Cleanup: Rename ARegion variables from ar to region

The old convention was easy to confuse with ScrArea.
Part of https://developer.blender.org/T74432.

This is mostly a batch rename with some manual fixing. Only single word
variable names are changed, no prefixed/suffixed names.

Brecht van Lommel and Campbell Barton both gave me a green light for
this convention change.

Also ran clan clang format on affected files.

13 files changed, 348 insertions, 334 deletions

diff --git a/source/blender/editors/space_clip/clip_dopesheet_draw.c b/source/blender/editors/space_clip/clip_dopesheet_draw.c
index e64f21f9307..e5c82a4a80e 100644
--- a/source/blender/editors/space_clip/clip_dopesheet_draw.c
+++ b/source/blender/editors/space_clip/clip_dopesheet_draw.c
@@ -79,9 +79,9 @@ static void draw_keyframe_shape(
   immVertex2f(pos_id, x, y);
 }
 
-static void clip_draw_dopesheet_background(ARegion *ar, MovieClip *clip, unsigned int pos_id)
+static void clip_draw_dopesheet_background(ARegion *region, MovieClip *clip, unsigned int pos_id)
 {
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   MovieTracking *tracking = &clip->tracking;
   MovieTrackingDopesheet *dopesheet = &tracking->dopesheet;
   MovieTrackingDopesheetCoverageSegment *coverage_segment;
@@ -105,10 +105,10 @@ static void clip_draw_dopesheet_background(ARegion *ar, MovieClip *clip, unsigne
   }
 }
 
-void clip_draw_dopesheet_main(SpaceClip *sc, ARegion *ar, Scene *scene)
+void clip_draw_dopesheet_main(SpaceClip *sc, ARegion *region, Scene *scene)
 {
   MovieClip *clip = ED_space_clip_get_clip(sc);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   /* frame range */
   clip_draw_sfra_efra(v2d, scene);
@@ -142,7 +142,7 @@ void clip_draw_dopesheet_main(SpaceClip *sc, ARegion *ar, Scene *scene)
 
     GPU_blend(true);
 
-    clip_draw_dopesheet_background(ar, clip, pos_id);
+    clip_draw_dopesheet_background(region, clip, pos_id);
 
     for (channel = dopesheet->channels.first; channel; channel = channel->next) {
       float yminc = (float)(y - CHANNEL_HEIGHT_HALF);
@@ -290,11 +290,11 @@ void clip_draw_dopesheet_main(SpaceClip *sc, ARegion *ar, Scene *scene)
   }
 }
 
-void clip_draw_dopesheet_channels(const bContext *C, ARegion *ar)
+void clip_draw_dopesheet_channels(const bContext *C, ARegion *region)
 {
   ScrArea *sa = CTX_wm_area(C);
   SpaceClip *sc = CTX_wm_space_clip(C);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   MovieClip *clip = ED_space_clip_get_clip(sc);
   uiStyle *style = UI_style_get();
   int fontid = style->widget.uifont_id;
@@ -380,7 +380,7 @@ void clip_draw_dopesheet_channels(const bContext *C, ARegion *ar)
   }
 
   /* third pass: widgets */
-  uiBlock *block = UI_block_begin(C, ar, __func__, UI_EMBOSS);
+  uiBlock *block = UI_block_begin(C, region, __func__, UI_EMBOSS);
   y = (float)CHANNEL_FIRST;
 
   /* get RNA properties (once) */
diff --git a/source/blender/editors/space_clip/clip_dopesheet_ops.c b/source/blender/editors/space_clip/clip_dopesheet_ops.c
index 785ced96b13..fbe92195a65 100644
--- a/source/blender/editors/space_clip/clip_dopesheet_ops.c
+++ b/source/blender/editors/space_clip/clip_dopesheet_ops.c
@@ -51,9 +51,9 @@ static bool space_clip_dopesheet_poll(bContext *C)
     SpaceClip *sc = CTX_wm_space_clip(C);
 
     if (sc->view == SC_VIEW_DOPESHEET) {
-      ARegion *ar = CTX_wm_region(C);
+      ARegion *region = CTX_wm_region(C);
 
-      return ar->regiontype == RGN_TYPE_PREVIEW;
+      return region->regiontype == RGN_TYPE_PREVIEW;
     }
   }
 
@@ -123,10 +123,11 @@ static int dopesheet_select_channel_exec(bContext *C, wmOperator *op)
 
 static int dopesheet_select_channel_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   float location[2];
 
-  UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &location[0], &location[1]);
+  UI_view2d_region_to_view(
+      &region->v2d, event->mval[0], event->mval[1], &location[0], &location[1]);
   RNA_float_set_array(op->ptr, "location", location);
 
   return dopesheet_select_channel_exec(C, op);
@@ -170,8 +171,8 @@ void CLIP_OT_dopesheet_select_channel(wmOperatorType *ot)
 static int dopesheet_view_all_exec(bContext *C, wmOperator *UNUSED(op))
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
-  View2D *v2d = &ar->v2d;
+  ARegion *region = CTX_wm_region(C);
+  View2D *v2d = &region->v2d;
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
   MovieTrackingDopesheet *dopesheet = &tracking->dopesheet;
@@ -194,7 +195,7 @@ static int dopesheet_view_all_exec(bContext *C, wmOperator *UNUSED(op))
     v2d->cur.xmin -= extra;
     v2d->cur.xmax += extra;
 
-    ED_region_tag_redraw(ar);
+    ED_region_tag_redraw(region);
   }
 
   return OPERATOR_FINISHED;
diff --git a/source/blender/editors/space_clip/clip_draw.c b/source/blender/editors/space_clip/clip_draw.c
index f9899135e2d..45502d1eb81 100644
--- a/source/blender/editors/space_clip/clip_draw.c
+++ b/source/blender/editors/space_clip/clip_draw.c
@@ -143,11 +143,11 @@ static bool generic_track_is_marker_keyframed(MovieTrackingTrack *track,
   return false;
 }
 
-static void draw_movieclip_cache(SpaceClip *sc, ARegion *ar, MovieClip *clip, Scene *scene)
+static void draw_movieclip_cache(SpaceClip *sc, ARegion *region, MovieClip *clip, Scene *scene)
 {
   float x;
   int *points, totseg, i, a;
-  float sfra = SFRA, efra = EFRA, framelen = ar->winx / (efra - sfra + 1);
+  float sfra = SFRA, efra = EFRA, framelen = region->winx / (efra - sfra + 1);
   MovieTracking *tracking = &clip->tracking;
   MovieTrackingObject *act_object = BKE_tracking_object_get_active(tracking);
   MovieTrackingTrack *act_track = BKE_tracking_track_get_active(&clip->tracking);
@@ -159,11 +159,11 @@ static void draw_movieclip_cache(SpaceClip *sc, ARegion *ar, MovieClip *clip, Sc
       GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA, GPU_ONE, GPU_ONE_MINUS_SRC_ALPHA);
 
   /* cache background */
-  ED_region_cache_draw_background(ar);
+  ED_region_cache_draw_background(region);
 
   /* cached segments -- could be useful to debug caching strategies */
   BKE_movieclip_get_cache_segments(clip, &sc->user, &totseg, &points);
-  ED_region_cache_draw_cached_segments(ar, totseg, points, sfra, efra);
+  ED_region_cache_draw_cached_segments(region, totseg, points, sfra, efra);
 
   uint pos = GPU_vertformat_attr_add(
       immVertexFormat(), "pos", GPU_COMP_I32, 2, GPU_FETCH_INT_TO_FLOAT);
@@ -249,7 +249,7 @@ static void draw_movieclip_cache(SpaceClip *sc, ARegion *ar, MovieClip *clip, Sc
   GPU_blend(false);
 
   /* current frame */
-  x = (sc->user.framenr - sfra) / (efra - sfra + 1) * ar->winx;
+  x = (sc->user.framenr - sfra) / (efra - sfra + 1) * region->winx;
 
   immUniformThemeColor(TH_CFRAME);
   immRecti(pos, x, 0, x + ceilf(framelen), 8 * UI_DPI_FAC);
@@ -270,11 +270,11 @@ static void draw_movieclip_cache(SpaceClip *sc, ARegion *ar, MovieClip *clip, Sc
 
   /* movie clip animation */
   if ((sc->mode == SC_MODE_MASKEDIT) && sc->mask_info.mask) {
-    ED_mask_draw_frames(sc->mask_info.mask, ar, CFRA, sfra, efra);
+    ED_mask_draw_frames(sc->mask_info.mask, region, CFRA, sfra, efra);
   }
 }
 
-static void draw_movieclip_notes(SpaceClip *sc, ARegion *ar)
+static void draw_movieclip_notes(SpaceClip *sc, ARegion *region)
 {
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
@@ -293,11 +293,11 @@ static void draw_movieclip_notes(SpaceClip *sc, ARegion *ar)
 
   if (str[0]) {
     float fill_color[4] = {0.0f, 0.0f, 0.0f, 0.6f};
-    ED_region_info_draw(ar, str, fill_color, full_redraw);
+    ED_region_info_draw(region, str, fill_color, full_redraw);
   }
 }
 
-static void draw_movieclip_muted(ARegion *ar, int width, int height, float zoomx, float zoomy)
+static void draw_movieclip_muted(ARegion *region, int width, int height, float zoomx, float zoomy)
 {
   int x, y;
 
@@ -305,7 +305,7 @@ static void draw_movieclip_muted(ARegion *ar, int width, int height, float zoomx
   immBindBuiltinProgram(GPU_SHADER_2D_UNIFORM_COLOR);
 
   /* find window pixel coordinates of origin */
-  UI_view2d_view_to_region(&ar->v2d, 0.0f, 0.0f, &x, &y);
+  UI_view2d_view_to_region(&region->v2d, 0.0f, 0.0f, &x, &y);
 
   immUniformColor3f(0.0f, 0.0f, 0.0f);
   immRectf(pos, x, y, x + zoomx * width, y + zoomy * height);
@@ -315,7 +315,7 @@ static void draw_movieclip_muted(ARegion *ar, int width, int height, float zoomx
 
 static void draw_movieclip_buffer(const bContext *C,
                                   SpaceClip *sc,
-                                  ARegion *ar,
+                                  ARegion *region,
                                   ImBuf *ibuf,
                                   int width,
                                   int height,
@@ -327,7 +327,7 @@ static void draw_movieclip_buffer(const bContext *C,
   int x, y;
 
   /* find window pixel coordinates of origin */
-  UI_view2d_view_to_region(&ar->v2d, 0.0f, 0.0f, &x, &y);
+  UI_view2d_view_to_region(&region->v2d, 0.0f, 0.0f, &x, &y);
 
   /* checkerboard for case alpha */
   if (ibuf->planes == 32) {
@@ -359,13 +359,13 @@ static void draw_movieclip_buffer(const bContext *C,
 }
 
 static void draw_stabilization_border(
-    SpaceClip *sc, ARegion *ar, int width, int height, float zoomx, float zoomy)
+    SpaceClip *sc, ARegion *region, int width, int height, float zoomx, float zoomy)
 {
   int x, y;
   MovieClip *clip = ED_space_clip_get_clip(sc);
 
   /* find window pixel coordinates of origin */
-  UI_view2d_view_to_region(&ar->v2d, 0.0f, 0.0f, &x, &y);
+  UI_view2d_view_to_region(&region->v2d, 0.0f, 0.0f, &x, &y);
 
   /* draw boundary border for frame if stabilization is enabled */
   if (sc->flag & SC_SHOW_STABLE && clip->tracking.stabilization.flag & TRACKING_2D_STABILIZATION) {
@@ -1459,7 +1459,7 @@ static void draw_plane_track(SpaceClip *sc,
 /* Draw all kind of tracks. */
 static void draw_tracking_tracks(SpaceClip *sc,
                                  Scene *scene,
-                                 ARegion *ar,
+                                 ARegion *region,
                                  MovieClip *clip,
                                  int width,
                                  int height,
@@ -1484,7 +1484,7 @@ static void draw_tracking_tracks(SpaceClip *sc,
    * to avoid this flickering, calculate base point in the same way as it happens
    * in UI_view2d_view_to_region_no_clip, but do it in floats here */
 
-  UI_view2d_view_to_region_fl(&ar->v2d, 0.0f, 0.0f, &x, &y);
+  UI_view2d_view_to_region_fl(&region->v2d, 0.0f, 0.0f, &x, &y);
 
   GPU_matrix_push();
   GPU_matrix_translate_2f(x, y);
@@ -1721,8 +1721,13 @@ static void draw_tracking_tracks(SpaceClip *sc,
   }
 }
 
-static void draw_distortion(
-    SpaceClip *sc, ARegion *ar, MovieClip *clip, int width, int height, float zoomx, float zoomy)
+static void draw_distortion(SpaceClip *sc,
+                            ARegion *region,
+                            MovieClip *clip,
+                            int width,
+                            int height,
+                            float zoomx,
+                            float zoomy)
 {
   float x, y;
   const int n = 10;
@@ -1742,7 +1747,7 @@ static void draw_distortion(
     return;
   }
 
-  UI_view2d_view_to_region_fl(&ar->v2d, 0.0f, 0.0f, &x, &y);
+  UI_view2d_view_to_region_fl(&region->v2d, 0.0f, 0.0f, &x, &y);
 
   GPU_matrix_push();
   GPU_matrix_translate_2f(x, y);
@@ -1934,7 +1939,7 @@ static void draw_distortion(
   GPU_matrix_pop();
 }
 
-void clip_draw_main(const bContext *C, SpaceClip *sc, ARegion *ar)
+void clip_draw_main(const bContext *C, SpaceClip *sc, ARegion *region)
 {
   MovieClip *clip = ED_space_clip_get_clip(sc);
   Scene *scene = CTX_data_scene(C);
@@ -1943,11 +1948,11 @@ void clip_draw_main(const bContext *C, SpaceClip *sc, ARegion *ar)
   float zoomx, zoomy;
 
   ED_space_clip_get_size(sc, &width, &height);
-  ED_space_clip_get_zoom(sc, ar, &zoomx, &zoomy);
+  ED_space_clip_get_zoom(sc, region, &zoomx, &zoomy);
 
   /* if no clip, nothing to do */
   if (!clip) {
-    ED_region_grid_draw(ar, zoomx, zoomy, 0.0f, 0.0f);
+    ED_region_grid_draw(region, zoomx, zoomy, 0.0f, 0.0f);
     return;
   }
 
@@ -1987,30 +1992,30 @@ void clip_draw_main(const bContext *C, SpaceClip *sc, ARegion *ar)
   }
 
   if (ibuf) {
-    draw_movieclip_buffer(C, sc, ar, ibuf, width, height, zoomx, zoomy);
+    draw_movieclip_buffer(C, sc, region, ibuf, width, height, zoomx, zoomy);
     IMB_freeImBuf(ibuf);
   }
   else if (sc->flag & SC_MUTE_FOOTAGE) {
-    draw_movieclip_muted(ar, width, height, zoomx, zoomy);
+    draw_movieclip_muted(region, width, height, zoomx, zoomy);
   }
   else {
-    ED_region_grid_draw(ar, zoomx, zoomy, 0.0f, 0.0f);
+    ED_region_grid_draw(region, zoomx, zoomy, 0.0f, 0.0f);
   }
 
   if (width && height) {
-    draw_stabilization_border(sc, ar, width, height, zoomx, zoomy);
-    draw_tracking_tracks(sc, scene, ar, clip, width, height, zoomx, zoomy);
-    draw_distortion(sc, ar, clip, width, height, zoomx, zoomy);
+    draw_stabilization_border(sc, region, width, height, zoomx, zoomy);
+    draw_tracking_tracks(sc, scene, region, clip, width, height, zoomx, zoomy);
+    draw_distortion(sc, region, clip, width, height, zoomx, zoomy);
   }
 }
 
-void clip_draw_cache_and_notes(const bContext *C, SpaceClip *sc, ARegion *ar)
+void clip_draw_cache_and_notes(const bContext *C, SpaceClip *sc, ARegion *region)
 {
   Scene *scene = CTX_data_scene(C);
   MovieClip *clip = ED_space_clip_get_clip(sc);
   if (clip) {
-    draw_movieclip_cache(sc, ar, clip, scene);
-    draw_movieclip_notes(sc, ar);
+    draw_movieclip_cache(sc, region, clip, scene);
+    draw_movieclip_notes(sc, region);
   }
 }
 
diff --git a/source/blender/editors/space_clip/clip_editor.c b/source/blender/editors/space_clip/clip_editor.c
index 2114c4cac79..9716ef48262 100644
--- a/source/blender/editors/space_clip/clip_editor.c
+++ b/source/blender/editors/space_clip/clip_editor.c
@@ -147,14 +147,16 @@ void ED_space_clip_get_size_fl(SpaceClip *sc, float size[2])
   size[1] = size_i[1];
 }
 
-void ED_space_clip_get_zoom(SpaceClip *sc, ARegion *ar, float *zoomx, float *zoomy)
+void ED_space_clip_get_zoom(SpaceClip *sc, ARegion *region, float *zoomx, float *zoomy)
 {
   int width, height;
 
   ED_space_clip_get_size(sc, &width, &height);
 
-  *zoomx = (float)(BLI_rcti_size_x(&ar->winrct) + 1) / (BLI_rctf_size_x(&ar->v2d.cur) * width);
-  *zoomy = (float)(BLI_rcti_size_y(&ar->winrct) + 1) / (BLI_rctf_size_y(&ar->v2d.cur) * height);
+  *zoomx = (float)(BLI_rcti_size_x(&region->winrct) + 1) /
+           (BLI_rctf_size_x(&region->v2d.cur) * width);
+  *zoomy = (float)(BLI_rcti_size_y(&region->winrct) + 1) /
+           (BLI_rctf_size_y(&region->v2d.cur) * height);
 }
 
 void ED_space_clip_get_aspect(SpaceClip *sc, float *aspx, float *aspy)
@@ -261,7 +263,7 @@ ImBuf *ED_space_clip_get_stable_buffer(SpaceClip *sc, float loc[2], float *scale
 }
 
 /* Returns color in linear space, matching ED_space_image_color_sample(). */
-bool ED_space_clip_color_sample(SpaceClip *sc, ARegion *ar, int mval[2], float r_col[3])
+bool ED_space_clip_color_sample(SpaceClip *sc, ARegion *region, int mval[2], float r_col[3])
 {
   ImBuf *ibuf;
   float fx, fy, co[2];
@@ -273,7 +275,7 @@ bool ED_space_clip_color_sample(SpaceClip *sc, ARegion *ar, int mval[2], float r
   }
 
   /* map the mouse coords to the backdrop image space */
-  ED_clip_mouse_pos(sc, ar, mval, co);
+  ED_clip_mouse_pos(sc, region, mval, co);
 
   fx = co[0];
   fy = co[1];
@@ -395,7 +397,7 @@ static bool selected_boundbox(const bContext *C, float min[2], float max[2])
   }
 }
 
-bool ED_clip_view_selection(const bContext *C, ARegion *ar, bool fit)
+bool ED_clip_view_selection(const bContext *C, ARegion *region, bool fit)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
   int w, h, frame_width, frame_height;
@@ -425,8 +427,8 @@ bool ED_clip_view_selection(const bContext *C, ARegion *ar, bool fit)
 
     ED_space_clip_get_aspect(sc, &aspx, &aspy);
 
-    width = BLI_rcti_size_x(&ar->winrct) + 1;
-    height = BLI_rcti_size_y(&ar->winrct) + 1;
+    width = BLI_rcti_size_x(&region->winrct) + 1;
+    height = BLI_rcti_size_y(&region->winrct) + 1;
 
     zoomx = (float)width / w / aspx;
     zoomy = (float)height / h / aspy;
@@ -550,15 +552,16 @@ void ED_clip_point_undistorted_pos(SpaceClip *sc, const float co[2], float r_co[
   }
 }
 
-void ED_clip_point_stable_pos(SpaceClip *sc, ARegion *ar, float x, float y, float *xr, float *yr)
+void ED_clip_point_stable_pos(
+    SpaceClip *sc, ARegion *region, float x, float y, float *xr, float *yr)
 {
   int sx, sy, width, height;
   float zoomx, zoomy, pos[3], imat[4][4];
 
-  ED_space_clip_get_zoom(sc, ar, &zoomx, &zoomy);
+  ED_space_clip_get_zoom(sc, region, &zoomx, &zoomy);
   ED_space_clip_get_size(sc, &width, &height);
 
-  UI_view2d_view_to_region(&ar->v2d, 0.0f, 0.0f, &sx, &sy);
+  UI_view2d_view_to_region(&region->v2d, 0.0f, 0.0f, &sx, &sy);
 
   pos[0] = (x - sx) / zoomx;
   pos[1] = (y - sy) / zoomy;
@@ -588,7 +591,7 @@ void ED_clip_point_stable_pos(SpaceClip *sc, ARegion *ar, float x, float y, floa
  * better name here? view_to_track / track_to_view or so?
  */
 void ED_clip_point_stable_pos__reverse(SpaceClip *sc,
-                                       ARegion *ar,
+                                       ARegion *region,
                                        const float co[2],
                                        float r_co[2])
 {
@@ -597,9 +600,9 @@ void ED_clip_point_stable_pos__reverse(SpaceClip *sc,
   int width, height;
   int sx, sy;
 
-  UI_view2d_view_to_region(&ar->v2d, 0.0f, 0.0f, &sx, &sy);
+  UI_view2d_view_to_region(&region->v2d, 0.0f, 0.0f, &sx, &sy);
   ED_space_clip_get_size(sc, &width, &height);
-  ED_space_clip_get_zoom(sc, ar, &zoomx, &zoomy);
+  ED_space_clip_get_zoom(sc, region, &zoomx, &zoomy);
 
   ED_clip_point_undistorted_pos(sc, co, pos);
   pos[2] = 0.0f;
@@ -612,9 +615,9 @@ void ED_clip_point_stable_pos__reverse(SpaceClip *sc,
 }
 
 /* takes event->mval */
-void ED_clip_mouse_pos(SpaceClip *sc, ARegion *ar, const int mval[2], float co[2])
+void ED_clip_mouse_pos(SpaceClip *sc, ARegion *region, const int mval[2], float co[2])
 {
-  ED_clip_point_stable_pos(sc, ar, mval[0], mval[1], &co[0], &co[1]);
+  ED_clip_point_stable_pos(sc, region, mval[0], mval[1], &co[0], &co[1]);
 }
 
 bool ED_space_clip_check_show_trackedit(SpaceClip *sc)
diff --git a/source/blender/editors/space_clip/clip_graph_draw.c b/source/blender/editors/space_clip/clip_graph_draw.c
index 3f705aad89a..10bf8d93983 100644
--- a/source/blender/editors/space_clip/clip_graph_draw.c
+++ b/source/blender/editors/space_clip/clip_graph_draw.c
@@ -249,10 +249,10 @@ static void draw_frame_curves(SpaceClip *sc, unsigned int pos)
   }
 }
 
-void clip_draw_graph(SpaceClip *sc, ARegion *ar, Scene *scene)
+void clip_draw_graph(SpaceClip *sc, ARegion *region, Scene *scene)
 {
   MovieClip *clip = ED_space_clip_get_clip(sc);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   /* grid */
   UI_view2d_draw_lines_x__values(v2d);
diff --git a/source/blender/editors/space_clip/clip_graph_ops.c b/source/blender/editors/space_clip/clip_graph_ops.c
index 58a00d2e6b9..9547c65ffab 100644
--- a/source/blender/editors/space_clip/clip_graph_ops.c
+++ b/source/blender/editors/space_clip/clip_graph_ops.c
@@ -182,8 +182,8 @@ static bool mouse_select_knot(bContext *C, float co[2], bool extend)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
   MovieClip *clip = ED_space_clip_get_clip(sc);
-  ARegion *ar = CTX_wm_region(C);
-  View2D *v2d = &ar->v2d;
+  ARegion *region = CTX_wm_region(C);
+  View2D *v2d = &region->v2d;
   MovieTracking *tracking = &clip->tracking;
   MovieTrackingTrack *act_track = BKE_tracking_track_get_active(tracking);
   static const int delta = 6;
@@ -316,10 +316,10 @@ static int select_exec(bContext *C, wmOperator *op)
 
 static int select_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   float co[2];
 
-  UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &co[0], &co[1]);
+  UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &co[0], &co[1]);
   RNA_float_set_array(op->ptr, "location", co);
 
   return select_exec(C, op);
@@ -403,7 +403,7 @@ static void box_select_cb(void *userdata,
 static int box_select_graph_exec(bContext *C, wmOperator *op)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
@@ -417,7 +417,7 @@ static int box_select_graph_exec(bContext *C, wmOperator *op)
 
   /* get rectangle from operator */
   WM_operator_properties_border_to_rctf(op, &rect);
-  UI_view2d_region_to_view_rctf(&ar->v2d, &rect, &userdata.rect);
+  UI_view2d_region_to_view_rctf(&region->v2d, &rect, &userdata.rect);
 
   userdata.changed = false;
   userdata.select = !RNA_boolean_get(op->ptr, "deselect");
@@ -624,9 +624,9 @@ static void view_all_cb(void *userdata,
 static int view_all_exec(bContext *C, wmOperator *UNUSED(op))
 {
   Scene *scene = CTX_data_scene(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   SpaceClip *sc = CTX_wm_space_clip(C);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   ViewAllUserData userdata;
   float extra;
 
@@ -663,7 +663,7 @@ static int view_all_exec(bContext *C, wmOperator *UNUSED(op))
   v2d->cur.ymin -= extra;
   v2d->cur.ymax += extra;
 
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
 
   return OPERATOR_FINISHED;
 }
@@ -682,9 +682,9 @@ void CLIP_OT_graph_view_all(wmOperatorType *ot)
 
 /******************** jump to current frame operator ********************/
 
-void ED_clip_graph_center_current_frame(Scene *scene, ARegion *ar)
+void ED_clip_graph_center_current_frame(Scene *scene, ARegion *region)
 {
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   float extra = BLI_rctf_size_x(&v2d->cur) / 2.0f;
 
   /* set extents of view to start/end frames */
@@ -695,11 +695,11 @@ void ED_clip_graph_center_current_frame(Scene *scene, ARegion *ar)
 static int center_current_frame_exec(bContext *C, wmOperator *UNUSED(op))
 {
   Scene *scene = CTX_data_scene(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
-  ED_clip_graph_center_current_frame(scene, ar);
+  ED_clip_graph_center_current_frame(scene, region);
 
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
 
   return OPERATOR_FINISHED;
 }
diff --git a/source/blender/editors/space_clip/clip_intern.h b/source/blender/editors/space_clip/clip_intern.h
index bd54d4f0016..b66f7605f41 100644
--- a/source/blender/editors/space_clip/clip_intern.h
+++ b/source/blender/editors/space_clip/clip_intern.h
@@ -54,26 +54,26 @@ struct wmOperatorType;
 void ED_clip_buttons_register(struct ARegionType *art);
 
 /* clip_dopesheet_draw.c */
-void clip_draw_dopesheet_main(struct SpaceClip *sc, struct ARegion *ar, struct Scene *scene);
-void clip_draw_dopesheet_channels(const struct bContext *C, struct ARegion *ar);
+void clip_draw_dopesheet_main(struct SpaceClip *sc, struct ARegion *region, struct Scene *scene);
+void clip_draw_dopesheet_channels(const struct bContext *C, struct ARegion *region);
 
 /* clip_dopesheet_ops.c */
 void CLIP_OT_dopesheet_select_channel(struct wmOperatorType *ot);
 void CLIP_OT_dopesheet_view_all(struct wmOperatorType *ot);
 
 /* clip_draw.c */
-void clip_draw_main(const struct bContext *C, struct SpaceClip *sc, struct ARegion *ar);
+void clip_draw_main(const struct bContext *C, struct SpaceClip *sc, struct ARegion *region);
 void clip_draw_grease_pencil(struct bContext *C, int onlyv2d);
-void clip_draw_cache_and_notes(const bContext *C, SpaceClip *sc, ARegion *ar);
+void clip_draw_cache_and_notes(const bContext *C, SpaceClip *sc, ARegion *region);
 
 /* clip_editor.c */
 void clip_start_prefetch_job(const struct bContext *C);
 
 /* clip_graph_draw.c */
-void clip_draw_graph(struct SpaceClip *sc, struct ARegion *ar, struct Scene *scene);
+void clip_draw_graph(struct SpaceClip *sc, struct ARegion *region, struct Scene *scene);
 
 /* clip_graph_ops.c */
-void ED_clip_graph_center_current_frame(struct Scene *scene, struct ARegion *ar);
+void ED_clip_graph_center_current_frame(struct Scene *scene, struct ARegion *region);
 
 void CLIP_OT_graph_select(struct wmOperatorType *ot);
 void CLIP_OT_graph_select_box(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_clip/clip_ops.c b/source/blender/editors/space_clip/clip_ops.c
index cc8c1a8f755..c6033ec6ca0 100644
--- a/source/blender/editors/space_clip/clip_ops.c
+++ b/source/blender/editors/space_clip/clip_ops.c
@@ -88,7 +88,7 @@ static void sclip_zoom_set(const bContext *C,
                            const bool zoom_to_pos)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   float oldzoom = sc->zoom;
   int width, height;
@@ -105,10 +105,10 @@ static void sclip_zoom_set(const bContext *C,
     if ((width < 4) && (height < 4) && sc->zoom < oldzoom) {
       sc->zoom = oldzoom;
     }
-    else if (BLI_rcti_size_x(&ar->winrct) <= sc->zoom) {
+    else if (BLI_rcti_size_x(&region->winrct) <= sc->zoom) {
       sc->zoom = oldzoom;
     }
-    else if (BLI_rcti_size_y(&ar->winrct) <= sc->zoom) {
+    else if (BLI_rcti_size_y(&region->winrct) <= sc->zoom) {
       sc->zoom = oldzoom;
     }
   }
@@ -148,20 +148,20 @@ static void sclip_zoom_set_factor(const bContext *C,
 
 static void sclip_zoom_set_factor_exec(bContext *C, const wmEvent *event, float factor)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   float location[2], *mpos = NULL;
 
   if (event) {
     SpaceClip *sc = CTX_wm_space_clip(C);
 
-    ED_clip_mouse_pos(sc, ar, event->mval, location);
+    ED_clip_mouse_pos(sc, region, event->mval, location);
     mpos = location;
   }
 
   sclip_zoom_set_factor(C, factor, mpos, mpos ? (U.uiflag & USER_ZOOM_TO_MOUSEPOS) : false);
 
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
 }
 
 /** \} */
@@ -559,7 +559,7 @@ static void view_zoom_init(bContext *C, wmOperator *op, const wmEvent *event)
 {
   wmWindow *win = CTX_wm_window(C);
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   ViewZoomData *vpd;
 
   op->customdata = vpd = MEM_callocN(sizeof(ViewZoomData), "ClipViewZoomData");
@@ -581,7 +581,7 @@ static void view_zoom_init(bContext *C, wmOperator *op, const wmEvent *event)
   vpd->zoom = sc->zoom;
   vpd->launch_event = WM_userdef_event_type_from_keymap_type(event->type);
 
-  ED_clip_mouse_pos(sc, ar, event->mval, vpd->location);
+  ED_clip_mouse_pos(sc, region, event->mval, vpd->location);
 
   WM_event_add_modal_handler(C, op);
 }
@@ -769,11 +769,11 @@ static int view_zoom_in_exec(bContext *C, wmOperator *op)
 static int view_zoom_in_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   float location[2];
 
-  ED_clip_mouse_pos(sc, ar, event->mval, location);
+  ED_clip_mouse_pos(sc, region, event->mval, location);
   RNA_float_set_array(op->ptr, "location", location);
 
   return view_zoom_in_exec(C, op);
@@ -826,11 +826,11 @@ static int view_zoom_out_exec(bContext *C, wmOperator *op)
 static int view_zoom_out_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   float location[2];
 
-  ED_clip_mouse_pos(sc, ar, event->mval, location);
+  ED_clip_mouse_pos(sc, region, event->mval, location);
   RNA_float_set_array(op->ptr, "location", location);
 
   return view_zoom_out_exec(C, op);
@@ -922,7 +922,7 @@ void CLIP_OT_view_zoom_ratio(wmOperatorType *ot)
 static int view_all_exec(bContext *C, wmOperator *op)
 {
   SpaceClip *sc;
-  ARegion *ar;
+  ARegion *region;
   int w, h, width, height;
   float aspx, aspy;
   bool fit_view = RNA_boolean_get(op->ptr, "fit_view");
@@ -930,7 +930,7 @@ static int view_all_exec(bContext *C, wmOperator *op)
 
   /* retrieve state */
   sc = CTX_wm_space_clip(C);
-  ar = CTX_wm_region(C);
+  region = CTX_wm_region(C);
 
   ED_space_clip_get_size(sc, &w, &h);
   ED_space_clip_get_aspect(sc, &aspx, &aspy);
@@ -939,8 +939,8 @@ static int view_all_exec(bContext *C, wmOperator *op)
   h = h * aspy;
 
   /* check if the image will fit in the image with zoom == 1 */
-  width = BLI_rcti_size_x(&ar->winrct) + 1;
-  height = BLI_rcti_size_y(&ar->winrct) + 1;
+  width = BLI_rcti_size_x(&region->winrct) + 1;
+  height = BLI_rcti_size_y(&region->winrct) + 1;
 
   if (fit_view) {
     const int margin = 5; /* margin from border */
@@ -965,7 +965,7 @@ static int view_all_exec(bContext *C, wmOperator *op)
 
   sc->xof = sc->yof = 0.0f;
 
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
 
   return OPERATOR_FINISHED;
 }
@@ -999,11 +999,11 @@ void CLIP_OT_view_all(wmOperatorType *ot)
 static int view_center_cursor_exec(bContext *C, wmOperator *UNUSED(op))
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   clip_view_center_to_point(sc, sc->cursor[0], sc->cursor[1]);
 
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
 
   return OPERATOR_FINISHED;
 }
@@ -1029,13 +1029,13 @@ void CLIP_OT_view_center_cursor(wmOperatorType *ot)
 static int view_selected_exec(bContext *C, wmOperator *UNUSED(op))
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   sc->xlockof = 0.0f;
   sc->ylockof = 0.0f;
 
-  ED_clip_view_selection(C, ar, 1);
-  ED_region_tag_redraw(ar);
+  ED_clip_view_selection(C, region, 1);
+  ED_region_tag_redraw(region);
 
   return OPERATOR_FINISHED;
 }
@@ -1093,19 +1093,19 @@ static int change_frame_exec(bContext *C, wmOperator *op)
 
 static int frame_from_event(bContext *C, const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   Scene *scene = CTX_data_scene(C);
   int framenr = 0;
 
-  if (ar->regiontype == RGN_TYPE_WINDOW) {
-    float sfra = SFRA, efra = EFRA, framelen = ar->winx / (efra - sfra + 1);
+  if (region->regiontype == RGN_TYPE_WINDOW) {
+    float sfra = SFRA, efra = EFRA, framelen = region->winx / (efra - sfra + 1);
 
     framenr = sfra + event->mval[0] / framelen;
   }
   else {
     float viewx, viewy;
 
-    UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &viewx, &viewy);
+    UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &viewx, &viewy);
 
     framenr = round_fl_to_int(viewx);
   }
@@ -1115,9 +1115,9 @@ static int frame_from_event(bContext *C, const wmEvent *event)
 
 static int change_frame_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
-  if (ar->regiontype == RGN_TYPE_WINDOW) {
+  if (region->regiontype == RGN_TYPE_WINDOW) {
     if (event->mval[1] > 16 * UI_DPI_FAC) {
       return OPERATOR_PASS_THROUGH;
     }
@@ -1649,7 +1649,7 @@ static int clip_view_ndof_invoke(bContext *C, wmOperator *UNUSED(op), const wmEv
   }
   else {
     SpaceClip *sc = CTX_wm_space_clip(C);
-    ARegion *ar = CTX_wm_region(C);
+    ARegion *region = CTX_wm_region(C);
     float pan_vec[3];
 
     const wmNDOFMotionData *ndof = event->customdata;
@@ -1664,7 +1664,7 @@ static int clip_view_ndof_invoke(bContext *C, wmOperator *UNUSED(op), const wmEv
     sc->xof += pan_vec[0];
     sc->yof += pan_vec[1];
 
-    ED_region_tag_redraw(ar);
+    ED_region_tag_redraw(region);
 
     return OPERATOR_FINISHED;
   }
@@ -1797,11 +1797,11 @@ static int clip_set_2d_cursor_exec(bContext *C, wmOperator *op)
 
 static int clip_set_2d_cursor_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   SpaceClip *sclip = CTX_wm_space_clip(C);
   float location[2];
 
-  ED_clip_mouse_pos(sclip, ar, event->mval, location);
+  ED_clip_mouse_pos(sclip, region, event->mval, location);
   RNA_float_set_array(op->ptr, "location", location);
 
   return clip_set_2d_cursor_exec(C, op);
diff --git a/source/blender/editors/space_clip/clip_toolbar.c b/source/blender/editors/space_clip/clip_toolbar.c
index fb0362fffd3..4c4110759cd 100644
--- a/source/blender/editors/space_clip/clip_toolbar.c
+++ b/source/blender/editors/space_clip/clip_toolbar.c
@@ -55,24 +55,24 @@
 
 ARegion *ED_clip_has_properties_region(ScrArea *sa)
 {
-  ARegion *ar, *arnew;
+  ARegion *region, *arnew;
 
-  ar = BKE_area_find_region_type(sa, RGN_TYPE_UI);
-  if (ar) {
-    return ar;
+  region = BKE_area_find_region_type(sa, RGN_TYPE_UI);
+  if (region) {
+    return region;
   }
 
   /* add subdiv level; after header */
-  ar = BKE_area_find_region_type(sa, RGN_TYPE_HEADER);
+  region = BKE_area_find_region_type(sa, RGN_TYPE_HEADER);
 
   /* is error! */
-  if (ar == NULL) {
+  if (region == NULL) {
     return NULL;
   }
 
   arnew = MEM_callocN(sizeof(ARegion), "clip properties region");
 
-  BLI_insertlinkafter(&sa->regionbase, ar, arnew);
+  BLI_insertlinkafter(&sa->regionbase, region, arnew);
   arnew->regiontype = RGN_TYPE_UI;
   arnew->alignment = RGN_ALIGN_RIGHT;
 
diff --git a/source/blender/editors/space_clip/space_clip.c b/source/blender/editors/space_clip/space_clip.c
index a0ac832522d..3256ee3eb73 100644
--- a/source/blender/editors/space_clip/space_clip.c
+++ b/source/blender/editors/space_clip/space_clip.c
@@ -73,101 +73,101 @@
 static void init_preview_region(const Scene *scene,
                                 const ScrArea *sa,
                                 const SpaceClip *sc,
-                                ARegion *ar)
+                                ARegion *region)
 {
-  ar->regiontype = RGN_TYPE_PREVIEW;
-  ar->alignment = RGN_ALIGN_TOP;
-  ar->flag |= RGN_FLAG_HIDDEN;
+  region->regiontype = RGN_TYPE_PREVIEW;
+  region->alignment = RGN_ALIGN_TOP;
+  region->flag |= RGN_FLAG_HIDDEN;
 
   if (sc->view == SC_VIEW_DOPESHEET) {
-    ar->v2d.tot.xmin = -10.0f;
-    ar->v2d.tot.ymin = (float)(-sa->winy) / 3.0f;
-    ar->v2d.tot.xmax = (float)(sa->winx);
-    ar->v2d.tot.ymax = 0.0f;
-
-    ar->v2d.cur = ar->v2d.tot;
-
-    ar->v2d.min[0] = 0.0f;
-    ar->v2d.min[1] = 0.0f;
-
-    ar->v2d.max[0] = MAXFRAMEF;
-    ar->v2d.max[1] = FLT_MAX;
-
-    ar->v2d.minzoom = 0.01f;
-    ar->v2d.maxzoom = 50;
-    ar->v2d.scroll = (V2D_SCROLL_BOTTOM | V2D_SCROLL_HORIZONTAL_HANDLES);
-    ar->v2d.scroll |= (V2D_SCROLL_RIGHT);
-    ar->v2d.keepzoom = V2D_LOCKZOOM_Y;
-    ar->v2d.keepofs = V2D_KEEPOFS_Y;
-    ar->v2d.align = V2D_ALIGN_NO_POS_Y;
-    ar->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
+    region->v2d.tot.xmin = -10.0f;
+    region->v2d.tot.ymin = (float)(-sa->winy) / 3.0f;
+    region->v2d.tot.xmax = (float)(sa->winx);
+    region->v2d.tot.ymax = 0.0f;
+
+    region->v2d.cur = region->v2d.tot;
+
+    region->v2d.min[0] = 0.0f;
+    region->v2d.min[1] = 0.0f;
+
+    region->v2d.max[0] = MAXFRAMEF;
+    region->v2d.max[1] = FLT_MAX;
+
+    region->v2d.minzoom = 0.01f;
+    region->v2d.maxzoom = 50;
+    region->v2d.scroll = (V2D_SCROLL_BOTTOM | V2D_SCROLL_HORIZONTAL_HANDLES);
+    region->v2d.scroll |= (V2D_SCROLL_RIGHT);
+    region->v2d.keepzoom = V2D_LOCKZOOM_Y;
+    region->v2d.keepofs = V2D_KEEPOFS_Y;
+    region->v2d.align = V2D_ALIGN_NO_POS_Y;
+    region->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
   }
   else {
-    ar->v2d.tot.xmin = 0.0f;
-    ar->v2d.tot.ymin = -10.0f;
-    ar->v2d.tot.xmax = (float)scene->r.efra;
-    ar->v2d.tot.ymax = 10.0f;
+    region->v2d.tot.xmin = 0.0f;
+    region->v2d.tot.ymin = -10.0f;
+    region->v2d.tot.xmax = (float)scene->r.efra;
+    region->v2d.tot.ymax = 10.0f;
 
-    ar->v2d.cur = ar->v2d.tot;
+    region->v2d.cur = region->v2d.tot;
 
-    ar->v2d.min[0] = FLT_MIN;
-    ar->v2d.min[1] = FLT_MIN;
+    region->v2d.min[0] = FLT_MIN;
+    region->v2d.min[1] = FLT_MIN;
 
-    ar->v2d.max[0] = MAXFRAMEF;
-    ar->v2d.max[1] = FLT_MAX;
+    region->v2d.max[0] = MAXFRAMEF;
+    region->v2d.max[1] = FLT_MAX;
 
-    ar->v2d.scroll = (V2D_SCROLL_BOTTOM | V2D_SCROLL_HORIZONTAL_HANDLES);
-    ar->v2d.scroll |= (V2D_SCROLL_RIGHT | V2D_SCROLL_VERTICAL_HANDLES);
+    region->v2d.scroll = (V2D_SCROLL_BOTTOM | V2D_SCROLL_HORIZONTAL_HANDLES);
+    region->v2d.scroll |= (V2D_SCROLL_RIGHT | V2D_SCROLL_VERTICAL_HANDLES);
 
-    ar->v2d.minzoom = 0.0f;
-    ar->v2d.maxzoom = 0.0f;
-    ar->v2d.keepzoom = 0;
-    ar->v2d.keepofs = 0;
-    ar->v2d.align = 0;
-    ar->v2d.flag = 0;
+    region->v2d.minzoom = 0.0f;
+    region->v2d.maxzoom = 0.0f;
+    region->v2d.keepzoom = 0;
+    region->v2d.keepofs = 0;
+    region->v2d.align = 0;
+    region->v2d.flag = 0;
 
-    ar->v2d.keeptot = 0;
+    region->v2d.keeptot = 0;
   }
 }
 
-static void reinit_preview_region(const bContext *C, ARegion *ar)
+static void reinit_preview_region(const bContext *C, ARegion *region)
 {
   Scene *scene = CTX_data_scene(C);
   ScrArea *sa = CTX_wm_area(C);
   SpaceClip *sc = CTX_wm_space_clip(C);
 
   if (sc->view == SC_VIEW_DOPESHEET) {
-    if ((ar->v2d.flag & V2D_VIEWSYNC_AREA_VERTICAL) == 0) {
-      init_preview_region(scene, sa, sc, ar);
+    if ((region->v2d.flag & V2D_VIEWSYNC_AREA_VERTICAL) == 0) {
+      init_preview_region(scene, sa, sc, region);
     }
   }
   else {
-    if (ar->v2d.flag & V2D_VIEWSYNC_AREA_VERTICAL) {
-      init_preview_region(scene, sa, sc, ar);
+    if (region->v2d.flag & V2D_VIEWSYNC_AREA_VERTICAL) {
+      init_preview_region(scene, sa, sc, region);
     }
   }
 }
 
 static ARegion *ED_clip_has_preview_region(const bContext *C, ScrArea *sa)
 {
-  ARegion *ar, *arnew;
+  ARegion *region, *arnew;
 
-  ar = BKE_area_find_region_type(sa, RGN_TYPE_PREVIEW);
-  if (ar) {
-    return ar;
+  region = BKE_area_find_region_type(sa, RGN_TYPE_PREVIEW);
+  if (region) {
+    return region;
   }
 
   /* add subdiv level; after header */
-  ar = BKE_area_find_region_type(sa, RGN_TYPE_WINDOW);
+  region = BKE_area_find_region_type(sa, RGN_TYPE_WINDOW);
 
   /* is error! */
-  if (ar == NULL) {
+  if (region == NULL) {
     return NULL;
   }
 
   arnew = MEM_callocN(sizeof(ARegion), "clip preview region");
 
-  BLI_insertlinkbefore(&sa->regionbase, ar, arnew);
+  BLI_insertlinkbefore(&sa->regionbase, region, arnew);
   init_preview_region(CTX_data_scene(C), sa, CTX_wm_space_clip(C), arnew);
 
   return arnew;
@@ -175,24 +175,24 @@ static ARegion *ED_clip_has_preview_region(const bContext *C, ScrArea *sa)
 
 static ARegion *ED_clip_has_channels_region(ScrArea *sa)
 {
-  ARegion *ar, *arnew;
+  ARegion *region, *arnew;
 
-  ar = BKE_area_find_region_type(sa, RGN_TYPE_CHANNELS);
-  if (ar) {
-    return ar;
+  region = BKE_area_find_region_type(sa, RGN_TYPE_CHANNELS);
+  if (region) {
+    return region;
   }
 
   /* add subdiv level; after header */
-  ar = BKE_area_find_region_type(sa, RGN_TYPE_PREVIEW);
+  region = BKE_area_find_region_type(sa, RGN_TYPE_PREVIEW);
 
   /* is error! */
-  if (ar == NULL) {
+  if (region == NULL) {
     return NULL;
   }
 
   arnew = MEM_callocN(sizeof(ARegion), "clip channels region");
 
-  BLI_insertlinkbefore(&sa->regionbase, ar, arnew);
+  BLI_insertlinkbefore(&sa->regionbase, region, arnew);
   arnew->regiontype = RGN_TYPE_CHANNELS;
   arnew->alignment = RGN_ALIGN_LEFT;
 
@@ -205,15 +205,15 @@ static ARegion *ED_clip_has_channels_region(ScrArea *sa)
 static void clip_scopes_tag_refresh(ScrArea *sa)
 {
   SpaceClip *sc = (SpaceClip *)sa->spacedata.first;
-  ARegion *ar;
+  ARegion *region;
 
   if (sc->mode != SC_MODE_TRACKING) {
     return;
   }
 
   /* only while properties are visible */
-  for (ar = sa->regionbase.first; ar; ar = ar->next) {
-    if (ar->regiontype == RGN_TYPE_UI && ar->flag & RGN_FLAG_HIDDEN) {
+  for (region = sa->regionbase.first; region; region = region->next) {
+    if (region->regiontype == RGN_TYPE_UI && region->flag & RGN_FLAG_HIDDEN) {
       return;
     }
   }
@@ -240,7 +240,7 @@ static void clip_area_sync_frame_from_scene(ScrArea *sa, Scene *scene)
 
 static SpaceLink *clip_new(const ScrArea *sa, const Scene *scene)
 {
-  ARegion *ar;
+  ARegion *region;
   SpaceClip *sc;
 
   sc = MEM_callocN(sizeof(SpaceClip), "initclip");
@@ -253,47 +253,47 @@ static SpaceLink *clip_new(const ScrArea *sa, const Scene *scene)
   sc->around = V3D_AROUND_CENTER_MEDIAN;
 
   /* header */
-  ar = MEM_callocN(sizeof(ARegion), "header for clip");
+  region = MEM_callocN(sizeof(ARegion), "header for clip");
 
-  BLI_addtail(&sc->regionbase, ar);
-  ar->regiontype = RGN_TYPE_HEADER;
-  ar->alignment = (U.uiflag & USER_HEADER_BOTTOM) ? RGN_ALIGN_BOTTOM : RGN_ALIGN_TOP;
+  BLI_addtail(&sc->regionbase, region);
+  region->regiontype = RGN_TYPE_HEADER;
+  region->alignment = (U.uiflag & USER_HEADER_BOTTOM) ? RGN_ALIGN_BOTTOM : RGN_ALIGN_TOP;
 
   /* tools view */
-  ar = MEM_callocN(sizeof(ARegion), "tools for clip");
+  region = MEM_callocN(sizeof(ARegion), "tools for clip");
 
-  BLI_addtail(&sc->regionbase, ar);
-  ar->regiontype = RGN_TYPE_TOOLS;
-  ar->alignment = RGN_ALIGN_LEFT;
+  BLI_addtail(&sc->regionbase, region);
+  region->regiontype = RGN_TYPE_TOOLS;
+  region->alignment = RGN_ALIGN_LEFT;
 
   /* properties view */
-  ar = MEM_callocN(sizeof(ARegion), "properties for clip");
+  region = MEM_callocN(sizeof(ARegion), "properties for clip");
 
-  BLI_addtail(&sc->regionbase, ar);
-  ar->regiontype = RGN_TYPE_UI;
-  ar->alignment = RGN_ALIGN_RIGHT;
+  BLI_addtail(&sc->regionbase, region);
+  region->regiontype = RGN_TYPE_UI;
+  region->alignment = RGN_ALIGN_RIGHT;
 
   /* channels view */
-  ar = MEM_callocN(sizeof(ARegion), "channels for clip");
+  region = MEM_callocN(sizeof(ARegion), "channels for clip");
 
-  BLI_addtail(&sc->regionbase, ar);
-  ar->regiontype = RGN_TYPE_CHANNELS;
-  ar->alignment = RGN_ALIGN_LEFT;
+  BLI_addtail(&sc->regionbase, region);
+  region->regiontype = RGN_TYPE_CHANNELS;
+  region->alignment = RGN_ALIGN_LEFT;
 
-  ar->v2d.scroll = V2D_SCROLL_BOTTOM;
-  ar->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
+  region->v2d.scroll = V2D_SCROLL_BOTTOM;
+  region->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
 
   /* preview view */
-  ar = MEM_callocN(sizeof(ARegion), "preview for clip");
+  region = MEM_callocN(sizeof(ARegion), "preview for clip");
 
-  BLI_addtail(&sc->regionbase, ar);
-  init_preview_region(scene, sa, sc, ar);
+  BLI_addtail(&sc->regionbase, region);
+  init_preview_region(scene, sa, sc, region);
 
   /* main region */
-  ar = MEM_callocN(sizeof(ARegion), "main region for clip");
+  region = MEM_callocN(sizeof(ARegion), "main region for clip");
 
-  BLI_addtail(&sc->regionbase, ar);
-  ar->regiontype = RGN_TYPE_WINDOW;
+  BLI_addtail(&sc->regionbase, region);
+  region->regiontype = RGN_TYPE_WINDOW;
 
   return (SpaceLink *)sc;
 }
@@ -828,7 +828,7 @@ static void clip_gizmos(void)
 /********************* main region ********************/
 
 /* sets up the fields of the View2D from zoom and offset */
-static void movieclip_main_area_set_view2d(const bContext *C, ARegion *ar)
+static void movieclip_main_area_set_view2d(const bContext *C, ARegion *region)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
   float x1, y1, w, h, aspx, aspy;
@@ -840,60 +840,60 @@ static void movieclip_main_area_set_view2d(const bContext *C, ARegion *ar)
   w = width * aspx;
   h = height * aspy;
 
-  winx = BLI_rcti_size_x(&ar->winrct) + 1;
-  winy = BLI_rcti_size_y(&ar->winrct) + 1;
+  winx = BLI_rcti_size_x(&region->winrct) + 1;
+  winy = BLI_rcti_size_y(&region->winrct) + 1;
 
-  ar->v2d.tot.xmin = 0;
-  ar->v2d.tot.ymin = 0;
-  ar->v2d.tot.xmax = w;
-  ar->v2d.tot.ymax = h;
+  region->v2d.tot.xmin = 0;
+  region->v2d.tot.ymin = 0;
+  region->v2d.tot.xmax = w;
+  region->v2d.tot.ymax = h;
 
-  ar->v2d.mask.xmin = ar->v2d.mask.ymin = 0;
-  ar->v2d.mask.xmax = winx;
-  ar->v2d.mask.ymax = winy;
+  region->v2d.mask.xmin = region->v2d.mask.ymin = 0;
+  region->v2d.mask.xmax = winx;
+  region->v2d.mask.ymax = winy;
 
   /* which part of the image space do we see? */
-  x1 = ar->winrct.xmin + (winx - sc->zoom * w) / 2.0f;
-  y1 = ar->winrct.ymin + (winy - sc->zoom * h) / 2.0f;
+  x1 = region->winrct.xmin + (winx - sc->zoom * w) / 2.0f;
+  y1 = region->winrct.ymin + (winy - sc->zoom * h) / 2.0f;
 
   x1 -= sc->zoom * sc->xof;
   y1 -= sc->zoom * sc->yof;
 
   /* relative display right */
-  ar->v2d.cur.xmin = (ar->winrct.xmin - (float)x1) / sc->zoom;
-  ar->v2d.cur.xmax = ar->v2d.cur.xmin + ((float)winx / sc->zoom);
+  region->v2d.cur.xmin = (region->winrct.xmin - (float)x1) / sc->zoom;
+  region->v2d.cur.xmax = region->v2d.cur.xmin + ((float)winx / sc->zoom);
 
   /* relative display left */
-  ar->v2d.cur.ymin = (ar->winrct.ymin - (float)y1) / sc->zoom;
-  ar->v2d.cur.ymax = ar->v2d.cur.ymin + ((float)winy / sc->zoom);
+  region->v2d.cur.ymin = (region->winrct.ymin - (float)y1) / sc->zoom;
+  region->v2d.cur.ymax = region->v2d.cur.ymin + ((float)winy / sc->zoom);
 
   /* normalize 0.0..1.0 */
-  ar->v2d.cur.xmin /= w;
-  ar->v2d.cur.xmax /= w;
-  ar->v2d.cur.ymin /= h;
-  ar->v2d.cur.ymax /= h;
+  region->v2d.cur.xmin /= w;
+  region->v2d.cur.xmax /= w;
+  region->v2d.cur.ymin /= h;
+  region->v2d.cur.ymax /= h;
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void clip_main_region_init(wmWindowManager *wm, ARegion *ar)
+static void clip_main_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
-  UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_STANDARD, ar->winx, ar->winy);
+  UI_view2d_region_reinit(&region->v2d, V2D_COMMONVIEW_STANDARD, region->winx, region->winy);
 
   /* mask polls mode */
   keymap = WM_keymap_ensure(wm->defaultconf, "Mask Editing", 0, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 
   /* own keymap */
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip Editor", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 }
 
-static void clip_main_region_draw(const bContext *C, ARegion *ar)
+static void clip_main_region_draw(const bContext *C, ARegion *region)
 {
   /* draw entirely, view changes should be handled here */
   SpaceClip *sc = CTX_wm_space_clip(C);
@@ -915,7 +915,7 @@ static void clip_main_region_draw(const bContext *C, ARegion *ar)
       tmpibuf = ED_space_clip_get_stable_buffer(sc, NULL, NULL, NULL);
     }
 
-    if (ED_clip_view_selection(C, ar, 0)) {
+    if (ED_clip_view_selection(C, region, 0)) {
       sc->xof += sc->xlockof;
       sc->yof += sc->ylockof;
     }
@@ -930,17 +930,17 @@ static void clip_main_region_draw(const bContext *C, ARegion *ar)
   GPU_clear(GPU_COLOR_BIT);
 
   /* data... */
-  movieclip_main_area_set_view2d(C, ar);
+  movieclip_main_area_set_view2d(C, region);
 
   /* callback */
-  ED_region_draw_cb_draw(C, ar, REGION_DRAW_PRE_VIEW);
+  ED_region_draw_cb_draw(C, region, REGION_DRAW_PRE_VIEW);
 
-  clip_draw_main(C, sc, ar);
+  clip_draw_main(C, sc, region);
 
   /* TODO(sergey): would be nice to find a way to de-duplicate all this space conversions */
-  UI_view2d_view_to_region_fl(&ar->v2d, 0.0f, 0.0f, &x, &y);
+  UI_view2d_view_to_region_fl(&region->v2d, 0.0f, 0.0f, &x, &y);
   ED_space_clip_get_size(sc, &width, &height);
-  ED_space_clip_get_zoom(sc, ar, &zoomx, &zoomy);
+  ED_space_clip_get_zoom(sc, region, &zoomx, &zoomy);
   ED_space_clip_get_aspect(sc, &aspx, &aspy);
 
   if (sc->mode == SC_MODE_MASKEDIT) {
@@ -951,7 +951,7 @@ static void clip_main_region_draw(const bContext *C, ARegion *ar)
       ED_mask_get_size(sa, &mask_width, &mask_height);
       ED_mask_draw_region(CTX_data_expect_evaluated_depsgraph(C),
                           mask,
-                          ar,
+                          region,
                           sc->mask_info.draw_flag,
                           sc->mask_info.draw_type,
                           sc->mask_info.overlay_mode,
@@ -975,11 +975,11 @@ static void clip_main_region_draw(const bContext *C, ARegion *ar)
     GPU_matrix_scale_2f(zoomx, zoomy);
     GPU_matrix_mul(sc->stabmat);
     GPU_matrix_scale_2f(width, height);
-    ED_image_draw_cursor(ar, sc->cursor);
+    ED_image_draw_cursor(region, sc->cursor);
     GPU_matrix_pop();
   }
 
-  clip_draw_cache_and_notes(C, sc, ar);
+  clip_draw_cache_and_notes(C, sc, region);
 
   if (sc->flag & SC_SHOW_ANNOTATION) {
     /* Grease Pencil */
@@ -987,7 +987,7 @@ static void clip_main_region_draw(const bContext *C, ARegion *ar)
   }
 
   /* callback */
-  ED_region_draw_cb_draw(C, ar, REGION_DRAW_POST_VIEW);
+  ED_region_draw_cb_draw(C, region, REGION_DRAW_POST_VIEW);
 
   /* reset view matrix */
   UI_view2d_view_restore(C);
@@ -997,12 +997,12 @@ static void clip_main_region_draw(const bContext *C, ARegion *ar)
     clip_draw_grease_pencil((bContext *)C, false);
   }
 
-  WM_gizmomap_draw(ar->gizmo_map, C, WM_GIZMOMAP_DRAWSTEP_2D);
+  WM_gizmomap_draw(region->gizmo_map, C, WM_GIZMOMAP_DRAWSTEP_2D);
 }
 
 static void clip_main_region_listener(wmWindow *UNUSED(win),
                                       ScrArea *UNUSED(sa),
-                                      ARegion *ar,
+                                      ARegion *region,
                                       wmNotifier *wmn,
                                       const Scene *UNUSED(scene))
 {
@@ -1010,10 +1010,10 @@ static void clip_main_region_listener(wmWindow *UNUSED(win),
   switch (wmn->category) {
     case NC_GPENCIL:
       if (wmn->action == NA_EDITED) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       else if (wmn->data & ND_GPENCIL_EDITMODE) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }
@@ -1021,37 +1021,37 @@ static void clip_main_region_listener(wmWindow *UNUSED(win),
 
 /****************** preview region ******************/
 
-static void clip_preview_region_init(wmWindowManager *wm, ARegion *ar)
+static void clip_preview_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
-  UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_CUSTOM, ar->winx, ar->winy);
+  UI_view2d_region_reinit(&region->v2d, V2D_COMMONVIEW_CUSTOM, region->winx, region->winy);
 
   /* own keymap */
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip Time Scrub", SPACE_CLIP, RGN_TYPE_PREVIEW);
-  WM_event_add_keymap_handler_poll(&ar->handlers, keymap, ED_time_scrub_event_in_region);
+  WM_event_add_keymap_handler_poll(&region->handlers, keymap, ED_time_scrub_event_in_region);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip Graph Editor", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip Dopesheet Editor", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 }
 
-static void graph_region_draw(const bContext *C, ARegion *ar)
+static void graph_region_draw(const bContext *C, ARegion *region)
 {
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   View2DScrollers *scrollers;
   SpaceClip *sc = CTX_wm_space_clip(C);
   Scene *scene = CTX_data_scene(C);
   short cfra_flag = 0;
 
   if (sc->flag & SC_LOCK_TIMECURSOR) {
-    ED_clip_graph_center_current_frame(scene, ar);
+    ED_clip_graph_center_current_frame(scene, region);
   }
 
   /* clear and setup matrix */
@@ -1061,7 +1061,7 @@ static void graph_region_draw(const bContext *C, ARegion *ar)
   UI_view2d_view_ortho(v2d);
 
   /* data... */
-  clip_draw_graph(sc, ar, scene);
+  clip_draw_graph(sc, region, scene);
 
   /* current frame indicator line */
   if (sc->flag & SC_SHOW_SECONDS) {
@@ -1073,7 +1073,7 @@ static void graph_region_draw(const bContext *C, ARegion *ar)
   UI_view2d_view_restore(C);
 
   /* time-scrubbing */
-  ED_time_scrub_draw(ar, scene, sc->flag & SC_SHOW_SECONDS, true);
+  ED_time_scrub_draw(region, scene, sc->flag & SC_SHOW_SECONDS, true);
 
   /* scrollers */
   scrollers = UI_view2d_scrollers_calc(v2d, NULL);
@@ -1083,17 +1083,18 @@ static void graph_region_draw(const bContext *C, ARegion *ar)
   /* scale indicators */
   {
     rcti rect;
-    BLI_rcti_init(&rect, 0, 15 * UI_DPI_FAC, 15 * UI_DPI_FAC, ar->winy - UI_TIME_SCRUB_MARGIN_Y);
-    UI_view2d_draw_scale_y__values(ar, v2d, &rect, TH_TEXT);
+    BLI_rcti_init(
+        &rect, 0, 15 * UI_DPI_FAC, 15 * UI_DPI_FAC, region->winy - UI_TIME_SCRUB_MARGIN_Y);
+    UI_view2d_draw_scale_y__values(region, v2d, &rect, TH_TEXT);
   }
 }
 
-static void dopesheet_region_draw(const bContext *C, ARegion *ar)
+static void dopesheet_region_draw(const bContext *C, ARegion *region)
 {
   Scene *scene = CTX_data_scene(C);
   SpaceClip *sc = CTX_wm_space_clip(C);
   MovieClip *clip = ED_space_clip_get_clip(sc);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   View2DScrollers *scrollers;
   short cfra_flag = 0;
 
@@ -1111,7 +1112,7 @@ static void dopesheet_region_draw(const bContext *C, ARegion *ar)
   UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, sc->flag & SC_SHOW_SECONDS);
 
   /* data... */
-  clip_draw_dopesheet_main(sc, ar, scene);
+  clip_draw_dopesheet_main(sc, region, scene);
 
   /* current frame indicator line */
   if (sc->flag & SC_SHOW_SECONDS) {
@@ -1123,7 +1124,7 @@ static void dopesheet_region_draw(const bContext *C, ARegion *ar)
   UI_view2d_view_restore(C);
 
   /* time-scrubbing */
-  ED_time_scrub_draw(ar, scene, sc->flag & SC_SHOW_SECONDS, true);
+  ED_time_scrub_draw(region, scene, sc->flag & SC_SHOW_SECONDS, true);
 
   /* scrollers */
   scrollers = UI_view2d_scrollers_calc(v2d, NULL);
@@ -1131,21 +1132,21 @@ static void dopesheet_region_draw(const bContext *C, ARegion *ar)
   UI_view2d_scrollers_free(scrollers);
 }
 
-static void clip_preview_region_draw(const bContext *C, ARegion *ar)
+static void clip_preview_region_draw(const bContext *C, ARegion *region)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
 
   if (sc->view == SC_VIEW_GRAPH) {
-    graph_region_draw(C, ar);
+    graph_region_draw(C, region);
   }
   else if (sc->view == SC_VIEW_DOPESHEET) {
-    dopesheet_region_draw(C, ar);
+    dopesheet_region_draw(C, region);
   }
 }
 
 static void clip_preview_region_listener(wmWindow *UNUSED(win),
                                          ScrArea *UNUSED(sa),
-                                         ARegion *UNUSED(ar),
+                                         ARegion *UNUSED(region),
                                          wmNotifier *UNUSED(wmn),
                                          const Scene *UNUSED(scene))
 {
@@ -1153,24 +1154,24 @@ static void clip_preview_region_listener(wmWindow *UNUSED(win),
 
 /****************** channels region ******************/
 
-static void clip_channels_region_init(wmWindowManager *wm, ARegion *ar)
+static void clip_channels_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
   /* ensure the 2d view sync works - main region has bottom scroller */
-  ar->v2d.scroll = V2D_SCROLL_BOTTOM;
+  region->v2d.scroll = V2D_SCROLL_BOTTOM;
 
-  UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_LIST, ar->winx, ar->winy);
+  UI_view2d_region_reinit(&region->v2d, V2D_COMMONVIEW_LIST, region->winx, region->winy);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip Dopesheet Editor", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 }
 
-static void clip_channels_region_draw(const bContext *C, ARegion *ar)
+static void clip_channels_region_draw(const bContext *C, ARegion *region)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
   MovieClip *clip = ED_space_clip_get_clip(sc);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   if (clip) {
     BKE_tracking_dopesheet_update(&clip->tracking);
@@ -1183,7 +1184,7 @@ static void clip_channels_region_draw(const bContext *C, ARegion *ar)
   UI_view2d_view_ortho(v2d);
 
   /* data... */
-  clip_draw_dopesheet_channels(C, ar);
+  clip_draw_dopesheet_channels(C, region);
 
   /* reset view matrix */
   UI_view2d_view_restore(C);
@@ -1191,7 +1192,7 @@ static void clip_channels_region_draw(const bContext *C, ARegion *ar)
 
 static void clip_channels_region_listener(wmWindow *UNUSED(win),
                                           ScrArea *UNUSED(sa),
-                                          ARegion *UNUSED(ar),
+                                          ARegion *UNUSED(region),
                                           wmNotifier *UNUSED(wmn),
                                           const Scene *UNUSED(scene))
 {
@@ -1200,19 +1201,19 @@ static void clip_channels_region_listener(wmWindow *UNUSED(win),
 /****************** header region ******************/
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void clip_header_region_init(wmWindowManager *UNUSED(wm), ARegion *ar)
+static void clip_header_region_init(wmWindowManager *UNUSED(wm), ARegion *region)
 {
-  ED_region_header_init(ar);
+  ED_region_header_init(region);
 }
 
-static void clip_header_region_draw(const bContext *C, ARegion *ar)
+static void clip_header_region_draw(const bContext *C, ARegion *region)
 {
-  ED_region_header(C, ar);
+  ED_region_header(C, region);
 }
 
 static void clip_header_region_listener(wmWindow *UNUSED(win),
                                         ScrArea *UNUSED(sa),
-                                        ARegion *ar,
+                                        ARegion *region,
                                         wmNotifier *wmn,
                                         const Scene *UNUSED(scene))
 {
@@ -1225,7 +1226,7 @@ static void clip_header_region_listener(wmWindow *UNUSED(win),
           /* TODO - should do this when in mask mode only but no data available */
           // if (sc->mode == SC_MODE_MASKEDIT)
           {
-            ED_region_tag_redraw(ar);
+            ED_region_tag_redraw(region);
             break;
           }
       }
@@ -1236,26 +1237,26 @@ static void clip_header_region_listener(wmWindow *UNUSED(win),
 /****************** tools region ******************/
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void clip_tools_region_init(wmWindowManager *wm, ARegion *ar)
+static void clip_tools_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
-  ED_region_panels_init(wm, ar);
+  ED_region_panels_init(wm, region);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void clip_tools_region_draw(const bContext *C, ARegion *ar)
+static void clip_tools_region_draw(const bContext *C, ARegion *region)
 {
-  ED_region_panels(C, ar);
+  ED_region_panels(C, region);
 }
 
 /****************** tool properties region ******************/
 
 static void clip_props_region_listener(wmWindow *UNUSED(win),
                                        ScrArea *UNUSED(sa),
-                                       ARegion *ar,
+                                       ARegion *region,
                                        wmNotifier *wmn,
                                        const Scene *UNUSED(scene))
 {
@@ -1263,22 +1264,22 @@ static void clip_props_region_listener(wmWindow *UNUSED(win),
   switch (wmn->category) {
     case NC_WM:
       if (wmn->data == ND_HISTORY) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_SCENE:
       if (wmn->data == ND_MODE) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_SPACE:
       if (wmn->data == ND_SPACE_CLIP) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_GPENCIL:
       if (wmn->action == NA_EDITED) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }
@@ -1287,28 +1288,28 @@ static void clip_props_region_listener(wmWindow *UNUSED(win),
 /****************** properties region ******************/
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void clip_properties_region_init(wmWindowManager *wm, ARegion *ar)
+static void clip_properties_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
-  ED_region_panels_init(wm, ar);
+  ED_region_panels_init(wm, region);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Clip", SPACE_CLIP, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void clip_properties_region_draw(const bContext *C, ARegion *ar)
+static void clip_properties_region_draw(const bContext *C, ARegion *region)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
 
   BKE_movieclip_update_scopes(sc->clip, &sc->user, &sc->scopes);
 
-  ED_region_panels(C, ar);
+  ED_region_panels(C, region);
 }
 
 static void clip_properties_region_listener(wmWindow *UNUSED(win),
                                             ScrArea *UNUSED(sa),
-                                            ARegion *ar,
+                                            ARegion *region,
                                             wmNotifier *wmn,
                                             const Scene *UNUSED(scene))
 {
@@ -1316,12 +1317,12 @@ static void clip_properties_region_listener(wmWindow *UNUSED(win),
   switch (wmn->category) {
     case NC_GPENCIL:
       if (ELEM(wmn->data, ND_DATA, ND_GPENCIL_EDITMODE)) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_BRUSH:
       if (wmn->action == NA_EDITED) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }
diff --git a/source/blender/editors/space_clip/tracking_ops.c b/source/blender/editors/space_clip/tracking_ops.c
index f1bce00ea0b..030b0625e32 100644
--- a/source/blender/editors/space_clip/tracking_ops.c
+++ b/source/blender/editors/space_clip/tracking_ops.c
@@ -108,12 +108,12 @@ static int add_marker_exec(bContext *C, wmOperator *op)
 static int add_marker_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   if (!RNA_struct_property_is_set(op->ptr, "location")) {
     /* If location is not set, use mouse positio nas default. */
     float co[2];
-    ED_clip_mouse_pos(sc, ar, event->mval, co);
+    ED_clip_mouse_pos(sc, region, event->mval, co);
     RNA_float_set_array(op->ptr, "location", co);
   }
 
@@ -169,13 +169,17 @@ static int add_marker_at_click_modal(bContext *C, wmOperator *UNUSED(op), const
     case LEFTMOUSE: {
       SpaceClip *sc = CTX_wm_space_clip(C);
       MovieClip *clip = ED_space_clip_get_clip(sc);
-      ARegion *ar = CTX_wm_region(C);
+      ARegion *region = CTX_wm_region(C);
       float pos[2];
 
       ED_workspace_status_text(C, NULL);
 
-      ED_clip_point_stable_pos(
-          sc, ar, event->x - ar->winrct.xmin, event->y - ar->winrct.ymin, &pos[0], &pos[1]);
+      ED_clip_point_stable_pos(sc,
+                               region,
+                               event->x - region->winrct.xmin,
+                               event->y - region->winrct.ymin,
+                               &pos[0],
+                               &pos[1]);
 
       if (!add_marker(C, pos[0], pos[1])) {
         return OPERATOR_CANCELLED;
@@ -544,7 +548,7 @@ MovieTrackingTrack *tracking_marker_check_slide(
 {
   const float distance_clip_squared = 12.0f * 12.0f;
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTrackingTrack *track;
@@ -566,7 +570,7 @@ MovieTrackingTrack *tracking_marker_check_slide(
     return NULL;
   }
 
-  ED_clip_mouse_pos(sc, ar, event->mval, co);
+  ED_clip_mouse_pos(sc, region, event->mval, co);
 
   track = tracksbase->first;
   while (track) {
@@ -670,7 +674,7 @@ MovieTrackingTrack *tracking_marker_check_slide(
 static void *slide_marker_customdata(bContext *C, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   MovieTrackingTrack *track;
   int width, height;
@@ -685,7 +689,7 @@ static void *slide_marker_customdata(bContext *C, const wmEvent *event)
     return NULL;
   }
 
-  ED_clip_mouse_pos(sc, ar, event->mval, co);
+  ED_clip_mouse_pos(sc, region, event->mval, co);
 
   track = tracking_marker_check_slide(C, event, &area, &action, &corner);
   if (track != NULL) {
@@ -770,7 +774,7 @@ static void free_slide_data(SlideMarkerData *data)
 static int slide_marker_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   SlideMarkerData *data = (SlideMarkerData *)op->customdata;
   float dx, dy, mdelta[2];
@@ -826,7 +830,7 @@ static int slide_marker_modal(bContext *C, wmOperator *op, const wmEvent *event)
           float start[2], end[2];
           float scale;
 
-          ED_clip_point_stable_pos(sc, ar, data->mval[0], data->mval[1], &start[0], &start[1]);
+          ED_clip_point_stable_pos(sc, region, data->mval[0], data->mval[1], &start[0], &start[1]);
 
           sub_v2_v2(start, data->old_pos);
 
@@ -842,7 +846,7 @@ static int slide_marker_modal(bContext *C, wmOperator *op, const wmEvent *event)
               mval[1] = event->mval[1];
             }
 
-            ED_clip_point_stable_pos(sc, ar, mval[0], mval[1], &end[0], &end[1]);
+            ED_clip_point_stable_pos(sc, region, mval[0], mval[1], &end[0], &end[1]);
 
             sub_v2_v2(end, data->old_pos);
             scale = len_v2(end) / len_v2(start);
@@ -896,7 +900,7 @@ static int slide_marker_modal(bContext *C, wmOperator *op, const wmEvent *event)
 
           sub_v2_v2v2(start, data->spos, data->old_pos);
 
-          ED_clip_point_stable_pos(sc, ar, mval[0], mval[1], &end[0], &end[1]);
+          ED_clip_point_stable_pos(sc, region, mval[0], mval[1], &end[0], &end[1]);
           sub_v2_v2(end, data->old_pos);
 
           if (len_squared_v2(start) != 0.0f) {
diff --git a/source/blender/editors/space_clip/tracking_ops_plane.c b/source/blender/editors/space_clip/tracking_ops_plane.c
index 03fe1c74e2a..ced51e4502a 100644
--- a/source/blender/editors/space_clip/tracking_ops_plane.c
+++ b/source/blender/editors/space_clip/tracking_ops_plane.c
@@ -126,7 +126,7 @@ static MovieTrackingPlaneTrack *tracking_plane_marker_check_slide(bContext *C,
 {
   const float distance_clip_squared = 12.0f * 12.0f;
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
   int width, height;
@@ -139,7 +139,7 @@ static MovieTrackingPlaneTrack *tracking_plane_marker_check_slide(bContext *C,
     return NULL;
   }
 
-  ED_clip_mouse_pos(sc, ar, event->mval, co);
+  ED_clip_mouse_pos(sc, region, event->mval, co);
 
   float min_distance_squared = FLT_MAX;
   int min_corner = -1;
@@ -174,7 +174,7 @@ static MovieTrackingPlaneTrack *tracking_plane_marker_check_slide(bContext *C,
 static void *slide_plane_marker_customdata(bContext *C, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   MovieTrackingPlaneTrack *plane_track;
   int width, height;
   float co[2];
@@ -187,7 +187,7 @@ static void *slide_plane_marker_customdata(bContext *C, const wmEvent *event)
     return NULL;
   }
 
-  ED_clip_mouse_pos(sc, ar, event->mval, co);
+  ED_clip_mouse_pos(sc, region, event->mval, co);
 
   plane_track = tracking_plane_marker_check_slide(C, event, &corner);
   if (plane_track) {
diff --git a/source/blender/editors/space_clip/tracking_select.c b/source/blender/editors/space_clip/tracking_select.c
index f6063b49005..36e529e47d0 100644
--- a/source/blender/editors/space_clip/tracking_select.c
+++ b/source/blender/editors/space_clip/tracking_select.c
@@ -407,7 +407,7 @@ static int select_exec(bContext *C, wmOperator *op)
 static int select_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   float co[2];
   const bool extend = RNA_boolean_get(op->ptr, "extend");
@@ -427,7 +427,7 @@ static int select_invoke(bContext *C, wmOperator *op, const wmEvent *event)
     }
   }
 
-  ED_clip_mouse_pos(sc, ar, event->mval, co);
+  ED_clip_mouse_pos(sc, region, event->mval, co);
   RNA_float_set_array(op->ptr, "location", co);
 
   return select_exec(C, op);
@@ -486,7 +486,7 @@ bool ED_clip_can_select(bContext *C)
 static int box_select_exec(bContext *C, wmOperator *op)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
@@ -502,8 +502,8 @@ static int box_select_exec(bContext *C, wmOperator *op)
   /* get rectangle from operator */
   WM_operator_properties_border_to_rcti(op, &rect);
 
-  ED_clip_point_stable_pos(sc, ar, rect.xmin, rect.ymin, &rectf.xmin, &rectf.ymin);
-  ED_clip_point_stable_pos(sc, ar, rect.xmax, rect.ymax, &rectf.xmax, &rectf.ymax);
+  ED_clip_point_stable_pos(sc, region, rect.xmin, rect.ymin, &rectf.xmin, &rectf.ymin);
+  ED_clip_point_stable_pos(sc, region, rect.xmax, rect.ymax, &rectf.xmax, &rectf.ymax);
 
   const eSelectOp sel_op = RNA_enum_get(op->ptr, "mode");
   const bool select = (sel_op != SEL_OP_SUB);
@@ -594,7 +594,7 @@ static int do_lasso_select_marker(bContext *C,
                                   bool select)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
@@ -619,7 +619,7 @@ static int do_lasso_select_marker(bContext *C,
         float screen_co[2];
 
         /* marker in screen coords */
-        ED_clip_point_stable_pos__reverse(sc, ar, marker->pos, screen_co);
+        ED_clip_point_stable_pos__reverse(sc, region, marker->pos, screen_co);
 
         if (BLI_rcti_isect_pt(&rect, screen_co[0], screen_co[1]) &&
             BLI_lasso_is_point_inside(mcords, moves, screen_co[0], screen_co[1], V2D_IS_CLIPPED)) {
@@ -647,7 +647,7 @@ static int do_lasso_select_marker(bContext *C,
         float screen_co[2];
 
         /* marker in screen coords */
-        ED_clip_point_stable_pos__reverse(sc, ar, plane_marker->corners[i], screen_co);
+        ED_clip_point_stable_pos__reverse(sc, region, plane_marker->corners[i], screen_co);
 
         if (BLI_rcti_isect_pt(&rect, screen_co[0], screen_co[1]) &&
             BLI_lasso_is_point_inside(mcords, moves, screen_co[0], screen_co[1], V2D_IS_CLIPPED)) {
@@ -739,7 +739,7 @@ static int marker_inside_ellipse(MovieTrackingMarker *marker, float offset[2], f
 static int circle_select_exec(bContext *C, wmOperator *op)
 {
   SpaceClip *sc = CTX_wm_space_clip(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   MovieClip *clip = ED_space_clip_get_clip(sc);
   MovieTracking *tracking = &clip->tracking;
@@ -767,12 +767,12 @@ static int circle_select_exec(bContext *C, wmOperator *op)
 
   /* compute ellipse and position in unified coordinates */
   ED_space_clip_get_size(sc, &width, &height);
-  ED_space_clip_get_zoom(sc, ar, &zoomx, &zoomy);
+  ED_space_clip_get_zoom(sc, region, &zoomx, &zoomy);
 
   ellipse[0] = width * zoomx / radius;
   ellipse[1] = height * zoomy / radius;
 
-  ED_clip_point_stable_pos(sc, ar, x, y, &offset[0], &offset[1]);
+  ED_clip_point_stable_pos(sc, region, x, y, &offset[0], &offset[1]);
 
   /* do selection */
   track = tracksbase->first;