UV: remove selection threshold for nearby coordinates

Internally UV selection considered close UV's to be connected.
While this could be convenient in some cases,
it complicates logic for more advanced selection operations that
need to check when UV's should be considered part of the same vertex
since simple threshold checks would give different results depending
on the order of UV's tested.

Users must now run "Merge by Distance" instead of relying
on this selection threshold.

1 files changed, 7 insertions, 14 deletions

diff --git a/source/blender/editors/mesh/editmesh_utils.c b/source/blender/editors/mesh/editmesh_utils.c
index 2188f758dc7..46c63d2e057 100644
--- a/source/blender/editors/mesh/editmesh_utils.c
+++ b/source/blender/editors/mesh/editmesh_utils.c
@@ -525,10 +525,7 @@ void EDBM_flag_enable_all(BMEditMesh *em, const char hflag)
 /**
  * Return a new UVVertMap from the editmesh
  */
-UvVertMap *BM_uv_vert_map_create(BMesh *bm,
-                                 const float limit[2],
-                                 const bool use_select,
-                                 const bool use_winding)
+UvVertMap *BM_uv_vert_map_create(BMesh *bm, const bool use_select, const bool use_winding)
 {
   BMVert *ev;
   BMFace *efa;
@@ -537,7 +534,7 @@ UvVertMap *BM_uv_vert_map_create(BMesh *bm,
   /* vars from original func */
   UvVertMap *vmap;
   UvMapVert *buf;
-  MLoopUV *luv;
+  const MLoopUV *luv;
   uint a;
   int totverts, i, totuv, totfaces;
   const int cd_loop_uv_offset = CustomData_get_offset(&bm->ldata, CD_MLOOPUV);
@@ -609,7 +606,7 @@ UvVertMap *BM_uv_vert_map_create(BMesh *bm,
   BM_ITER_MESH_INDEX (ev, &iter, bm, BM_VERTS_OF_MESH, a) {
     UvMapVert *newvlist = NULL, *vlist = vmap->vert[a];
     UvMapVert *iterv, *v, *lastv, *next;
-    float *uv, *uv2, uvdiff[2];
+    const float *uv, *uv2;
 
     while (vlist) {
       v = vlist;
@@ -633,9 +630,7 @@ UvVertMap *BM_uv_vert_map_create(BMesh *bm,
         luv = BM_ELEM_CD_GET_VOID_P(l, cd_loop_uv_offset);
         uv2 = luv->uv;
 
-        sub_v2_v2v2(uvdiff, uv2, uv);
-
-        if (fabsf(uvdiff[0]) < limit[0] && fabsf(uvdiff[1]) < limit[1] &&
+        if (compare_v2v2(uv2, uv, STD_UV_CONNECT_LIMIT) &&
             (!use_winding || winding[iterv->poly_index] == winding[v->poly_index])) {
           if (lastv) {
             lastv->next = next;
@@ -777,7 +772,7 @@ UvElementMap *BM_uv_element_map_create(BMesh *bm,
   BM_ITER_MESH_INDEX (ev, &iter, bm, BM_VERTS_OF_MESH, i) {
     UvElement *newvlist = NULL, *vlist = element_map->vert[i];
     UvElement *iterv, *v, *lastv, *next;
-    float *uv, *uv2, uvdiff[2];
+    const float *uv, *uv2;
     bool uv_vert_sel, uv2_vert_sel;
 
     while (vlist) {
@@ -802,12 +797,10 @@ UvElementMap *BM_uv_element_map_create(BMesh *bm,
         uv2 = luv->uv;
         uv2_vert_sel = luv->flag & MLOOPUV_VERTSEL;
 
-        sub_v2_v2v2(uvdiff, uv2, uv);
-
         /* Check if the uv loops share the same selection state (if not, they are not connected as
          * they have been ripped or other edit commands have separated them). */
-        bool connected = uv_vert_sel == uv2_vert_sel && fabsf(uvdiff[0]) < STD_UV_CONNECT_LIMIT &&
-                         fabsf(uvdiff[1]) < STD_UV_CONNECT_LIMIT;
+        const bool connected = (uv_vert_sel == uv2_vert_sel) &&
+                               compare_v2v2(uv2, uv, STD_UV_CONNECT_LIMIT);
 
         if (connected && (!use_winding || winding[BM_elem_index_get(iterv->l->f)] ==
                                               winding[BM_elem_index_get(v->l->f)])) {