Fix bone select failing with end-points outside the view

Apply the same fix for T32214 (edge-select failing) to bones
which also failed when their end-points were outside of the view.

- Add V3D_PROJ_TEST_CLIP_CONTENT support for edit & pose bone iterator
  and use for selection operators.
- Remove unnecessarily complicated checks with pose-mode lasso tagging.
- Correct error in pose-mode LassoSelectUserData.is_changed
  (currently harmless as it's not read back).

2 files changed, 295 insertions, 177 deletions

diff --git a/source/blender/editors/space_view3d/view3d_iterators.c b/source/blender/editors/space_view3d/view3d_iterators.c
index 0eb594fb3dc..5e0101e4160 100644
--- a/source/blender/editors/space_view3d/view3d_iterators.c
+++ b/source/blender/editors/space_view3d/view3d_iterators.c
@@ -97,6 +97,110 @@ static int content_planes_from_clip_flag(const ARegion *region,
   return planes_len;
 }
 
+/**
+ * Edge projection is more involved since part of the edge may be behind the view
+ * or extend beyond the far limits. In the case of single points, these can be ignored.
+ * However it just may still be visible on screen, so constrained the edge to planes
+ * defined by the port to ensure both ends of the edge can be projected, see T32214.
+ *
+ * \note This is unrelated to #V3D_PROJ_TEST_CLIP_BB which must be checked separately.
+ */
+static bool view3d_project_segment_to_screen_with_content_clip_planes(
+    const ARegion *region,
+    const float v_a[3],
+    const float v_b[3],
+    const eV3DProjTest clip_flag,
+    const rctf *win_rect,
+    const float content_planes[][4],
+    const int content_planes_len,
+    /* Output. */
+    float r_screen_co_a[2],
+    float r_screen_co_b[2])
+{
+  /* Clipping already handled, no need to check in projection. */
+  eV3DProjTest clip_flag_nowin = clip_flag & ~V3D_PROJ_TEST_CLIP_WIN;
+
+  const eV3DProjStatus status_a = ED_view3d_project_float_object(
+      region, v_a, r_screen_co_a, clip_flag_nowin);
+  const eV3DProjStatus status_b = ED_view3d_project_float_object(
+      region, v_b, r_screen_co_b, clip_flag_nowin);
+
+  if ((status_a == V3D_PROJ_RET_OK) && (status_b == V3D_PROJ_RET_OK)) {
+    if (clip_flag & V3D_PROJ_TEST_CLIP_WIN) {
+      if (!BLI_rctf_isect_segment(win_rect, r_screen_co_a, r_screen_co_b)) {
+        return false;
+      }
+    }
+  }
+  else {
+    if (content_planes_len == 0) {
+      return false;
+    }
+
+    /* Both too near, ignore. */
+    if ((status_a & V3D_PROJ_TEST_CLIP_NEAR) && (status_b & V3D_PROJ_TEST_CLIP_NEAR)) {
+      return false;
+    }
+
+    /* Both too far, ignore. */
+    if ((status_a & V3D_PROJ_TEST_CLIP_FAR) && (status_b & V3D_PROJ_TEST_CLIP_FAR)) {
+      return false;
+    }
+
+    /* Simple cases have been ruled out, clip by viewport planes, then re-project. */
+    float v_a_clip[3], v_b_clip[3];
+    if (!clip_segment_v3_plane_n(
+            v_a, v_b, content_planes, content_planes_len, v_a_clip, v_b_clip)) {
+      return false;
+    }
+
+    if ((ED_view3d_project_float_object(region, v_a_clip, r_screen_co_a, clip_flag_nowin) !=
+         V3D_PROJ_RET_OK) ||
+        (ED_view3d_project_float_object(region, v_b_clip, r_screen_co_b, clip_flag_nowin) !=
+         V3D_PROJ_RET_OK)) {
+      return false;
+    }
+
+    /* No need for #V3D_PROJ_TEST_CLIP_WIN check here,
+     * clipping the segment by planes handle this. */
+  }
+
+  return true;
+}
+
+/**
+ * Project an edge, points that fail to project are tagged with #IS_CLIPPED.
+ */
+static bool view3d_project_segment_to_screen_with_clip_tag(const ARegion *region,
+                                                           const float v_a[3],
+                                                           const float v_b[3],
+                                                           const eV3DProjTest clip_flag,
+                                                           /* Output. */
+                                                           float r_screen_co_a[2],
+                                                           float r_screen_co_b[2])
+{
+  int count = 0;
+
+  if (ED_view3d_project_float_object(region, v_a, r_screen_co_a, clip_flag) == V3D_PROJ_RET_OK) {
+    count++;
+  }
+  else {
+    r_screen_co_a[0] = IS_CLIPPED; /* weak */
+    /* screen_co_a[1]: intentionally don't set this so we get errors on misuse */
+  }
+
+  if (ED_view3d_project_float_object(region, v_b, r_screen_co_b, clip_flag) == V3D_PROJ_RET_OK) {
+    count++;
+  }
+  else {
+    r_screen_co_b[0] = IS_CLIPPED; /* weak */
+    /* screen_co_b[1]: intentionally don't set this so we get errors on misuse */
+  }
+
+  /* Caller may want to know this value, for now it's not needed. */
+  return count != 0;
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
@@ -261,76 +365,6 @@ void mesh_foreachScreenVert(
 /** \name Edit-Mesh: For Each Screen Mesh Edge
  * \{ */
 
-/**
- * Edge projection is more involved since part of the edge may be behind the view
- * or extend beyond the far limits. In the case of single points, these can be ignored.
- * However it just may still be visible on screen, so constrained the edge to planes
- * defined by the port to ensure both ends of the edge can be projected, see T32214.
- *
- * \note This is unrelated to #V3D_PROJ_TEST_CLIP_BB which must be checked separately.
- */
-static bool mesh_foreachScreenEdge_shared_project_and_test(const ARegion *region,
-                                                           const float v_a[3],
-                                                           const float v_b[3],
-                                                           const eV3DProjTest clip_flag,
-                                                           const rctf *win_rect,
-                                                           const float content_planes[][4],
-                                                           const int content_planes_len,
-                                                           /* Output. */
-                                                           float r_screen_co_a[2],
-                                                           float r_screen_co_b[2])
-{
-  /* Clipping already handled, no need to check in projection. */
-  eV3DProjTest clip_flag_nowin = clip_flag & ~V3D_PROJ_TEST_CLIP_WIN;
-
-  const eV3DProjStatus status_a = ED_view3d_project_float_object(
-      region, v_a, r_screen_co_a, clip_flag_nowin);
-  const eV3DProjStatus status_b = ED_view3d_project_float_object(
-      region, v_b, r_screen_co_b, clip_flag_nowin);
-
-  if ((status_a == V3D_PROJ_RET_OK) && (status_b == V3D_PROJ_RET_OK)) {
-    if (clip_flag & V3D_PROJ_TEST_CLIP_WIN) {
-      if (!BLI_rctf_isect_segment(win_rect, r_screen_co_a, r_screen_co_b)) {
-        return false;
-      }
-    }
-  }
-  else {
-    if (content_planes_len == 0) {
-      return false;
-    }
-
-    /* Both too near, ignore. */
-    if ((status_a & V3D_PROJ_TEST_CLIP_NEAR) && (status_b & V3D_PROJ_TEST_CLIP_NEAR)) {
-      return false;
-    }
-
-    /* Both too far, ignore. */
-    if ((status_a & V3D_PROJ_TEST_CLIP_FAR) && (status_b & V3D_PROJ_TEST_CLIP_FAR)) {
-      return false;
-    }
-
-    /* Simple cases have been ruled out, clip by viewport planes, then re-project. */
-    float v_a_clip[3], v_b_clip[3];
-    if (!clip_segment_v3_plane_n(
-            v_a, v_b, content_planes, content_planes_len, v_a_clip, v_b_clip)) {
-      return false;
-    }
-
-    if ((ED_view3d_project_float_object(region, v_a_clip, r_screen_co_a, clip_flag_nowin) !=
-         V3D_PROJ_RET_OK) ||
-        (ED_view3d_project_float_object(region, v_b_clip, r_screen_co_b, clip_flag_nowin) !=
-         V3D_PROJ_RET_OK)) {
-      return false;
-    }
-
-    /* No need for #V3D_PROJ_TEST_CLIP_WIN check here,
-     * clipping the segment by planes handle this. */
-  }
-
-  return true;
-}
-
 static void mesh_foreachScreenEdge__mapFunc(void *userData,
                                             int index,
                                             const float v_a[3],
@@ -343,15 +377,15 @@ static void mesh_foreachScreenEdge__mapFunc(void *userData,
   }
 
   float screen_co_a[2], screen_co_b[2];
-  if (!mesh_foreachScreenEdge_shared_project_and_test(data->vc.region,
-                                                      v_a,
-                                                      v_b,
-                                                      data->clip_flag,
-                                                      &data->win_rect,
-                                                      data->content_planes,
-                                                      data->content_planes_len,
-                                                      screen_co_a,
-                                                      screen_co_b)) {
+  if (!view3d_project_segment_to_screen_with_content_clip_planes(data->vc.region,
+                                                                 v_a,
+                                                                 v_b,
+                                                                 data->clip_flag,
+                                                                 &data->win_rect,
+                                                                 data->content_planes,
+                                                                 data->content_planes_len,
+                                                                 screen_co_a,
+                                                                 screen_co_b)) {
     return;
   }
 
@@ -430,15 +464,15 @@ static void mesh_foreachScreenEdge_clip_bb_segment__mapFunc(void *userData,
   }
 
   float screen_co_a[2], screen_co_b[2];
-  if (!mesh_foreachScreenEdge_shared_project_and_test(data->vc.region,
-                                                      v_a_clip,
-                                                      v_b_clip,
-                                                      data->clip_flag,
-                                                      &data->win_rect,
-                                                      data->content_planes,
-                                                      data->content_planes_len,
-                                                      screen_co_a,
-                                                      screen_co_b)) {
+  if (!view3d_project_segment_to_screen_with_content_clip_planes(data->vc.region,
+                                                                 v_a_clip,
+                                                                 v_b_clip,
+                                                                 data->clip_flag,
+                                                                 &data->win_rect,
+                                                                 data->content_planes,
+                                                                 data->content_planes_len,
+                                                                 screen_co_a,
+                                                                 screen_co_b)) {
     return;
   }
 
@@ -728,35 +762,51 @@ void armature_foreachScreenBone(struct ViewContext *vc,
 
   ED_view3d_check_mats_rv3d(vc->rv3d);
 
-  for (ebone = arm->edbo->first; ebone; ebone = ebone->next) {
-    if (EBONE_VISIBLE(arm, ebone)) {
-      float screen_co_a[2], screen_co_b[2];
-      int points_proj_tot = 0;
+  float content_planes[6][4];
+  int content_planes_len;
+  rctf win_rect;
 
-      /* project head location to screenspace */
-      if (ED_view3d_project_float_object(vc->region, ebone->head, screen_co_a, clip_flag) ==
-          V3D_PROJ_RET_OK) {
-        points_proj_tot++;
-      }
-      else {
-        screen_co_a[0] = IS_CLIPPED; /* weak */
-        /* screen_co_a[1]: intentionally don't set this so we get errors on misuse */
-      }
+  if (clip_flag & V3D_PROJ_TEST_CLIP_CONTENT) {
+    content_planes_len = content_planes_from_clip_flag(
+        vc->region, vc->obedit, clip_flag, content_planes);
+    win_rect.xmin = 0;
+    win_rect.ymin = 0;
+    win_rect.xmax = vc->region->winx;
+    win_rect.ymax = vc->region->winy;
+  }
+  else {
+    content_planes_len = 0;
+  }
 
-      /* project tail location to screenspace */
-      if (ED_view3d_project_float_object(vc->region, ebone->tail, screen_co_b, clip_flag) ==
-          V3D_PROJ_RET_OK) {
-        points_proj_tot++;
-      }
-      else {
-        screen_co_b[0] = IS_CLIPPED; /* weak */
-        /* screen_co_b[1]: intentionally don't set this so we get errors on misuse */
-      }
+  for (ebone = arm->edbo->first; ebone; ebone = ebone->next) {
+    if (!EBONE_VISIBLE(arm, ebone)) {
+      continue;
+    }
 
-      if (points_proj_tot) { /* at least one point's projection worked */
-        func(userData, ebone, screen_co_a, screen_co_b);
+    float screen_co_a[2], screen_co_b[2];
+    const float *v_a = ebone->head, *v_b = ebone->tail;
+
+    if (clip_flag & V3D_PROJ_TEST_CLIP_CONTENT) {
+      if (!view3d_project_segment_to_screen_with_content_clip_planes(vc->region,
+                                                                     v_a,
+                                                                     v_b,
+                                                                     clip_flag,
+                                                                     &win_rect,
+                                                                     content_planes,
+                                                                     content_planes_len,
+                                                                     screen_co_a,
+                                                                     screen_co_b)) {
+        continue;
+      }
+    }
+    else {
+      if (!view3d_project_segment_to_screen_with_clip_tag(
+              vc->region, v_a, v_b, clip_flag, screen_co_a, screen_co_b)) {
+        continue;
       }
     }
+
+    func(userData, ebone, screen_co_a, screen_co_b);
   }
 }
 
@@ -783,36 +833,52 @@ void pose_foreachScreenBone(struct ViewContext *vc,
 
   ED_view3d_check_mats_rv3d(vc->rv3d);
 
+  float content_planes[6][4];
+  int content_planes_len;
+  rctf win_rect;
+
+  if (clip_flag & V3D_PROJ_TEST_CLIP_CONTENT) {
+    content_planes_len = content_planes_from_clip_flag(
+        vc->region, ob_eval, clip_flag, content_planes);
+    win_rect.xmin = 0;
+    win_rect.ymin = 0;
+    win_rect.xmax = vc->region->winx;
+    win_rect.ymax = vc->region->winy;
+  }
+  else {
+    content_planes_len = 0;
+  }
+
   for (pchan = pose->chanbase.first; pchan; pchan = pchan->next) {
-    if (PBONE_VISIBLE(arm_eval, pchan->bone)) {
-      bPoseChannel *pchan_eval = BKE_pose_channel_find_name(ob_eval->pose, pchan->name);
-      float screen_co_a[2], screen_co_b[2];
-      int points_proj_tot = 0;
-
-      /* project head location to screenspace */
-      if (ED_view3d_project_float_object(
-              vc->region, pchan_eval->pose_head, screen_co_a, clip_flag) == V3D_PROJ_RET_OK) {
-        points_proj_tot++;
-      }
-      else {
-        screen_co_a[0] = IS_CLIPPED; /* weak */
-        /* screen_co_a[1]: intentionally don't set this so we get errors on misuse */
-      }
+    if (!PBONE_VISIBLE(arm_eval, pchan->bone)) {
+      continue;
+    }
 
-      /* project tail location to screenspace */
-      if (ED_view3d_project_float_object(
-              vc->region, pchan_eval->pose_tail, screen_co_b, clip_flag) == V3D_PROJ_RET_OK) {
-        points_proj_tot++;
+    bPoseChannel *pchan_eval = BKE_pose_channel_find_name(ob_eval->pose, pchan->name);
+    float screen_co_a[2], screen_co_b[2];
+    const float *v_a = pchan_eval->pose_head, *v_b = pchan_eval->pose_tail;
+
+    if (clip_flag & V3D_PROJ_TEST_CLIP_CONTENT) {
+      if (!view3d_project_segment_to_screen_with_content_clip_planes(vc->region,
+                                                                     v_a,
+                                                                     v_b,
+                                                                     clip_flag,
+                                                                     &win_rect,
+                                                                     content_planes,
+                                                                     content_planes_len,
+                                                                     screen_co_a,
+                                                                     screen_co_b)) {
+        continue;
       }
-      else {
-        screen_co_b[0] = IS_CLIPPED; /* weak */
-        /* screen_co_b[1]: intentionally don't set this so we get errors on misuse */
-      }
-
-      if (points_proj_tot) { /* at least one point's projection worked */
-        func(userData, pchan, screen_co_a, screen_co_b);
+    }
+    else {
+      if (!view3d_project_segment_to_screen_with_clip_tag(
+              vc->region, v_a, v_b, clip_flag, screen_co_a, screen_co_b)) {
+        continue;
       }
     }
+
+    func(userData, pchan, screen_co_a, screen_co_b);
   }
 }
 
diff --git a/source/blender/editors/space_view3d/view3d_select.c b/source/blender/editors/space_view3d/view3d_select.c
index fcd735d63a2..02ed9f6d791 100644
--- a/source/blender/editors/space_view3d/view3d_select.c
+++ b/source/blender/editors/space_view3d/view3d_select.c
@@ -525,39 +525,12 @@ static void do_lasso_select_pose__do_tag(void *userData,
     return;
   }
 
-  bool is_point_done = false;
-  int points_proj_tot = 0;
-
-  /* project head location to screenspace */
-  if (screen_co_a[0] != IS_CLIPPED) {
-    points_proj_tot++;
-    if (BLI_rcti_isect_pt(data->rect, UNPACK2(screen_co_a)) &&
-        BLI_lasso_is_point_inside(
-            data->mcoords, data->mcoords_len, UNPACK2(screen_co_a), INT_MAX)) {
-      is_point_done = true;
-    }
-  }
-
-  /* project tail location to screenspace */
-  if (screen_co_b[0] != IS_CLIPPED) {
-    points_proj_tot++;
-    if (BLI_rcti_isect_pt(data->rect, UNPACK2(screen_co_b)) &&
-        BLI_lasso_is_point_inside(
-            data->mcoords, data->mcoords_len, UNPACK2(screen_co_b), INT_MAX)) {
-      is_point_done = true;
-    }
-  }
-
-  /* if one of points selected, we skip the bone itself */
-  if ((is_point_done == true) || ((is_point_done == false) && (points_proj_tot == 2) &&
-                                  BLI_lasso_is_edge_inside(data->mcoords,
-                                                           data->mcoords_len,
-                                                           UNPACK2(screen_co_a),
-                                                           UNPACK2(screen_co_b),
-                                                           INT_MAX))) {
+  if (BLI_rctf_isect_segment(data->rect_fl, screen_co_a, screen_co_b) &&
+      BLI_lasso_is_edge_inside(
+          data->mcoords, data->mcoords_len, UNPACK2(screen_co_a), UNPACK2(screen_co_b), INT_MAX)) {
     pchan->bone->flag |= BONE_DONE;
+    data->is_changed = true;
   }
-  data->is_changed |= is_point_done;
 }
 static void do_lasso_tag_pose(ViewContext *vc,
                               Object *ob,
@@ -581,7 +554,11 @@ static void do_lasso_tag_pose(ViewContext *vc,
 
   ED_view3d_init_mats_rv3d(vc_tmp.obact, vc->rv3d);
 
-  pose_foreachScreenBone(&vc_tmp, do_lasso_select_pose__do_tag, &data, V3D_PROJ_TEST_CLIP_DEFAULT);
+  /* Treat bones as clipped segments (no joints). */
+  pose_foreachScreenBone(&vc_tmp,
+                         do_lasso_select_pose__do_tag,
+                         &data,
+                         V3D_PROJ_TEST_CLIP_DEFAULT | V3D_PROJ_TEST_CLIP_CONTENT_DEFAULT);
 }
 
 static bool do_lasso_select_objects(ViewContext *vc,
@@ -1071,6 +1048,34 @@ static void do_lasso_select_armature__doSelectBone(void *userData,
 
   ebone->temp.i = is_inside_flag | (is_ignore_flag >> 16);
 }
+static void do_lasso_select_armature__doSelectBone_clip_content(void *userData,
+                                                                EditBone *ebone,
+                                                                const float screen_co_a[2],
+                                                                const float screen_co_b[2])
+{
+  LassoSelectUserData *data = userData;
+  bArmature *arm = data->vc->obedit->data;
+  if (!EBONE_VISIBLE(arm, ebone)) {
+    return;
+  }
+
+  const int is_ignore_flag = ebone->temp.i << 16;
+  int is_inside_flag = ebone->temp.i & ~0xFFFF;
+
+  /* - When #BONESEL_BONE is set, there is nothing to do.
+   * - When #BONE_ROOTSEL or #BONE_TIPSEL have been set - they take priority over bone selection.
+   */
+  if (is_inside_flag & (BONESEL_BONE | BONE_ROOTSEL | BONE_TIPSEL)) {
+    return;
+  }
+
+  if (BLI_lasso_is_edge_inside(
+          data->mcoords, data->mcoords_len, UNPACK2(screen_co_a), UNPACK2(screen_co_b), INT_MAX)) {
+    is_inside_flag |= BONESEL_BONE;
+  }
+
+  ebone->temp.i = is_inside_flag | (is_ignore_flag >> 16);
+}
 
 static bool do_lasso_select_armature(ViewContext *vc,
                                      const int mcoords[][2],
@@ -1094,9 +1099,18 @@ static bool do_lasso_select_armature(ViewContext *vc,
 
   ED_view3d_init_mats_rv3d(vc->obedit, vc->rv3d);
 
+  /* Operate on fully visible (non-clipped) points. */
   armature_foreachScreenBone(
       vc, do_lasso_select_armature__doSelectBone, &data, V3D_PROJ_TEST_CLIP_DEFAULT);
 
+  /* Operate on bones as segments clipped to the viewport bounds
+   * (needed to handle bones with both points outside the view).
+   * A separate pass is needed since clipped coordinates can't be used for selecting joints. */
+  armature_foreachScreenBone(vc,
+                             do_lasso_select_armature__doSelectBone_clip_content,
+                             &data,
+                             V3D_PROJ_TEST_CLIP_DEFAULT | V3D_PROJ_TEST_CLIP_CONTENT_DEFAULT);
+
   data.is_changed |= ED_armature_edit_select_op_from_tagged(vc->obedit->data, sel_op);
 
   if (data.is_changed) {
@@ -4102,8 +4116,11 @@ static bool pose_circle_select(ViewContext *vc,
 
   ED_view3d_init_mats_rv3d(vc->obact, vc->rv3d); /* for foreach's screen/vert projection */
 
-  pose_foreachScreenBone(
-      vc, do_circle_select_pose__doSelectBone, &data, V3D_PROJ_TEST_CLIP_DEFAULT);
+  /* Treat bones as clipped segments (no joints). */
+  pose_foreachScreenBone(vc,
+                         do_circle_select_pose__doSelectBone,
+                         &data,
+                         V3D_PROJ_TEST_CLIP_DEFAULT | V3D_PROJ_TEST_CLIP_CONTENT_DEFAULT);
 
   if (data.is_changed) {
     ED_pose_bone_select_tag_update(vc->obact);
@@ -4150,7 +4167,11 @@ static void do_circle_select_armature__doSelectBone(void *userData,
     return;
   }
 
+  /* When true, ignore in the next pass. */
+  ebone->temp.i = false;
+
   bool is_point_done = false;
+  bool is_edge_done = false;
   int points_proj_tot = 0;
 
   /* project head location to screenspace */
@@ -4178,17 +4199,39 @@ static void do_circle_select_armature__doSelectBone(void *userData,
    * otherwise there is no way to circle select joints alone */
   if ((is_point_done == false) && (points_proj_tot == 2) &&
       edge_inside_circle(data->mval_fl, data->radius, screen_co_a, screen_co_b)) {
-    if (data->select) {
-      ebone->flag |= (BONE_SELECTED | BONE_TIPSEL | BONE_ROOTSEL);
-    }
-    else {
-      ebone->flag &= ~(BONE_SELECTED | BONE_TIPSEL | BONE_ROOTSEL);
-    }
+    SET_FLAG_FROM_TEST(ebone->flag, data->select, BONE_SELECTED | BONE_TIPSEL | BONE_ROOTSEL);
+    is_edge_done = true;
     data->is_changed = true;
   }
 
+  if (is_point_done || is_edge_done) {
+    ebone->temp.i = true;
+  }
+
   data->is_changed |= is_point_done;
 }
+static void do_circle_select_armature__doSelectBone_clip_content(void *userData,
+                                                                 struct EditBone *ebone,
+                                                                 const float screen_co_a[2],
+                                                                 const float screen_co_b[2])
+{
+  CircleSelectUserData *data = userData;
+  bArmature *arm = data->vc->obedit->data;
+
+  if (!(data->select ? EBONE_SELECTABLE(arm, ebone) : EBONE_VISIBLE(arm, ebone))) {
+    return;
+  }
+
+  /* Set in the first pass, needed so circle select prioritizes joints. */
+  if (ebone->temp.i == true) {
+    return;
+  }
+
+  if (edge_inside_circle(data->mval_fl, data->radius, screen_co_a, screen_co_b)) {
+    SET_FLAG_FROM_TEST(ebone->flag, data->select, BONE_SELECTED | BONE_TIPSEL | BONE_ROOTSEL);
+    data->is_changed = true;
+  }
+}
 static bool armature_circle_select(ViewContext *vc,
                                    const eSelectOp sel_op,
                                    const int mval[2],
@@ -4207,9 +4250,18 @@ static bool armature_circle_select(ViewContext *vc,
 
   ED_view3d_init_mats_rv3d(vc->obedit, vc->rv3d);
 
+  /* Operate on fully visible (non-clipped) points. */
   armature_foreachScreenBone(
       vc, do_circle_select_armature__doSelectBone, &data, V3D_PROJ_TEST_CLIP_DEFAULT);
 
+  /* Operate on bones as segments clipped to the viewport bounds
+   * (needed to handle bones with both points outside the view).
+   * A separate pass is needed since clipped coordinates can't be used for selecting joints. */
+  armature_foreachScreenBone(vc,
+                             do_circle_select_armature__doSelectBone_clip_content,
+                             &data,
+                             V3D_PROJ_TEST_CLIP_DEFAULT | V3D_PROJ_TEST_CLIP_CONTENT_DEFAULT);
+
   if (data.is_changed) {
     ED_armature_edit_sync_selection(arm->edbo);
     ED_armature_edit_validate_active(arm);