1 files changed, 25 insertions, 1 deletions
diff --git a/source/blender/draw/intern/draw_attributes.h b/source/blender/draw/intern/draw_attributes.h
index b577c6c4162..00621c711bf 100644
--- a/source/blender/draw/intern/draw_attributes.h
+++ b/source/blender/draw/intern/draw_attributes.h
@@ -9,6 +9,10 @@
 
 #pragma once
 
+#ifdef __cplusplus
+#  include <mutex>
+#endif
+
 #include "DNA_customdata_types.h"
 #include "DNA_meshdata_types.h"
 
@@ -16,6 +20,7 @@
 
 #include "BLI_sys_types.h"
 #include "BLI_threads.h"
+#include "BLI_utildefines.h"
 
 #include "GPU_shader.h"
 #include "GPU_vertex_format.h"
@@ -36,11 +41,30 @@ typedef struct DRW_Attributes {
   int num_requests;
 } DRW_Attributes;
 
+typedef struct DRW_MeshCDMask {
+  uint32_t uv : 8;
+  uint32_t tan : 8;
+  uint32_t orco : 1;
+  uint32_t tan_orco : 1;
+  uint32_t sculpt_overlays : 1;
+  /**
+   * Edit uv layer is from the base edit mesh as modifiers could remove it. (see T68857)
+   */
+  uint32_t edit_uv : 1;
+} DRW_MeshCDMask;
+
+/* Keep `DRW_MeshCDMask` struct within a `uint32_t`.
+ * bit-wise and atomic operations are used to compare and update the struct.
+ * See `mesh_cd_layers_type_*` functions. */
+BLI_STATIC_ASSERT(sizeof(DRW_MeshCDMask) <= sizeof(uint32_t), "DRW_MeshCDMask exceeds 32 bits")
+
 void drw_attributes_clear(DRW_Attributes *attributes);
 
+#ifdef __cplusplus
 void drw_attributes_merge(DRW_Attributes *dst,
                           const DRW_Attributes *src,
-                          ThreadMutex *render_mutex);
+                          std::mutex &render_mutex);
+#endif
 
 /* Return true if all requests in b are in a. */
 bool drw_attributes_overlap(const DRW_Attributes *a, const DRW_Attributes *b);