Cleanup: Remove unused DerivedMesh flag

The value of this flag was never used.

source/blender/blenkernel/BKE_DerivedMesh.h

@@ -104,11 +104,6 @@ typedef enum DerivedMeshType {
   DM_TYPE_CCGDM,
 } DerivedMeshType;
 
-typedef enum DMDirtyFlag {
-  /* dm has valid tessellated faces, but tessellated CDDATA need to be updated. */
-  DM_DIRTY_TESS_CDLAYERS = 1 << 0,
-} DMDirtyFlag;
-
 typedef struct DerivedMesh DerivedMesh;
 struct DerivedMesh {
   /** Private DerivedMesh data, only for internal DerivedMesh use */
@@ -117,7 +112,6 @@ struct DerivedMesh {
   int needsFree;    /* checked on ->release, is set to 0 for cached results */
   int deformedOnly; /* set by modifier stack if only deformed from original */
   DerivedMeshType type;
-  DMDirtyFlag dirty;
 
   /**
    * \warning Typical access is done via #getLoopTriArray, #getNumLoopTri.

source/blender/blenkernel/intern/DerivedMesh.cc

@@ -275,7 +275,6 @@ void DM_init(DerivedMesh *dm,
   DM_init_funcs(dm);
 
   dm->needsFree = 1;
-  dm->dirty = (DMDirtyFlag)0;
 
   /* Don't use #CustomData_reset because we don't want to touch custom-data. */
   copy_vn_i(dm->vertData.typemap, CD_NUMTYPES, -1);
@@ -313,7 +312,6 @@ void DM_from_template_ex(DerivedMesh *dm,
   DM_init_funcs(dm);
 
   dm->needsFree = 1;
-  dm->dirty = (DMDirtyFlag)0;
 }
 void DM_from_template(DerivedMesh *dm,
                       DerivedMesh *source,

source/blender/blenkernel/intern/cdderivedmesh.c

@@ -238,9 +238,6 @@ static DerivedMesh *cdDM_from_mesh_ex(Mesh *mesh,
   dm->deformedOnly = 1;
   dm->cd_flag = mesh->cd_flag;
 
-  /* TODO: DM_DIRTY_TESS_CDLAYERS ? Maybe not though,
-   * since we probably want to switch to looptris? */
-
   CustomData_merge(&mesh->vdata, &dm->vertData, cddata_masks.vmask, alloctype, mesh->totvert);
   CustomData_merge(&mesh->edata, &dm->edgeData, cddata_masks.emask, alloctype, mesh->totedge);
   CustomData_merge(&mesh->fdata,
@@ -299,12 +296,6 @@ DerivedMesh *CDDM_copy(DerivedMesh *source)
   DM_from_template(dm, source, DM_TYPE_CDDM, numVerts, numEdges, numTessFaces, numLoops, numPolys);
   dm->deformedOnly = source->deformedOnly;
   dm->cd_flag = source->cd_flag;
-  dm->dirty = source->dirty;
-
-  /* Tessellation data is never copied, so tag it here.
-   * Only tag dirty layers if we really ignored tessellation faces.
-   */
-  dm->dirty |= DM_DIRTY_TESS_CDLAYERS;
 
   CustomData_copy_data(&source->vertData, &dm->vertData, 0, 0, numVerts);
   CustomData_copy_data(&source->edgeData, &dm->edgeData, 0, 0, numEdges);

source/blender/blenkernel/intern/dynamicpaint.c

@@ -1985,9 +1985,6 @@ static Mesh *dynamicPaint_Modifier_apply(DynamicPaintModifierData *pmd, Object *
             }
 
             MEM_freeN(fcolor);
-
-            /* Mark tessellated CD layers as dirty. */
-            // result->dirty |= DM_DIRTY_TESS_CDLAYERS;
           }
           /* vertex group paint */
           else if (surface->type == MOD_DPAINT_SURFACE_T_WEIGHT) {

source/blender/modifiers/intern/MOD_normal_edit.c

@@ -336,8 +336,6 @@ static void normalEditModifier_do_radial(NormalEditModifierData *enmd,
   if (do_polynors_fix &&
       polygons_check_flip(
           mloop, nos, &mesh->ldata, mpoly, BKE_mesh_poly_normals_for_write(mesh), num_polys)) {
-    /* XXX TODO: is this still needed? */
-    // mesh->dirty |= DM_DIRTY_TESS_CDLAYERS;
     /* We need to recompute vertex normals! */
     BKE_mesh_normals_tag_dirty(mesh);
   }

source/blender/modifiers/intern/MOD_uvwarp.c

@@ -233,9 +233,6 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
   settings.use_threading = (numPolys > 1000);
   BLI_task_parallel_range(0, numPolys, &data, uv_warp_compute, &settings);
 
-  /* XXX TODO: is this still needed? */
-  //  me_eval->dirty |= DM_DIRTY_TESS_CDLAYERS;
-
   mesh->runtime.is_original = false;
 
   return mesh;