Edit Mesh: multi-thread auto-smooth & custom normal calculations

Supported multi-threading for bm_mesh_loops_calc_normals.

This is done by operating on vertex-loops instead of face-loops.

Single threaded operation still loops over faces since iterating
over vertices adds some overhead in the case of custom-normals
as the order used for accessing loops must be the same as iterating
of a faces loops.

From isolated timing tests of bm_mesh_loops_calc_normals on high
poly models, this gives between 3.5x to 10x speedup,
with larger gains for meshes with custom-normals.

NOTE: this is part one of two patches for multi-threaded auto-smooth,
tagging edges as sharp is still single threaded.

Reviewed By: mont29

Ref D11928

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_mesh.h b/source/blender/blenkernel/BKE_mesh.h
index 7846619577e..e3be9cd8ef8 100644
--- a/source/blender/blenkernel/BKE_mesh.h
+++ b/source/blender/blenkernel/BKE_mesh.h
@@ -399,6 +399,12 @@ void BKE_lnor_spacearr_init(MLoopNorSpaceArray *lnors_spacearr,
                             const char data_type);
 void BKE_lnor_spacearr_clear(MLoopNorSpaceArray *lnors_spacearr);
 void BKE_lnor_spacearr_free(MLoopNorSpaceArray *lnors_spacearr);
+
+void BKE_lnor_spacearr_tls_init(MLoopNorSpaceArray *lnors_spacearr,
+                                MLoopNorSpaceArray *lnors_spacearr_tls);
+void BKE_lnor_spacearr_tls_join(MLoopNorSpaceArray *lnors_spacearr,
+                                MLoopNorSpaceArray *lnors_spacearr_tls);
+
 MLoopNorSpace *BKE_lnor_space_create(MLoopNorSpaceArray *lnors_spacearr);
 void BKE_lnor_space_define(MLoopNorSpace *lnor_space,
                            const float lnor[3],