[Bf-blender-cvs] [ac3f4db7194] master: Cleanup: Mesh normal calculation comments and logic

[Hans Goudey]

Commit: ac3f4db719451acc9ee846b37c77912e2735e4be
Author: Hans Goudey
Date:   Fri Feb 25 17:47:42 2022 -0500
Branches: master
https://developer.blender.org/rBac3f4db719451acc9ee846b37c77912e2735e4be

Cleanup: Mesh normal calculation comments and logic

Some logic and comments in the vertex normal calculation were
left over from when normals were stored in MVert, before
cfa53e0fbeed7178c7. Normals are never allocated and freed
locally anymore.

===================================================================

M	source/blender/blenkernel/intern/mesh_normals.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/mesh_normals.cc b/source/blender/blenkernel/intern/mesh_normals.cc
index 89aa1dbfa94..1c2a903d8c3 100644
--- a/source/blender/blenkernel/intern/mesh_normals.cc
+++ b/source/blender/blenkernel/intern/mesh_normals.cc
@@ -220,14 +220,13 @@ void BKE_mesh_calc_normals_poly(const MVert *mvert,
  * \{ */
 
 struct MeshCalcNormalsData_PolyAndVertex {
-  /** Write into vertex normals #MVert.no. */
-  MVert *mvert;
+  const MVert *mvert;
   const MLoop *mloop;
   const MPoly *mpoly;
 
   /** Polygon normal output. */
   float (*pnors)[3];
-  /** Vertex normal output (may be freed, copied into #MVert.no). */
+  /** Vertex normal output. */
   float (*vnors)[3];
 };
 
@@ -298,7 +297,7 @@ static void mesh_calc_normals_poly_and_vertex_finalize_fn(
 {
   MeshCalcNormalsData_PolyAndVertex *data = (MeshCalcNormalsData_PolyAndVertex *)userdata;
 
-  MVert *mv = &data->mvert[vidx];
+  const MVert *mv = &data->mvert[vidx];
   float *no = data->vnors[vidx];
 
   if (UNLIKELY(normalize_v3(no) == 0.0f)) {
@@ -307,7 +306,7 @@ static void mesh_calc_normals_poly_and_vertex_finalize_fn(
   }
 }
 
-static void mesh_calc_normals_poly_and_vertex(MVert *mvert,
+static void mesh_calc_normals_poly_and_vertex(const MVert *mvert,
                                               const int mvert_len,
                                               const MLoop *mloop,
                                               const int UNUSED(mloop_len),
@@ -320,36 +319,22 @@ static void mesh_calc_normals_poly_and_vertex(MVert *mvert,
   BLI_parallel_range_settings_defaults(&settings);
   settings.min_iter_per_thread = 1024;
 
-  float(*vnors)[3] = r_vert_normals;
-  bool free_vnors = false;
-
-  /* First go through and calculate normals for all the polys. */
-  if (vnors == nullptr) {
-    vnors = (float(*)[3])MEM_calloc_arrayN((size_t)mvert_len, sizeof(*vnors), __func__);
-    free_vnors = true;
-  }
-  else {
-    memset(vnors, 0, sizeof(*vnors) * (size_t)mvert_len);
-  }
+  memset(r_vert_normals, 0, sizeof(*r_vert_normals) * (size_t)mvert_len);
 
   MeshCalcNormalsData_PolyAndVertex data = {};
   data.mpoly = mpoly;
   data.mloop = mloop;
   data.mvert = mvert;
   data.pnors = r_poly_normals;
-  data.vnors = vnors;
+  data.vnors = r_vert_normals;
 
-  /* Compute poly normals (`pnors`), accumulating them into vertex normals (`vnors`). */
+  /* Compute poly normals, accumulating them into vertex normals. */
   BLI_task_parallel_range(
       0, mpoly_len, &data, mesh_calc_normals_poly_and_vertex_accum_fn, &settings);
 
-  /* Normalize and validate computed vertex normals (`vnors`). */
+  /* Normalize and validate computed vertex normals. */
   BLI_task_parallel_range(
       0, mvert_len, &data, mesh_calc_normals_poly_and_vertex_finalize_fn, &settings);
-
-  if (free_vnors) {
-    MEM_freeN(vnors);
-  }
 }
 
 /** \} */