Sculpt: Opaque vertex type for sculpt

This is a port of sculpt-dev's `SculptVertRef` refactor
(note that `SculptVertRef was renamed to PBVHVertRef`)
to master. `PBVHVertRef` is a structure that abstracts
the concept of a vertex in the sculpt code; it's simply
an `intptr_t` wrapped in a struct.

For `PBVH_FACES` and `PBVH_GRIDS` this struct stores a
vertex index, but for `BMesh` it stores a direct pointer
to a BMVert.  The intptr_t is wrapped in a struct to prevent
the accidental usage of it as an index.

There are many reasons to do this:

* Right now `BMesh` verts are not logical sculpt verts;
  to use the sculpt API they must first be converted to indices.
  This requires a lot of indirect lookups into tables, leading to performance
  loss.  It has also led to greater code complexity and duplication.
* Having an abstract vertex type makes it feasible to have one unified
  temporary attribute API for all three PBVH modes, which in turn
  made it rather trivial to port sculpt brushes to DynTopo in
  sculpt-dev (e.g. the layer brush, draw sharp, the smooth brushes,
  the paint brushes, etc).  This attribute API will be in a future patch.
* We need to do this anyway for the eventual move to C++.

Differential Revision: https://developer.blender.org/D14272
Reviewed By: Brecht Van Lommel
Ref D14272

1 files changed, 15 insertions, 11 deletions

diff --git a/source/blender/blenkernel/intern/pbvh.cc b/source/blender/blenkernel/intern/pbvh.cc
index dec93826b9b..70aeb10f087 100644
--- a/source/blender/blenkernel/intern/pbvh.cc
+++ b/source/blender/blenkernel/intern/pbvh.cc
@@ -86,10 +86,12 @@ template<> void from_float(const float src[4], MPropCol &dst)
 }
 
 template<typename T>
-static void pbvh_vertex_color_get(const PBVH &pbvh, int vertex, float r_color[4])
+static void pbvh_vertex_color_get(const PBVH &pbvh, PBVHVertRef vertex, float r_color[4])
 {
+  int index = vertex.i;
+
   if (pbvh.color_domain == ATTR_DOMAIN_CORNER) {
-    const MeshElemMap &melem = pbvh.pmap[vertex];
+    const MeshElemMap &melem = pbvh.pmap[index];
 
     int count = 0;
     zero_v4(r_color);
@@ -99,7 +101,7 @@ static void pbvh_vertex_color_get(const PBVH &pbvh, int vertex, float r_color[4]
       Span<MLoop> loops{pbvh.mloop + mp.loopstart, mp.totloop};
 
       for (const int i_loop : IndexRange(mp.totloop)) {
-        if (loops[i_loop].v == vertex) {
+        if (loops[i_loop].v == index) {
           float temp[4];
           to_float(colors[i_loop], temp);
 
@@ -114,15 +116,17 @@ static void pbvh_vertex_color_get(const PBVH &pbvh, int vertex, float r_color[4]
     }
   }
   else {
-    to_float(static_cast<T *>(pbvh.color_layer->data)[vertex], r_color);
+    to_float(static_cast<T *>(pbvh.color_layer->data)[index], r_color);
   }
 }
 
 template<typename T>
-static void pbvh_vertex_color_set(PBVH &pbvh, int vertex, const float color[4])
+static void pbvh_vertex_color_set(PBVH &pbvh, PBVHVertRef vertex, const float color[4])
 {
+  int index = vertex.i;
+
   if (pbvh.color_domain == ATTR_DOMAIN_CORNER) {
-    const MeshElemMap &melem = pbvh.pmap[vertex];
+    const MeshElemMap &melem = pbvh.pmap[index];
 
     for (const int i_poly : Span(melem.indices, melem.count)) {
       const MPoly &mp = pbvh.mpoly[i_poly];
@@ -130,21 +134,21 @@ static void pbvh_vertex_color_set(PBVH &pbvh, int vertex, const float color[4])
       Span<MLoop> loops{pbvh.mloop + mp.loopstart, mp.totloop};
 
       for (const int i_loop : IndexRange(mp.totloop)) {
-        if (loops[i_loop].v == vertex) {
+        if (loops[i_loop].v == index) {
           from_float(color, colors[i_loop]);
         }
       }
     }
   }
   else {
-    from_float(color, static_cast<T *>(pbvh.color_layer->data)[vertex]);
+    from_float(color, static_cast<T *>(pbvh.color_layer->data)[index]);
   }
 }
 
 }  // namespace blender::bke
 
 extern "C" {
-void BKE_pbvh_vertex_color_get(const PBVH *pbvh, int vertex, float r_color[4])
+void BKE_pbvh_vertex_color_get(const PBVH *pbvh, PBVHVertRef vertex, float r_color[4])
 {
   blender::bke::to_static_color_type(eCustomDataType(pbvh->color_layer->type), [&](auto dummy) {
     using T = decltype(dummy);
@@ -152,7 +156,7 @@ void BKE_pbvh_vertex_color_get(const PBVH *pbvh, int vertex, float r_color[4])
   });
 }
 
-void BKE_pbvh_vertex_color_set(PBVH *pbvh, int vertex, const float color[4])
+void BKE_pbvh_vertex_color_set(PBVH *pbvh, PBVHVertRef vertex, const float color[4])
 {
   blender::bke::to_static_color_type(eCustomDataType(pbvh->color_layer->type), [&](auto dummy) {
     using T = decltype(dummy);
@@ -202,7 +206,7 @@ void BKE_pbvh_store_colors_vertex(PBVH *pbvh,
     blender::bke::to_static_color_type(eCustomDataType(pbvh->color_layer->type), [&](auto dummy) {
       using T = decltype(dummy);
       for (const int i : IndexRange(indices_num)) {
-        blender::bke::pbvh_vertex_color_get<T>(*pbvh, indices[i], r_colors[i]);
+        blender::bke::pbvh_vertex_color_get<T>(*pbvh, BKE_pbvh_make_vref(indices[i]), r_colors[i]);
       }
     });
   }