[Bf-blender-cvs] [a294c353701] master: Docs: expand on doc-string for seam_connected_recursive

[Campbell Barton]

Commit: a294c353701f26d81b3f87ae4d9c8d2d55c88ebf
Author: Campbell Barton
Date:   Mon Jan 16 14:49:49 2023 +1100
Branches: master
https://developer.blender.org/rBa294c353701f26d81b3f87ae4d9c8d2d55c88ebf

Docs: expand on doc-string for seam_connected_recursive

Also use const UVs where possible.

===================================================================

M	source/blender/editors/mesh/editmesh_utils.c

===================================================================

diff --git a/source/blender/editors/mesh/editmesh_utils.c b/source/blender/editors/mesh/editmesh_utils.c
index 21fb223e1de..764344fbd68 100644
--- a/source/blender/editors/mesh/editmesh_utils.c
+++ b/source/blender/editors/mesh/editmesh_utils.c
@@ -899,14 +899,29 @@ static bool loop_uv_match(BMLoop *loop,
          compare_v2v2(luv_b, luv_d, STD_UV_CONNECT_LIMIT);
 }
 
-/* Given `luv_anchor` and `needle`, return true if there are edges that fan between them that are
- * seam-free. */
+/**
+ * Utility function to implement #seam_connected.
+ *
+ * Given `edge`, `luv_anchor` & `luv_fan` find if `needle` is connected without
+ * seams or disjoint UVs which would delimit causing them not to be considered connected.
+ *
+ * \note The term *anchor* is used for the vertex at the center of a face-fan
+ * which is being stepped over. Even though every connected face may have a different UV,
+ * loops are only stepped onto which match the initial `luv_anchor`.
+ *
+ * \param edge: Search for `needle` in all loops connected to `edge` (recursively).
+ * \param luv_anchor: The UV of the anchor (vertex that's being stepped around).
+ * \param luv_fan: The UV of the outer edge, this changes as the fan is stepped over.
+ * \param visited: A set of edges to prevent recursing down the same edge multiple times.
+ * \param cd_loop_uv_offset: The UV layer.
+ * \return true if there are edges that fan between them that are seam-free.
+ * */
 static bool seam_connected_recursive(BMEdge *edge,
                                      const float luv_anchor[2],
                                      const float luv_fan[2],
-                                     BMLoop *needle,
+                                     const BMLoop *needle,
                                      GSet *visited,
-                                     int cd_loop_uv_offset)
+                                     const int cd_loop_uv_offset)
 {
   BMVert *anchor = needle->v;
   BLI_assert(edge->v1 == anchor || edge->v2 == anchor);
@@ -931,7 +946,7 @@ static bool seam_connected_recursive(BMEdge *edge,
         return true; /* Success. */
       }
 
-      float *luv_far = BM_ELEM_CD_GET_FLOAT_P(loop->prev, cd_loop_uv_offset);
+      const float *luv_far = BM_ELEM_CD_GET_FLOAT_P(loop->prev, cd_loop_uv_offset);
       if (seam_connected_recursive(
               loop->prev->e, luv_anchor, luv_far, needle, visited, cd_loop_uv_offset)) {
         return true;
@@ -947,7 +962,7 @@ static bool seam_connected_recursive(BMEdge *edge,
         return true; /* Success. */
       }
 
-      float *luv_far = BM_ELEM_CD_GET_FLOAT_P(loop->next->next, cd_loop_uv_offset);
+      const float *luv_far = BM_ELEM_CD_GET_FLOAT_P(loop->next->next, cd_loop_uv_offset);
       if (seam_connected_recursive(
               loop->next->e, luv_anchor, luv_far, needle, visited, cd_loop_uv_offset)) {
         return true;
@@ -958,8 +973,10 @@ static bool seam_connected_recursive(BMEdge *edge,
   return false;
 }
 
-/* Given `loop_a` and `loop_b` originate from the same vertex and share a UV,
- * return true if there are edges that fan between them that are seam-free.
+/**
+ * Given `loop_a` and `loop_b` originate from the same vertex and share a UV,
+ *
+ * \return true if there are edges that fan between them that are seam-free.
  * return false otherwise.
  */
 static bool seam_connected(BMLoop *loop_a, BMLoop *loop_b, GSet *visited, int cd_loop_uv_offset)
@@ -977,7 +994,7 @@ static bool seam_connected(BMLoop *loop_a, BMLoop *loop_b, GSet *visited, int cd
   if (!result) {
     /* Search around `loop_a` in the opposite direction, as one of the edges may be delimited by
      * a boundary, seam or disjoint UV, or itself be one of these. See: T103670, T103787. */
-    float *luv_prev_fan = BM_ELEM_CD_GET_FLOAT_P(loop_a->prev, cd_loop_uv_offset);
+    const float *luv_prev_fan = BM_ELEM_CD_GET_FLOAT_P(loop_a->prev, cd_loop_uv_offset);
     result = seam_connected_recursive(
         loop_a->prev->e, luv_anchor, luv_prev_fan, loop_b, visited, cd_loop_uv_offset);
   }