Manipulator: experimental lamp positioning tool

- New manipulator tracks lamps to position under cursor.
- Works with multiple lamps, keeping relative offsets.
- Holding Ctrl moves the lamp.
- Access via manipulator or Shift-T.

Code could be improved, but like to get feedback from users.

3 files changed, 70 insertions, 4 deletions

diff --git a/source/blender/editors/space_view3d/space_view3d.c b/source/blender/editors/space_view3d/space_view3d.c
index f67684295a6..74103c4873d 100644
--- a/source/blender/editors/space_view3d/space_view3d.c
+++ b/source/blender/editors/space_view3d/space_view3d.c
@@ -737,6 +737,7 @@ static void view3d_widgets(void)
 	WM_manipulatorgrouptype_append_and_link(mmap_type, TRANSFORM_WGT_manipulator);
 	WM_manipulatorgrouptype_append_and_link(mmap_type, VIEW3D_WGT_lamp_spot);
 	WM_manipulatorgrouptype_append_and_link(mmap_type, VIEW3D_WGT_lamp_area);
+	WM_manipulatorgrouptype_append_and_link(mmap_type, VIEW3D_WGT_lamp_target);
 	WM_manipulatorgrouptype_append_and_link(mmap_type, VIEW3D_WGT_force_field);
 	WM_manipulatorgrouptype_append_and_link(mmap_type, VIEW3D_WGT_camera);
 	WM_manipulatorgrouptype_append_and_link(mmap_type, VIEW3D_WGT_camera_view);
diff --git a/source/blender/editors/space_view3d/view3d_intern.h b/source/blender/editors/space_view3d/view3d_intern.h
index c9f48e137f5..bc600f3e58e 100644
--- a/source/blender/editors/space_view3d/view3d_intern.h
+++ b/source/blender/editors/space_view3d/view3d_intern.h
@@ -321,6 +321,7 @@ extern const char *view3d_context_dir[]; /* doc access */
 /* view3d_widgets.c */
 void VIEW3D_WGT_lamp_spot        (struct wmManipulatorGroupType *wgt);
 void VIEW3D_WGT_lamp_area        (struct wmManipulatorGroupType *wgt);
+void VIEW3D_WGT_lamp_target      (struct wmManipulatorGroupType *wgt);
 void VIEW3D_WGT_camera           (struct wmManipulatorGroupType *wgt);
 void VIEW3D_WGT_camera_view      (struct wmManipulatorGroupType *wgt);
 void VIEW3D_WGT_force_field      (struct wmManipulatorGroupType *wgt);
diff --git a/source/blender/editors/space_view3d/view3d_manipulator_lamp.c b/source/blender/editors/space_view3d/view3d_manipulator_lamp.c
index 451addaaeae..4b550fd0b2e 100644
--- a/source/blender/editors/space_view3d/view3d_manipulator_lamp.c
+++ b/source/blender/editors/space_view3d/view3d_manipulator_lamp.c
@@ -50,8 +50,6 @@
 /** \name Spot Lamp Manipulators
  * \{ */
 
-/* Spot Lamp */
-
 static bool WIDGETGROUP_lamp_spot_poll(const bContext *C, wmManipulatorGroupType *UNUSED(wgt))
 {
 	Object *ob = CTX_data_active_object(C);
@@ -122,8 +120,6 @@ void VIEW3D_WGT_lamp_spot(wmManipulatorGroupType *wgt)
 /** \name Area Lamp Manipulators
  * \{ */
 
-/* Area Lamp */
-
 /* translate callbacks */
 static void manipulator_area_lamp_prop_size_get(
         const wmManipulator *UNUSED(mpr), wmManipulatorProperty *mpr_prop,
@@ -231,3 +227,71 @@ void VIEW3D_WGT_lamp_area(wmManipulatorGroupType *wgt)
 }
 
 /** \} */
+
+
+/* -------------------------------------------------------------------- */
+
+/** \name Lamp Target Manipulator
+ * \{ */
+
+static bool WIDGETGROUP_lamp_target_poll(const bContext *C, wmManipulatorGroupType *UNUSED(wgt))
+{
+	Object *ob = CTX_data_active_object(C);
+
+	if (ob != NULL) {
+		if (ob->type == OB_LAMP) {
+			Lamp *la = ob->data;
+			return (ELEM(la->type, LA_SUN, LA_SPOT, LA_HEMI, LA_AREA));
+		}
+		else if (ob->type == OB_CAMERA) {
+			return true;
+		}
+	}
+	return false;
+}
+
+static void WIDGETGROUP_lamp_target_setup(const bContext *UNUSED(C), wmManipulatorGroup *mgroup)
+{
+	const float color[4] = {1.0f, 1.0f, 0.5f, 1.0f};
+	const float color_hi[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+
+	wmManipulatorWrapper *wwrapper = MEM_mallocN(sizeof(wmManipulatorWrapper), __func__);
+	wwrapper->manipulator = WM_manipulator_new("MANIPULATOR_WT_grab_3d", mgroup, NULL);
+	wmManipulator *mpr = wwrapper->manipulator;
+
+	mgroup->customdata = wwrapper;
+
+	WM_manipulator_set_color(mpr, color);
+	WM_manipulator_set_color_highlight(mpr, color_hi);
+
+	mpr->scale_basis = 0.05f;
+
+	wmOperatorType *ot = WM_operatortype_find("OBJECT_OT_transform_axis_target", true);
+	WM_manipulator_set_operator(mpr, ot, NULL);
+}
+
+static void WIDGETGROUP_lamp_target_draw_prepare(const bContext *C, wmManipulatorGroup *mgroup)
+{
+	wmManipulatorWrapper *wwrapper = mgroup->customdata;
+	Object *ob = CTX_data_active_object(C);
+	wmManipulator *mpr = wwrapper->manipulator;
+
+	copy_m4_m4(mpr->matrix_basis, ob->obmat);
+	unit_m4(mpr->matrix_offset);
+	mpr->matrix_offset[3][2] = -2.4f / mpr->scale_basis;
+}
+
+void VIEW3D_WGT_lamp_target(wmManipulatorGroupType *wgt)
+{
+	wgt->name = "Target Lamp Widgets";
+	wgt->idname = "VIEW3D_WGT_lamp_target";
+
+	wgt->flag |= (WM_MANIPULATORGROUPTYPE_PERSISTENT |
+	              WM_MANIPULATORGROUPTYPE_3D);
+
+	wgt->poll = WIDGETGROUP_lamp_target_poll;
+	wgt->setup = WIDGETGROUP_lamp_target_setup;
+	wgt->draw_prepare = WIDGETGROUP_lamp_target_draw_prepare;
+}
+
+/** \} */
\ No newline at end of file