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, 12 insertions, 0 deletions

diff --git a/source/blender/gpu/opengl/gl_state.cc b/source/blender/gpu/opengl/gl_state.cc
index 3c577bf1ccd..cd24fa0e0e4 100644
--- a/source/blender/gpu/opengl/gl_state.cc
+++ b/source/blender/gpu/opengl/gl_state.cc
@@ -80,6 +80,17 @@ void GLStateManager::apply_state(void)
   active_fb->apply_state();
 };
 
+void GLStateManager::force_state(void)
+{
+  /* Little exception for clip distances since they need to keep the old count correct. */
+  uint32_t clip_distances = current_.clip_distances;
+  current_ = ~this->state;
+  current_.clip_distances = clip_distances;
+  current_mutable_ = ~this->mutable_state;
+  this->set_state(this->state);
+  this->set_mutable_state(this->mutable_state);
+};
+
 void GLStateManager::set_state(const GPUState &state)
 {
   GPUState changed = state ^ current_;
diff --git a/source/blender/gpu/opengl/gl_state.hh b/source/blender/gpu/opengl/gl_state.hh
index b98c4b300f3..cab654006c6 100644
--- a/source/blender/gpu/opengl/gl_state.hh
+++ b/source/blender/gpu/opengl/gl_state.hh
@@ -72,6 +72,7 @@ class GLStateManager : public StateManager {
   GLStateManager();
 
   void apply_state(void) override;
+  void force_state(void) override;
 
   void issue_barrier(eGPUBarrier barrier_bits) override;