Cleanup: Remove scene frame macros (`CFRA` et al.)

Removes the following macros for scene/render frame values:
- `CFRA`
- `SUBFRA`
- `SFRA`
- `EFRA`

These macros don't add much, other than saving a few characters when typing.
It's not immediately clear what they refer to, they just hide what they
actually access. Just be explicit and clear about that.
Plus these macros gave read and write access to the variables, so eyesores like
this would be done (eyesore because it looks like assigning to a constant):
```
CFRA = some_frame_nbr;
```

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D15311

3 files changed, 8 insertions, 8 deletions

diff --git a/source/blender/editors/space_nla/nla_edit.c b/source/blender/editors/space_nla/nla_edit.c
index 81520445000..50f00aed867 100644
--- a/source/blender/editors/space_nla/nla_edit.c
+++ b/source/blender/editors/space_nla/nla_edit.c
@@ -625,7 +625,7 @@ static int nlaedit_add_actionclip_exec(bContext *C, wmOperator *op)
   }
 
   scene = ac.scene;
-  cfra = (float)CFRA;
+  cfra = (float)scene->r.cfra;
 
   /* get action to use */
   act = BLI_findlink(&bmain->actions, RNA_enum_get(op->ptr, "action"));
@@ -901,7 +901,7 @@ static int nlaedit_add_sound_exec(bContext *C, wmOperator *UNUSED(op))
   }
 
   scene = ac.scene;
-  cfra = CFRA;
+  cfra = scene->r.cfra;
 
   /* get a list of the editable tracks being shown in the NLA */
   filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_SEL |
@@ -2388,7 +2388,7 @@ static int nlaedit_snap_exec(bContext *C, wmOperator *op)
         /* calculate new start position based on snapping mode */
         switch (mode) {
           case NLAEDIT_SNAP_CFRA: /* to current frame */
-            strip->start = (float)CFRA;
+            strip->start = (float)scene->r.cfra;
             break;
           case NLAEDIT_SNAP_NEAREST_FRAME: /* to nearest frame */
             strip->start = floorf(start + 0.5f);
diff --git a/source/blender/editors/space_nla/nla_select.c b/source/blender/editors/space_nla/nla_select.c
index 1efb91bc99f..d51bfce6355 100644
--- a/source/blender/editors/space_nla/nla_select.c
+++ b/source/blender/editors/space_nla/nla_select.c
@@ -455,10 +455,10 @@ static void nlaedit_select_leftright(bContext *C,
   /* get range, and get the right flag-setting mode */
   if (leftright == NLAEDIT_LRSEL_LEFT) {
     xmin = MINAFRAMEF;
-    xmax = (float)(CFRA + 0.1f);
+    xmax = (float)(scene->r.cfra + 0.1f);
   }
   else {
-    xmin = (float)(CFRA - 0.1f);
+    xmin = (float)(scene->r.cfra - 0.1f);
     xmax = MAXFRAMEF;
   }
 
@@ -540,7 +540,7 @@ static int nlaedit_select_leftright_invoke(bContext *C, wmOperator *op, const wm
 
     /* determine which side of the current frame mouse is on */
     x = UI_view2d_region_to_view_x(v2d, event->mval[0]);
-    if (x < CFRA) {
+    if (x < scene->r.cfra) {
       RNA_enum_set(op->ptr, "mode", NLAEDIT_LRSEL_LEFT);
     }
     else {
diff --git a/source/blender/editors/space_nla/space_nla.c b/source/blender/editors/space_nla/space_nla.c
index c50278518de..13035a9d5fd 100644
--- a/source/blender/editors/space_nla/space_nla.c
+++ b/source/blender/editors/space_nla/space_nla.c
@@ -87,9 +87,9 @@ static SpaceLink *nla_create(const ScrArea *area, const Scene *scene)
   BLI_addtail(&snla->regionbase, region);
   region->regiontype = RGN_TYPE_WINDOW;
 
-  region->v2d.tot.xmin = (float)(SFRA - 10);
+  region->v2d.tot.xmin = (float)(scene->r.sfra - 10);
   region->v2d.tot.ymin = (float)(-area->winy) / 3.0f;
-  region->v2d.tot.xmax = (float)(EFRA + 10);
+  region->v2d.tot.xmax = (float)(scene->r.efra + 10);
   region->v2d.tot.ymax = 0.0f;
 
   region->v2d.cur = region->v2d.tot;