Transform: use a threshold for UV snapping

Unlike 3Dview snapping, UV snapping is always done to the UV closest to
the mouse cursor, no matter the distance.

From the user's point of view, this appears to be an inconsistency (See
{T93538}).

Therefore, set a minimum distance for snapping and, as in 3D View and
highlight the snap with a drawing of a circle.

Release Note: https://wiki.blender.org/wiki/Reference/Release_Notes/3.3/Modeling

Reviewed By: #uv_editing, campbellbarton

Maniphest Tasks: T93538

Differential Revision: https://developer.blender.org/D13873

1 files changed, 27 insertions, 6 deletions

diff --git a/source/blender/editors/uvedit/uvedit_select.c b/source/blender/editors/uvedit/uvedit_select.c
index 1287804d9ee..13dac431b57 100644
--- a/source/blender/editors/uvedit/uvedit_select.c
+++ b/source/blender/editors/uvedit/uvedit_select.c
@@ -1019,8 +1019,13 @@ bool uv_find_nearest_vert_multi(Scene *scene,
   return found;
 }
 
-bool ED_uvedit_nearest_uv(
-    const Scene *scene, Object *obedit, const float co[2], float *dist_sq, float r_uv[2])
+static bool uvedit_nearest_uv(const Scene *scene,
+                              Object *obedit,
+                              const float co[2],
+                              const float scale[2],
+                              const bool ignore_selected,
+                              float *dist_sq,
+                              float r_uv[2])
 {
   BMEditMesh *em = BKE_editmesh_from_object(obedit);
   BMIter iter;
@@ -1035,8 +1040,14 @@ bool ED_uvedit_nearest_uv(
     BMLoop *l_iter, *l_first;
     l_iter = l_first = BM_FACE_FIRST_LOOP(efa);
     do {
+      if (ignore_selected && uvedit_uv_select_test(scene, l_iter, cd_loop_uv_offset)) {
+        continue;
+      }
+
       const float *uv = ((const MLoopUV *)BM_ELEM_CD_GET_VOID_P(l_iter, cd_loop_uv_offset))->uv;
-      const float dist_test = len_squared_v2v2(co, uv);
+      float co_tmp[2];
+      mul_v2_v2v2(co_tmp, scale, uv);
+      const float dist_test = len_squared_v2v2(co, co_tmp);
       if (dist_best > dist_test) {
         dist_best = dist_test;
         uv_best = uv;
@@ -1052,17 +1063,27 @@ bool ED_uvedit_nearest_uv(
   return false;
 }
 
-bool ED_uvedit_nearest_uv_multi(const Scene *scene,
+bool ED_uvedit_nearest_uv_multi(const View2D *v2d,
+                                const Scene *scene,
                                 Object **objects,
                                 const uint objects_len,
-                                const float co[2],
+                                const int mval[2],
+                                const bool ignore_selected,
                                 float *dist_sq,
                                 float r_uv[2])
 {
   bool found = false;
+
+  float scale[2], offset[2];
+  UI_view2d_scale_get(v2d, &scale[0], &scale[1]);
+  UI_view2d_view_to_region_fl(v2d, 0.0f, 0.0f, &offset[0], &offset[1]);
+
+  float co[2];
+  sub_v2_v2v2(co, (float[2]){UNPACK2(mval)}, offset);
+
   for (uint ob_index = 0; ob_index < objects_len; ob_index++) {
     Object *obedit = objects[ob_index];
-    if (ED_uvedit_nearest_uv(scene, obedit, co, dist_sq, r_uv)) {
+    if (uvedit_nearest_uv(scene, obedit, co, scale, ignore_selected, dist_sq, r_uv)) {
       found = true;
     }
   }