Cleanup: Clarify a few comments in pbvh_intern.h

1 files changed, 17 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/pbvh_intern.h b/source/blender/blenkernel/intern/pbvh_intern.h
index 37f8dfd9b6b..ea1f0632f32 100644
--- a/source/blender/blenkernel/intern/pbvh_intern.h
+++ b/source/blender/blenkernel/intern/pbvh_intern.h
@@ -32,13 +32,18 @@ struct PBVHNode {
    * 'nodes' array. */
   int children_offset;
 
-  /* Pointer into the PBVH prim_indices array and the number of
-   * primitives used by this leaf node.
+  /* List of primitives for this node. Semantics depends on
+   * PBVH type:
    *
-   * Used for leaf nodes in both mesh- and multires-based PBVHs.
+   * - PBVH_FACES: Indices into the PBVH.looptri array.
+   * - PBVH_GRIDS: Multires grid indices.
+   * - PBVH_BMESH: Unused.  See PBVHNode.bm_faces.
+   *
+   * NOTE: This is a pointer inside of PBVH.prim_indices; it
+   * is not allocated separately per node.
    */
   int *prim_indices;
-  unsigned int totprim;
+  unsigned int totprim; /* Number of primitives inside prim_indices. */
 
   /* Array of indices into the mesh's MVert array. Contains the
    * indices of all vertices used by faces that are within this
@@ -63,9 +68,8 @@ struct PBVHNode {
   unsigned int uniq_verts, face_verts;
 
   /* Array of indices into the Mesh's MLoop array.
-   * PBVH_FACES only.  The first part of the array
-   * are loops unique to this node, see comment for
-   * vert_indices for more details.*/
+   * PBVH_FACES only.
+   */
   int *loop_indices;
   unsigned int loop_indices_num;
 
@@ -93,6 +97,11 @@ struct PBVHNode {
   PBVHProxyNode *proxies;
 
   /* Dyntopo */
+
+  /* GSet of pointers to the BMFaces used by this node.
+   * NOTE: PBVH_BMESH only. Faces are always triangles
+   * (dynamic topology forcibly triangulates the mesh).
+   */
   GSet *bm_faces;
   GSet *bm_unique_verts;
   GSet *bm_other_verts;
@@ -117,6 +126,7 @@ struct PBVH {
   PBVHNode *nodes;
   int node_mem_count, totnode;
 
+  /* Memory backing for PBVHNode.prim_indices. */
   int *prim_indices;
   int totprim;
   int totvert;