From 51aba69b89372f13ace4a278d9a23999dfd755d9 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Thu, 3 May 2018 07:15:34 +0200
Subject: [PATCH] Transform: expose 3D center/axis calculation

This is needed for other manipulator placement.
---
 source/blender/editors/include/ED_transform.h | 18 ++++++++++++++++
 .../editors/transform/transform_manipulator.c | 21 ++++---------------
 2 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/source/blender/editors/include/ED_transform.h b/source/blender/editors/include/ED_transform.h
index a6bed6c1ee6..a974b6cfe9e 100644
--- a/source/blender/editors/include/ED_transform.h
+++ b/source/blender/editors/include/ED_transform.h
@@ -194,4 +194,22 @@ bool snapNodesTransform(
         /* return args */
         float r_loc[2], float *r_dist_px, char *r_node_border);
 
+
+#define USE_AXIS_BOUNDS
+
+struct TransformBounds {
+	float center[3];		/* Center for transform widget. */
+	float min[3], max[3];	/* Boundbox of selection for transform widget. */
+
+#ifdef USE_AXIS_BOUNDS
+	/* Normalized axis */
+	float axis[3][3];
+	float axis_min[3], axis_max[3];
+#endif
+};
+
+int ED_transform_calc_manipulator_stats(
+        const struct bContext *C, bool use_only_center,
+        struct TransformBounds *tbounds);
+
 #endif  /* __ED_TRANSFORM_H__ */
diff --git a/source/blender/editors/transform/transform_manipulator.c b/source/blender/editors/transform/transform_manipulator.c
index a56d057cb3b..6fe44d22114 100644
--- a/source/blender/editors/transform/transform_manipulator.c
+++ b/source/blender/editors/transform/transform_manipulator.c
@@ -92,8 +92,6 @@
 
 #include "DEG_depsgraph_query.h"
 
-#define USE_AXIS_BOUNDS
-
 /* return codes for select, and drawing flags */
 
 #define MAN_TRANS_X		(1 << 0)
@@ -172,17 +170,6 @@ typedef struct ManipulatorGroup {
 	struct wmManipulator *manipulators[MAN_AXIS_LAST];
 } ManipulatorGroup;
 
-struct TransformBounds {
-	float center[3];		/* Center for transform widget. */
-	float min[3], max[3];	/* Boundbox of selection for transform widget. */
-
-#ifdef USE_AXIS_BOUNDS
-	/* Normalized axis */
-	float axis[3][3];
-	float axis_min[3], axis_max[3];
-#endif
-};
-
 /* -------------------------------------------------------------------- */
 /** \name Utilities
  * \{ */
@@ -599,7 +586,7 @@ bool gimbal_axis(Object *ob, float gmat[3][3])
 
 /* centroid, boundbox, of selection */
 /* returns total items selected */
-static int calc_manipulator_stats(
+int ED_transform_calc_manipulator_stats(
         const bContext *C, bool use_only_center,
         struct TransformBounds *tbounds)
 {
@@ -1261,7 +1248,7 @@ static int manipulator_modal(
 	struct TransformBounds tbounds;
 
 
-	if (calc_manipulator_stats(C, true, &tbounds)) {
+	if (ED_transform_calc_manipulator_stats(C, true, &tbounds)) {
 		manipulator_prepare_mat(C, v3d, rv3d, &tbounds);
 		WM_manipulator_set_matrix_location(widget, rv3d->twmat[3]);
 	}
@@ -1421,7 +1408,7 @@ static void WIDGETGROUP_manipulator_refresh(const bContext *C, wmManipulatorGrou
 	struct TransformBounds tbounds;
 
 	/* skip, we don't draw anything anyway */
-	if ((man->all_hidden = (calc_manipulator_stats(C, true, &tbounds) == 0)))
+	if ((man->all_hidden = (ED_transform_calc_manipulator_stats(C, true, &tbounds) == 0)))
 		return;
 
 	manipulator_prepare_mat(C, v3d, rv3d, &tbounds);
@@ -1653,7 +1640,7 @@ static void WIDGETGROUP_xform_cage_refresh(const bContext *C, wmManipulatorGroup
 
 	struct TransformBounds tbounds;
 
-	if ((calc_manipulator_stats(C, false, &tbounds) == 0) ||
+	if ((ED_transform_calc_manipulator_stats(C, false, &tbounds) == 0) ||
 	    equals_v3v3(rv3d->tw_axis_min, rv3d->tw_axis_max))
 	{
 		WM_manipulator_set_flag(mpr, WM_MANIPULATOR_HIDDEN, true);