Cleanup: ED_view3d_win_to_delta & ED_view3d_calc_zfac usage

- Rename ED_view3d_win_to_delta `mval` argument to `xy_delta` as it
  as it was misleading since this is an screen-space offset not a region
  relative cursor position (typical use of the name `mval`).
  Also rename the variable passed to this function which also used the
  term `mval` in many places.
- Re-order the output argument of ED_view3d_win_to_delta last.
  use an r_ prefix for return arguments.
- Document how the `zfac` argument is intended to be used.
- Split ED_view3d_calc_zfac into two functions as the `r_flip` argument
  was only used in some special cases.

1 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c b/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c
index aea6d41202e..447fe1005a1 100644
--- a/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c
+++ b/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c
@@ -147,7 +147,7 @@ static void move3d_get_translate(const wmGizmo *gz,
                                  float co_delta[3])
 {
   MoveInteraction *inter = gz->interaction_data;
-  const float mval_delta[2] = {
+  const float xy_delta[2] = {
       event->mval[0] - inter->init.mval[0],
       event->mval[1] - inter->init.mval[1],
   };
@@ -155,9 +155,9 @@ static void move3d_get_translate(const wmGizmo *gz,
   RegionView3D *rv3d = region->regiondata;
   float co_ref[3];
   mul_v3_mat3_m4v3(co_ref, gz->matrix_space, inter->init.prop_co);
-  const float zfac = ED_view3d_calc_zfac(rv3d, co_ref, NULL);
+  const float zfac = ED_view3d_calc_zfac(rv3d, co_ref);
 
-  ED_view3d_win_to_delta(region, mval_delta, co_delta, zfac);
+  ED_view3d_win_to_delta(region, xy_delta, zfac, co_delta);
 
   float matrix_space_inv[3][3];
   copy_m3_m4(matrix_space_inv, gz->matrix_space);