Cleanup: Use const when retrieving custom data layers

Knowing when layers are retrieved for write access will be essential
when adding proper copy-on-write support. This commit makes that
clearer by adding `const` where the retrieved data is not modified.

Ref T95842

3 files changed, 8 insertions, 9 deletions

diff --git a/source/blender/render/intern/bake.c b/source/blender/render/intern/bake.c
index bf876163013..9ffe2879779 100644
--- a/source/blender/render/intern/bake.c
+++ b/source/blender/render/intern/bake.c
@@ -96,7 +96,7 @@ typedef struct TriTessFace {
   const MVert *mverts[3];
   const float *vert_normals[3];
   const TSpace *tspace[3];
-  float *loop_normal[3];
+  const float *loop_normal[3];
   float normal[3]; /* for flat faces */
   bool is_smooth;
 } TriTessFace;
@@ -451,9 +451,6 @@ static bool cast_ray_highpoly(BVHTreeFromMesh *treeData,
 static TriTessFace *mesh_calc_tri_tessface(Mesh *me, bool tangent, Mesh *me_eval)
 {
   int i;
-  MVert *mvert;
-  TSpace *tspace = NULL;
-  float(*loop_normals)[3] = NULL;
 
   const int tottri = poly_to_tri_count(me->totpoly, me->totloop);
   MLoopTri *looptri;
@@ -463,7 +460,7 @@ static TriTessFace *mesh_calc_tri_tessface(Mesh *me, bool tangent, Mesh *me_eval
   unsigned int mpoly_prev = UINT_MAX;
   float no[3];
 
-  mvert = CustomData_get_layer(&me->vdata, CD_MVERT);
+  const MVert *mvert = CustomData_get_layer(&me->vdata, CD_MVERT);
   looptri = MEM_mallocN(sizeof(*looptri) * tottri, __func__);
   triangles = MEM_callocN(sizeof(TriTessFace) * tottri, __func__);
 
@@ -480,6 +477,8 @@ static TriTessFace *mesh_calc_tri_tessface(Mesh *me, bool tangent, Mesh *me_eval
     BKE_mesh_recalc_looptri(me->mloop, me->mpoly, me->mvert, me->totloop, me->totpoly, looptri);
   }
 
+  const TSpace *tspace = NULL;
+  const float(*loop_normals)[3] = NULL;
   if (tangent) {
     BKE_mesh_ensure_normals_for_display(me_eval);
     BKE_mesh_calc_normals_split(me_eval);
diff --git a/source/blender/render/intern/texture_margin.cc b/source/blender/render/intern/texture_margin.cc
index 2d68148a86a..60585789416 100644
--- a/source/blender/render/intern/texture_margin.cc
+++ b/source/blender/render/intern/texture_margin.cc
@@ -492,11 +492,11 @@ static void generate_margin(ImBuf *ibuf,
 
   MPoly *mpoly;
   MLoop *mloop;
-  MLoopUV const *mloopuv;
+  const MLoopUV *mloopuv;
   int totpoly, totloop, totedge;
 
   int tottri;
-  MLoopTri const *looptri;
+  const MLoopTri *looptri;
   MLoopTri *looptri_mem = nullptr;
 
   if (me) {
diff --git a/source/blender/render/intern/texture_pointdensity.c b/source/blender/render/intern/texture_pointdensity.c
index 8ba3bac7cad..b9721f49ce7 100644
--- a/source/blender/render/intern/texture_pointdensity.c
+++ b/source/blender/render/intern/texture_pointdensity.c
@@ -323,13 +323,12 @@ static void pointdensity_cache_vertex_weight(PointDensity *pd,
                                              float *data_color)
 {
   const int totvert = mesh->totvert;
-  const MDeformVert *mdef, *dv;
   int mdef_index;
   int i;
 
   BLI_assert(data_color);
 
-  mdef = CustomData_get_layer(&mesh->vdata, CD_MDEFORMVERT);
+  const MDeformVert *mdef = CustomData_get_layer(&mesh->vdata, CD_MDEFORMVERT);
   if (!mdef) {
     return;
   }
@@ -341,6 +340,7 @@ static void pointdensity_cache_vertex_weight(PointDensity *pd,
     return;
   }
 
+  const MDeformVert *dv;
   for (i = 0, dv = mdef; i < totvert; i++, dv++, data_color += 3) {
     MDeformWeight *dw;
     int j;