Fix T88456: DrawManager: Keep subset RenderMeshData around when geometry does not change.

Reuse loose geometry during selection (and other operations) from
previous calculation. Loose geometry stays the same, but was
recalculated to determine the size of GPU buffers. This patch would
reuse the previous loose geometry when geometry wasn't changed.

Although not the main bottleneck during selection it is measurable.

Master.
`rdata 46ms iter 55ms (frame 410ms)`

This patch.
`rdata 5ms iter 52ms (frame 342ms)`

Reviewed By: mano-wii

Differential Revision: https://developer.blender.org/D11339

1 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_cache_extract.h b/source/blender/draw/intern/draw_cache_extract.h
index a3e43ff2ec5..14cbba82fba 100644
--- a/source/blender/draw/intern/draw_cache_extract.h
+++ b/source/blender/draw/intern/draw_cache_extract.h
@@ -150,6 +150,18 @@ typedef struct MeshBufferCache {
   GPUIndexBuf **tris_per_mat;
 } MeshBufferCache;
 
+/**
+ * Data that are kept around between extractions to reduce rebuilding time.
+ *
+ * - Loose geometry.
+ */
+typedef struct MeshBufferExtractionCache {
+  int edge_loose_len;
+  int vert_loose_len;
+  int *lverts;
+  int *ledges;
+} MeshBufferExtractionCache;
+
 typedef enum DRWBatchFlag {
   MBC_SURFACE = (1 << 0),
   MBC_SURFACE_WEIGHTS = (1 << 1),
@@ -195,6 +207,10 @@ typedef enum DRWBatchFlag {
 typedef struct MeshBatchCache {
   MeshBufferCache final, cage, uv_cage;
 
+  MeshBufferExtractionCache final_extraction_cache;
+  MeshBufferExtractionCache cage_extraction_cache;
+  MeshBufferExtractionCache uv_cage_extraction_cache;
+
   struct {
     /* Surfaces / Render */
     GPUBatch *surface;
@@ -271,6 +287,7 @@ typedef struct MeshBatchCache {
 void mesh_buffer_cache_create_requested(struct TaskGraph *task_graph,
                                         MeshBatchCache *cache,
                                         MeshBufferCache mbc,
+                                        MeshBufferExtractionCache *extraction_cache,
                                         Mesh *me,
                                         const bool is_editmode,
                                         const bool is_paint_mode,