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.

10 files changed, 233 insertions, 225 deletions

diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index 6d37d0d1b7e..148c1669b06 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -447,7 +447,7 @@ static void node_draw_frame_label(bNodeTree *ntree, bNode *node, const float asp
 }
 
 static void node_draw_frame(const bContext *C,
-                            ARegion *ar,
+                            ARegion *region,
                             SpaceNode *snode,
                             bNodeTree *ntree,
                             bNode *node,
@@ -459,7 +459,7 @@ static void node_draw_frame(const bContext *C,
   float alpha;
 
   /* skip if out of view */
-  if (BLI_rctf_isect(&node->totr, &ar->v2d.cur, NULL) == false) {
+  if (BLI_rctf_isect(&node->totr, &region->v2d.cur, NULL) == false) {
     UI_block_end(C, node->block);
     node->block = NULL;
     return;
@@ -569,7 +569,7 @@ static void node_draw_reroute_prepare(const bContext *UNUSED(C),
 }
 
 static void node_draw_reroute(const bContext *C,
-                              ARegion *ar,
+                              ARegion *region,
                               SpaceNode *UNUSED(snode),
                               bNodeTree *ntree,
                               bNode *node,
@@ -579,8 +579,8 @@ static void node_draw_reroute(const bContext *C,
   rctf *rct = &node->totr;
 
   /* skip if out of view */
-  if (node->totr.xmax < ar->v2d.cur.xmin || node->totr.xmin > ar->v2d.cur.xmax ||
-      node->totr.ymax < ar->v2d.cur.ymin || node->totr.ymin > ar->v2d.cur.ymax) {
+  if (node->totr.xmax < region->v2d.cur.xmin || node->totr.xmin > region->v2d.cur.xmax ||
+      node->totr.ymax < region->v2d.cur.ymin || node->totr.ymin > region->v2d.cur.ymax) {
     UI_block_end(C, node->block);
     node->block = NULL;
     return;
@@ -638,7 +638,7 @@ static void node_draw_reroute(const bContext *C,
   /* only draw input socket. as they all are placed on the same position.
    * highlight also if node itself is selected, since we don't display the node body separately!
    */
-  node_draw_sockets(&ar->v2d, C, ntree, node, false, node->flag & SELECT);
+  node_draw_sockets(&region->v2d, C, ntree, node, false, node->flag & SELECT);
 
   UI_block_end(C, node->block);
   UI_block_draw(C, node->block);
@@ -3457,7 +3457,7 @@ void ED_init_node_socket_type_virtual(bNodeSocketType *stype)
 /* ************** Generic drawing ************** */
 
 void draw_nodespace_back_pix(const bContext *C,
-                             ARegion *ar,
+                             ARegion *region,
                              SpaceNode *snode,
                              bNodeInstanceKey parent_key)
 {
@@ -3471,9 +3471,9 @@ void draw_nodespace_back_pix(const bContext *C,
 
   GPU_matrix_push_projection();
   GPU_matrix_push();
-  wmOrtho2_region_pixelspace(ar);
+  wmOrtho2_region_pixelspace(region);
   GPU_matrix_identity_set();
-  ED_region_draw_cb_draw(C, ar, REGION_DRAW_BACKDROP);
+  ED_region_draw_cb_draw(C, region, REGION_DRAW_BACKDROP);
   GPU_matrix_pop_projection();
   GPU_matrix_pop();
 
@@ -3494,10 +3494,10 @@ void draw_nodespace_back_pix(const bContext *C,
     GPU_matrix_push();
 
     /* somehow the offset has to be calculated inverse */
-    wmOrtho2_region_pixelspace(ar);
+    wmOrtho2_region_pixelspace(region);
 
-    x = (ar->winx - snode->zoom * ibuf->x) / 2 + snode->xof;
-    y = (ar->winy - snode->zoom * ibuf->y) / 2 + snode->yof;
+    x = (region->winx - snode->zoom * ibuf->x) / 2 + snode->xof;
+    y = (region->winy - snode->zoom * ibuf->y) / 2 + snode->yof;
 
     if (ibuf->rect || ibuf->rect_float) {
       uchar *display_buffer = NULL;
diff --git a/source/blender/editors/space_node/node_add.c b/source/blender/editors/space_node/node_add.c
index 31b27adb226..644f2b2dc5b 100644
--- a/source/blender/editors/space_node/node_add.c
+++ b/source/blender/editors/space_node/node_add.c
@@ -215,7 +215,7 @@ static bNodeSocketLink *add_reroute_do_socket_section(bContext *C,
 static int add_reroute_exec(bContext *C, wmOperator *op)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNodeTree *ntree = snode->edittree;
   float mcoords[256][2];
   int i = 0;
@@ -226,7 +226,7 @@ static int add_reroute_exec(bContext *C, wmOperator *op)
 
     RNA_float_get_array(&itemptr, "loc", loc);
     UI_view2d_region_to_view(
-        &ar->v2d, (short)loc[0], (short)loc[1], &mcoords[i][0], &mcoords[i][1]);
+        &region->v2d, (short)loc[0], (short)loc[1], &mcoords[i][0], &mcoords[i][1]);
     i++;
     if (i >= 256) {
       break;
@@ -368,12 +368,12 @@ static int node_add_file_exec(bContext *C, wmOperator *op)
 
 static int node_add_file_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   SpaceNode *snode = CTX_wm_space_node(C);
 
   /* convert mouse coordinates to v2d space */
   UI_view2d_region_to_view(
-      &ar->v2d, event->mval[0], event->mval[1], &snode->cursor[0], &snode->cursor[1]);
+      &region->v2d, event->mval[0], event->mval[1], &snode->cursor[0], &snode->cursor[1]);
 
   snode->cursor[0] /= UI_DPI_FAC;
   snode->cursor[1] /= UI_DPI_FAC;
diff --git a/source/blender/editors/space_node/node_draw.c b/source/blender/editors/space_node/node_draw.c
index 91a42de05f2..35fbbad14b0 100644
--- a/source/blender/editors/space_node/node_draw.c
+++ b/source/blender/editors/space_node/node_draw.c
@@ -1085,7 +1085,7 @@ void node_draw_sockets(View2D *v2d,
 }
 
 static void node_draw_basis(const bContext *C,
-                            ARegion *ar,
+                            ARegion *region,
                             SpaceNode *snode,
                             bNodeTree *ntree,
                             bNode *node,
@@ -1099,7 +1099,7 @@ static void node_draw_basis(const bContext *C,
   int color_id = node_get_colorid(node);
   float color[4];
   char showname[128]; /* 128 used below */
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   /* skip if out of view */
   if (BLI_rctf_isect(&node->totr, &v2d->cur, NULL) == false) {
@@ -1296,7 +1296,7 @@ static void node_draw_basis(const bContext *C,
 }
 
 static void node_draw_hidden(const bContext *C,
-                             ARegion *ar,
+                             ARegion *region,
                              SpaceNode *snode,
                              bNodeTree *ntree,
                              bNode *node,
@@ -1308,7 +1308,7 @@ static void node_draw_hidden(const bContext *C,
   int color_id = node_get_colorid(node);
   float color[4];
   char showname[128]; /* 128 is used below */
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   float scale;
 
   UI_view2d_scale_get(v2d, &scale, NULL);
@@ -1392,7 +1392,7 @@ static void node_draw_hidden(const bContext *C,
 
   /* disable lines */
   if (node->flag & NODE_MUTED) {
-    node_draw_mute_line(&ar->v2d, snode, node);
+    node_draw_mute_line(&region->v2d, snode, node);
   }
 
   nodeLabel(ntree, node, showname, sizeof(showname));
@@ -1499,17 +1499,17 @@ void node_set_cursor(wmWindow *win, SpaceNode *snode, float cursor[2])
 }
 
 void node_draw_default(const bContext *C,
-                       ARegion *ar,
+                       ARegion *region,
                        SpaceNode *snode,
                        bNodeTree *ntree,
                        bNode *node,
                        bNodeInstanceKey key)
 {
   if (node->flag & NODE_HIDDEN) {
-    node_draw_hidden(C, ar, snode, ntree, node, key);
+    node_draw_hidden(C, region, snode, ntree, node, key);
   }
   else {
-    node_draw_basis(C, ar, snode, ntree, node, key);
+    node_draw_basis(C, region, snode, ntree, node, key);
   }
 }
 
@@ -1534,21 +1534,21 @@ void node_update_nodetree(const bContext *C, bNodeTree *ntree)
 }
 
 static void node_draw(const bContext *C,
-                      ARegion *ar,
+                      ARegion *region,
                       SpaceNode *snode,
                       bNodeTree *ntree,
                       bNode *node,
                       bNodeInstanceKey key)
 {
   if (node->typeinfo->draw_nodetype) {
-    node->typeinfo->draw_nodetype(C, ar, snode, ntree, node, key);
+    node->typeinfo->draw_nodetype(C, region, snode, ntree, node, key);
   }
 }
 
 #define USE_DRAW_TOT_UPDATE
 
 void node_draw_nodetree(const bContext *C,
-                        ARegion *ar,
+                        ARegion *region,
                         SpaceNode *snode,
                         bNodeTree *ntree,
                         bNodeInstanceKey parent_key)
@@ -1563,7 +1563,7 @@ void node_draw_nodetree(const bContext *C,
 
 #ifdef USE_DRAW_TOT_UPDATE
   if (ntree->nodes.first) {
-    BLI_rctf_init_minmax(&ar->v2d.tot);
+    BLI_rctf_init_minmax(&region->v2d.tot);
   }
 #endif
 
@@ -1574,7 +1574,7 @@ void node_draw_nodetree(const bContext *C,
 #ifdef USE_DRAW_TOT_UPDATE
     /* unrelated to background nodes, update the v2d->tot,
      * can be anywhere before we draw the scroll bars */
-    BLI_rctf_union(&ar->v2d.tot, &node->totr);
+    BLI_rctf_union(&region->v2d.tot, &node->totr);
 #endif
 
     if (!(node->flag & NODE_BACKGROUND)) {
@@ -1583,7 +1583,7 @@ void node_draw_nodetree(const bContext *C,
 
     key = BKE_node_instance_key(parent_key, ntree, node);
     node->nr = a; /* index of node in list, used for exec event code */
-    node_draw(C, ar, snode, ntree, node, key);
+    node_draw(C, region, snode, ntree, node, key);
   }
 
   /* node lines */
@@ -1591,7 +1591,7 @@ void node_draw_nodetree(const bContext *C,
   nodelink_batch_start(snode);
   for (link = ntree->links.first; link; link = link->next) {
     if (!nodeLinkIsHidden(link)) {
-      node_draw_link(&ar->v2d, snode, link);
+      node_draw_link(&region->v2d, snode, link);
     }
   }
   nodelink_batch_end(snode);
@@ -1606,7 +1606,7 @@ void node_draw_nodetree(const bContext *C,
 
     key = BKE_node_instance_key(parent_key, ntree, node);
     node->nr = a; /* index of node in list, used for exec event code */
-    node_draw(C, ar, snode, ntree, node, key);
+    node_draw(C, region, snode, ntree, node, key);
   }
 }
 
@@ -1621,21 +1621,21 @@ static void draw_tree_path(SpaceNode *snode)
   BLF_draw_default(1.5f * UI_UNIT_X, 1.5f * UI_UNIT_Y, 0.0f, info, sizeof(info));
 }
 
-static void snode_setup_v2d(SpaceNode *snode, ARegion *ar, const float center[2])
+static void snode_setup_v2d(SpaceNode *snode, ARegion *region, const float center[2])
 {
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   /* shift view to node tree center */
   UI_view2d_center_set(v2d, center[0], center[1]);
   UI_view2d_view_ortho(v2d);
 
   /* aspect+font, set each time */
-  snode->aspect = BLI_rctf_size_x(&v2d->cur) / (float)ar->winx;
+  snode->aspect = BLI_rctf_size_x(&v2d->cur) / (float)region->winx;
   // XXX snode->curfont = uiSetCurFont_ext(snode->aspect);
 }
 
 static void draw_nodetree(const bContext *C,
-                          ARegion *ar,
+                          ARegion *region,
                           bNodeTree *ntree,
                           bNodeInstanceKey parent_key)
 {
@@ -1644,13 +1644,13 @@ static void draw_nodetree(const bContext *C,
   node_uiblocks_init(C, ntree);
 
   node_update_nodetree(C, ntree);
-  node_draw_nodetree(C, ar, snode, ntree, parent_key);
+  node_draw_nodetree(C, region, snode, ntree, parent_key);
 }
 
 /* shade the parent node group and add a uiBlock to clip mouse events */
-static void draw_group_overlay(const bContext *C, ARegion *ar)
+static void draw_group_overlay(const bContext *C, ARegion *region)
 {
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   rctf rect = v2d->cur;
   uiBlock *block;
   float color[4];
@@ -1664,18 +1664,18 @@ static void draw_group_overlay(const bContext *C, ARegion *ar)
   GPU_blend(false);
 
   /* set the block bounds to clip mouse events from underlying nodes */
-  block = UI_block_begin(C, ar, "node tree bounds block", UI_EMBOSS);
+  block = UI_block_begin(C, region, "node tree bounds block", UI_EMBOSS);
   UI_block_bounds_set_explicit(block, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
   UI_block_flag_enable(block, UI_BLOCK_CLIP_EVENTS);
   UI_block_end(C, block);
 }
 
-void drawnodespace(const bContext *C, ARegion *ar)
+void drawnodespace(const bContext *C, ARegion *region)
 {
   wmWindow *win = CTX_wm_window(C);
   View2DScrollers *scrollers;
   SpaceNode *snode = CTX_wm_space_node(C);
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   UI_ThemeClearColor(TH_BACK);
   GPU_clear(GPU_COLOR_BIT);
@@ -1683,9 +1683,9 @@ void drawnodespace(const bContext *C, ARegion *ar)
   UI_view2d_view_ortho(v2d);
 
   /* XXX snode->cursor set in coordspace for placing new nodes, used for drawing noodles too */
-  UI_view2d_region_to_view(&ar->v2d,
-                           win->eventstate->x - ar->winrct.xmin,
-                           win->eventstate->y - ar->winrct.ymin,
+  UI_view2d_region_to_view(&region->v2d,
+                           win->eventstate->x - region->winrct.xmin,
+                           win->eventstate->y - region->winrct.ymin,
                            &snode->cursor[0],
                            &snode->cursor[1]);
   snode->cursor[0] /= UI_DPI_FAC;
@@ -1693,7 +1693,7 @@ void drawnodespace(const bContext *C, ARegion *ar)
 
   int grid_levels = UI_GetThemeValueType(TH_NODE_GRID_LEVELS, SPACE_NODE);
 
-  ED_region_draw_cb_draw(C, ar, REGION_DRAW_PRE_VIEW);
+  ED_region_draw_cb_draw(C, region, REGION_DRAW_PRE_VIEW);
 
   /* only set once */
   GPU_blend_set_func_separate(
@@ -1741,18 +1741,18 @@ void drawnodespace(const bContext *C, ARegion *ar)
     for (curdepth = depth; curdepth > 0; path = path->next, curdepth--) {
       ntree = path->nodetree;
       if (ntree) {
-        snode_setup_v2d(snode, ar, path->view_center);
+        snode_setup_v2d(snode, region, path->view_center);
 
-        draw_nodetree(C, ar, ntree, path->parent_key);
+        draw_nodetree(C, region, ntree, path->parent_key);
 
-        draw_group_overlay(C, ar);
+        draw_group_overlay(C, region);
       }
     }
 
     /* top-level edit tree */
     ntree = path->nodetree;
     if (ntree) {
-      snode_setup_v2d(snode, ar, center);
+      snode_setup_v2d(snode, region, center);
 
       /* grid, uses theme color based on node path depth */
       UI_view2d_multi_grid_draw(v2d,
@@ -1762,7 +1762,7 @@ void drawnodespace(const bContext *C, ARegion *ar)
                                 grid_levels);
 
       /* backdrop */
-      draw_nodespace_back_pix(C, ar, snode, path->parent_key);
+      draw_nodespace_back_pix(C, region, snode, path->parent_key);
 
       {
         float original_proj[4][4];
@@ -1771,15 +1771,15 @@ void drawnodespace(const bContext *C, ARegion *ar)
         GPU_matrix_push();
         GPU_matrix_identity_set();
 
-        wmOrtho2_pixelspace(ar->winx, ar->winy);
+        wmOrtho2_pixelspace(region->winx, region->winy);
 
-        WM_gizmomap_draw(ar->gizmo_map, C, WM_GIZMOMAP_DRAWSTEP_2D);
+        WM_gizmomap_draw(region->gizmo_map, C, WM_GIZMOMAP_DRAWSTEP_2D);
 
         GPU_matrix_pop();
         GPU_matrix_projection_set(original_proj);
       }
 
-      draw_nodetree(C, ar, ntree, path->parent_key);
+      draw_nodetree(C, region, ntree, path->parent_key);
     }
 
     /* temporary links */
@@ -1803,10 +1803,10 @@ void drawnodespace(const bContext *C, ARegion *ar)
     UI_view2d_multi_grid_draw(v2d, TH_BACK, ED_node_grid_size(), NODE_GRID_STEPS, grid_levels);
 
     /* backdrop */
-    draw_nodespace_back_pix(C, ar, snode, NODE_INSTANCE_KEY_NONE);
+    draw_nodespace_back_pix(C, region, snode, NODE_INSTANCE_KEY_NONE);
   }
 
-  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);
diff --git a/source/blender/editors/space_node/node_edit.c b/source/blender/editors/space_node/node_edit.c
index a690aa75e3c..025de1c898c 100644
--- a/source/blender/editors/space_node/node_edit.c
+++ b/source/blender/editors/space_node/node_edit.c
@@ -920,7 +920,7 @@ static void node_resize_exit(bContext *C, wmOperator *op, bool cancel)
 static int node_resize_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNode *node = nodeGetActive(snode->edittree);
   NodeSizeWidget *nsw = op->customdata;
   float mx, my, dx, dy;
@@ -928,7 +928,7 @@ static int node_resize_modal(bContext *C, wmOperator *op, const wmEvent *event)
   switch (event->type) {
     case MOUSEMOVE:
 
-      UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &mx, &my);
+      UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &mx, &my);
       dx = (mx - nsw->mxstart) / UI_DPI_FAC;
       dy = (my - nsw->mystart) / UI_DPI_FAC;
 
@@ -994,7 +994,7 @@ static int node_resize_modal(bContext *C, wmOperator *op, const wmEvent *event)
         }
       }
 
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
 
       break;
 
@@ -1009,7 +1009,7 @@ static int node_resize_modal(bContext *C, wmOperator *op, const wmEvent *event)
       }
       else if (event->val == KM_PRESS) {
         node_resize_exit(C, op, true);
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
 
         return OPERATOR_CANCELLED;
       }
@@ -1022,7 +1022,7 @@ static int node_resize_modal(bContext *C, wmOperator *op, const wmEvent *event)
 static int node_resize_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNode *node = nodeGetActive(snode->edittree);
   int dir;
 
@@ -1030,7 +1030,7 @@ static int node_resize_invoke(bContext *C, wmOperator *op, const wmEvent *event)
     float cursor[2];
 
     /* convert mouse coordinates to v2d space */
-    UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &cursor[0], &cursor[1]);
+    UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &cursor[0], &cursor[1]);
     dir = node->typeinfo->resize_area_func(node, cursor[0], cursor[1]);
     if (dir != 0) {
       node_resize_init(C, op, event, node, dir);
@@ -2598,7 +2598,7 @@ void NODE_OT_shader_script_update(wmOperatorType *ot)
 /* ********************** Viewer border ******************/
 
 static void viewer_border_corner_to_backdrop(SpaceNode *snode,
-                                             ARegion *ar,
+                                             ARegion *region,
                                              int x,
                                              int y,
                                              int backdrop_width,
@@ -2611,8 +2611,8 @@ static void viewer_border_corner_to_backdrop(SpaceNode *snode,
   bufx = backdrop_width * snode->zoom;
   bufy = backdrop_height * snode->zoom;
 
-  *fx = (bufx > 0.0f ? ((float)x - 0.5f * ar->winx - snode->xof) / bufx + 0.5f : 0.0f);
-  *fy = (bufy > 0.0f ? ((float)y - 0.5f * ar->winy - snode->yof) / bufy + 0.5f : 0.0f);
+  *fx = (bufx > 0.0f ? ((float)x - 0.5f * region->winx - snode->xof) / bufx + 0.5f : 0.0f);
+  *fy = (bufy > 0.0f ? ((float)y - 0.5f * region->winy - snode->yof) / bufy + 0.5f : 0.0f);
 }
 
 static int viewer_border_exec(bContext *C, wmOperator *op)
@@ -2628,7 +2628,7 @@ static int viewer_border_exec(bContext *C, wmOperator *op)
   ibuf = BKE_image_acquire_ibuf(ima, NULL, &lock);
 
   if (ibuf) {
-    ARegion *ar = CTX_wm_region(C);
+    ARegion *region = CTX_wm_region(C);
     SpaceNode *snode = CTX_wm_space_node(C);
     bNodeTree *btree = snode->nodetree;
     rcti rect;
@@ -2639,10 +2639,10 @@ static int viewer_border_exec(bContext *C, wmOperator *op)
 
     /* convert border to unified space within backdrop image */
     viewer_border_corner_to_backdrop(
-        snode, ar, rect.xmin, rect.ymin, ibuf->x, ibuf->y, &rectf.xmin, &rectf.ymin);
+        snode, region, rect.xmin, rect.ymin, ibuf->x, ibuf->y, &rectf.xmin, &rectf.ymin);
 
     viewer_border_corner_to_backdrop(
-        snode, ar, rect.xmax, rect.ymax, ibuf->x, ibuf->y, &rectf.xmax, &rectf.ymax);
+        snode, region, rect.xmax, rect.ymax, ibuf->x, ibuf->y, &rectf.xmax, &rectf.ymax);
 
     /* clamp coordinates */
     rectf.xmin = max_ff(rectf.xmin, 0.0f);
diff --git a/source/blender/editors/space_node/node_gizmo.c b/source/blender/editors/space_node/node_gizmo.c
index ad959570acd..3048c14dddb 100644
--- a/source/blender/editors/space_node/node_gizmo.c
+++ b/source/blender/editors/space_node/node_gizmo.c
@@ -48,26 +48,26 @@
  * \{ */
 
 static void node_gizmo_calc_matrix_space(const SpaceNode *snode,
-                                         const ARegion *ar,
+                                         const ARegion *region,
                                          float matrix_space[4][4])
 {
   unit_m4(matrix_space);
   mul_v3_fl(matrix_space[0], snode->zoom);
   mul_v3_fl(matrix_space[1], snode->zoom);
-  matrix_space[3][0] = (ar->winx / 2) + snode->xof;
-  matrix_space[3][1] = (ar->winy / 2) + snode->yof;
+  matrix_space[3][0] = (region->winx / 2) + snode->xof;
+  matrix_space[3][1] = (region->winy / 2) + snode->yof;
 }
 
 static void node_gizmo_calc_matrix_space_with_image_dims(const SpaceNode *snode,
-                                                         const ARegion *ar,
+                                                         const ARegion *region,
                                                          const float image_dims[2],
                                                          float matrix_space[4][4])
 {
   unit_m4(matrix_space);
   mul_v3_fl(matrix_space[0], snode->zoom * image_dims[0]);
   mul_v3_fl(matrix_space[1], snode->zoom * image_dims[1]);
-  matrix_space[3][0] = ((ar->winx / 2) + snode->xof) - ((image_dims[0] / 2.0f) * snode->zoom);
-  matrix_space[3][1] = ((ar->winy / 2) + snode->yof) - ((image_dims[1] / 2.0f) * snode->zoom);
+  matrix_space[3][0] = ((region->winx / 2) + snode->xof) - ((image_dims[0] / 2.0f) * snode->zoom);
+  matrix_space[3][1] = ((region->winy / 2) + snode->yof) - ((image_dims[1] / 2.0f) * snode->zoom);
 }
 
 /** \} */
@@ -138,9 +138,9 @@ static void WIDGETGROUP_node_transform_refresh(const bContext *C, wmGizmoGroup *
 {
   Main *bmain = CTX_data_main(C);
   wmGizmo *cage = ((wmGizmoWrapper *)gzgroup->customdata)->gizmo;
-  const ARegion *ar = CTX_wm_region(C);
+  const ARegion *region = CTX_wm_region(C);
   /* center is always at the origin */
-  const float origin[3] = {ar->winx / 2, ar->winy / 2};
+  const float origin[3] = {region->winx / 2, region->winy / 2};
 
   void *lock;
   Image *ima = BKE_image_ensure_viewer(bmain, IMA_TYPE_COMPOSITE, "Viewer Node");
@@ -352,12 +352,12 @@ static void WIDGETGROUP_node_crop_setup(const bContext *UNUSED(C), wmGizmoGroup
 
 static void WIDGETGROUP_node_crop_draw_prepare(const bContext *C, wmGizmoGroup *gzgroup)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   wmGizmo *gz = gzgroup->gizmos.first;
 
   SpaceNode *snode = CTX_wm_space_node(C);
 
-  node_gizmo_calc_matrix_space(snode, ar, gz->matrix_space);
+  node_gizmo_calc_matrix_space(snode, region, gz->matrix_space);
 }
 
 static void WIDGETGROUP_node_crop_refresh(const bContext *C, wmGizmoGroup *gzgroup)
@@ -467,13 +467,13 @@ static void WIDGETGROUP_node_sbeam_setup(const bContext *UNUSED(C), wmGizmoGroup
 static void WIDGETGROUP_node_sbeam_draw_prepare(const bContext *C, wmGizmoGroup *gzgroup)
 {
   struct NodeSunBeamsWidgetGroup *sbeam_group = gzgroup->customdata;
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   wmGizmo *gz = gzgroup->gizmos.first;
 
   SpaceNode *snode = CTX_wm_space_node(C);
 
   node_gizmo_calc_matrix_space_with_image_dims(
-      snode, ar, sbeam_group->state.dims, gz->matrix_space);
+      snode, region, sbeam_group->state.dims, gz->matrix_space);
 }
 
 static void WIDGETGROUP_node_sbeam_refresh(const bContext *C, wmGizmoGroup *gzgroup)
@@ -575,12 +575,13 @@ static void WIDGETGROUP_node_corner_pin_setup(const bContext *UNUSED(C), wmGizmo
 static void WIDGETGROUP_node_corner_pin_draw_prepare(const bContext *C, wmGizmoGroup *gzgroup)
 {
   struct NodeCornerPinWidgetGroup *cpin_group = gzgroup->customdata;
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   SpaceNode *snode = CTX_wm_space_node(C);
 
   float matrix_space[4][4];
-  node_gizmo_calc_matrix_space_with_image_dims(snode, ar, cpin_group->state.dims, matrix_space);
+  node_gizmo_calc_matrix_space_with_image_dims(
+      snode, region, cpin_group->state.dims, matrix_space);
 
   for (int i = 0; i < 4; i++) {
     wmGizmo *gz = cpin_group->gizmos[i];
diff --git a/source/blender/editors/space_node/node_intern.h b/source/blender/editors/space_node/node_intern.h
index 1825396805c..c1aeca87d7b 100644
--- a/source/blender/editors/space_node/node_intern.h
+++ b/source/blender/editors/space_node/node_intern.h
@@ -63,7 +63,7 @@ int node_get_colorid(struct bNode *node);
 int node_get_resize_cursor(int directions);
 void node_draw_shadow(struct SpaceNode *snode, struct bNode *node, float radius, float alpha);
 void node_draw_default(const struct bContext *C,
-                       struct ARegion *ar,
+                       struct ARegion *region,
                        struct SpaceNode *snode,
                        struct bNodeTree *ntree,
                        struct bNode *node,
@@ -79,11 +79,11 @@ int node_select_area_default(struct bNode *node, int x, int y);
 int node_tweak_area_default(struct bNode *node, int x, int y);
 void node_update_nodetree(const struct bContext *C, struct bNodeTree *ntree);
 void node_draw_nodetree(const struct bContext *C,
-                        struct ARegion *ar,
+                        struct ARegion *region,
                         struct SpaceNode *snode,
                         struct bNodeTree *ntree,
                         bNodeInstanceKey parent_key);
-void drawnodespace(const bContext *C, ARegion *ar);
+void drawnodespace(const bContext *C, ARegion *region);
 
 void node_set_cursor(struct wmWindow *win, struct SpaceNode *snode, float cursor[2]);
 /* DPI scaled coords */
@@ -123,7 +123,7 @@ void NODE_OT_find_node(struct wmOperatorType *ot);
 /* node_view.c */
 int space_node_view_flag(struct bContext *C,
                          SpaceNode *snode,
-                         ARegion *ar,
+                         ARegion *region,
                          const int node_flag,
                          const int smooth_viewtx);
 
@@ -162,7 +162,7 @@ void node_draw_link_straight(View2D *v2d,
                              int th_col3);
 #endif
 void draw_nodespace_back_pix(const struct bContext *C,
-                             struct ARegion *ar,
+                             struct ARegion *region,
                              struct SpaceNode *snode,
                              bNodeInstanceKey parent_key);
 
diff --git a/source/blender/editors/space_node/node_relationships.c b/source/blender/editors/space_node/node_relationships.c
index 75937d8da4e..7556b6ebd06 100644
--- a/source/blender/editors/space_node/node_relationships.c
+++ b/source/blender/editors/space_node/node_relationships.c
@@ -750,17 +750,17 @@ static void node_link_find_socket(bContext *C, wmOperator *op, float cursor[2])
 static int node_link_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
   bNodeLinkDrag *nldrag = op->customdata;
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   float cursor[2];
 
-  UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &cursor[0], &cursor[1]);
+  UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &cursor[0], &cursor[1]);
 
   switch (event->type) {
     case MOUSEMOVE:
       node_link_find_socket(C, op, cursor);
 
       node_link_update_header(C, nldrag);
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       break;
 
     case LEFTMOUSE:
@@ -770,7 +770,7 @@ static int node_link_modal(bContext *C, wmOperator *op, const wmEvent *event)
         node_link_exit(C, op, true);
 
         ED_workspace_status_text(C, NULL);
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
         return OPERATOR_FINISHED;
       }
       break;
@@ -900,13 +900,13 @@ static int node_link_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   Main *bmain = CTX_data_main(C);
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNodeLinkDrag *nldrag;
   float cursor[2];
 
   bool detach = RNA_boolean_get(op->ptr, "detach");
 
-  UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &cursor[0], &cursor[1]);
+  UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &cursor[0], &cursor[1]);
 
   ED_preview_kill_jobs(CTX_wm_manager(C), bmain);
 
@@ -1023,7 +1023,7 @@ static int cut_links_exec(bContext *C, wmOperator *op)
 {
   Main *bmain = CTX_data_main(C);
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   float mcoords[256][2];
   int i = 0;
   bool do_tag_update = false;
@@ -1032,7 +1032,8 @@ static int cut_links_exec(bContext *C, wmOperator *op)
     float loc[2];
 
     RNA_float_get_array(&itemptr, "loc", loc);
-    UI_view2d_region_to_view(&ar->v2d, (int)loc[0], (int)loc[1], &mcoords[i][0], &mcoords[i][1]);
+    UI_view2d_region_to_view(
+        &region->v2d, (int)loc[0], (int)loc[1], &mcoords[i][0], &mcoords[i][1]);
     i++;
     if (i >= 256) {
       break;
@@ -1286,13 +1287,15 @@ void NODE_OT_join(wmOperatorType *ot)
 
 /* ****************** Attach ******************* */
 
-static bNode *node_find_frame_to_attach(ARegion *ar, const bNodeTree *ntree, const int mouse_xy[2])
+static bNode *node_find_frame_to_attach(ARegion *region,
+                                        const bNodeTree *ntree,
+                                        const int mouse_xy[2])
 {
   bNode *frame;
   float cursor[2];
 
   /* convert mouse coordinates to v2d space */
-  UI_view2d_region_to_view(&ar->v2d, UNPACK2(mouse_xy), &cursor[0], &cursor[1]);
+  UI_view2d_region_to_view(&region->v2d, UNPACK2(mouse_xy), &cursor[0], &cursor[1]);
 
   /* check nodes front to back */
   for (frame = ntree->nodes.last; frame; frame = frame->prev) {
@@ -1310,10 +1313,10 @@ static bNode *node_find_frame_to_attach(ARegion *ar, const bNodeTree *ntree, con
 
 static int node_attach_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent *event)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   SpaceNode *snode = CTX_wm_space_node(C);
   bNodeTree *ntree = snode->edittree;
-  bNode *frame = node_find_frame_to_attach(ar, ntree, event->mval);
+  bNode *frame = node_find_frame_to_attach(region, ntree, event->mval);
 
   if (frame) {
     bNode *node, *parent;
@@ -1704,7 +1707,7 @@ static bool node_link_insert_offset_chain_cb(bNode *fromnode,
 }
 
 static void node_link_insert_offset_ntree(NodeInsertOfsData *iofsd,
-                                          ARegion *ar,
+                                          ARegion *region,
                                           const int mouse_xy[2],
                                           const bool right_alignment)
 {
@@ -1730,7 +1733,7 @@ static void node_link_insert_offset_ntree(NodeInsertOfsData *iofsd,
 
   /* frame attachment wasn't handled yet
    * so we search the frame that the node will be attached to later */
-  insert->parent = node_find_frame_to_attach(ar, ntree, mouse_xy);
+  insert->parent = node_find_frame_to_attach(region, ntree, mouse_xy);
 
   /* this makes sure nodes are also correctly offset when inserting a node on top of a frame
    * without actually making it a part of the frame (because mouse isn't intersecting it)
diff --git a/source/blender/editors/space_node/node_select.c b/source/blender/editors/space_node/node_select.c
index e22ef389516..a2453cb0837 100644
--- a/source/blender/editors/space_node/node_select.c
+++ b/source/blender/editors/space_node/node_select.c
@@ -104,9 +104,9 @@ static bool is_position_over_node_or_socket(SpaceNode *snode, float mouse[2])
 static bool is_event_over_node_or_socket(bContext *C, const wmEvent *event)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   float mouse[2];
-  UI_view2d_region_to_view(&ar->v2d, event->mval[0], event->mval[1], &mouse[0], &mouse[1]);
+  UI_view2d_region_to_view(&region->v2d, event->mval[0], event->mval[1], &mouse[0], &mouse[1]);
   return is_position_over_node_or_socket(snode, mouse);
 }
 
@@ -436,7 +436,7 @@ static int node_mouse_select(bContext *C,
 {
   Main *bmain = CTX_data_main(C);
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNode *node, *tnode;
   bNodeSocket *sock = NULL;
   bNodeSocket *tsock;
@@ -454,7 +454,7 @@ static int node_mouse_select(bContext *C,
   }
 
   /* get mouse coordinates in view2d space */
-  UI_view2d_region_to_view(&ar->v2d, mval[0], mval[1], &cursor[0], &cursor[1]);
+  UI_view2d_region_to_view(&region->v2d, mval[0], mval[1], &cursor[0], &cursor[1]);
 
   /* first do socket selection, these generally overlap with nodes. */
   if (socket_select) {
@@ -610,11 +610,11 @@ void NODE_OT_select(wmOperatorType *ot)
 static int node_box_select_exec(bContext *C, wmOperator *op)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   rctf rectf;
 
   WM_operator_properties_border_to_rctf(op, &rectf);
-  UI_view2d_region_to_view_rctf(&ar->v2d, &rectf, &rectf);
+  UI_view2d_region_to_view_rctf(&region->v2d, &rectf, &rectf);
 
   const eSelectOp sel_op = RNA_enum_get(op->ptr, "mode");
   const bool select = (sel_op != SEL_OP_SUB);
@@ -692,13 +692,14 @@ void NODE_OT_select_box(wmOperatorType *ot)
 static int node_circleselect_exec(bContext *C, wmOperator *op)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNode *node;
 
   int x, y, radius;
   float offset[2];
 
-  float zoom = (float)(BLI_rcti_size_x(&ar->winrct)) / (float)(BLI_rctf_size_x(&ar->v2d.cur));
+  float zoom = (float)(BLI_rcti_size_x(&region->winrct)) /
+               (float)(BLI_rctf_size_x(&region->v2d.cur));
 
   const eSelectOp sel_op = ED_select_op_modal(RNA_enum_get(op->ptr, "mode"),
                                               WM_gesture_is_modal_first(op->customdata));
@@ -712,7 +713,7 @@ static int node_circleselect_exec(bContext *C, wmOperator *op)
   y = RNA_int_get(op->ptr, "y");
   radius = RNA_int_get(op->ptr, "radius");
 
-  UI_view2d_region_to_view(&ar->v2d, x, y, &offset[0], &offset[1]);
+  UI_view2d_region_to_view(&region->v2d, x, y, &offset[0], &offset[1]);
 
   for (node = snode->edittree->nodes.first; node; node = node->next) {
     if (BLI_rctf_isect_circle(&node->totr, offset, radius / zoom)) {
@@ -769,7 +770,7 @@ static bool do_lasso_select_node(bContext *C, const int mcords[][2], short moves
   SpaceNode *snode = CTX_wm_space_node(C);
   bNode *node;
 
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   rcti rect;
   bool changed = false;
@@ -794,7 +795,8 @@ static bool do_lasso_select_node(bContext *C, const int mcords[][2], short moves
     const float cent[2] = {BLI_rctf_cent_x(&node->totr), BLI_rctf_cent_y(&node->totr)};
 
     /* marker in screen coords */
-    if (UI_view2d_view_to_region_clip(&ar->v2d, cent[0], cent[1], &screen_co[0], &screen_co[1]) &&
+    if (UI_view2d_view_to_region_clip(
+            &region->v2d, cent[0], cent[1], &screen_co[0], &screen_co[1]) &&
         BLI_rcti_isect_pt(&rect, screen_co[0], screen_co[1]) &&
         BLI_lasso_is_point_inside(mcords, moves, screen_co[0], screen_co[1], INT_MAX)) {
       nodeSetSelected(node, select);
@@ -1004,7 +1006,7 @@ void NODE_OT_select_linked_from(wmOperatorType *ot)
 static int node_select_same_type_step_exec(bContext *C, wmOperator *op)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   bNode **node_array;
   bNode *active = nodeGetActive(snode->edittree);
   int totnodes;
@@ -1072,10 +1074,10 @@ static int node_select_same_type_step_exec(bContext *C, wmOperator *op)
     node_select_single(C, active);
 
     /* is note outside view? */
-    if (active->totr.xmax < ar->v2d.cur.xmin || active->totr.xmin > ar->v2d.cur.xmax ||
-        active->totr.ymax < ar->v2d.cur.ymin || active->totr.ymin > ar->v2d.cur.ymax) {
+    if (active->totr.xmax < region->v2d.cur.xmin || active->totr.xmin > region->v2d.cur.xmax ||
+        active->totr.ymax < region->v2d.cur.ymin || active->totr.ymin > region->v2d.cur.ymax) {
       const int smooth_viewtx = WM_operator_smooth_viewtx_get(op);
-      space_node_view_flag(C, snode, ar, NODE_SELECT, smooth_viewtx);
+      space_node_view_flag(C, snode, region, NODE_SELECT, smooth_viewtx);
     }
   }
 
@@ -1142,25 +1144,25 @@ static void node_find_call_cb(struct bContext *C, void *UNUSED(arg1), void *arg2
   bNode *active = arg2;
 
   if (active) {
-    ARegion *ar = CTX_wm_region(C);
+    ARegion *region = CTX_wm_region(C);
     node_select_single(C, active);
 
     /* is note outside view? */
-    if (active->totr.xmax < ar->v2d.cur.xmin || active->totr.xmin > ar->v2d.cur.xmax ||
-        active->totr.ymax < ar->v2d.cur.ymin || active->totr.ymin > ar->v2d.cur.ymax) {
-      space_node_view_flag(C, snode, ar, NODE_SELECT, U.smooth_viewtx);
+    if (active->totr.xmax < region->v2d.cur.xmin || active->totr.xmin > region->v2d.cur.xmax ||
+        active->totr.ymax < region->v2d.cur.ymin || active->totr.ymin > region->v2d.cur.ymax) {
+      space_node_view_flag(C, snode, region, NODE_SELECT, U.smooth_viewtx);
     }
   }
 }
 
-static uiBlock *node_find_menu(bContext *C, ARegion *ar, void *arg_op)
+static uiBlock *node_find_menu(bContext *C, ARegion *region, void *arg_op)
 {
   static char search[256] = "";
   uiBlock *block;
   uiBut *but;
   wmOperator *op = (wmOperator *)arg_op;
 
-  block = UI_block_begin(C, ar, "_popup", UI_EMBOSS);
+  block = UI_block_begin(C, region, "_popup", UI_EMBOSS);
   UI_block_flag_enable(block, UI_BLOCK_LOOP | UI_BLOCK_MOVEMOUSE_QUIT | UI_BLOCK_SEARCH_MENU);
   UI_block_theme_style_set(block, UI_BLOCK_THEME_STYLE_POPUP);
 
diff --git a/source/blender/editors/space_node/node_view.c b/source/blender/editors/space_node/node_view.c
index 9a13032b0bc..7023a3ebd18 100644
--- a/source/blender/editors/space_node/node_view.c
+++ b/source/blender/editors/space_node/node_view.c
@@ -58,7 +58,7 @@
 /* **************** View All Operator ************** */
 
 int space_node_view_flag(
-    bContext *C, SpaceNode *snode, ARegion *ar, const int node_flag, const int smooth_viewtx)
+    bContext *C, SpaceNode *snode, ARegion *region, const int node_flag, const int smooth_viewtx)
 {
   bNode *node;
   rctf cur_new;
@@ -67,8 +67,8 @@ int space_node_view_flag(
   int tot = 0;
   bool has_frame = false;
 
-  oldwidth = BLI_rctf_size_x(&ar->v2d.cur);
-  oldheight = BLI_rctf_size_y(&ar->v2d.cur);
+  oldwidth = BLI_rctf_size_x(&region->v2d.cur);
+  oldheight = BLI_rctf_size_y(&region->v2d.cur);
 
   oldasp = oldwidth / oldheight;
 
@@ -114,7 +114,7 @@ int space_node_view_flag(
       BLI_rctf_scale(&cur_new, 1.1f);
     }
 
-    UI_view2d_smooth_view(C, ar, &cur_new, smooth_viewtx);
+    UI_view2d_smooth_view(C, region, &cur_new, smooth_viewtx);
   }
 
   return (tot != 0);
@@ -122,7 +122,7 @@ int space_node_view_flag(
 
 static int node_view_all_exec(bContext *C, wmOperator *op)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   SpaceNode *snode = CTX_wm_space_node(C);
   const int smooth_viewtx = WM_operator_smooth_viewtx_get(op);
 
@@ -130,7 +130,7 @@ static int node_view_all_exec(bContext *C, wmOperator *op)
   snode->xof = 0;
   snode->yof = 0;
 
-  if (space_node_view_flag(C, snode, ar, 0, smooth_viewtx)) {
+  if (space_node_view_flag(C, snode, region, 0, smooth_viewtx)) {
     return OPERATOR_FINISHED;
   }
   else {
@@ -155,11 +155,11 @@ void NODE_OT_view_all(wmOperatorType *ot)
 
 static int node_view_selected_exec(bContext *C, wmOperator *op)
 {
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   SpaceNode *snode = CTX_wm_space_node(C);
   const int smooth_viewtx = WM_operator_smooth_viewtx_get(op);
 
-  if (space_node_view_flag(C, snode, ar, NODE_SELECT, smooth_viewtx)) {
+  if (space_node_view_flag(C, snode, region, NODE_SELECT, smooth_viewtx)) {
     return OPERATOR_FINISHED;
   }
   else {
@@ -192,7 +192,7 @@ typedef struct NodeViewMove {
 static int snode_bg_viewmove_modal(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   NodeViewMove *nvm = op->customdata;
 
   switch (event->type) {
@@ -207,7 +207,7 @@ static int snode_bg_viewmove_modal(bContext *C, wmOperator *op, const wmEvent *e
       CLAMP(snode->xof, nvm->xmin, nvm->xmax);
       CLAMP(snode->yof, nvm->ymin, nvm->ymax);
 
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       WM_main_add_notifier(NC_NODE | ND_DISPLAY, NULL);
 
       break;
@@ -230,7 +230,7 @@ static int snode_bg_viewmove_invoke(bContext *C, wmOperator *op, const wmEvent *
 {
   Main *bmain = CTX_data_main(C);
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   NodeViewMove *nvm;
   Image *ima;
   ImBuf *ibuf;
@@ -251,10 +251,10 @@ static int snode_bg_viewmove_invoke(bContext *C, wmOperator *op, const wmEvent *
   nvm->mvalo[0] = event->mval[0];
   nvm->mvalo[1] = event->mval[1];
 
-  nvm->xmin = -(ar->winx / 2) - (ibuf->x * (0.5f * snode->zoom)) + pad;
-  nvm->xmax = (ar->winx / 2) + (ibuf->x * (0.5f * snode->zoom)) - pad;
-  nvm->ymin = -(ar->winy / 2) - (ibuf->y * (0.5f * snode->zoom)) + pad;
-  nvm->ymax = (ar->winy / 2) + (ibuf->y * (0.5f * snode->zoom)) - pad;
+  nvm->xmin = -(region->winx / 2) - (ibuf->x * (0.5f * snode->zoom)) + pad;
+  nvm->xmax = (region->winx / 2) + (ibuf->x * (0.5f * snode->zoom)) - pad;
+  nvm->ymin = -(region->winy / 2) - (ibuf->y * (0.5f * snode->zoom)) + pad;
+  nvm->ymax = (region->winy / 2) + (ibuf->y * (0.5f * snode->zoom)) - pad;
 
   BKE_image_release_ibuf(ima, ibuf, lock);
 
@@ -290,11 +290,11 @@ void NODE_OT_backimage_move(wmOperatorType *ot)
 static int backimage_zoom_exec(bContext *C, wmOperator *op)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   float fac = RNA_float_get(op->ptr, "factor");
 
   snode->zoom *= fac;
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
   WM_main_add_notifier(NC_NODE | ND_DISPLAY, NULL);
 
   return OPERATOR_FINISHED;
@@ -323,7 +323,7 @@ static int backimage_fit_exec(bContext *C, wmOperator *UNUSED(op))
 {
   Main *bmain = CTX_data_main(C);
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
 
   Image *ima;
   ImBuf *ibuf;
@@ -342,8 +342,8 @@ static int backimage_fit_exec(bContext *C, wmOperator *UNUSED(op))
     return OPERATOR_CANCELLED;
   }
 
-  facx = 1.0f * (ar->sizex - pad) / (ibuf->x * snode->zoom);
-  facy = 1.0f * (ar->sizey - pad) / (ibuf->y * snode->zoom);
+  facx = 1.0f * (region->sizex - pad) / (ibuf->x * snode->zoom);
+  facy = 1.0f * (region->sizey - pad) / (ibuf->y * snode->zoom);
 
   BKE_image_release_ibuf(ima, ibuf, lock);
 
@@ -352,7 +352,7 @@ static int backimage_fit_exec(bContext *C, wmOperator *UNUSED(op))
   snode->xof = 0;
   snode->yof = 0;
 
-  ED_region_tag_redraw(ar);
+  ED_region_tag_redraw(region);
   WM_main_add_notifier(NC_NODE | ND_DISPLAY, NULL);
 
   return OPERATOR_FINISHED;
@@ -396,14 +396,14 @@ typedef struct ImageSampleInfo {
   int color_manage;
 } ImageSampleInfo;
 
-static void sample_draw(const bContext *C, ARegion *ar, void *arg_info)
+static void sample_draw(const bContext *C, ARegion *region, void *arg_info)
 {
   Scene *scene = CTX_data_scene(C);
   ImageSampleInfo *info = arg_info;
 
   if (info->draw) {
     ED_image_draw_info(scene,
-                       ar,
+                       region,
                        info->color_manage,
                        false,
                        info->channels,
@@ -421,7 +421,7 @@ static void sample_draw(const bContext *C, ARegion *ar, void *arg_info)
  * And here we've got recursion in the comments tips...
  */
 bool ED_space_node_color_sample(
-    Main *bmain, SpaceNode *snode, ARegion *ar, int mval[2], float r_col[3])
+    Main *bmain, SpaceNode *snode, ARegion *region, int mval[2], float r_col[3])
 {
   void *lock;
   Image *ima;
@@ -445,8 +445,8 @@ bool ED_space_node_color_sample(
   /* map the mouse coords to the backdrop image space */
   bufx = ibuf->x * snode->zoom;
   bufy = ibuf->y * snode->zoom;
-  fx = (bufx > 0.0f ? ((float)mval[0] - 0.5f * ar->winx - snode->xof) / bufx + 0.5f : 0.0f);
-  fy = (bufy > 0.0f ? ((float)mval[1] - 0.5f * ar->winy - snode->yof) / bufy + 0.5f : 0.0f);
+  fx = (bufx > 0.0f ? ((float)mval[0] - 0.5f * region->winx - snode->xof) / bufx + 0.5f : 0.0f);
+  fy = (bufy > 0.0f ? ((float)mval[1] - 0.5f * region->winy - snode->yof) / bufy + 0.5f : 0.0f);
 
   if (fx >= 0.0f && fy >= 0.0f && fx < 1.0f && fy < 1.0f) {
     const float *fp;
@@ -479,7 +479,7 @@ static void sample_apply(bContext *C, wmOperator *op, const wmEvent *event)
 {
   Main *bmain = CTX_data_main(C);
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   ImageSampleInfo *info = op->customdata;
   void *lock;
   Image *ima;
@@ -500,8 +500,10 @@ static void sample_apply(bContext *C, wmOperator *op, const wmEvent *event)
   /* map the mouse coords to the backdrop image space */
   bufx = ibuf->x * snode->zoom;
   bufy = ibuf->y * snode->zoom;
-  fx = (bufx > 0.0f ? ((float)event->mval[0] - 0.5f * ar->winx - snode->xof) / bufx + 0.5f : 0.0f);
-  fy = (bufy > 0.0f ? ((float)event->mval[1] - 0.5f * ar->winy - snode->yof) / bufy + 0.5f : 0.0f);
+  fx = (bufx > 0.0f ? ((float)event->mval[0] - 0.5f * region->winx - snode->xof) / bufx + 0.5f :
+                      0.0f);
+  fy = (bufy > 0.0f ? ((float)event->mval[1] - 0.5f * region->winy - snode->yof) / bufy + 0.5f :
+                      0.0f);
 
   if (fx >= 0.0f && fy >= 0.0f && fx < 1.0f && fy < 1.0f) {
     const float *fp;
@@ -583,7 +585,7 @@ static void sample_exit(bContext *C, wmOperator *op)
 static int sample_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
   SpaceNode *snode = CTX_wm_space_node(C);
-  ARegion *ar = CTX_wm_region(C);
+  ARegion *region = CTX_wm_region(C);
   ImageSampleInfo *info;
 
   if (!ED_node_is_compositor(snode) || !(snode->flag & SNODE_BACKDRAW)) {
@@ -591,9 +593,9 @@ static int sample_invoke(bContext *C, wmOperator *op, const wmEvent *event)
   }
 
   info = MEM_callocN(sizeof(ImageSampleInfo), "ImageSampleInfo");
-  info->art = ar->type;
+  info->art = region->type;
   info->draw_handle = ED_region_draw_cb_activate(
-      ar->type, sample_draw, info, REGION_DRAW_POST_PIXEL);
+      region->type, sample_draw, info, REGION_DRAW_POST_PIXEL);
   op->customdata = info;
 
   sample_apply(C, op, event);
diff --git a/source/blender/editors/space_node/space_node.c b/source/blender/editors/space_node/space_node.c
index 6eab0dfff40..d3c7374e782 100644
--- a/source/blender/editors/space_node/space_node.c
+++ b/source/blender/editors/space_node/space_node.c
@@ -246,7 +246,7 @@ void snode_group_offset(SpaceNode *snode, float *x, float *y)
 
 static SpaceLink *node_new(const ScrArea *UNUSED(area), const Scene *UNUSED(scene))
 {
-  ARegion *ar;
+  ARegion *region;
   SpaceNode *snode;
 
   snode = MEM_callocN(sizeof(SpaceNode), "initnode");
@@ -265,53 +265,53 @@ static SpaceLink *node_new(const ScrArea *UNUSED(area), const Scene *UNUSED(scen
   NODE_TREE_TYPES_END;
 
   /* header */
-  ar = MEM_callocN(sizeof(ARegion), "header for node");
+  region = MEM_callocN(sizeof(ARegion), "header for node");
 
-  BLI_addtail(&snode->regionbase, ar);
-  ar->regiontype = RGN_TYPE_HEADER;
-  ar->alignment = (U.uiflag & USER_HEADER_BOTTOM) ? RGN_ALIGN_BOTTOM : RGN_ALIGN_TOP;
+  BLI_addtail(&snode->regionbase, region);
+  region->regiontype = RGN_TYPE_HEADER;
+  region->alignment = (U.uiflag & USER_HEADER_BOTTOM) ? RGN_ALIGN_BOTTOM : RGN_ALIGN_TOP;
 
   /* buttons/list view */
-  ar = MEM_callocN(sizeof(ARegion), "buttons for node");
+  region = MEM_callocN(sizeof(ARegion), "buttons for node");
 
-  BLI_addtail(&snode->regionbase, ar);
-  ar->regiontype = RGN_TYPE_UI;
-  ar->alignment = RGN_ALIGN_RIGHT;
+  BLI_addtail(&snode->regionbase, region);
+  region->regiontype = RGN_TYPE_UI;
+  region->alignment = RGN_ALIGN_RIGHT;
 
   /* toolbar */
-  ar = MEM_callocN(sizeof(ARegion), "node tools");
+  region = MEM_callocN(sizeof(ARegion), "node tools");
 
-  BLI_addtail(&snode->regionbase, ar);
-  ar->regiontype = RGN_TYPE_TOOLS;
-  ar->alignment = RGN_ALIGN_LEFT;
+  BLI_addtail(&snode->regionbase, region);
+  region->regiontype = RGN_TYPE_TOOLS;
+  region->alignment = RGN_ALIGN_LEFT;
 
-  ar->flag = RGN_FLAG_HIDDEN;
+  region->flag = RGN_FLAG_HIDDEN;
 
   /* main region */
-  ar = MEM_callocN(sizeof(ARegion), "main region for node");
+  region = MEM_callocN(sizeof(ARegion), "main region for node");
 
-  BLI_addtail(&snode->regionbase, ar);
-  ar->regiontype = RGN_TYPE_WINDOW;
+  BLI_addtail(&snode->regionbase, region);
+  region->regiontype = RGN_TYPE_WINDOW;
 
-  ar->v2d.tot.xmin = -12.8f * U.widget_unit;
-  ar->v2d.tot.ymin = -12.8f * U.widget_unit;
-  ar->v2d.tot.xmax = 38.4f * U.widget_unit;
-  ar->v2d.tot.ymax = 38.4f * U.widget_unit;
+  region->v2d.tot.xmin = -12.8f * U.widget_unit;
+  region->v2d.tot.ymin = -12.8f * U.widget_unit;
+  region->v2d.tot.xmax = 38.4f * U.widget_unit;
+  region->v2d.tot.ymax = 38.4f * U.widget_unit;
 
-  ar->v2d.cur = ar->v2d.tot;
+  region->v2d.cur = region->v2d.tot;
 
-  ar->v2d.min[0] = 1.0f;
-  ar->v2d.min[1] = 1.0f;
+  region->v2d.min[0] = 1.0f;
+  region->v2d.min[1] = 1.0f;
 
-  ar->v2d.max[0] = 32000.0f;
-  ar->v2d.max[1] = 32000.0f;
+  region->v2d.max[0] = 32000.0f;
+  region->v2d.max[1] = 32000.0f;
 
-  ar->v2d.minzoom = 0.09f;
-  ar->v2d.maxzoom = 2.31f;
+  region->v2d.minzoom = 0.09f;
+  region->v2d.maxzoom = 2.31f;
 
-  ar->v2d.scroll = (V2D_SCROLL_RIGHT | V2D_SCROLL_BOTTOM);
-  ar->v2d.keepzoom = V2D_LIMITZOOM | V2D_KEEPASPECT;
-  ar->v2d.keeptot = 0;
+  region->v2d.scroll = (V2D_SCROLL_RIGHT | V2D_SCROLL_BOTTOM);
+  region->v2d.keepzoom = V2D_LIMITZOOM | V2D_KEEPASPECT;
+  region->v2d.keeptot = 0;
 
   return (SpaceLink *)snode;
 }
@@ -347,11 +347,11 @@ static void node_area_listener(wmWindow *UNUSED(win),
     case NC_SCENE:
       switch (wmn->data) {
         case ND_NODES: {
-          ARegion *ar = BKE_area_find_region_type(sa, RGN_TYPE_WINDOW);
+          ARegion *region = BKE_area_find_region_type(sa, RGN_TYPE_WINDOW);
           bNodeTreePath *path = snode->treepath.last;
           /* shift view to node tree center */
-          if (ar && path) {
-            UI_view2d_center_set(&ar->v2d, path->view_center[0], path->view_center[1]);
+          if (region && path) {
+            UI_view2d_center_set(&region->v2d, path->view_center[0], path->view_center[1]);
           }
 
           ED_area_tag_refresh(sa);
@@ -554,45 +554,45 @@ static SpaceLink *node_duplicate(SpaceLink *sl)
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void node_buttons_region_init(wmWindowManager *wm, ARegion *ar)
+static void node_buttons_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, "Node Generic", SPACE_NODE, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void node_buttons_region_draw(const bContext *C, ARegion *ar)
+static void node_buttons_region_draw(const bContext *C, ARegion *region)
 {
-  ED_region_panels(C, ar);
+  ED_region_panels(C, region);
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void node_toolbar_region_init(wmWindowManager *wm, ARegion *ar)
+static void node_toolbar_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, "Node Generic", SPACE_NODE, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void node_toolbar_region_draw(const bContext *C, ARegion *ar)
+static void node_toolbar_region_draw(const bContext *C, ARegion *region)
 {
-  ED_region_panels(C, ar);
+  ED_region_panels(C, region);
 }
 
-static void node_cursor(wmWindow *win, ScrArea *sa, ARegion *ar)
+static void node_cursor(wmWindow *win, ScrArea *sa, ARegion *region)
 {
   SpaceNode *snode = sa->spacedata.first;
 
   /* convert mouse coordinates to v2d space */
-  UI_view2d_region_to_view(&ar->v2d,
-                           win->eventstate->x - ar->winrct.xmin,
-                           win->eventstate->y - ar->winrct.ymin,
+  UI_view2d_region_to_view(&region->v2d,
+                           win->eventstate->x - region->winrct.xmin,
+                           win->eventstate->y - region->winrct.ymin,
                            &snode->cursor[0],
                            &snode->cursor[1]);
 
@@ -605,29 +605,29 @@ static void node_cursor(wmWindow *win, ScrArea *sa, ARegion *ar)
 }
 
 /* Initialize main region, setting handlers. */
-static void node_main_region_init(wmWindowManager *wm, ARegion *ar)
+static void node_main_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
   ListBase *lb;
 
-  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 keymaps */
   keymap = WM_keymap_ensure(wm->defaultconf, "Node Generic", SPACE_NODE, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Node Editor", SPACE_NODE, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 
   /* add drop boxes */
   lb = WM_dropboxmap_find("Node Editor", SPACE_NODE, RGN_TYPE_WINDOW);
 
-  WM_event_add_dropbox_handler(&ar->handlers, lb);
+  WM_event_add_dropbox_handler(&region->handlers, lb);
 }
 
-static void node_main_region_draw(const bContext *C, ARegion *ar)
+static void node_main_region_draw(const bContext *C, ARegion *region)
 {
-  drawnodespace(C, ar);
+  drawnodespace(C, region);
 }
 
 /* ************* dropboxes ************* */
@@ -687,34 +687,34 @@ static void node_dropboxes(void)
 /* ************* end drop *********** */
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void node_header_region_init(wmWindowManager *UNUSED(wm), ARegion *ar)
+static void node_header_region_init(wmWindowManager *UNUSED(wm), ARegion *region)
 {
-  ED_region_header_init(ar);
+  ED_region_header_init(region);
 }
 
-static void node_header_region_draw(const bContext *C, ARegion *ar)
+static void node_header_region_draw(const bContext *C, ARegion *region)
 {
   /* find and set the context */
   snode_set_context(C);
 
-  ED_region_header(C, ar);
+  ED_region_header(C, region);
 }
 
 /* used for header + main region */
 static void node_region_listener(wmWindow *UNUSED(win),
                                  ScrArea *UNUSED(sa),
-                                 ARegion *ar,
+                                 ARegion *region,
                                  wmNotifier *wmn,
                                  const Scene *UNUSED(scene))
 {
-  wmGizmoMap *gzmap = ar->gizmo_map;
+  wmGizmoMap *gzmap = region->gizmo_map;
 
   /* context changes */
   switch (wmn->category) {
     case NC_SPACE:
       switch (wmn->data) {
         case ND_SPACE_NODE:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
         case ND_SPACE_NODE_VIEW:
           WM_gizmomap_tag_refresh(gzmap);
@@ -728,23 +728,23 @@ static void node_region_listener(wmWindow *UNUSED(win),
       switch (wmn->data) {
         case ND_ANIMPLAY:
         case ND_LAYER:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
     case NC_WM:
       if (wmn->data == ND_JOB) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_SCENE:
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       if (wmn->data == ND_RENDER_RESULT) {
         WM_gizmomap_tag_refresh(gzmap);
       }
       break;
     case NC_NODE:
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       if (ELEM(wmn->action, NA_EDITED, NA_SELECTED)) {
         WM_gizmomap_tag_refresh(gzmap);
       }
@@ -753,24 +753,24 @@ static void node_region_listener(wmWindow *UNUSED(win),
     case NC_TEXTURE:
     case NC_WORLD:
     case NC_LINESTYLE:
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       break;
     case NC_OBJECT:
       if (wmn->data == ND_OB_SHADING) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_ID:
       if (wmn->action == NA_RENAME) {
-        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);
       }
       else if (wmn->data & ND_GPENCIL_EDITMODE) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }