Refactor: Sculpt: Remove PBVHVertRef usage in sculpt_expand.cc

Part of #118145

Also removes other now-unused functions & macros.

Pull Request: https://projects.blender.org/blender/blender/pulls/127821

source/blender/blenkernel/BKE_paint.hh

@@ -489,7 +489,6 @@ struct SculptSession : blender::NonCopyable, blender::NonMovable {
   PBVHVertRef active_vert_ref() const;
   ActiveVert active_vert() const;
 
-  PBVHVertRef last_active_vert_ref() const;
   ActiveVert last_active_vert() const;
 
   /**
@@ -502,6 +501,7 @@ struct SculptSession : blender::NonCopyable, blender::NonMovable {
    * \returns -1 if there is no currently active vertex.
    */
   int active_vert_index() const;
+  int last_active_vert_index() const;
 
   /**
    * Retrieves the active vertex position.

source/blender/blenkernel/BKE_pbvh_api.hh

@@ -281,13 +281,6 @@ struct PBVHFrustumPlanes {
   int num_planes;
 };
 
-BLI_INLINE int BKE_pbvh_vertex_to_index(const blender::bke::pbvh::Tree &pbvh, PBVHVertRef v)
-{
-  return (pbvh.type() == blender::bke::pbvh::Type::BMesh && v.i != PBVH_REF_NONE ?
-              BM_elem_index_get((BMVert *)(v.i)) :
-              (v.i));
-}
-
 /* Callbacks */
 
 namespace blender::bke::pbvh {

source/blender/blenkernel/intern/paint.cc

@@ -1768,22 +1768,6 @@ ActiveVert SculptSession::active_vert() const
   return active_vert_;
 }
 
-PBVHVertRef SculptSession::last_active_vert_ref() const
-{
-  if (std::holds_alternative<int>(last_active_vert_)) {
-    return {std::get<int>(last_active_vert_)};
-  }
-  if (std::holds_alternative<SubdivCCGCoord>(last_active_vert_)) {
-    const CCGKey key = BKE_subdiv_ccg_key_top_level(*this->subdiv_ccg);
-    const int index = std::get<SubdivCCGCoord>(last_active_vert_).to_index(key);
-    return {index};
-  }
-  if (std::holds_alternative<BMVert *>(last_active_vert_)) {
-    return {reinterpret_cast<intptr_t>(std::get<BMVert *>(last_active_vert_))};
-  }
-  return {PBVH_REF_NONE};
-}
-
 ActiveVert SculptSession::last_active_vert() const
 {
   return active_vert_;
@@ -1806,6 +1790,23 @@ int SculptSession::active_vert_index() const
   return -1;
 }
 
+int SculptSession::last_active_vert_index() const
+{
+  if (std::holds_alternative<int>(last_active_vert_)) {
+    return std::get<int>(last_active_vert_);
+  }
+  if (std::holds_alternative<SubdivCCGCoord>(last_active_vert_)) {
+    const SubdivCCGCoord coord = std::get<SubdivCCGCoord>(last_active_vert_);
+    return coord.to_index(BKE_subdiv_ccg_key_top_level(*this->subdiv_ccg));
+  }
+  if (std::holds_alternative<BMVert *>(last_active_vert_)) {
+    BMVert *bm_vert = std::get<BMVert *>(last_active_vert_);
+    return BM_elem_index_get(bm_vert);
+  }
+
+  return -1;
+}
+
 blender::float3 SculptSession::active_vert_position(const Depsgraph &depsgraph,
                                                     const Object &object) const
 {

source/blender/editors/sculpt_paint/sculpt_expand.cc

@@ -2151,11 +2151,16 @@ static bool set_initial_components_for_mouse(bContext *C,
   if (!initial_vert) {
     /* Cursor not over the mesh, for creating valid initial falloffs, fallback to the last active
      * vertex in the sculpt session. */
-    const PBVHVertRef last_active_vert = ss.last_active_vert_ref();
-    if (last_active_vert.i == PBVH_REF_NONE) {
+    const int last_active_vert_index = ss.last_active_vert_index();
+    /* It still may be the case that there is no last active vert in rare circumstances for
+     * everyday usage.
+     * (i.e. if the cursor has never been over the mesh at all. A solutoin to both this problem
+     * and needing to store this data is to figure out which is the nearest vertex to the current
+     * cursor position */
+    if (last_active_vert_index == -1) {
       return false;
     }
-    initial_vert = BKE_pbvh_vertex_to_index(*bke::object::pbvh_get(ob), ss.last_active_vert_ref());
+    initial_vert = last_active_vert_index;
   }
 
   copy_v2_v2(ss.expand_cache->initial_mouse, mval);