Cleanup: move editmesh spin gizmo into own file

To mix both initial spin and redo ends up being more involved,
move into own file.

4 files changed, 433 insertions, 394 deletions

diff --git a/source/blender/editors/mesh/CMakeLists.txt b/source/blender/editors/mesh/CMakeLists.txt
index 592b87fe20c..7dfdf0729c0 100644
--- a/source/blender/editors/mesh/CMakeLists.txt
+++ b/source/blender/editors/mesh/CMakeLists.txt
@@ -50,6 +50,7 @@ set(SRC
 	editmesh_extrude.c
 	editmesh_extrude_screw.c
 	editmesh_extrude_spin.c
+	editmesh_extrude_spin_gizmo.c
 	editmesh_inset.c
 	editmesh_intersect.c
 	editmesh_knife.c
diff --git a/source/blender/editors/mesh/editmesh_extrude_spin.c b/source/blender/editors/mesh/editmesh_extrude_spin.c
index ec15919ab4e..87814bc44c6 100644
--- a/source/blender/editors/mesh/editmesh_extrude_spin.c
+++ b/source/blender/editors/mesh/editmesh_extrude_spin.c
@@ -56,400 +56,6 @@
 
 #define USE_GIZMO
 
-#ifdef USE_GIZMO
-#include "ED_gizmo_library.h"
-#include "ED_undo.h"
-#endif
-
-/* -------------------------------------------------------------------- */
-/** \name Spin Gizmo
- * \{ */
-
-#ifdef USE_GIZMO
-typedef struct GizmoSpinGroup {
-	/* Arrow to change plane depth. */
-	struct wmGizmo *translate_z;
-	/* Translate XYZ */
-	struct wmGizmo *translate_c;
-	/* For grabbing the gizmo and moving freely. */
-	struct wmGizmo *rotate_c;
-	/* Spin angle */
-	struct wmGizmo *angle_z;
-
-	/* We could store more vars here! */
-	struct {
-		bContext *context;
-		wmOperatorType *ot;
-		wmOperator *op;
-		PropertyRNA *prop_axis_co;
-		PropertyRNA *prop_axis_no;
-		PropertyRNA *prop_angle;
-
-		float rotate_axis[3];
-		float rotate_up[3];
-	} data;
-} GizmoSpinGroup;
-
-/**
- * XXX. calling redo from property updates is not great.
- * This is needed because changing the RNA doesn't cause a redo
- * and we're not using operator UI which does just this.
- */
-static void gizmo_spin_exec(GizmoSpinGroup *ggd)
-{
-	wmOperator *op = ggd->data.op;
-	if (op == WM_operator_last_redo((bContext *)ggd->data.context)) {
-		ED_undo_operator_repeat((bContext *)ggd->data.context, op);
-	}
-}
-
-static void gizmo_mesh_spin_update_from_op(GizmoSpinGroup *ggd)
-{
-	wmOperator *op = ggd->data.op;
-
-	float plane_co[3], plane_no[3];
-
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, plane_co);
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
-
-	WM_gizmo_set_matrix_location(ggd->translate_z, plane_co);
-	WM_gizmo_set_matrix_location(ggd->rotate_c, plane_co);
-	WM_gizmo_set_matrix_location(ggd->angle_z, plane_co);
-	/* translate_c location comes from the property. */
-
-	WM_gizmo_set_matrix_rotation_from_z_axis(ggd->translate_z, plane_no);
-	WM_gizmo_set_matrix_rotation_from_z_axis(ggd->angle_z, plane_no);
-
-	WM_gizmo_set_scale(ggd->translate_c, 0.2);
-
-	RegionView3D *rv3d = ED_view3d_context_rv3d(ggd->data.context);
-	if (rv3d) {
-		normalize_v3_v3(ggd->data.rotate_axis, rv3d->viewinv[2]);
-		normalize_v3_v3(ggd->data.rotate_up, rv3d->viewinv[1]);
-
-		/* ensure its orthogonal */
-		project_plane_normalized_v3_v3v3(ggd->data.rotate_up, ggd->data.rotate_up, ggd->data.rotate_axis);
-		normalize_v3(ggd->data.rotate_up);
-
-		WM_gizmo_set_matrix_rotation_from_z_axis(ggd->translate_c, plane_no);
-		WM_gizmo_set_matrix_rotation_from_yz_axis(ggd->rotate_c, plane_no, ggd->data.rotate_axis);
-
-		/* show the axis instead of mouse cursor */
-		RNA_enum_set(ggd->rotate_c->ptr, "draw_options",
-		             ED_GIZMO_DIAL_DRAW_FLAG_ANGLE_MIRROR |
-		             ED_GIZMO_DIAL_DRAW_FLAG_ANGLE_START_Y);
-
-	}
-}
-
-/* depth callbacks */
-static void gizmo_spin_prop_depth_get(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	float *value = value_p;
-
-	BLI_assert(gz_prop->type->array_length == 1);
-	UNUSED_VARS_NDEBUG(gz_prop);
-
-	float plane_co[3], plane_no[3];
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, plane_co);
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
-
-	value[0] = dot_v3v3(plane_no, plane_co) - dot_v3v3(plane_no, gz->matrix_basis[3]);
-}
-
-static void gizmo_spin_prop_depth_set(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        const void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	const float *value = value_p;
-
-	BLI_assert(gz_prop->type->array_length == 1);
-	UNUSED_VARS_NDEBUG(gz_prop);
-
-	float plane_co[3], plane[4];
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, plane_co);
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane);
-	normalize_v3(plane);
-
-	plane[3] = -value[0] - dot_v3v3(plane, gz->matrix_basis[3]);
-
-	/* Keep our location, may be offset simply to be inside the viewport. */
-	closest_to_plane_normalized_v3(plane_co, plane, plane_co);
-
-	RNA_property_float_set_array(op->ptr, ggd->data.prop_axis_co, plane_co);
-
-	gizmo_spin_exec(ggd);
-}
-
-/* translate callbacks */
-static void gizmo_spin_prop_translate_get(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	float *value = value_p;
-
-	BLI_assert(gz_prop->type->array_length == 3);
-	UNUSED_VARS_NDEBUG(gz_prop);
-
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, value);
-}
-
-static void gizmo_spin_prop_translate_set(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        const void *value)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-
-	BLI_assert(gz_prop->type->array_length == 3);
-	UNUSED_VARS_NDEBUG(gz_prop);
-
-	RNA_property_float_set_array(op->ptr, ggd->data.prop_axis_co, value);
-
-	gizmo_spin_exec(ggd);
-}
-
-/* angle callbacks */
-static void gizmo_spin_prop_axis_angle_get(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	float *value = value_p;
-
-	BLI_assert(gz_prop->type->array_length == 1);
-	UNUSED_VARS_NDEBUG(gz_prop);
-
-	float plane_no[4];
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
-	normalize_v3(plane_no);
-
-	float plane_no_proj[3];
-	project_plane_normalized_v3_v3v3(plane_no_proj, plane_no, ggd->data.rotate_axis);
-
-	if (!is_zero_v3(plane_no_proj)) {
-		const float angle = -angle_signed_on_axis_v3v3_v3(plane_no_proj, ggd->data.rotate_up, ggd->data.rotate_axis);
-		value[0] = angle;
-	}
-	else {
-		value[0] = 0.0f;
-	}
-}
-
-static void gizmo_spin_prop_axis_angle_set(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        const void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	const float *value = value_p;
-
-	BLI_assert(gz_prop->type->array_length == 1);
-	UNUSED_VARS_NDEBUG(gz_prop);
-
-	float plane_no[4];
-	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
-	normalize_v3(plane_no);
-
-	float plane_no_proj[3];
-	project_plane_normalized_v3_v3v3(plane_no_proj, plane_no, ggd->data.rotate_axis);
-
-	if (!is_zero_v3(plane_no_proj)) {
-		const float angle = -angle_signed_on_axis_v3v3_v3(plane_no_proj, ggd->data.rotate_up, ggd->data.rotate_axis);
-		const float angle_delta = angle - angle_compat_rad(value[0], angle);
-		if (angle_delta != 0.0f) {
-			float mat[3][3];
-			axis_angle_normalized_to_mat3(mat, ggd->data.rotate_axis, angle_delta);
-			mul_m3_v3(mat, plane_no);
-
-			/* re-normalize - seems acceptable */
-			RNA_property_float_set_array(op->ptr, ggd->data.prop_axis_no, plane_no);
-
-			gizmo_spin_exec(ggd);
-		}
-	}
-}
-
-/* angle callbacks */
-static void gizmo_spin_prop_angle_get(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	float *value = value_p;
-
-	BLI_assert(gz_prop->type->array_length == 1);
-	UNUSED_VARS_NDEBUG(gz_prop);
-	value[0] = RNA_property_float_get(op->ptr, ggd->data.prop_angle);
-}
-
-static void gizmo_spin_prop_angle_set(
-        const wmGizmo *gz, wmGizmoProperty *gz_prop,
-        const void *value_p)
-{
-	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
-	wmOperator *op = ggd->data.op;
-	BLI_assert(gz_prop->type->array_length == 1);
-	UNUSED_VARS_NDEBUG(gz_prop);
-	const float *value = value_p;
-	RNA_property_float_set(op->ptr, ggd->data.prop_angle, value[0]);
-
-	gizmo_spin_exec(ggd);
-}
-
-static bool gizmo_mesh_spin_poll(const bContext *C, wmGizmoGroupType *gzgt)
-{
-	wmOperator *op = WM_operator_last_redo(C);
-	if (op == NULL || !STREQ(op->type->idname, "MESH_OT_spin")) {
-		WM_gizmo_group_type_unlink_delayed_ptr(gzgt);
-		return false;
-	}
-	return true;
-}
-
-
-static void gizmo_mesh_spin_redo_modal_from_setup(
-        const bContext *C, wmGizmoGroup *gzgroup)
-{
-	/* Start off dragging. */
-	struct GizmoSpinGroup *ggd = gzgroup->customdata;
-	wmWindow *win = CTX_wm_window(C);
-	wmGizmo *gz = ggd->angle_z;
-	wmGizmoMap *gzmap = gzgroup->parent_gzmap;
-	WM_gizmo_modal_set_from_setup(
-	        gzmap, (bContext *)C, gz, 0, win->eventstate);
-}
-
-static void gizmo_mesh_spin_setup(const bContext *C, wmGizmoGroup *gzgroup)
-{
-	wmOperatorType *ot = WM_operatortype_find("MESH_OT_spin", true);
-	wmOperator *op = WM_operator_last_redo(C);
-
-	if ((op == NULL) || (op->type != ot)) {
-		return;
-	}
-
-	struct GizmoSpinGroup *ggd = MEM_callocN(sizeof(GizmoSpinGroup), __func__);
-	gzgroup->customdata = ggd;
-
-	const wmGizmoType *gzt_arrow = WM_gizmotype_find("GIZMO_GT_arrow_3d", true);
-	const wmGizmoType *gzt_move = WM_gizmotype_find("GIZMO_GT_move_3d", true);
-	const wmGizmoType *gzt_dial = WM_gizmotype_find("GIZMO_GT_dial_3d", true);
-
-	ggd->translate_z = WM_gizmo_new_ptr(gzt_arrow, gzgroup, NULL);
-	ggd->translate_c = WM_gizmo_new_ptr(gzt_move, gzgroup, NULL);
-	ggd->rotate_c = WM_gizmo_new_ptr(gzt_dial, gzgroup, NULL);
-	ggd->angle_z = WM_gizmo_new_ptr(gzt_dial, gzgroup, NULL);
-
-	UI_GetThemeColor3fv(TH_GIZMO_PRIMARY, ggd->translate_z->color);
-	UI_GetThemeColor3fv(TH_GIZMO_PRIMARY, ggd->translate_c->color);
-	UI_GetThemeColor3fv(TH_GIZMO_SECONDARY, ggd->rotate_c->color);
-	UI_GetThemeColor3fv(TH_AXIS_Z, ggd->angle_z->color);
-
-
-	RNA_enum_set(ggd->translate_z->ptr, "draw_style", ED_GIZMO_ARROW_STYLE_NORMAL);
-	RNA_enum_set(ggd->translate_c->ptr, "draw_style", ED_GIZMO_MOVE_STYLE_RING_2D);
-
-	WM_gizmo_set_flag(ggd->translate_c, WM_GIZMO_DRAW_VALUE, true);
-	WM_gizmo_set_flag(ggd->rotate_c, WM_GIZMO_DRAW_VALUE, true);
-	WM_gizmo_set_flag(ggd->angle_z, WM_GIZMO_DRAW_VALUE, true);
-
-	WM_gizmo_set_scale(ggd->rotate_c, 0.8f);
-
-	{
-		ggd->data.context = (bContext *)C;
-		ggd->data.ot = ot;
-		ggd->data.op = op;
-		ggd->data.prop_axis_co = RNA_struct_type_find_property(ot->srna, "center");
-		ggd->data.prop_axis_no = RNA_struct_type_find_property(ot->srna, "axis");
-		ggd->data.prop_angle = RNA_struct_type_find_property(ot->srna, "angle");
-	}
-
-	gizmo_mesh_spin_update_from_op(ggd);
-
-	/* Setup property callbacks */
-	{
-		WM_gizmo_target_property_def_func(
-		        ggd->translate_z, "offset",
-		        &(const struct wmGizmoPropertyFnParams) {
-		            .value_get_fn = gizmo_spin_prop_depth_get,
-		            .value_set_fn = gizmo_spin_prop_depth_set,
-		            .range_get_fn = NULL,
-		            .user_data = NULL,
-		        });
-
-		WM_gizmo_target_property_def_func(
-		        ggd->translate_c, "offset",
-		        &(const struct wmGizmoPropertyFnParams) {
-		            .value_get_fn = gizmo_spin_prop_translate_get,
-		            .value_set_fn = gizmo_spin_prop_translate_set,
-		            .range_get_fn = NULL,
-		            .user_data = NULL,
-		        });
-
-		WM_gizmo_target_property_def_func(
-		        ggd->rotate_c, "offset",
-		        &(const struct wmGizmoPropertyFnParams) {
-		            .value_get_fn = gizmo_spin_prop_axis_angle_get,
-		            .value_set_fn = gizmo_spin_prop_axis_angle_set,
-		            .range_get_fn = NULL,
-		            .user_data = NULL,
-		        });
-
-		WM_gizmo_target_property_def_func(
-		        ggd->angle_z, "offset",
-		        &(const struct wmGizmoPropertyFnParams) {
-		            .value_get_fn = gizmo_spin_prop_angle_get,
-		            .value_set_fn = gizmo_spin_prop_angle_set,
-		            .range_get_fn = NULL,
-		            .user_data = NULL,
-		        });
-
-	}
-
-	/* Become modal as soon as it's started. */
-	gizmo_mesh_spin_redo_modal_from_setup(C, gzgroup);
-}
-
-static void gizmo_mesh_spin_draw_prepare(
-        const bContext *UNUSED(C), wmGizmoGroup *gzgroup)
-{
-	GizmoSpinGroup *ggd = gzgroup->customdata;
-	if (ggd->data.op->next) {
-		ggd->data.op = WM_operator_last_redo((bContext *)ggd->data.context);
-	}
-	gizmo_mesh_spin_update_from_op(ggd);
-}
-
-static void MESH_GGT_spin(struct wmGizmoGroupType *gzgt)
-{
-	gzgt->name = "Mesh Spin";
-	gzgt->idname = "MESH_GGT_spin";
-
-	gzgt->flag = WM_GIZMOGROUPTYPE_3D;
-
-	gzgt->gzmap_params.spaceid = SPACE_VIEW3D;
-	gzgt->gzmap_params.regionid = RGN_TYPE_WINDOW;
-
-	gzgt->poll = gizmo_mesh_spin_poll;
-	gzgt->setup = gizmo_mesh_spin_setup;
-	gzgt->draw_prepare = gizmo_mesh_spin_draw_prepare;
-}
-
-/** \} */
-
-#endif  /* USE_GIZMO */
-
 /* -------------------------------------------------------------------- */
 /** \name Spin Operator
  * \{ */
diff --git a/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c b/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c
new file mode 100644
index 00000000000..b86d6f9dd20
--- /dev/null
+++ b/source/blender/editors/mesh/editmesh_extrude_spin_gizmo.c
@@ -0,0 +1,430 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/editors/mesh/editmesh_extrude_spin_gizmo.c
+ *  \ingroup edmesh
+ */
+
+#include "BLI_math.h"
+
+#include "BKE_context.h"
+
+#include "RNA_access.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+#include "ED_screen.h"
+#include "ED_view3d.h"
+
+#include "UI_resources.h"
+
+#include "MEM_guardedalloc.h"
+
+#include "mesh_intern.h"  /* own include */
+
+#include "ED_gizmo_library.h"
+#include "ED_undo.h"
+
+/* -------------------------------------------------------------------- */
+/** \name Spin Gizmo
+ * \{ */
+
+typedef struct GizmoSpinGroup {
+	/* Arrow to change plane depth. */
+	struct wmGizmo *translate_z;
+	/* Translate XYZ */
+	struct wmGizmo *translate_c;
+	/* For grabbing the gizmo and moving freely. */
+	struct wmGizmo *rotate_c;
+	/* Spin angle */
+	struct wmGizmo *angle_z;
+
+	/* We could store more vars here! */
+	struct {
+		bContext *context;
+		wmOperatorType *ot;
+		wmOperator *op;
+		PropertyRNA *prop_axis_co;
+		PropertyRNA *prop_axis_no;
+		PropertyRNA *prop_angle;
+
+		float rotate_axis[3];
+		float rotate_up[3];
+	} data;
+} GizmoSpinGroup;
+
+/**
+ * XXX. calling redo from property updates is not great.
+ * This is needed because changing the RNA doesn't cause a redo
+ * and we're not using operator UI which does just this.
+ */
+static void gizmo_spin_exec(GizmoSpinGroup *ggd)
+{
+	wmOperator *op = ggd->data.op;
+	if (op == WM_operator_last_redo((bContext *)ggd->data.context)) {
+		ED_undo_operator_repeat((bContext *)ggd->data.context, op);
+	}
+}
+
+static void gizmo_mesh_spin_update_from_op(GizmoSpinGroup *ggd)
+{
+	wmOperator *op = ggd->data.op;
+
+	float plane_co[3], plane_no[3];
+
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, plane_co);
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
+
+	WM_gizmo_set_matrix_location(ggd->translate_z, plane_co);
+	WM_gizmo_set_matrix_location(ggd->rotate_c, plane_co);
+	WM_gizmo_set_matrix_location(ggd->angle_z, plane_co);
+	/* translate_c location comes from the property. */
+
+	WM_gizmo_set_matrix_rotation_from_z_axis(ggd->translate_z, plane_no);
+	WM_gizmo_set_matrix_rotation_from_z_axis(ggd->angle_z, plane_no);
+
+	WM_gizmo_set_scale(ggd->translate_c, 0.2);
+
+	RegionView3D *rv3d = ED_view3d_context_rv3d(ggd->data.context);
+	if (rv3d) {
+		normalize_v3_v3(ggd->data.rotate_axis, rv3d->viewinv[2]);
+		normalize_v3_v3(ggd->data.rotate_up, rv3d->viewinv[1]);
+
+		/* ensure its orthogonal */
+		project_plane_normalized_v3_v3v3(ggd->data.rotate_up, ggd->data.rotate_up, ggd->data.rotate_axis);
+		normalize_v3(ggd->data.rotate_up);
+
+		WM_gizmo_set_matrix_rotation_from_z_axis(ggd->translate_c, plane_no);
+		WM_gizmo_set_matrix_rotation_from_yz_axis(ggd->rotate_c, plane_no, ggd->data.rotate_axis);
+
+		/* show the axis instead of mouse cursor */
+		RNA_enum_set(ggd->rotate_c->ptr, "draw_options",
+		             ED_GIZMO_DIAL_DRAW_FLAG_ANGLE_MIRROR |
+		             ED_GIZMO_DIAL_DRAW_FLAG_ANGLE_START_Y);
+
+	}
+}
+
+/* depth callbacks */
+static void gizmo_spin_prop_depth_get(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	float *value = value_p;
+
+	BLI_assert(gz_prop->type->array_length == 1);
+	UNUSED_VARS_NDEBUG(gz_prop);
+
+	float plane_co[3], plane_no[3];
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, plane_co);
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
+
+	value[0] = dot_v3v3(plane_no, plane_co) - dot_v3v3(plane_no, gz->matrix_basis[3]);
+}
+
+static void gizmo_spin_prop_depth_set(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        const void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	const float *value = value_p;
+
+	BLI_assert(gz_prop->type->array_length == 1);
+	UNUSED_VARS_NDEBUG(gz_prop);
+
+	float plane_co[3], plane[4];
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, plane_co);
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane);
+	normalize_v3(plane);
+
+	plane[3] = -value[0] - dot_v3v3(plane, gz->matrix_basis[3]);
+
+	/* Keep our location, may be offset simply to be inside the viewport. */
+	closest_to_plane_normalized_v3(plane_co, plane, plane_co);
+
+	RNA_property_float_set_array(op->ptr, ggd->data.prop_axis_co, plane_co);
+
+	gizmo_spin_exec(ggd);
+}
+
+/* translate callbacks */
+static void gizmo_spin_prop_translate_get(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	float *value = value_p;
+
+	BLI_assert(gz_prop->type->array_length == 3);
+	UNUSED_VARS_NDEBUG(gz_prop);
+
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_co, value);
+}
+
+static void gizmo_spin_prop_translate_set(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        const void *value)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+
+	BLI_assert(gz_prop->type->array_length == 3);
+	UNUSED_VARS_NDEBUG(gz_prop);
+
+	RNA_property_float_set_array(op->ptr, ggd->data.prop_axis_co, value);
+
+	gizmo_spin_exec(ggd);
+}
+
+/* angle callbacks */
+static void gizmo_spin_prop_axis_angle_get(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	float *value = value_p;
+
+	BLI_assert(gz_prop->type->array_length == 1);
+	UNUSED_VARS_NDEBUG(gz_prop);
+
+	float plane_no[4];
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
+	normalize_v3(plane_no);
+
+	float plane_no_proj[3];
+	project_plane_normalized_v3_v3v3(plane_no_proj, plane_no, ggd->data.rotate_axis);
+
+	if (!is_zero_v3(plane_no_proj)) {
+		const float angle = -angle_signed_on_axis_v3v3_v3(plane_no_proj, ggd->data.rotate_up, ggd->data.rotate_axis);
+		value[0] = angle;
+	}
+	else {
+		value[0] = 0.0f;
+	}
+}
+
+static void gizmo_spin_prop_axis_angle_set(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        const void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	const float *value = value_p;
+
+	BLI_assert(gz_prop->type->array_length == 1);
+	UNUSED_VARS_NDEBUG(gz_prop);
+
+	float plane_no[4];
+	RNA_property_float_get_array(op->ptr, ggd->data.prop_axis_no, plane_no);
+	normalize_v3(plane_no);
+
+	float plane_no_proj[3];
+	project_plane_normalized_v3_v3v3(plane_no_proj, plane_no, ggd->data.rotate_axis);
+
+	if (!is_zero_v3(plane_no_proj)) {
+		const float angle = -angle_signed_on_axis_v3v3_v3(plane_no_proj, ggd->data.rotate_up, ggd->data.rotate_axis);
+		const float angle_delta = angle - angle_compat_rad(value[0], angle);
+		if (angle_delta != 0.0f) {
+			float mat[3][3];
+			axis_angle_normalized_to_mat3(mat, ggd->data.rotate_axis, angle_delta);
+			mul_m3_v3(mat, plane_no);
+
+			/* re-normalize - seems acceptable */
+			RNA_property_float_set_array(op->ptr, ggd->data.prop_axis_no, plane_no);
+
+			gizmo_spin_exec(ggd);
+		}
+	}
+}
+
+/* angle callbacks */
+static void gizmo_spin_prop_angle_get(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	float *value = value_p;
+
+	BLI_assert(gz_prop->type->array_length == 1);
+	UNUSED_VARS_NDEBUG(gz_prop);
+	value[0] = RNA_property_float_get(op->ptr, ggd->data.prop_angle);
+}
+
+static void gizmo_spin_prop_angle_set(
+        const wmGizmo *gz, wmGizmoProperty *gz_prop,
+        const void *value_p)
+{
+	GizmoSpinGroup *ggd = gz->parent_gzgroup->customdata;
+	wmOperator *op = ggd->data.op;
+	BLI_assert(gz_prop->type->array_length == 1);
+	UNUSED_VARS_NDEBUG(gz_prop);
+	const float *value = value_p;
+	RNA_property_float_set(op->ptr, ggd->data.prop_angle, value[0]);
+
+	gizmo_spin_exec(ggd);
+}
+
+static bool gizmo_mesh_spin_poll(const bContext *C, wmGizmoGroupType *gzgt)
+{
+	wmOperator *op = WM_operator_last_redo(C);
+	if (op == NULL || !STREQ(op->type->idname, "MESH_OT_spin")) {
+		WM_gizmo_group_type_unlink_delayed_ptr(gzgt);
+		return false;
+	}
+	return true;
+}
+
+
+static void gizmo_mesh_spin_redo_modal_from_setup(
+        const bContext *C, wmGizmoGroup *gzgroup)
+{
+	/* Start off dragging. */
+	struct GizmoSpinGroup *ggd = gzgroup->customdata;
+	wmWindow *win = CTX_wm_window(C);
+	wmGizmo *gz = ggd->angle_z;
+	wmGizmoMap *gzmap = gzgroup->parent_gzmap;
+	WM_gizmo_modal_set_from_setup(
+	        gzmap, (bContext *)C, gz, 0, win->eventstate);
+}
+
+static void gizmo_mesh_spin_setup(const bContext *C, wmGizmoGroup *gzgroup)
+{
+	wmOperatorType *ot = WM_operatortype_find("MESH_OT_spin", true);
+	wmOperator *op = WM_operator_last_redo(C);
+
+	if ((op == NULL) || (op->type != ot)) {
+		return;
+	}
+
+	struct GizmoSpinGroup *ggd = MEM_callocN(sizeof(GizmoSpinGroup), __func__);
+	gzgroup->customdata = ggd;
+
+	const wmGizmoType *gzt_arrow = WM_gizmotype_find("GIZMO_GT_arrow_3d", true);
+	const wmGizmoType *gzt_move = WM_gizmotype_find("GIZMO_GT_move_3d", true);
+	const wmGizmoType *gzt_dial = WM_gizmotype_find("GIZMO_GT_dial_3d", true);
+
+	ggd->translate_z = WM_gizmo_new_ptr(gzt_arrow, gzgroup, NULL);
+	ggd->translate_c = WM_gizmo_new_ptr(gzt_move, gzgroup, NULL);
+	ggd->rotate_c = WM_gizmo_new_ptr(gzt_dial, gzgroup, NULL);
+	ggd->angle_z = WM_gizmo_new_ptr(gzt_dial, gzgroup, NULL);
+
+	UI_GetThemeColor3fv(TH_GIZMO_PRIMARY, ggd->translate_z->color);
+	UI_GetThemeColor3fv(TH_GIZMO_PRIMARY, ggd->translate_c->color);
+	UI_GetThemeColor3fv(TH_GIZMO_SECONDARY, ggd->rotate_c->color);
+	UI_GetThemeColor3fv(TH_AXIS_Z, ggd->angle_z->color);
+
+
+	RNA_enum_set(ggd->translate_z->ptr, "draw_style", ED_GIZMO_ARROW_STYLE_NORMAL);
+	RNA_enum_set(ggd->translate_c->ptr, "draw_style", ED_GIZMO_MOVE_STYLE_RING_2D);
+
+	WM_gizmo_set_flag(ggd->translate_c, WM_GIZMO_DRAW_VALUE, true);
+	WM_gizmo_set_flag(ggd->rotate_c, WM_GIZMO_DRAW_VALUE, true);
+	WM_gizmo_set_flag(ggd->angle_z, WM_GIZMO_DRAW_VALUE, true);
+
+	WM_gizmo_set_scale(ggd->rotate_c, 0.8f);
+
+	{
+		ggd->data.context = (bContext *)C;
+		ggd->data.ot = ot;
+		ggd->data.op = op;
+		ggd->data.prop_axis_co = RNA_struct_type_find_property(ot->srna, "center");
+		ggd->data.prop_axis_no = RNA_struct_type_find_property(ot->srna, "axis");
+		ggd->data.prop_angle = RNA_struct_type_find_property(ot->srna, "angle");
+	}
+
+	gizmo_mesh_spin_update_from_op(ggd);
+
+	/* Setup property callbacks */
+	{
+		WM_gizmo_target_property_def_func(
+		        ggd->translate_z, "offset",
+		        &(const struct wmGizmoPropertyFnParams) {
+		            .value_get_fn = gizmo_spin_prop_depth_get,
+		            .value_set_fn = gizmo_spin_prop_depth_set,
+		            .range_get_fn = NULL,
+		            .user_data = NULL,
+		        });
+
+		WM_gizmo_target_property_def_func(
+		        ggd->translate_c, "offset",
+		        &(const struct wmGizmoPropertyFnParams) {
+		            .value_get_fn = gizmo_spin_prop_translate_get,
+		            .value_set_fn = gizmo_spin_prop_translate_set,
+		            .range_get_fn = NULL,
+		            .user_data = NULL,
+		        });
+
+		WM_gizmo_target_property_def_func(
+		        ggd->rotate_c, "offset",
+		        &(const struct wmGizmoPropertyFnParams) {
+		            .value_get_fn = gizmo_spin_prop_axis_angle_get,
+		            .value_set_fn = gizmo_spin_prop_axis_angle_set,
+		            .range_get_fn = NULL,
+		            .user_data = NULL,
+		        });
+
+		WM_gizmo_target_property_def_func(
+		        ggd->angle_z, "offset",
+		        &(const struct wmGizmoPropertyFnParams) {
+		            .value_get_fn = gizmo_spin_prop_angle_get,
+		            .value_set_fn = gizmo_spin_prop_angle_set,
+		            .range_get_fn = NULL,
+		            .user_data = NULL,
+		        });
+
+	}
+
+	/* Become modal as soon as it's started. */
+	gizmo_mesh_spin_redo_modal_from_setup(C, gzgroup);
+}
+
+static void gizmo_mesh_spin_draw_prepare(
+        const bContext *UNUSED(C), wmGizmoGroup *gzgroup)
+{
+	GizmoSpinGroup *ggd = gzgroup->customdata;
+	if (ggd->data.op->next) {
+		ggd->data.op = WM_operator_last_redo((bContext *)ggd->data.context);
+	}
+	gizmo_mesh_spin_update_from_op(ggd);
+}
+
+void MESH_GGT_spin(struct wmGizmoGroupType *gzgt)
+{
+	gzgt->name = "Mesh Spin";
+	gzgt->idname = "MESH_GGT_spin";
+
+	gzgt->flag = WM_GIZMOGROUPTYPE_3D;
+
+	gzgt->gzmap_params.spaceid = SPACE_VIEW3D;
+	gzgt->gzmap_params.regionid = RGN_TYPE_WINDOW;
+
+	gzgt->poll = gizmo_mesh_spin_poll;
+	gzgt->setup = gizmo_mesh_spin_setup;
+	gzgt->draw_prepare = gizmo_mesh_spin_draw_prepare;
+}
+
+/** \} */
diff --git a/source/blender/editors/mesh/mesh_intern.h b/source/blender/editors/mesh/mesh_intern.h
index efaf90fd8ef..b4835f30bcb 100644
--- a/source/blender/editors/mesh/mesh_intern.h
+++ b/source/blender/editors/mesh/mesh_intern.h
@@ -115,6 +115,8 @@ void MESH_OT_screw(struct wmOperatorType *ot);
 
 /* *** editmesh_extrude_spin.c *** */
 void MESH_OT_spin(struct wmOperatorType *ot);
+/* *** editmesh_extrude_spin_gizmo.c *** */
+void MESH_GGT_spin(struct wmGizmoGroupType *gzgt);
 
 /* *** editmesh_polybuild.c *** */
 void MESH_OT_polybuild_face_at_cursor(struct wmOperatorType *ot);