /* this gets used when current_orientation is V3D_MANIP_CUSTOM */
 	short		twtype;			/* backup from view3d, to restore on end */
 
 	short		prop_mode;
@@ -788,7 +789,7 @@ bool createSpaceNormalTangent(float mat[3][3], const float normal[3], const floa
 
 struct TransformOrientation *addMatrixSpace(struct bContext *C, float mat[3][3],
                                             const char *name, const bool overwrite);
-bool applyTransformOrientation(const struct bContext *C, float mat[3][3], char r_name[64], int index);
+bool applyTransformOrientation(const struct TransformOrientation *ts, float r_mat[3][3], char r_name[64]);
 
 #define ORIENTATION_NONE	0
 #define ORIENTATION_NORMAL	1
diff --git a/source/blender/editors/transform/transform_constraints.c b/source/blender/editors/transform/transform_constraints.c
index 7b658d9c636..9360727e9cf 100644
--- a/source/blender/editors/transform/transform_constraints.c
+++ b/source/blender/editors/transform/transform_constraints.c
@@ -653,7 +653,7 @@ void setLocalConstraint(TransInfo *t, int mode, const char text[])
  */
 void setUserConstraint(TransInfo *t, short orientation, int mode, const char ftext[])
 {
-	char text[40];
+	char text[256];
 
 	switch (orientation) {
 		case V3D_MANIP_GLOBAL:
@@ -685,10 +685,15 @@ void setUserConstraint(TransInfo *t, short orientation, int mode, const char fte
 			BLI_snprintf(text, sizeof(text), ftext, IFACE_("gimbal"));
 			setConstraint(t, t->spacemtx, mode, text);
 			break;
-		default: /* V3D_MANIP_CUSTOM */
-			BLI_snprintf(text, sizeof(text), ftext, t->spacename);
+		case V3D_MANIP_CUSTOM:
+		{
+			char orientation_str[128];
+			BLI_snprintf(orientation_str, sizeof(orientation_str), "%s \"%s\"",
+			             IFACE_("custom orientation"), t->custom_orientation->name);
+			BLI_snprintf(text, sizeof(text), ftext, orientation_str);
 			setConstraint(t, t->spacemtx, mode, text);
 			break;
+		}
 	}
 
 	t->con.orientation = orientation;
diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index 0009ae13117..adff98cc99b 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -83,6 +83,7 @@
 #include "BKE_tracking.h"
 #include "BKE_mask.h"
 #include "BKE_utildefines.h"
+#include "BKE_workspace.h"
 
 #include "ED_anim_api.h"
 #include "ED_armature.h"
@@ -1242,6 +1243,8 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 		}
 
 		t->current_orientation = v3d->twmode;
+		t->custom_orientation = BKE_workspace_transform_orientation_find(
+		                            CTX_wm_workspace(C), v3d->custom_orientation_index);
 
 		/* exceptional case */
 		if (t->around == V3D_AROUND_LOCAL_ORIGINS) {
@@ -1332,13 +1335,24 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 	if (op && ((prop = RNA_struct_find_property(op->ptr, "constraint_orientation")) &&
 	           RNA_property_is_set(op->ptr, prop)))
 	{
-		t->current_orientation = RNA_property_enum_get(op->ptr, prop);
+		short orientation = RNA_property_enum_get(op->ptr, prop);
+		TransformOrientation *custom_orientation = NULL;
 
-		if (t->current_orientation >= V3D_MANIP_CUSTOM + BIF_countTransformOrientation(C)) {
-			t->current_orientation = V3D_MANIP_GLOBAL;
+		if (orientation >= V3D_MANIP_CUSTOM) {
+			if (orientation >= V3D_MANIP_CUSTOM + BIF_countTransformOrientation(C)) {
+				orientation = V3D_MANIP_GLOBAL;
+			}
+			else {
+				custom_orientation = BKE_workspace_transform_orientation_find(
+				                         CTX_wm_workspace(C), orientation - V3D_MANIP_CUSTOM);
+				orientation = V3D_MANIP_CUSTOM;
+			}
 		}
+
+		t->current_orientation = orientation;
+		t->custom_orientation = custom_orientation;
 	}
-	
+
 	if (op && ((prop = RNA_struct_find_property(op->ptr, "release_confirm")) &&
 	           RNA_property_is_set(op->ptr, prop)))
 	{
diff --git a/source/blender/editors/transform/transform_manipulator.c b/source/blender/editors/transform/transform_manipulator.c
index 009cb2bac63..df529b0054d 100644
--- a/source/blender/editors/transform/transform_manipulator.c
+++ b/source/blender/editors/transform/transform_manipulator.c
@@ -60,6 +60,7 @@
 #include "BKE_editmesh.h"
 #include "BKE_lattice.h"
 #include "BKE_gpencil.h"
+#include "BKE_workspace.h"
 
 #include "BIF_gl.h"
 
@@ -986,10 +987,13 @@ static int calc_manipulator_stats(const bContext *C)
 				copy_m4_m3(rv3d->twmat, mat);
 				break;
 			}
-			default: /* V3D_MANIP_CUSTOM */
+			case V3D_MANIP_CUSTOM:
 			{
+				TransformOrientation *custom_orientation = BKE_workspace_transform_orientation_find(
+				                                               CTX_wm_workspace(C), v3d->custom_orientation_index);
 				float mat[3][3];
-				if (applyTransformOrientation(C, mat, NULL, v3d->twmode - V3D_MANIP_CUSTOM)) {
+
+				if (applyTransformOrientation(custom_orientation, mat, NULL)) {
 					copy_m4_m3(rv3d->twmat, mat);
 				}
 				break;
diff --git a/source/blender/editors/transform/transform_ops.c b/source/blender/editors/transform/transform_ops.c
index a2a5307c707..dba442259d1 100644
--- a/source/blender/editors/transform/transform_ops.c
+++ b/source/blender/editors/transform/transform_ops.c
@@ -160,11 +160,12 @@ EnumPropertyItem rna_enum_transform_mode_types[] =
 
 static int select_orientation_exec(bContext *C, wmOperator *op)
 {
+	View3D *v3d = CTX_wm_view3d(C);
 	int orientation = RNA_enum_get(op->ptr, "orientation");
 
-	BIF_selectTransformOrientationValue(C, orientation);
+	BIF_selectTransformOrientationValue(v3d, orientation);
 	
-	WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, CTX_wm_view3d(C));
+	WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
 
 	return OPERATOR_FINISHED;
 }
@@ -206,10 +207,9 @@ static void TRANSFORM_OT_select_orientation(struct wmOperatorType *ot)
 static int delete_orientation_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	View3D *v3d = CTX_wm_view3d(C);
-	int selected_index = (v3d->twmode - V3D_MANIP_CUSTOM);
 
-	BIF_removeTransformOrientationIndex(C, selected_index);
-	
+	BIF_removeTransformOrientationIndex(C, v3d->custom_orientation_index);
+
 	WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
 	WM_event_add_notifier(C, NC_SCENE | NA_EDITED, CTX_data_scene(C));
 
@@ -223,18 +223,12 @@ static int delete_orientation_invoke(bContext *C, wmOperator *op, const wmEvent
 
 static int delete_orientation_poll(bContext *C)
 {
-	int selected_index = -1;
 	View3D *v3d = CTX_wm_view3d(C);
-	
+
 	if (ED_operator_areaactive(C) == 0)
 		return 0;
-	
-
-	if (v3d) {
-		selected_index = (v3d->twmode - V3D_MANIP_CUSTOM);
-	}
 
-	return selected_index >= 0;
+	return (v3d->twmode >= V3D_MANIP_CUSTOM) && (v3d->custom_orientation_index != -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 2ba640500c7..5aa391f1f0b 100644
--- a/source/blender/editors/transform/transform_orientations.c
+++ b/source/blender/editors/transform/transform_orientations.c
@@ -52,6 +52,7 @@
 #include "BKE_report.h"
 #include "BKE_main.h"
 #include "BKE_screen.h"
+#include "BKE_workspace.h"
 
 #include "BLT_translation.h"
 
@@ -63,14 +64,16 @@
 
 void BIF_clearTransformOrientation(bContext *C)
 {
+	WorkSpace *workspace = CTX_wm_workspace(C);
+	ListBase *transform_orientations = BKE_workspace_transform_orientations_get(workspace);
 	View3D *v3d = CTX_wm_view3d(C);
 
-	ListBase *transform_spaces = &CTX_data_scene(C)->transform_spaces;
-	BLI_freelistN(transform_spaces);
+	BLI_freelistN(transform_orientations);
 	
 	// Need to loop over all view3d
-	if (v3d && v3d->twmode >= V3D_MANIP_CUSTOM) {
-		v3d->twmode = V3D_MANIP_GLOBAL; /* fallback to global	*/
+	if (v3d && v3d->twmode == V3D_MANIP_CUSTOM) {
+		v3d->twmode = V3D_MANIP_GLOBAL; /* fallback to global */
+		v3d->custom_orientation_index = -1;
 	}
 }
 
@@ -318,23 +321,24 @@ void BIF_createTransformOrientation(bContext *C, ReportList *reports,
 TransformOrientation *addMatrixSpace(bContext *C, float mat[3][3],
                                      const char *name, const bool overwrite)
 {
-	ListBase *transform_spaces = &CTX_data_scene(C)->transform_spaces;
 	TransformOrientation *ts = NULL;
+	WorkSpace *workspace = CTX_wm_workspace(C);
+	ListBase *transform_orientations = BKE_workspace_transform_orientations_get(workspace);
 	char name_unique[sizeof(ts->name)];
 
 	if (overwrite) {
-		ts = findOrientationName(transform_spaces, name);
+		ts = findOrientationName(transform_orientations, name);
 	}
 	else {
 		BLI_strncpy(name_unique, name, sizeof(name_unique));
-		uniqueOrientationName(transform_spaces, name_unique);
+		uniqueOrientationName(transform_orientations, name_unique);
 		name = name_unique;
 	}
 
 	/* if not, create a new one */
 	if (ts == NULL) {
 		ts = MEM_callocN(sizeof(TransformOrientation), "UserTransSpace from matrix");
-		BLI_addtail(transform_spaces, ts);
+		BLI_addtail(transform_orientations, ts);
 		BLI_strncpy(ts->name, name, sizeof(ts->name));
 	}
 
@@ -346,72 +350,55 @@ TransformOrientation *addMatrixSpace(bContext *C, float mat[3][3],
 
 void BIF_removeTransformOrientation(bContext *C, TransformOrientation *target)
 {
-	Scene *scene = CTX_data_scene(C);
-	ListBase *transform_spaces = &scene->transform_spaces;
-	const int i = BLI_findindex(transform_spaces, target);
-
-	if (i != -1) {
-		Main *bmain = CTX_data_main(C);
-		BKE_screen_view3d_main_twmode_remove(&bmain->screen, scene, i);
-		BLI_freelinkN(transform_spaces, target);
-	}
+	BKE_workspace_transform_orientation_remove(CTX_wm_workspace(C), target);
 }
 
 void BIF_removeTransformOrientationIndex(bContext *C, int index)
 {
-	ListBase *transform_spaces = &CTX_data_scene(C)->transform_spaces;
-	TransformOrientation *ts = BLI_findlink(transform_spaces, index);
-
-	if (ts) {
-		BIF_removeTransformOrientation(C, ts);
-	}
+	TransformOrientation *target = BKE_workspace_transform_orientation_find(CTX_wm_workspace(C), index);
+	BIF_removeTransformOrientation(C, target);
 }
 
 void BIF_selectTransformOrientation(bContext *C, TransformOrientation *target)
 {
-	ListBase *transform_spaces = &CTX_data_scene(C)->transform_spaces;
-	const int i = BLI_findindex(transform_spaces, target);
+	int index = BKE_workspace_transform_orientation_get_index(CTX_wm_workspace(C), target);
+	View3D *v3d = CTX_wm_view3d(C);
 
-	if (i != -1) {
-		View3D *v3d = CTX_wm_view3d(C);
-		v3d->twmode = V3D_MANIP_CUSTOM + i;
-	}
+	BLI_assert(index != -1);
+
+	v3d->twmode = V3D_MANIP_CUSTOM;
+	v3d->custom_orientation_index = index;
 }
 
-void BIF_selectTransformOrientationValue(bContext *C, int orientation)
+/**
+ * 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(View3D *v3d, int orientation)
 {
-	View3D *v3d = CTX_wm_view3d(C);
+	const bool is_custom = orientation >= V3D_MANIP_CUSTOM;
 
-	if (v3d) { /* currently using generic poll */
-		v3d->twmode = orientation;
-	}
+	v3d->twmode = is_custom ? V3D_MANIP_CUSTOM : orientation;
+	v3d->custom_orientation_index = is_custom ? (orientation - V3D_MANIP_CUSTOM) : -1;
 }
 
 int BIF_countTransformOrientation(const bContext *C)
 {
-	ListBase *transform_spaces = &CTX_data_scene(C)->transform_spaces;
-	return BLI_listbase_count(transform_spaces);
+	WorkSpace *workspace = CTX_wm_workspace(C);
+	ListBase *transform_orientations = BKE_workspace_transform_orientations_get(workspace);
+	return BLI_listbase_count(transform_orientations);
 }
 
-bool applyTransformOrientation(const bContext *C, float mat[3][3], char *r_name, int index)
+bool applyTransformOrientation(const TransformOrientation *ts, float r_mat[3][3], char *r_name)
 {
-	ListBase *transform_spaces = &CTX_data_scene(C)->transform_spaces;
-	TransformOrientation *ts = BLI_findlink(transform_spaces, index);
-
-	BLI_assert(index >= 0);
-
-	if (ts) {
-		if (r_name) {
-			BLI_strncpy(r_name, ts->name, MAX_NAME);
-		}
-
-		copy_m3_m3(mat, ts->mat);
-		return true;
-	}
-	else {
-		/* invalid index, can happen sometimes */
-		return false;
+	if (r_name) {
+		BLI_strncpy(r_name, ts->name, MAX_NAME);
 	}
+	copy_m3_m3(r_mat, ts->mat);
+
+	return true;
 }
 
 static int count_bone_select(bArmature *arm, ListBase *lb, const bool do_it)
@@ -494,8 +481,10 @@ void initTransformOrientation(bContext *C, TransInfo *t)
 				unit_m3(t->spacemtx);
 			}
 			break;
-		default: /* V3D_MANIP_CUSTOM */
-			if (applyTransformOrientation(C, t->spacemtx, t->spacename, t->current_orientation - V3D_MANIP_CUSTOM)) {
+		case V3D_MANIP_CUSTOM:
+			BLI_strncpy(t->spacename, t->custom_orientation->name, sizeof(t->spacename));
+
+			if (applyTransformOrientation(t->custom_orientation, t->spacemtx, t->spacename)) {
 				/* pass */
 			}
 			else {
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 506e98edc7b..f21cee80f80 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -1297,17 +1297,6 @@ typedef enum eGP_Interpolate_Type {
 	GP_IPO_SINE = 12,
 } eGP_Interpolate_Type;
 
-
-/* *************************************************************** */
-/* Transform Orientations */
-
-typedef struct TransformOrientation {
-	struct TransformOrientation *next, *prev;
-	char name[64];	/* MAX_NAME */
-	float mat[3][3];
-	int pad;
-} TransformOrientation;
-
 /* *************************************************************** */
 /* Unified Paint Settings
  */
@@ -1696,10 +1685,10 @@ typedef struct Scene {
 	/* no, is on the right place (ton) */
 	struct RenderData r;
 	struct AudioData audio;
-	
+
 	ListBase markers;
-	ListBase transform_spaces;
-	
+	ListBase transform_spaces DNA_DEPRECATED;
+
 	void *sound_scene;
 	void *playback_handle;
 	void *sound_scrub_handle;
diff --git a/source/blender/makesdna/DNA_screen_types.h b/source/blender/makesdna/DNA_screen_types.h
index 2524bad7c0f..75ae1cdab95 100644
--- a/source/blender/makesdna/DNA_screen_types.h
+++ b/source/blender/makesdna/DNA_screen_types.h
@@ -193,6 +193,13 @@ typedef struct uiList {           /* some list UI data need to be saved in file
 	uiListDyn *dyn_data;
 } uiList;
 
+typedef struct TransformOrientation {
+	struct TransformOrientation *next, *prev;
+	char name[64];	/* MAX_NAME */
+	float mat[3][3];
+	int pad;
+} TransformOrientation;
+
 typedef struct uiPreview {           /* some preview UI data need to be saved in file */
 	struct uiPreview *next, *prev;
 
diff --git a/source/blender/makesdna/DNA_view3d_types.h b/source/blender/makesdna/DNA_view3d_types.h
index f50222859f1..6c526d125d6 100644
--- a/source/blender/makesdna/DNA_view3d_types.h
+++ b/source/blender/makesdna/DNA_view3d_types.h
@@ -225,7 +225,9 @@ typedef struct View3D {
 
 	char multiview_eye;				/* multiview current eye - for internal use */
 
-	char pad3[4];
+	/* The active custom transform orientation of this 3D view. */
+	short custom_orientation_index;
+	char pad3[2];
 
 	/* note, 'fx_settings.dof' is currently _not_ allocated,
 	 * instead set (temporarily) from camera */
@@ -376,7 +378,7 @@ enum {
 #define V3D_MANIP_NORMAL		2
 #define V3D_MANIP_VIEW			3
 #define V3D_MANIP_GIMBAL		4
-#define V3D_MANIP_CUSTOM		5 /* anything of value 5 or higher is custom */
+#define V3D_MANIP_CUSTOM		5
 
 /* View3d->twflag */
    /* USE = user setting, DRAW = based on selection */
diff --git a/source/blender/makesdna/DNA_workspace_types.h b/source/blender/makesdna/DNA_workspace_types.h
index 56221242fbf..3805e1c0a8a 100644
--- a/source/blender/makesdna/DNA_workspace_types.h
+++ b/source/blender/makesdna/DNA_workspace_types.h
@@ -73,6 +73,9 @@ typedef struct WorkSpace {
 	 * been activated the last time this workspace was visible. */
 	ListBase hook_layout_relations DNA_PRIVATE_WORKSPACE_READ_WRITE; /* WorkSpaceDataRelation */
 
+	/* Custom transform orientations */
+	ListBase transform_orientations DNA_PRIVATE_WORKSPACE;
+
 	int object_mode DNA_PRIVATE_WORKSPACE; /* enum ObjectMode */
 	int pad;
 
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index 266838153e9..ee695caf1fa 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -3377,24 +3377,6 @@ static void rna_def_gpencil_brushes(BlenderRNA *brna, PropertyRNA *cprop)
 	RNA_def_property_ui_text(prop, "Active Brush Index", "Index of active brush");
 }
 
-static void rna_def_transform_orientation(BlenderRNA *brna)
-{
-	StructRNA *srna;
-	PropertyRNA *prop;
-	
-	srna = RNA_def_struct(brna, "TransformOrientation", NULL);
-	
-	prop = RNA_def_property(srna, "matrix", PROP_FLOAT, PROP_MATRIX);
-	RNA_def_property_float_sdna(prop, NULL, "mat");
-	RNA_def_property_multi_array(prop, 2, rna_matrix_dimsize_3x3);
-	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
-	
-	prop = RNA_def_property(srna, "name", PROP_STRING, PROP_NONE);
-	RNA_def_struct_name_property(srna, prop);
-	RNA_def_property_ui_text(prop, "Name", "Name of the custom transform orientation");
-	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
-}
-
 static void rna_def_tool_settings(BlenderRNA  *brna)
 {
 	StructRNA *srna;
@@ -9240,12 +9222,6 @@ void RNA_def_scene(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_REFCOUNT);
 	RNA_def_property_ui_text(prop, "Grease Pencil Data", "Grease Pencil data-block");
 	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA | NA_EDITED, NULL);
-	
-	/* Transform Orientations */
-	prop = RNA_def_property(srna, "orientations", PROP_COLLECTION, PROP_NONE);
-	RNA_def_property_collection_sdna(prop, NULL, "transform_spaces", NULL);
-	RNA_def_property_struct_type(prop, "TransformOrientation");
-	RNA_def_property_ui_text(prop, "Transform Orientations", "");
 
 	/* active MovieClip */
 	prop = RNA_def_property(srna, "active_clip", PROP_POINTER, PROP_NONE);
@@ -9301,7 +9277,6 @@ void RNA_def_scene(BlenderRNA *brna)
 	rna_def_unit_settings(brna);
 	rna_def_scene_image_format_data(brna);
 	rna_def_scene_game_data(brna);
-	rna_def_transform_orientation(brna);
 	rna_def_selected_uv_element(brna);
 	rna_def_display_safe_areas(brna);
 	rna_def_scene_collection(brna);
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 0e16b410dc7..65217cfcc4d 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -262,11 +262,13 @@ EnumPropertyItem rna_enum_file_sort_items[] = {
 #include "BKE_scene.h"
 #include "BKE_screen.h"
 #include "BKE_icons.h"
+#include "BKE_workspace.h"
 
 #include "ED_buttons.h"
 #include "ED_fileselect.h"
 #include "ED_image.h"
 #include "ED_node.h"
+#include "ED_transform.h"
 #include "ED_screen.h"
 #include "ED_view3d.h"
 #include "ED_sequencer.h"
@@ -406,43 +408,63 @@ static void rna_Space_view2d_sync_update(Main *UNUSED(bmain), Scene *UNUSED(scen
 	}
 }
 
-static PointerRNA rna_CurrentOrientation_get(PointerRNA *ptr)
+static int rna_View3D_transform_orientation_get(PointerRNA *ptr)
+{
+	const View3D *v3d = (View3D *)ptr->data;
+	/* convert to enum value */
+	return (v3d->twmode == V3D_MANIP_CUSTOM) ? (v3d->twmode + v3d->custom_orientation_index) : v3d->twmode;
+}
+
+void rna_View3D_transform_orientation_set(PointerRNA *ptr, int value)
+{
+	View3D *v3d = (View3D *)ptr->data;
+	BIF_selectTransformOrientationValue(v3d, value);
+}
+
+static PointerRNA rna_View3D_current_orientation_get(PointerRNA *ptr)
 {
-	Scene *scene = WM_windows_scene_get_from_screen(G.main->wm.first, ptr->id.data);
 	View3D *v3d = (View3D *)ptr->data;
+	TransformOrientation *orientation;
 
-	if (v3d->twmode < V3D_MANIP_CUSTOM)
-		return rna_pointer_inherit_refine(ptr, &RNA_TransformOrientation, NULL);
-	else
-		return rna_pointer_inherit_refine(ptr, &RNA_TransformOrientation,
-		                                  BLI_findlink(&scene->transform_spaces, v3d->twmode - V3D_MANIP_CUSTOM));
+	if (v3d->twmode < V3D_MANIP_CUSTOM) {
+		orientation = NULL;
+	}
+	else {
+		WorkSpace *workspace;
+		bScreen *screen = ptr->id.data;
+
+		BKE_workspace_layout_find_global(G.main, screen, &workspace);
+		orientation = BKE_workspace_transform_orientation_find(workspace, v3d->custom_orientation_index);
+	}
+
+	return rna_pointer_inherit_refine(ptr, &RNA_TransformOrientation, orientation);
 }
 
 EnumPropertyItem *rna_TransformOrientation_itemf(bContext *C, PointerRNA *ptr, PropertyRNA *UNUSED(prop), bool *r_free)
 {
-	Scene *scene = NULL;
-	ListBase *transform_spaces;
-	TransformOrientation *ts = NULL;
+	WorkSpace *workspace;
+	ListBase *transform_orientations;
 	EnumPropertyItem tmp = {0, "", 0, "", ""};
 	EnumPropertyItem *item = NULL;
 	int i = V3D_MANIP_CUSTOM, totitem = 0;
 
 	RNA_enum_items_add(&item, &totitem, transform_orientation_items);
 
-	if (ptr->type == &RNA_SpaceView3D)
-		scene = WM_windows_scene_get_from_screen(G.main->wm.first, ptr->id.data);
-	else
-		scene = CTX_data_scene(C);  /* can't use scene from ptr->id.data because that enum is also used by operators */
-
-	if (scene) {
-		transform_spaces = &scene->transform_spaces;
-		ts = transform_spaces->first;
+	if (ptr->type == &RNA_SpaceView3D) {
+		bScreen *screen = ptr->id.data;
+		BKE_workspace_layout_find_global(G.main, screen, &workspace);
+	}
+	else {
+		/* can't use scene from ptr->id.data because that enum is also used by operators */
+		workspace = CTX_wm_workspace(C);
 	}
 
-	if (ts) {
+	transform_orientations = BKE_workspace_transform_orientations_get(workspace);
+
+	if (BLI_listbase_is_empty(transform_orientations) == false) {
 		RNA_enum_item_add_separator(&item, &totitem);
 
-		for (; ts; ts = ts->next) {
+		for (TransformOrientation *ts = transform_orientations->first; ts; ts = ts->next) {
 			tmp.identifier = ts->name;
 			tmp.name = ts->name;
 			tmp.value = i++;
@@ -2668,13 +2690,14 @@ static void rna_def_space_view3d(BlenderRNA *brna)
 	prop = RNA_def_property(srna, "transform_orientation", PROP_ENUM, PROP_NONE);
 	RNA_def_property_enum_sdna(prop, NULL, "twmode");
 	RNA_def_property_enum_items(prop, transform_orientation_items);
-	RNA_def_property_enum_funcs(prop, NULL, NULL, "rna_TransformOrientation_itemf");
+	RNA_def_property_enum_funcs(prop, "rna_View3D_transform_orientation_get", "rna_View3D_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_CurrentOrientation_get", NULL, NULL, NULL);
+	RNA_def_property_pointer_funcs(prop, "rna_View3D_current_orientation_get", NULL, NULL, NULL);
 	RNA_def_property_ui_text(prop, "Current Transform Orientation", "Current transformation orientation");
 
 	prop = RNA_def_property(srna, "lock_camera_and_layers", PROP_BOOLEAN, PROP_NONE);
diff --git a/source/blender/makesrna/intern/rna_workspace.c b/source/blender/makesrna/intern/rna_workspace.c
index 29fe5bae0e4..adea8ea4556 100644
--- a/source/blender/makesrna/intern/rna_workspace.c
+++ b/source/blender/makesrna/intern/rna_workspace.c
@@ -76,6 +76,18 @@ static void rna_workspace_object_mode_set(PointerRNA *ptr, int value)
 
 #endif /* USE_WORKSPACE_MODE */
 
+void rna_workspace_transform_orientations_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
+{
+	WorkSpace *workspace = ptr->id.data;
+	rna_iterator_listbase_begin(iter, BKE_workspace_transform_orientations_get(workspace), NULL);
+}
+
+static PointerRNA rna_workspace_transform_orientations_item_get(CollectionPropertyIterator *iter)
+{
+	TransformOrientation *transform_orientation = rna_iterator_listbase_get(iter);
+	return rna_pointer_inherit_refine(&iter->parent, &RNA_TransformOrientation, transform_orientation);
+}
+
 static PointerRNA rna_workspace_render_layer_get(PointerRNA *ptr)
 {
 	WorkSpace *workspace = ptr->data;
@@ -127,6 +139,13 @@ static void rna_def_workspace(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Mode", "Object interaction mode");
 #endif
 
+	prop = RNA_def_property(srna, "orientations", PROP_COLLECTION, PROP_NONE);
+	RNA_def_property_collection_sdna(prop, NULL, "transform_orientations", NULL);
+	RNA_def_property_struct_type(prop, "TransformOrientation");
+	RNA_def_property_collection_funcs(prop, "rna_workspace_transform_orientations_begin", NULL, NULL,
+	                                  "rna_workspace_transform_orientations_item_get", NULL, NULL, NULL, NULL);
+	RNA_def_property_ui_text(prop, "Transform Orientations", "");
+
 	prop = RNA_def_property(srna, "render_layer", PROP_POINTER, PROP_NONE);
 	RNA_def_property_struct_type(prop, "SceneLayer");
 	RNA_def_property_pointer_funcs(prop, "rna_workspace_render_layer_get", "rna_workspace_render_layer_set",
@@ -136,9 +155,28 @@ static void rna_def_workspace(BlenderRNA *brna)
 	RNA_def_property_update(prop, NC_SCREEN | ND_LAYER, NULL);
 }
 
+static void rna_def_transform_orientation(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+
+	srna = RNA_def_struct(brna, "TransformOrientation", NULL);
+
+	prop = RNA_def_property(srna, "matrix", PROP_FLOAT, PROP_MATRIX);
+	RNA_def_property_float_sdna(prop, NULL, "mat");
+	RNA_def_property_multi_array(prop, 2, rna_matrix_dimsize_3x3);
+	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+
+	prop = RNA_def_property(srna, "name", PROP_STRING, PROP_NONE);
+	RNA_def_struct_name_property(srna, prop);
+	RNA_def_property_ui_text(prop, "Name", "Name of the custom transform orientation");
+	RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+}
+
 void RNA_def_workspace(BlenderRNA *brna)
 {
 	rna_def_workspace(brna);
+	rna_def_transform_orientation(brna);
 }
 
 #endif /* RNA_RUNTIME */
diff --git a/source/blenderplayer/bad_level_call_stubs/stubs.c b/source/blenderplayer/bad_level_call_stubs/stubs.c
index 9d5d4d37a13..dae76c798f7 100644
--- a/source/blenderplayer/bad_level_call_stubs/stubs.c
+++ b/source/blenderplayer/bad_level_call_stubs/stubs.c
@@ -573,6 +573,7 @@ bool ED_transform_snap_object_project_ray_ex(
         /* return args */
         float r_loc[3], float r_no[3], int *r_index,
         struct Object **r_ob, float r_obmat[4][4]) RET_ZERO
+void BIF_selectTransformOrientationValue(struct View3D *v3d, int orientation) RET_NONE
 
 void ED_lattice_editlatt_make(struct Object *obedit) RET_NONE
 void ED_lattice_editlatt_load(struct Object *obedit) RET_NONE