DRW: Add batch garbage collection

This is only working for shading batches for the moment and only if some Custom data layer are not needed anymore.

The collection rate is hardcoded at 60 sec but could be exposed to the user.

This system can be extended and discard most unused batches in the future.

This commit is in prevision of removing BKE_MESH_BATCH_DIRTY_SHADING when changing shader parameters.

1 files changed, 25 insertions, 1 deletions

diff --git a/source/blender/draw/intern/draw_cache_impl_mesh.c b/source/blender/draw/intern/draw_cache_impl_mesh.c
index 6b43fbed49f..41de51fde96 100644
--- a/source/blender/draw/intern/draw_cache_impl_mesh.c
+++ b/source/blender/draw/intern/draw_cache_impl_mesh.c
@@ -364,6 +364,11 @@ BLI_INLINE bool mesh_cd_layers_type_overlap(DRW_MeshCDMask a, DRW_MeshCDMask b)
   return (*((uint32_t *)&a) & *((uint32_t *)&b)) == *((uint32_t *)&b);
 }
 
+BLI_INLINE bool mesh_cd_layers_type_equal(DRW_MeshCDMask a, DRW_MeshCDMask b)
+{
+  return *((uint32_t *)&a) == *((uint32_t *)&b);
+}
+
 BLI_INLINE void mesh_cd_layers_type_merge(DRW_MeshCDMask *a, DRW_MeshCDMask b)
 {
   atomic_fetch_and_or_uint32((uint32_t *)a, *(uint32_t *)&b);
@@ -1997,7 +2002,7 @@ typedef struct MeshBatchCache {
 
   struct DRW_MeshWeightState weight_state;
 
-  DRW_MeshCDMask cd_used, cd_needed;
+  DRW_MeshCDMask cd_used, cd_needed, cd_used_over_time;
 
   /* XXX, only keep for as long as sculpt mode uses shaded drawing. */
   bool is_sculpt_points_tag;
@@ -2121,6 +2126,8 @@ static void mesh_batch_cache_discard_shaded_tri(MeshBatchCache *cache)
   MEM_SAFE_FREE(cache->auto_layer_names);
   MEM_SAFE_FREE(cache->auto_layer_is_srgb);
 
+  mesh_cd_layers_type_clear(&cache->cd_used);
+
   cache->mat_len = 0;
 }
 
@@ -4717,6 +4724,22 @@ static void mesh_create_uvedit_buffers(MeshRenderData *rdata,
 /** \name Grouped batch generation
  * \{ */
 
+/* Thread safety need to be assured by caller. Don't call this during drawing.
+ * Note: For now this only free the shading batches / vbo if any cd layers is
+ * not needed anymore. */
+void DRW_mesh_batch_cache_free_old(Mesh *me, int UNUSED(ctime))
+{
+  MeshBatchCache *cache = me->runtime.batch_cache;
+
+  if (cache == NULL)
+    return;
+
+  if (mesh_cd_layers_type_equal(cache->cd_used_over_time, cache->cd_used) == false) {
+    mesh_batch_cache_discard_shaded_tri(cache);
+  }
+  mesh_cd_layers_type_clear(&cache->cd_used_over_time);
+}
+
 /* Can be called for any surface type. Mesh *me is the final mesh. */
 void DRW_mesh_batch_cache_create_requested(
     Object *ob, Mesh *me, const ToolSettings *ts, const bool is_paint_mode, const bool use_hide)
@@ -4769,6 +4792,7 @@ void DRW_mesh_batch_cache_create_requested(
 
     mesh_cd_layers_type_merge(&cache->cd_used, cache->cd_needed);
   }
+  mesh_cd_layers_type_merge(&cache->cd_used_over_time, cache->cd_needed);
   mesh_cd_layers_type_clear(&cache->cd_needed);
 
   /* Discard UV batches if sync_selection changes */