Fix T99659: Improve UV Island calculation with hidden faces.

Simplify interface, regularize implementation and some light cleanup.

See also: T79304 and D15419.

8 files changed, 54 insertions, 65 deletions

diff --git a/source/blender/blenkernel/BKE_mesh_mapping.h b/source/blender/blenkernel/BKE_mesh_mapping.h
index 163acf062e0..c58bcbea242 100644
--- a/source/blender/blenkernel/BKE_mesh_mapping.h
+++ b/source/blender/blenkernel/BKE_mesh_mapping.h
@@ -69,8 +69,6 @@ typedef struct UvElementMap {
   int *islandIndices;
 } UvElementMap;
 
-#define INVALID_ISLAND ((unsigned int)-1)
-
 /* Connectivity data */
 typedef struct MeshElemMap {
   int *indices;
diff --git a/source/blender/editors/include/ED_mesh.h b/source/blender/editors/include/ED_mesh.h
index 52044109702..b73b62d5a9d 100644
--- a/source/blender/editors/include/ED_mesh.h
+++ b/source/blender/editors/include/ED_mesh.h
@@ -137,7 +137,6 @@ void EDBM_update_extern(struct Mesh *me, bool do_tessellation, bool is_destructi
  */
 struct UvElementMap *BM_uv_element_map_create(struct BMesh *bm,
                                               const struct Scene *scene,
-                                              bool face_selected,
                                               bool uv_selected,
                                               bool use_winding,
                                               bool do_islands);
diff --git a/source/blender/editors/mesh/editmesh_utils.c b/source/blender/editors/mesh/editmesh_utils.c
index 83968955583..60a666ee755 100644
--- a/source/blender/editors/mesh/editmesh_utils.c
+++ b/source/blender/editors/mesh/editmesh_utils.c
@@ -593,13 +593,17 @@ UvMapVert *BM_uv_vert_map_at_index(UvVertMap *vmap, uint v)
   return vmap->vert[v];
 }
 
+#define INVALID_ISLAND ((unsigned int)-1)
+
 UvElementMap *BM_uv_element_map_create(BMesh *bm,
                                        const Scene *scene,
-                                       const bool face_selected,
                                        const bool uv_selected,
                                        const bool use_winding,
                                        const bool do_islands)
 {
+  /* In uv sync selection, all UVs are visible. */
+  const bool face_selected = !(scene->toolsettings->uv_flag & UV_SYNC_SELECTION);
+
   BMVert *ev;
   BMFace *efa;
   BMLoop *l;
@@ -623,15 +627,21 @@ UvElementMap *BM_uv_element_map_create(BMesh *bm,
 
   /* generate UvElement array */
   BM_ITER_MESH (efa, &iter, bm, BM_FACES_OF_MESH) {
-    if (!face_selected || BM_elem_flag_test(efa, BM_ELEM_SELECT)) {
-      if (!uv_selected) {
-        totuv += efa->len;
-      }
-      else {
-        BM_ITER_ELEM (l, &liter, efa, BM_LOOPS_OF_FACE) {
-          if (uvedit_uv_select_test(scene, l, cd_loop_uv_offset)) {
-            totuv++;
-          }
+    if (BM_elem_flag_test(efa, BM_ELEM_HIDDEN)) {
+      continue;
+    }
+
+    if (face_selected && !BM_elem_flag_test(efa, BM_ELEM_SELECT)) {
+      continue;
+    }
+
+    if (!uv_selected) {
+      totuv += efa->len;
+    }
+    else {
+      BM_ITER_ELEM (l, &liter, efa, BM_LOOPS_OF_FACE) {
+        if (uvedit_uv_select_test(scene, l, cd_loop_uv_offset)) {
+          totuv++;
         }
       }
     }
@@ -649,46 +659,48 @@ UvElementMap *BM_uv_element_map_create(BMesh *bm,
                                                     "UvElement");
 
   if (use_winding) {
-    winding = MEM_mallocN(sizeof(*winding) * totfaces, "winding");
+    winding = MEM_callocN(sizeof(*winding) * totfaces, "winding");
   }
 
   BM_ITER_MESH_INDEX (efa, &iter, bm, BM_FACES_OF_MESH, j) {
 
-    if (use_winding) {
-      winding[j] = false;
+    if (BM_elem_flag_test(efa, BM_ELEM_HIDDEN)) {
+      continue;
     }
 
-    if (!face_selected || BM_elem_flag_test(efa, BM_ELEM_SELECT)) {
-      float(*tf_uv)[2] = NULL;
-
-      if (use_winding) {
-        tf_uv = (float(*)[2])BLI_buffer_reinit_data(&tf_uv_buf, vec2f, efa->len);
-      }
+    if (face_selected && !BM_elem_flag_test(efa, BM_ELEM_SELECT)) {
+      continue;
+    }
 
-      BM_ITER_ELEM_INDEX (l, &liter, efa, BM_LOOPS_OF_FACE, i) {
-        if (uv_selected && !uvedit_uv_select_test(scene, l, cd_loop_uv_offset)) {
-          continue;
-        }
+    float(*tf_uv)[2] = NULL;
 
-        buf->l = l;
-        buf->separate = 0;
-        buf->island = INVALID_ISLAND;
-        buf->loop_of_poly_index = i;
+    if (use_winding) {
+      tf_uv = (float(*)[2])BLI_buffer_reinit_data(&tf_uv_buf, vec2f, efa->len);
+    }
 
-        buf->next = element_map->vert[BM_elem_index_get(l->v)];
-        element_map->vert[BM_elem_index_get(l->v)] = buf;
+    BM_ITER_ELEM_INDEX (l, &liter, efa, BM_LOOPS_OF_FACE, i) {
+      if (uv_selected && !uvedit_uv_select_test(scene, l, cd_loop_uv_offset)) {
+        continue;
+      }
 
-        if (use_winding) {
-          luv = BM_ELEM_CD_GET_VOID_P(l, cd_loop_uv_offset);
-          copy_v2_v2(tf_uv[i], luv->uv);
-        }
+      buf->l = l;
+      buf->separate = 0;
+      buf->island = INVALID_ISLAND;
+      buf->loop_of_poly_index = i;
 
-        buf++;
-      }
+      buf->next = element_map->vert[BM_elem_index_get(l->v)];
+      element_map->vert[BM_elem_index_get(l->v)] = buf;
 
       if (use_winding) {
-        winding[j] = cross_poly_v2(tf_uv, efa->len) > 0;
+        luv = BM_ELEM_CD_GET_VOID_P(l, cd_loop_uv_offset);
+        copy_v2_v2(tf_uv[i], luv->uv);
       }
+
+      buf++;
+    }
+
+    if (winding) {
+      winding[j] = cross_poly_v2(tf_uv, efa->len) > 0;
     }
   }
 
diff --git a/source/blender/editors/sculpt_paint/sculpt_uv.c b/source/blender/editors/sculpt_paint/sculpt_uv.c
index 8e1f4f4d495..5c2dff7b252 100644
--- a/source/blender/editors/sculpt_paint/sculpt_uv.c
+++ b/source/blender/editors/sculpt_paint/sculpt_uv.c
@@ -500,20 +500,10 @@ static UvSculptData *uv_sculpt_stroke_init(bContext *C, wmOperator *op, const wm
 
     if (do_island_optimization) {
       /* We will need island information */
-      if (ts->uv_flag & UV_SYNC_SELECTION) {
-        data->elementMap = BM_uv_element_map_create(bm, scene, false, false, true, true);
-      }
-      else {
-        data->elementMap = BM_uv_element_map_create(bm, scene, true, false, true, true);
-      }
+      data->elementMap = BM_uv_element_map_create(bm, scene, false, true, true);
     }
     else {
-      if (ts->uv_flag & UV_SYNC_SELECTION) {
-        data->elementMap = BM_uv_element_map_create(bm, scene, false, false, true, false);
-      }
-      else {
-        data->elementMap = BM_uv_element_map_create(bm, scene, true, false, true, false);
-      }
+      data->elementMap = BM_uv_element_map_create(bm, scene, false, true, false);
     }
 
     if (!data->elementMap) {
diff --git a/source/blender/editors/transform/transform_convert_mesh_uv.c b/source/blender/editors/transform/transform_convert_mesh_uv.c
index 18868643b6d..bb550909407 100644
--- a/source/blender/editors/transform/transform_convert_mesh_uv.c
+++ b/source/blender/editors/transform/transform_convert_mesh_uv.c
@@ -238,7 +238,6 @@ void createTransUVs(bContext *C, TransInfo *t)
 {
   SpaceImage *sima = CTX_wm_space_image(C);
   Scene *scene = t->scene;
-  ToolSettings *ts = CTX_data_tool_settings(C);
 
   const bool is_prop_edit = (t->flag & T_PROP_EDIT) != 0;
   const bool is_prop_connected = (t->flag & T_PROP_CONNECTED) != 0;
@@ -266,8 +265,7 @@ void createTransUVs(bContext *C, TransInfo *t)
     /* count */
     if (is_island_center) {
       /* create element map with island information */
-      const bool use_facesel = (ts->uv_flag & UV_SYNC_SELECTION) == 0;
-      elementmap = BM_uv_element_map_create(em->bm, scene, use_facesel, true, false, true);
+      elementmap = BM_uv_element_map_create(em->bm, scene, true, false, true);
       if (elementmap == NULL) {
         continue;
       }
diff --git a/source/blender/editors/uvedit/uvedit_ops.c b/source/blender/editors/uvedit/uvedit_ops.c
index 4844ff22b68..4e99eb3fc0f 100644
--- a/source/blender/editors/uvedit/uvedit_ops.c
+++ b/source/blender/editors/uvedit/uvedit_ops.c
@@ -544,7 +544,7 @@ static bool uvedit_uv_straighten(Scene *scene, BMesh *bm, eUVWeldAlign tool)
     return false;
   }
 
-  UvElementMap *element_map = BM_uv_element_map_create(bm, scene, false, true, false, true);
+  UvElementMap *element_map = BM_uv_element_map_create(bm, scene, true, false, true);
   if (element_map == NULL) {
     return false;
   }
diff --git a/source/blender/editors/uvedit/uvedit_select.c b/source/blender/editors/uvedit/uvedit_select.c
index b5a564fd984..d59dcb4f4ed 100644
--- a/source/blender/editors/uvedit/uvedit_select.c
+++ b/source/blender/editors/uvedit/uvedit_select.c
@@ -5223,7 +5223,7 @@ static void uv_isolate_selected_islands(const Scene *scene,
   BLI_assert((scene->toolsettings->uv_flag & UV_SYNC_SELECTION) == 0);
   BMFace *efa;
   BMIter iter, liter;
-  UvElementMap *elementmap = BM_uv_element_map_create(em->bm, scene, true, false, false, true);
+  UvElementMap *elementmap = BM_uv_element_map_create(em->bm, scene, false, false, true);
   if (elementmap == NULL) {
     return;
   }
diff --git a/source/blender/editors/uvedit/uvedit_smart_stitch.c b/source/blender/editors/uvedit/uvedit_smart_stitch.c
index 55e44607f6f..579674930a6 100644
--- a/source/blender/editors/uvedit/uvedit_smart_stitch.c
+++ b/source/blender/editors/uvedit/uvedit_smart_stitch.c
@@ -1902,15 +1902,7 @@ static StitchState *stitch_init(bContext *C,
    * for stitch this isn't useful behavior, see T86924. */
   const int selectmode_orig = scene->toolsettings->selectmode;
   scene->toolsettings->selectmode = SCE_SELECT_VERTEX;
-
-  /* in uv synch selection, all uv's are visible */
-  if (ts->uv_flag & UV_SYNC_SELECTION) {
-    state->element_map = BM_uv_element_map_create(state->em->bm, scene, false, false, true, true);
-  }
-  else {
-    state->element_map = BM_uv_element_map_create(state->em->bm, scene, true, false, true, true);
-  }
-
+  state->element_map = BM_uv_element_map_create(state->em->bm, scene, false, true, true);
   scene->toolsettings->selectmode = selectmode_orig;
 
   if (!state->element_map) {