Draw Manager: Prevent misuse of static draw context

This is supposed to help catch bugs if referrencing stack data out of
the draw loop context.

No change is suppose to happen for users (specially because the changes
here happens mostly on debug).

It includes a change in the logic for render loop, to make sure DST is
not accessed before we enter it - contribution by Campbell Barton.

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/draw/DRW_engine.h b/source/blender/draw/DRW_engine.h
index 0aca41a970d..b780e86b9ec 100644
--- a/source/blender/draw/DRW_engine.h
+++ b/source/blender/draw/DRW_engine.h
@@ -65,6 +65,10 @@ void DRW_engine_viewport_data_size_get(
 
 void DRW_draw_view(const struct bContext *C);
 
+void DRW_draw_render_loop_ex(
+        struct Depsgraph *graph,
+        struct ARegion *ar, struct View3D *v3d,
+        const struct bContext *evil_C);
 void DRW_draw_render_loop(
         struct Depsgraph *graph,
         struct ARegion *ar, struct View3D *v3d);