GPU: Fix wrong state before python callbacks

This was caused by a missing state apply.

We force the GPUState to be set after the callbacks to avoid
desync between our state tracker and the real gl state.

This fixes some issues but a better general fix for all BGL would
be better.

This fix T80297 2.91 texture alpha is not transparent

2 files changed, 9 insertions, 0 deletions

diff --git a/source/blender/editors/space_api/CMakeLists.txt b/source/blender/editors/space_api/CMakeLists.txt
index d948d84f1c3..573afb76f0e 100644
--- a/source/blender/editors/space_api/CMakeLists.txt
+++ b/source/blender/editors/space_api/CMakeLists.txt
@@ -20,6 +20,7 @@ set(INC
   ../io
   ../../blenkernel
   ../../blenlib
+  ../../gpu
   ../../makesdna
   ../../makesrna
   ../../windowmanager
diff --git a/source/blender/editors/space_api/spacetypes.c b/source/blender/editors/space_api/spacetypes.c
index 29ad314cd65..2a18ffafc6c 100644
--- a/source/blender/editors/space_api/spacetypes.c
+++ b/source/blender/editors/space_api/spacetypes.c
@@ -33,6 +33,8 @@
 #include "BKE_context.h"
 #include "BKE_screen.h"
 
+#include "GPU_state.h"
+
 #include "UI_interface.h"
 #include "UI_view2d.h"
 
@@ -269,12 +271,18 @@ void ED_region_draw_cb_exit(ARegionType *art, void *handle)
 void ED_region_draw_cb_draw(const bContext *C, ARegion *region, int type)
 {
   RegionDrawCB *rdc;
+  bool has_drawn_something = false;
 
   for (rdc = region->type->drawcalls.first; rdc; rdc = rdc->next) {
     if (rdc->type == type) {
       rdc->draw(C, region, rdc->customdata);
+      has_drawn_something = true;
     }
   }
+  if (has_drawn_something) {
+    /* This is needed until we get rid of BGL which can change the states we are tracking. */
+    GPU_force_state();
+  }
 }
 
 /* ********************* space template *********************** */